Green fibers, blue microalgae: a scoping review of spirulina in the textile industry

1 Introduction

The global textile industry is currently facing an unprecedented sustainability crisis, driven by its heavy reliance on petrochemical-derived synthetic fibers, water-intensive manufacturing, and the widespread use of toxic synthetic colorants (Cardona-Acevedo et al., 2026). As the sector accounts for a significant portion of global wastewater and greenhouse gas emissions, transitioning from linear production models to circular, bio-based economies is no longer merely advantageous—it is imperative (Al-Dmour et al., 2026). In this context, the development of “green fibers” and bio-functionalized textiles has emerged as a key frontier in materials science and biotechnology, aiming to replace hazardous synthetic chemicals with renewable, biodegradable alternatives.

Among the diverse array of biological resources, microalgae and cyanobacteria have garnered substantial attention as highly sustainable third-generation feedstocks (Reimão et al., 2025; Sarwar et al., 2026). Specifically, Limnospira (commercially known as Spirulina) stands out for its rapid growth kinetics, high photosynthetic efficiency, and ability to thrive on non-arable land without competing with food crops Chia et al., 2019). Beyond its established value in nutrition and cosmetics, Spirulina represents a versatile bio-factory capable of synthesizing a rich spectrum of bioactive compounds, including proteins, polysaccharides, and natural pigments such as C-phycocyanin—a unique light-harvesting protein complex responsible for its signature blue-green hue (Bürck et al., 2024).

The integration of Spirulina into textile manufacturing presents several promising avenues. On one hand, its natural pigments offer a non-toxic, biodegradable alternative to synthetic dyes, which are notorious for their environmental persistence and toxicity (Dwivedi, 2013; Rathinamoorthy and Rajesh Kumar, 2025). On the other hand, the biochemical profile of Spirulina enables the development of advanced functional finishes that impart antimicrobial, antioxidant, and UV-protective properties directly onto textile substrates (Yadav et al., 2026). Furthermore, recent advancements in biopolymer extraction have opened possibilities for using microalgal biomass as a precursor for biosynthetic fibers, bridging the gap between biotechnology and wearable materials.

While individual studies have explored isolated applications of Spirulina in textile dyeing or functionalization, a comprehensive, systematic mapping of the literature is still lacking. To address this gap, this scoping review systematically examines the current state of the art in the use of Spirulina in the textile sector. By synthesizing existing research on cultivation parameters, downstream extraction techniques, and textile integration methods, this work aims to identify current technological bottlenecks, map the intellectual landscape, and outline critical pathways for scaling these green technologies into commercially viable, circular textile systems. Accordingly, this scoping review aims to assess the potential applications of Spirulina in the textile sector by integrating evidence from the scientific literature to identify current advances, technological opportunities, existing challenges, and future research directions.

2 Materials and methods

A systematic literature search was conducted in May 2026 using the Scopus database to identify relevant studies on Spirulina and its applications. The search string was constructed using the Boolean operator AND with the following keywords: “Spirulina” AND “Textile”. No year or language restrictions were applied to the initial search. The screening and selection process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 46 records were initially retrieved. Two independent reviewers screened the titles and abstracts based on pre-defined eligibility criteria. Inclusion criteria comprised (1) original research articles; and (2) studies investigating cosmetic formulations containing Spirulina and/or its phycocyanin pigment. Exclusion criteria were: (1) review articles, book chapters, conference proceedings, and editorials; and (2) studies discussing potential textile applications without experimental formulation data or direct relevance to cosmetic development. Discrepancies between reviewers during the screening phase were resolved through consensus or consultation with a third reviewer. After full-text evaluation, 46 articles met all eligibility criteria and were included in this study. Based on the search conducted, it was possible to create Figure 1, which summarizes the keywords most frequently cited in the articles consulted for this study.

3 Spirulina as a source of textile ingredients

3.1 Biology and cultivation

Spirulina, currently taxonomically classified within the genus Limnospira (formerly Arthrospira), is a filamentous photosynthetic cyanobacterium widely recognized for its high biomass productivity and remarkable capacity to accumulate metabolites of significant biotechnological value. Although the term Spirulina remains widely used in both scientific and commercial contexts, particularly for the species Limnospira platensis and L. maxima, its taxonomic reclassification reflects advances in the phylogenetic characterization of this group Nowicka-Krawczyk et al., 2019; Santos et al., 2023; Castillo et al., 2024). The biomass exhibits a characteristic blue-green coloration resulting from the combined presence of chlorophylls, carotenoids, and phycobiliproteins, particularly C-phycocyanin, which is considered its primary photosynthetic pigment and one of its most valuable industrial compounds (Ramos et al., 2025; Vela-Albarrán et al., 2026).

Morphologically, Spirulina consists of multicellular, unbranched helical filaments. This spiral configuration increases the surface area available for light capture and nutrient uptake, promoting high photosynthetic efficiency and rapid cellular growth (Sinetova et al., 2024). Furthermore, its relatively thin cell wall, composed mainly of peptidoglycans and polysaccharides, facilitates the recovery of biomolecules via physical extraction, a feature particularly advantageous for industrial applications that require natural pigments and bioactive compounds (Park et al., 2018; Arslan et al., 2021; Prabhath et al., 2022). This cellular architecture also facilitates the comprehensive utilization of biomass in biorefinery processes, minimizing biomass losses during downstream processing (Bürck et al., 2024).

The cultivation of Spirulina is characterized by operational simplicity and high production efficiency compared with conventional agricultural crops. Its growth is favored in media enriched with bicarbonate, nitrate, phosphate, sulfate, and micronutrients, under high light intensity, at temperatures typically ranging from 30 °C to 35 °C, and under alkaline conditions, generally at pH values above 9 (Ragaza et al., 2020; Zrimec et al., 2024; Binkanat and Ozkan, 2026). These cultivation conditions naturally inhibit the proliferation of contaminating microorganisms, reducing the need for pesticides or antimicrobial agents during biomass production. Depending on the production scale, Spirulina can be cultivated in open raceway ponds or closed photobioreactors, the latter providing superior control over environmental conditions, higher biomass productivity, and improved batch-to-batch consistency (Ramos et al., 2025).

Another characteristic that makes Spirulina particularly attractive for industrial applications is its remarkable adaptability (Prates et al., 2018; Ye et al., 2018; Uebel et al., 2019). Unlike conventional agricultural crops, its cultivation does not require fertile land and can be carried out in non-arable areas, semi-arid regions, or using brackish water, thereby minimizing competition with food production. In addition, several studies have demonstrated the feasibility of using pretreated wastewater as a partial nutrient source, thereby supporting biomass production while contributing to environmental remediation (de Morais et al., 2018; Binkanat and Ozkan, 2026). This integration of biotechnological production with wastewater treatment reinforces Spirulina’s role within the circular bioeconomy, an approach that has attracted growing attention across multiple industrial sectors, including the textile industry (Mahmod et al., 2025).

Beyond its cultivation sustainability, Spirulina exhibits substantially higher biomass productivity than many terrestrial crops, high carbon dioxide assimilation efficiency, and relatively low natural resource requirements per unit biomass yield. These characteristics support its integration into more sustainable production chains by providing renewable feedstocks to produce natural pigments, functional biomolecules, and biopolymers for a wide range of industrial applications. Within the textile sector, these attributes position Spirulina as a promising biotechnological platform for the development of sustainable dyeing processes, textile surface functionalization, and bioactive materials, topics that are discussed in the following sections of this review.

3.2 Chemical composition

The growing interest in Spirulina for industrial applications is closely associated with the complexity of its chemical composition. Although it is widely recognized for its exceptionally high protein content (Thevarajah et al., 2022), its technological potential extends far beyond its nutritional value, primarily due to the abundance of photosynthetic pigments, polysaccharides, lipids, phenolic compounds, vitamins, minerals, and other secondary metabolites that impart functional properties to the biomass (Liu et al., 2019; Ramírez-Rodrigues et al., 2021; Silva et al., 2022; Elkady et al., 2024). The richness of these bioactive constituents makes Spirulina a highly versatile feedstock for a broad range of industrial sectors, including food (Bürck et al., 2024), cosmetics (Ramos et al., 2025), packaging (Nakamoto et al., 2023), and, more recently, functional textile materials. Among its constituents, proteins are the predominant fraction of the biomass, typically accounting for 55%–70% of the dry weight, depending on cultivation conditions (Spínola et al., 2024). In addition to supplying essential amino acids, these proteins play important structural and functional roles by promoting intermolecular interactions with natural fibers and polymeric matrices. In textile applications, this high protein content may enhance the affinity between Spirulina-derived biomolecules and fibrous substrates, facilitating the coating, encapsulation, or immobilization of bioactive compounds on textile surfaces (Ramos et al., 2025).

Among all bioactive compounds, however, the natural pigments are the most relevant for textile applications. Spirulina contains three major classes of photosynthetic pigments: chlorophylls, carotenoids, and phycobiliproteins. Chlorophylls, predominantly chlorophyll a, are responsible for the characteristic green coloration and play a central role in light energy conversion during photosynthesis. Carotenoids, including β-carotene, zeaxanthin, and other xanthophylls, impart yellow to orange hues while exhibiting remarkable antioxidant activity, thereby contributing to the protection of both the biomass and the materials into which they are incorporated against photooxidative degradation.

The most distinctive chemical feature of Spirulina, however, is its high concentration of phycobiliproteins, particularly C-phycocyanin (C-PC) (Sasi Rekha et al., 2024; Bürck et al., 2026). This water-soluble protein belongs to the phycobilisome antenna complex, which is responsible for light harvesting during photosynthesis. Besides imparting the characteristic intense blue color of the biomass, C-PC exhibits pronounced antioxidant (Fratelli et al., 2022), anti-inflammatory (Remirez et al., 2003; Romay et al., 2003; Nowruzi and Zakerfirouzabad, 2024), and antimicrobial activities (Negm El-Dein et al., 2025), properties that have been extensively explored in a wide range of biotechnological applications. Structurally, C-PC is a chromoprotein composed of a protein backbone covalently linked to chromophoric phycocyanobilin groups, which are responsible for light absorption in the red region of the visible spectrum and for its characteristic intense blue coloration (Lissi, 2000). These features make C-PC one of the few naturally occurring pigments capable of producing vivid blue shades, representing a particularly valuable alternative considering the limited availability of natural blue colorants for industrial applications (Fratelli et al., 2021). From a technological perspective, however, C-PC exhibits inherent limitations in stability (Braga et al., 2016).

Elevated temperatures, prolonged light exposure, pH fluctuations, organic solvents, and inadequate storage conditions can induce partial protein denaturation, simultaneously reducing both its color intensity and biological activity (Braga et al., 2016; Adjali et al., 2022). Consequently, considerable research efforts have focused on developing stabilization strategies, including encapsulation, incorporation into natural polymer matrices, protein-based carriers, and nanostructured delivery systems, to improve its industrial applicability (Chaiklahan et al., 2012; Pradeep and Nayak, 2019; İlter et al., 2021; Alavi et al., 2022). Within the textile field, these approaches are particularly relevant for enhancing pigment resistance against laundering, ultraviolet radiation, and material aging, thereby extending the functional lifetime of naturally dyed and functionalized fabrics (Fratelli et al., 2021).

Beyond its pigments, Spirulina biomass contains significant amounts of proteins, polysaccharides, polyunsaturated fatty acids, phenolic compounds, vitamins, and minerals, whose synergistic interactions contribute to the remarkable antioxidant capacity of this microorganism (Bürck et al., 2024). Although these constituents have traditionally been investigated from a nutritional perspective, their physicochemical and biological properties have attracted increasing interest in the development of functional materials. Recent studies have demonstrated that these compounds can impart antioxidant, antimicrobial, and photoprotective properties to textile substrates, further expanding the potential of Spirulina as a renewable source of functional ingredients for natural dyes, active textile finishes, and smart textile materials (Abdelgawad et al., 2025).

3.3 Properties relevant to textiles

The chemical composition of Spirulina endows its biomass with a unique combination of physicochemical and biological properties that extend far beyond its nutritional applications. The synergistic combination of natural pigments, proteins, polysaccharides, lipids, and antioxidant metabolites transforms this cyanobacterium into a versatile biotechnological platform capable of imparting functionality to textile materials (Dwivedi, 2013). Unlike conventional synthetic dyes, whose role is generally limited to coloration, Spirulina-derived compounds can simultaneously modify the optical, biological, and surface properties of textiles, enabling the development of multifunctional materials aligned with the principles of sustainability and the circular bioeconomy (Bowman et al., 2025; Hou et al., 2026).

Among all the functional attributes of Spirulina, its ability to provide natural pigments currently represents the greatest interest for the textile industry. The biomass contains a diverse range of chromophoric molecules, including chlorophylls, carotenoids, and, most importantly, C-phycocyanin, the pigment responsible for the characteristic intense blue coloration of this cyanobacterium. The coexistence of these pigments expands the range of achievable colors through adjustments in extraction, purification, and formulation processes, thereby reducing dependence on petroleum-derived synthetic dyes (Ciptandi et al., 2021; Naviglio et al., 2022; Rathinamoorthy and Rajesh Kumar, 2025).

C-phycocyanin deserves particular attention because it represents one of the few naturally occurring pigments capable of producing vivid blue shades. Historically, obtaining natural blue colorants at industrial scale has been a major technological challenge, which helps explain why most textile dyeing processes still rely heavily on synthetic dyes. In this context, Spirulina emerges as a renewable alternative for developing environmentally friendly coloration processes, particularly for natural fibers (Naviglio et al., 2022; Rathinamoorthy and Rajesh Kumar, 2025).

Recent studies have demonstrated that Spirulina extracts can produce homogeneous coloration on cotton, silk, and other natural fibers while maintaining satisfactory color intensity and significantly reducing the use of harsh chemical reagents. Beyond coloration itself, the presence of proteins and polysaccharides in the biomass appears to promote stronger interactions between pigments and the fiber surface, thereby improving dye deposition during dyeing. Although pigment stability remains a major challenge, strategies such as optimizing extraction conditions, using natural mordants, employing encapsulation techniques, and associating with nanoparticles have significantly enhanced resistance to laundering, light exposure, and pH variations, thereby expanding the industrial applicability of Spirulina. These advances demonstrate that Spirulina should no longer be regarded merely as a source of natural dyes but rather as a multifunctional coloration platform capable of simultaneously providing aesthetic performance and biological functionality (Ciptandi et al., 2021; Moldovan et al., 2022; Abdelgawad et al., 2025).

Beyond coloration, several compounds naturally present in Spirulina impart biological properties that can enhance the functional value of textile materials. Among the most relevant are antioxidant, antimicrobial, anti-inflammatory, and ultraviolet (UV)-protective activities, which are particularly attractive for the development of textiles intended for healthcare, sportswear, technical apparel, and wellness applications (Mahltig et al., 2013; Terra et al., 2019; Abdelgawad et al., 2025).

The remarkable antioxidant activity of Spirulina biomass primarily arises from the synergistic action of C-phycocyanin, carotenoids, and phenolic compounds. These metabolites exhibit a high capacity to scavenge reactive oxygen species (ROS), thereby mitigating oxidative processes and protecting biomolecules from degradation. When incorporated into textile fibers or surface coatings, these compounds can contribute to the development of bioactive fabrics that provide additional protection against oxidative stress induced by ultraviolet radiation and other adverse environmental conditions (Naviglio et al., 2022; Abdelgawad et al., 2025).

Another extensively investigated feature is its antimicrobial activity. Recent studies have demonstrated that incorporating Spirulina biomass or cyanobacteria-mediated metallic nanoparticles into textile substrates significantly inhibits the growth of pathogenic microorganisms on natural fabrics. In particular, the combination of Spirulina-derived bioactive compounds with biosynthesized silver nanoparticles has exhibited a synergistic effect, simultaneously enhancing color intensity and antimicrobial performance. These multifunctional characteristics substantially broaden the potential application of Spirulina-based materials in hospital textiles, sportswear, wound dressings, hygiene products, and cosmetotextiles (Mahltig et al., 2013; Abdelgawad et al., 2025; Gouda et al., 2025).

In addition, photosynthetic pigments such as carotenoids and phycobiliproteins have the intrinsic ability to absorb a portion of incident solar radiation, a characteristic that may contribute to the development of photoprotective textile materials. Although this application remains at an early stage of development, using naturally derived compounds to enhance ultraviolet protection represents a promising alternative to the conventional chemical finishes currently employed by the textile industry (Naviglio et al., 2022; Rathinamoorthy and Rajesh Kumar, 2025).

3.4 Physicochemical properties

The physicochemical characteristics of Spirulina biomass also play a fundamental role in its integration into textile materials. Its high protein and polysaccharide content promotes intermolecular interactions with a wide variety of substrates, thereby enhancing biomass adhesion to natural fibers and polymeric matrices. This property facilitates the fabrication of coatings, polymeric films, hydrogels, hybrid fibers, and encapsulation systems designed for the controlled release of bioactive compounds (Bowman et al., 2025; Hou et al., 2026).

More recently, various processing strategies have leveraged this structural versatility to develop advanced functional materials. The production of fluorescent carbon dots from protein-rich Spirulina biomass demonstrates that its biochemical constituents can be converted into highly functional nanomaterials that impart advanced optical properties to textile yarns and fabrics. Likewise, incorporating cyanobacterial biomass into polylactic acid (PLA) composites for additive manufacturing demonstrates that Spirulina-derived components can serve as both structural reinforcements and functional additives in three-dimensional (3D)-printed textile accessories (Abdelgawad et al., 2025; Bowman et al., 2025; Hou et al., 2026).

Collectively, these findings demonstrate that Spirulina’s contribution to textile engineering extends well beyond its role as a natural source of pigments. Its incorporation into textile systems enables the simultaneous modulation of mechanical, optical, and surface properties, considerably expanding the range of potential applications for this renewable biomass in next-generation functional textile materials.

3.5 Environmental properties

From an environmental perspective, Spirulina offers advantages that extend well beyond its chemical composition. Its high biomass productivity, rapid growth rate, and ability to be cultivated in either closed photobioreactors or open raceway ponds using brackish water or industrial wastewater significantly reduce the demand for arable land and freshwater resources compared with conventional terrestrial crops (Terra et al., 2019; Selvaraj and Arivazhagan, 2024).

Several studies have further demonstrated that the integrated cultivation of Spirulina in textile wastewater enables the simultaneous removal of nutrients, organic matter, and textile dyes while generating high-value biomass. This approach combines phycoremediation with biomass production, transforming wastewater treatment into a resource-recovery process rather than a waste-disposal strategy. The resulting biomass can be valorized to produce natural pigments, biosorbents, biocomposites, and functional materials, thereby establishing a production chain fully aligned with the principles of the circular bioeconomy (Moradi et al., 2021; Selvaraj and Arivazhagan, 2024).

Moreover, the residual biomass remaining after pigment extraction still retains a high protein content and considerable potential for subsequent industrial applications, thereby minimizing waste generation and promoting the comprehensive utilization of the raw material. This biorefinery approach makes Spirulina particularly attractive for the textile industry, a sector historically associated with intensive water consumption, high energy demand, and extensive use of chemical reagents (Naviglio et al., 2022; Hanifa et al., 2025).

Despite its remarkable technological potential, several challenges still hinder the large-scale implementation of Spirulina as a raw material for textile applications. The limited stability of C-phycocyanin under light exposure, elevated temperatures, and pH fluctuations remains a major barrier to commercial utilization, particularly in applications requiring high resistance to laundering and long-term environmental exposure. Furthermore, variations in biomass composition resulting from differences in cultivation conditions complicate the industrial standardization of pigments and bioactive compounds (Naviglio et al., 2022; Rathinamoorthy and Rajesh Kumar, 2025).

Another important challenge concerns the scale-up of extraction and textile functionalization processes. Although numerous laboratory-scale technologies have demonstrated promising results, further research is still required to assess their economic feasibility, optimize production processes, and evaluate the long-term durability of the functional finishes under realistic service conditions (Naviglio et al., 2022; Abdelgawad et al., 2025).

Nevertheless, recent advances involving nanomaterials, the biosynthesis of metallic nanoparticles, biodegradable composites, carbon dots, additive manufacturing, and encapsulation technologies indicate that Spirulina has evolved far beyond its traditional role as a natural pigment source. It is now emerging as a multifunctional biotechnological platform capable of integrating coloration, surface functionalization, advanced material design, and environmental sustainability. This evolution considerably expands its potential within the textile industry and lays the foundation for the development of a new generation of sustainable, smart, and bioactive textile materials (Abdelgawad et al., 2025; Gouda et al., 2025; Hou et al., 2026).

4 Applications in the textile industry

4.1 Natural colorants

The growing demand for more sustainable textile processes has spurred the search for renewable dye sources to replace petroleum-derived synthetic colorants, whose production and application are associated with high water consumption, toxic effluents, and the use of potentially carcinogenic compounds. Within this context, microalgae have attracted increasing attention as promising sources of natural pigments owing to their high biomass productivity, rapid growth, and ability to synthesize chromophoric compounds with significant added value. Among them, Spirulina stands out for its simultaneous production of chlorophylls, carotenoids, and phycobiliproteins, particularly C-phycocyanin (C-PC). Unlike most plant-derived natural dyes, Spirulina can be cultivated under controlled conditions, independent of agricultural seasonality, making it a promising alternative for developing more sustainable textile coloration processes (Fratelli et al., 2021).

The use of Spirulina as a source of natural colorants for textile applications has been investigated through various approaches, ranging from the direct use of whole biomass to the use of phycocyanin-rich extracts obtained via dedicated extraction and purification processes. More recently, research has expanded beyond pigment extraction to include evaluations of dyeing performance, pigment stability, and the environmental impact of textile coloration processes, demonstrating that the interest in Spirulina extends far beyond the simple replacement of synthetic dyes. Instead, both the biomass and its pigments have been explored as components of multifunctional coloration systems that combine sustainability, functionality, and reduced environmental impact, in line with the increasing demand for cleaner textile technologies (Ciptandi et al., 2021; Moldovan et al., 2022; Naviglio et al., 2022). The earliest studies investigating Spirulina as a textile colorant focused on the direct application of the whole biomass, aiming to develop simple, cost-effective methods compatible with artisanal textile production. From the perspective of the circular bioeconomy, this strategy offers important advantages by eliminating additional pigment extraction and purification steps, thereby enabling the full utilization of the produced biomass.

Within this context, Ciptandi et al. (2021) investigated the use of powdered Spirulina biomass as a natural dye for cotton and linen fabrics using conventional immersion dyeing methods under both cold and hot conditions. Their results demonstrated that direct use of the biomass in aqueous solution led to poor affinity between the pigments and the textile fibers, resulting in low color intensity regardless of dyeing temperature or processing time. These findings indicated that simply adapting dyeing procedures traditionally employed for plant-derived dyes is insufficient to achieve efficient fixation of Spirulina pigments onto cellulosic fibers. Rather than interpreting this limitation as a barrier to biomass utilization, the authors proposed an alternative formulation consisting of Spirulina, alginate, and glycerol. This formulation enabled pigment application through screen printing, exhibiting good printing stability while allowing the production of a variety of decorative patterns on cotton and linen fabrics. Interestingly, although the printing paste appeared predominantly green before application, blue shades became evident after printing, an effect attributed to the presence of phycocyanin. These observations demonstrate that the final color expression depends not only on the chemical composition of the biomass but also on the interactions among the pigments, the formulation, and the textile substrate (Ciptandi et al., 2021).

Despite these promising results, wash fastness remained the major limitation of this approach. Fastness tests revealed considerable pigment loss after repeated laundering cycles. Conversely, the limited color transfer to adjacent fabrics indicated that the problem was not due to dye migration but rather to the relatively low affinity between the biomass-derived pigments and the textile fibers. Consequently, the authors concluded that additional fixation strategies or protective surface coatings would be required to improve color durability. Nevertheless, this study provided the first demonstration that whole Spirulina biomass can be successfully incorporated into conventional artisanal textile printing techniques, opening new opportunities for sustainable fashion and small-scale textile production (Ciptandi et al., 2021). Although the direct use of whole biomass offers clear economic and environmental advantages, subsequent studies demonstrated that the purification of C-phycocyanin enables greater control over the resulting color shade while substantially improving the reproducibility of textile dyeing processes. This transition represents an important technological milestone, shifting the focus from the direct use of biomass toward the development of coloration systems based on a highly characterized natural pigment.

C-phycocyanin possesses several characteristics that make it particularly attractive for textile applications. In addition to producing an intense blue coloration, it is a water-soluble, biodegradable, and biologically active pigment that exhibits antioxidant and anti-inflammatory properties and can impart additional functionality to textile materials. However, the successful implementation of this approach depends directly on the efficiency of pigment extraction and purification. Conventional techniques, including sonication, freeze–thaw cycles, and enzymatic cell wall disruption, often produce complex extracts containing proteins, polysaccharides, and other cellular constituents that compromise pigment purity. In this context, green extraction technologies have emerged as promising alternatives because they provide higher extraction yields, shorter processing times, and reduced solvent consumption while improving the quality of the recovered pigment (Fratelli et al., 2021; Naviglio et al., 2022).

The availability of higher-purity extracts has enabled more systematic investigations into the performance of phycocyanin in textile dyeing processes. Recent studies have demonstrated that pre-mordanted cotton and wool fabrics exhibit significantly greater color intensity when dyed with phycocyanin-rich extracts. Among the mordanting systems evaluated, the combination of tannic acid and ferrous sulfate produced the highest color strength (K/S) values, highlighting the critical role of mordant selection in promoting effective interactions between the pigment and textile fibers (Rathinamoorthy and Rajesh Kumar, 2025). These studies have also incorporated standardized methodologies for evaluating textile performance, including CIELAB color coordinates, color strength (K/S), dye exhaustion, and color fastness to laundering, rubbing, perspiration, and dry cleaning. Although the results demonstrate the considerable potential of phycocyanin as a natural textile colorant, further improvements in resistance to repeated laundering and prolonged light exposure are still required before it can effectively compete with the synthetic dyes currently used by the textile industry.

More recently, environmental assessment has become an integral component of studies investigating Spirulina-based dyeing processes, representing an important shift in research priorities. Whereas earlier investigations primarily focused on color development and textile performance, current studies increasingly recognize that the sustainability of natural dyeing processes must be evaluated from a life-cycle perspective, including the environmental quality of the wastewater generated during textile processing.

Within this context, investigations employing phycocyanin-rich extracts for the exhaustion dyeing of cotton and wool have simultaneously evaluated both the colorimetric performance of the dyed fabrics and the environmental characteristics of the resulting dyeing effluents. Parameters, including chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), and metal concentrations, were assessed across different dyeing temperatures, pH levels, processing times, and mordanting systems. The results demonstrated that optimizing dyeing conditions substantially reduced the pollutant load in the effluents, making their subsequent reuse feasible after biological treatment. Furthermore, fungal treatment of these wastewater streams reduced COD and BOD values by approximately 80%, further reinforcing the environmental advantages of textile dyeing processes based on Spirulina-derived pigments (Moldovan et al., 2022).

Collectively, these findings considerably broaden the discussion surrounding natural textile colorants. Rather than simply replacing synthetic dyes, Spirulina integrates biomass production, natural pigment extraction, textile coloration, and sustainable wastewater management into a single production chain, bringing the textile industry closer to the principles of the circular bioeconomy. In parallel, successful case studies involving microbial pigments across different industrial sectors suggest that continued advances in biotechnology, microalgal cultivation, and extraction technologies will progressively narrow the gap between laboratory research and commercial implementation (Kumar et al., 2025). Table 1 summarizes representative experimental studies on Spirulina-derived materials for textile applications. Although using whole Spirulina biomass generally results in lower dye fixation than purified pigments, this approach offers important economic and environmental advantages (Bowman et al., 2025).

TABLE 1. Synthesis of representative experimental studies on Spirulina-derived materials for textile applications.

The direct application of the biomass eliminates pigment extraction and purification steps, reducing the number of unit operations, reagent consumption, processing time, and, consequently, overall production costs. Furthermore, it promotes the complete utilization of the biomass, fully aligning with the principles of biorefineries and the circular bioeconomy. However, the limited affinity observed between whole biomass and textile fibers remains one of the major challenges for its commercial application. This limitation may be associated with the intrinsic complexity of the Spirulina matrix, which is composed of proteins, polysaccharides, lipids, pigments, and numerous other metabolites with distinct physicochemical characteristics. The simultaneous presence of hydrophilic and hydrophobic compounds may influence the interactions between pigments and textile fibers, reducing the effective interaction between the coloring molecules and the functional groups present on the textile substrate. In addition, although phycocyanin, chlorophylls, and carotenoids differ in their chemical structures and physicochemical properties, all these natural pigments exhibit, to varying degrees, susceptibility to light exposure, oxidation, temperature fluctuations, and pH changes. These factors compromise not only color intensity but also color durability and resistance throughout the product’s service life (Ciptandi et al., 2021).

Therefore, future studies should focus not only on improving pigment fixation onto textile fibers but also on developing strategies to protect these compounds during processing and subsequent textile use. Technologies such as encapsulation, incorporation into polymeric matrices, the use of natural binders, and the development of hybrid delivery systems represent promising alternatives to simultaneously improve washing resistance and photostability. Nevertheless, these approaches inevitably increase process complexity and production costs, highlighting the important trade-off between technological performance and economic feasibility.

An additional advantage of phycocyanin extraction that deserves greater attention is the generation of residual biomass rich in chlorophylls, carotenoids, proteins, polysaccharides, and other high-value bioactive compounds (Hou et al., 2026). This demonstrates that phycocyanin extraction does not exhaust the biotechnological potential of Spirulina biomass. Instead, it creates opportunities for the sequential utilization of multiple biomass fractions within an integrated biorefinery approach. Rather than being regarded as a processing by-product, this residual biomass should be considered a valuable renewable feedstock for high-value applications, including functional textile finishes, biocomposites, polymer reinforcement, biodegradable materials, and applications in the cosmetic, food, and packaging industries. From a biorefinery perspective, the integrated utilization of purified phycocyanin and the residual biomass can substantially improve both the sustainability and the economic viability of the process by minimizing waste generation and increasing the value of the entire Spirulina production chain. This strategy is fully consistent with the concept of cascading biomass valorization, in which different biomass fractions are directed toward distinct applications according to their chemical composition and added value, thereby maximizing resource utilization while minimizing waste generation. From this perspective, the discussion should move beyond choosing between whole biomass and purified pigments toward identifying the most appropriate application for each biomass fraction according to its composition and added value. Such an approach maximizes resource efficiency, minimizes waste generation, and further strengthens the role of Spirulina as a renewable feedstock for sustainable textile manufacturing.

Finally, the successful industrial implementation of natural colorants will likely depend not only on technological advances but also on consumer perception of their environmental value. Although strategies aimed at improving pigment stability and durability may increase production costs, the environmental benefits associated with renewable raw materials, reduced dependence on petroleum-derived synthetic dyes, and lower generation of toxic effluents add significant value to the final products. Consequently, increasing consumer awareness of these environmental advantages may become a key driver for the broader acceptance of sustainable textile products, even when associated with moderately higher production costs.

4.2 Textile finishing

Textile finishing represents one of the most critical stages of textile manufacturing, being responsible for modifying the surface properties of fibers and imparting functionalities that extend far beyond aesthetics and coloration. Traditionally, these treatments rely on the application of chemical agents to provide antimicrobial, hydrophobic, ultraviolet (UV)-protective, antistatic, or self-cleaning properties. However, many of the chemicals currently employed are associated with considerable environmental toxicity, poor biodegradability, and manufacturing processes that require substantial energy inputs and large amounts of chemical reagents. Consequently, increasing attention has been paid to renewable raw materials and environmentally benign synthetic routes that can replace or reduce the use of conventional finishing agents.

Among these emerging alternatives, Spirulina has attracted considerable interest not only for its high content of bioactive compounds but, more importantly, for its ability to serve multiple functions in the development of functional textile finishes. Unlike the applications discussed in the previous section, where biomass was primarily used as a source of natural pigments, Spirulina is employed here as a multifunctional biological platform that can directly participate in the synthesis, stabilization, and incorporation of nanomaterials into textile substrates. This versatility enables a single biomass to simultaneously function as a reducing agent, a stabilizing matrix, a reservoir of metallic ions, and a source of bioactive compounds, thereby significantly reducing dependence on synthetic reagents during material processing. Such multifunctionality represents one of the major distinctions between conventional textile finishing technologies and more recent microalgae-based strategies, bringing textile nanotechnology closer to the principles of Green Chemistry and the circular bioeconomy.

Early studies on the functionalization of materials using Spirulina focused primarily on the biomass’s natural ability to adsorb metal ions. Mahltig et al. (2013) demonstrated that various algal species, including Spirulina platensis, can serve as natural reservoirs for Ag⁺, Cu²⁺, and Zn²⁺ via biosorption. Although zinc- and copper-loaded biomasses exhibited only limited antimicrobial activity, silver-enriched biomass produced pronounced bactericidal effects against Escherichia coli, even with relatively low silver release rates. Unlike conventional metallic nanoparticles, this strategy employs the biomass itself as a natural matrix for the controlled release of metallic ions, reducing concerns associated with the direct use of nanomaterials while opening new opportunities for the development of safer and more sustainable antimicrobial papers, polymers, and textile materials.

Subsequent research shifted the focus from the simple adsorption of metallic ions toward the green biosynthesis of silver nanoparticles. In this approach, Spirulina-derived metabolites no longer act solely as passive supports but actively participate in both the reduction of Ag⁺ ions and the stabilization of the resulting nanoparticles. Cicci et al. demonstrated that cultures of Arthrospira platensis can produce stable silver nanoparticles whose formation can be modulated by parameters such as pH and extracellular polysaccharide (EPS) concentration, thereby directly influencing nanoparticle size, colloidal stability, and structural characteristics. Compared with conventional chemical synthesis routes, this strategy eliminates the need for toxic reducing agents while exploiting a biomass recognized as Generally Recognized as Safe (GRAS) to produce nanomaterials intended for biomedical, cosmetic, and textile applications (Cicci et al., 2017).

The evolution of this concept became even more evident with the demonstration that nanoparticle biosynthesis can occur simultaneously with microalgal cultivation. In this integrated system, Spirulina removes silver ions from industrial effluents while concurrently producing biomass and silver nanoparticles within a single biotechnological process. Besides reducing the contaminant load of industrial wastewater, this strategy transforms a potentially hazardous waste stream into a high-value nanomaterial, bringing textile finishing technologies closer to the concepts of biorefineries and the circular bioeconomy. The integration of bioremediation and nanomaterial production represents one of the most innovative applications of Spirulina, demonstrating that the biomass can simultaneously contribute to environmental remediation and to the production of functional materials (Terra et al., 2019).

More recently, Spirulina has evolved beyond its role as a biological platform for nanoparticle synthesis to become an integral component of multifunctional textile finishing systems. Abdelgawad et al. developed silver nanoparticles using S. platensis as both reducing and stabilizing agents via a solvent-free, solid-state synthesis process, thereby eliminating solvent consumption and significantly simplifying nanoparticle production. In addition to obtaining highly homogeneous nanoparticles, the authors incorporated phycocyanin as a natural pigment into textile printing pastes, producing cotton and wool fabrics that simultaneously combined sustainable coloration and antimicrobial activity within a single processing step. Unlike previous studies, in which pigmentation and functionalization were investigated independently, this work demonstrated that both properties can be achieved simultaneously using exclusively Spirulina-derived components, highlighting the potential of this microalga as a multifunctional platform for sustainable textile finishing (Abdelgawad et al., 2025).

Similar findings were recently reported by Gouda et al. (2025), who employed Spirulina extracts to synthesize silver nanoparticles, which were subsequently deposited onto cotton fabrics. The resulting coating exhibited remarkable antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as fungi, while simultaneously displaying excellent photocatalytic performance for the degradation of Congo Red dye and maintaining high efficiency after multiple reuse cycles. These findings substantially expand the conventional concept of textile finishing by demonstrating that Spirulina-based coatings can simultaneously provide microbiological protection and environmental remediation, enabling the development of textile materials capable of performing active functions throughout their service life (Gouda et al., 2025).

Overall, a consistent evolution can be observed in the role of Spirulina within textile systems. Initially explored primarily as a source of bioactive compounds and natural pigments, the biomass has progressively evolved into a multifunctional platform capable of integrating coloring, antimicrobial, and nanotechnological properties within a single material. This transition reflects a paradigm shift in the development of sustainable textile finishes by reducing process complexity, minimizing the use of conventional chemical reagents, and significantly expanding the application potential of Spirulina in textile engineering.

Nevertheless, direct comparison among published studies remains limited due to the considerable heterogeneity of experimental protocols, including differences in synthesis methods, textile substrates, nanoparticle concentrations, and methodologies used to evaluate antimicrobial activity and other functional properties. Furthermore, although the reported results are promising, most studies investigate integrated systems containing both Spirulina and metallic nanoparticles, making it difficult to distinguish the specific contribution of each component to the observed properties and to identify possible synergistic effects between them.

Another important consideration is that most investigations remain focused on demonstrating material functionality under laboratory conditions, whereas relatively few studies have assessed finish durability after repeated laundering, long-term stability during use, the reproducibility of biosynthetic processes, or the feasibility of industrial-scale production. From an industrial perspective, the adoption of these finishes will also depend on the development of reproducible and economically competitive processes that can be integrated into conventional textile finishing lines without requiring extensive operational modifications. Therefore, although the convergence of nanotechnology, Green Chemistry, and bio-based materials positions Spirulina as one of the most promising biological platforms for the development of the next-generation of functional textile finishes, the successful industrial implementation of these technologies will depend on the standardization of evaluation methods and on overcoming challenges related to durability, scalability, and process reproducibility.

4.3 Textiles cosmetic and wellness textiles

The concept of cosmetotextiles refers to textile materials that gradually release bioactive substances upon skin contact, thereby providing benefits that extend beyond the conventional functions of clothing. Unlike traditional textile finishes, whose primary objective is to modify the properties of the textile substrate itself, cosmetotextiles are designed to promote biological interactions between the fabric and the wearer, contributing to skin hydration, antioxidant protection, antimicrobial activity, photoprotection, and overall wellbeing. Within this context, wellness textiles further expand this concept by incorporating active ingredients that support skin health and physiological comfort, reflecting the growing demand for sustainable, multifunctional, and bio-inspired textile products (Cheng et al., 2010; Ripoll et al., 2010).

Although the direct application of Spirulina in cosmetotextiles is still at an early stage compared with other bioactive systems, the chemical composition of this microalga provides a unique combination of characteristics that justify its growing interest for this purpose. As discussed in previous sections, Spirulina biomass is rich in phycocyanin, carotenoids, phenolic compounds, vitamins, polysaccharides, minerals, and proteins containing essential amino acids. These metabolites are widely recognized for their antioxidant, anti-inflammatory, antimicrobial, and photoprotective properties, all of which are highly desirable for textile materials intended for prolonged skin contact. Consequently, Spirulina should be regarded not only as a source of natural pigments but also as a reservoir of bioactive compounds capable of transforming passive textiles into functional platforms for personal care (Ramos et al., 2025).

Among these constituents, C-phycocyanin (C-PC) deserves particular attention as the principal bioactive pigment of Spirulina. In addition to imparting its characteristic intense blue coloration, this phycobiliprotein exhibits well-documented antioxidant activity, an exceptional capacity to scavenge reactive oxygen species (ROS), and anti-inflammatory properties that have been extensively reported in cosmetic and biomedical applications. The development of more efficient and sustainable extraction technologies has demonstrated that obtaining high-purity phycocyanin extracts is a fundamental step toward expanding their industrial utilization, including applications in textile materials designed to function as controlled-release systems for functional ingredients. Although this work primarily focused on pigment extraction, it clearly highlights the importance of extract purity for high-value applications in cosmetics, biomaterials, and functional textiles (Fratelli et al., 2021; Naviglio et al., 2022).

Another relevant aspect is that incorporating Spirulina into textile systems can provide benefits that extend well beyond antimicrobial protection. Recent studies on the green biosynthesis of silver nanoparticles using Spirulina extracts have demonstrated that metabolites naturally present in the biomass simultaneously function as reducing and stabilizing agents while preserving part of their intrinsic bioactivity throughout the synthesis process. The resulting nanoparticles exhibited pronounced antimicrobial activity against various bacterial and fungal species, together with significant antioxidant capacity and considerable potential for applications in biomedical devices, personal care products, and antimicrobial textile coatings. These findings suggest that combining Spirulina-derived metabolites with metallic nanomaterials may substantially enhance the functionality of cosmetotextiles, enabling a single textile material to simultaneously provide antimicrobial protection, mitigate oxidative stress, and promote skin health (Venkatesh et al., 2023).

This trend becomes even more evident in studies that functionalize cotton fabrics with biologically synthesized silver nanoparticles derived from Spirulina extracts. In addition to exhibiting remarkable antimicrobial activity against Gram-positive, Gram-negative, and yeast bacteria, the functionalized textiles demonstrated excellent durability and reusability, maintaining their performance after repeated use. Although the primary objective of these investigations was the development of materials for environmental remediation and antimicrobial surfaces, their findings provide valuable insights for future cosmetotextile applications, since textile products intended for prolonged skin contact also require effective microbiological protection, long-term stability, and biocompatibility. Moreover, the use of Spirulina as both a reducing and stabilizing agent substantially decreases the need for aggressive chemical reagents, bringing the development of these materials closer to the principles of Green Chemistry and sustainable manufacturing (Gouda et al., 2025).

A particularly noteworthy strategy was reported by Abdelgawad et al. (2025), who developed a multifunctional system that integrates natural coloration and biological functionalization in a single processing step. In this work, Spirulina simultaneously acted as the reducing and stabilizing agent during the solid-state synthesis of silver nanoparticles, while phycocyanin served as a natural dye for printing cotton and wool fabrics. In addition to providing sustainable coloration, the resulting textiles exhibited pronounced antimicrobial activity, demonstrating that the biomass can simultaneously serve multiple functions within a single material. From the perspective of cosmetotextiles, this strategy is especially relevant because it demonstrates the potential of integrating aesthetics, microbiological protection, and naturally derived functional ingredients into a single textile finish, bringing multifunctional wellness textiles closer to practical implementation.

Although the cosmetotextile and wellness textile market has experienced continuous growth driven by the demand for sustainable, multifunctional, and health-promoting products, the scientific literature involving Spirulina for these applications is still in its early stages. Current studies consistently demonstrate the remarkable biological potential of the microalga, including antioxidant, anti-inflammatory, antimicrobial, photoprotective, and wound-healing properties, together with recent advances in incorporating its bioactive compounds into functional textile materials (Gouda et al., 2025). Nevertheless, most of these findings have been obtained from isolated extracts, nanoparticle systems, or functional textile finishes rather than from true cosmetotextile systems intended for prolonged skin contact.

This distinction is particularly important because incorporating bioactive compounds into textile substrates introduces challenges that extend beyond demonstrating biological activity alone. A compound exhibiting excellent bioactivity in solution does not necessarily retain the same performance once incorporated into a textile matrix, where interactions with fibers, encapsulating materials, or finishing agents may affect its stability, availability, and release profile. Consequently, the development of cosmetotextiles requires not only the successful incorporation of bioactive compounds but also the demonstration of their stability during storage and use, resistance to repeated laundering, controlled release from the textile substrate, and, ultimately, their ability to provide measurable physiological benefits to the skin under real-use conditions.

Therefore, the currently available evidence should be interpreted as demonstrating the technological feasibility of incorporating Spirulina-derived compounds into functional textile systems rather than as definitive proof of cosmetotextile performance. Considering the expanding market for sustainable wellness textiles, future research should prioritize developing delivery systems capable of preserving bioactivity after textile processing while ensuring controlled release and long-term functionality. Overcoming these challenges will be essential to translate the well-established biological properties of Spirulina into commercially viable cosmetotextile products.

4.4 Biomedical textiles, smart and advanced textiles

The development of biomedical, smart, and advanced textiles represents one of the fastest-growing areas in contemporary textile engineering. Unlike conventional fabrics, these materials are specifically designed to perform functions that extend beyond mechanical protection and comfort, including physiological monitoring, responsiveness to external stimuli, optical functionality, antimicrobial activity, controlled release of bioactive compounds, and integration with electronic devices. The increasing incorporation of renewable biomaterials and sustainable nanomaterials into this field has driven the development of multifunctional platforms that combine technological performance, biological safety, and environmental sustainability. In this context, Spirulina has emerged not only as a valuable source of bioactive compounds but also as a renewable precursor for producing nanomaterials, biocomposites, and functional architectures for the next-generation of textile technologies (Gospodinova et al., 2024; Bowman et al., 2025; Hou et al., 2026).

Among the most promising advances is the use of Spirulina as a precursor for synthesizing carbon dots (CDs), fluorescent carbon-based nanomaterials that have attracted considerable attention for smart textile applications. Unlike conventional synthesis routes, which typically rely on petrochemical precursors or highly toxic reagents, using microalgal biomass enables the production of biocompatible nanomaterials from renewable resources. A significant breakthrough in this field was achieved by using purified phycocyanin as a nitrogen-rich precursor and combining it with urea doping to synthesize nitrogen-enriched carbon dots. This strategy substantially increased the fluorescence quantum yield while improving reproducibility and reducing batch-to-batch variability. The resulting nanomaterials exhibited excellent photostability, low cytotoxicity, and outstanding biocompatibility, and were subsequently incorporated into nylon yarns through both conventional dyeing and electrospinning. The functionalized yarns exhibited intense fluorescence under ultraviolet irradiation and retained more than 90% of their fluorescence intensity after prolonged exposure, highlighting their potential for textile authentication (anti-counterfeiting), optical labeling, wearable devices, and smart materials intended for prolonged contact with the human body (Hou et al., 2026).

In a complementary study, carbon dots synthesized from Spirulina also exhibited remarkable structural stability, intense fluorescence emission, high antioxidant activity, and low cellular toxicity. These nanomaterials were produced through a microwave-assisted synthesis route, yielding predominantly spherical nanoparticles enriched with oxygen- and nitrogen-containing functional groups that exhibited efficient photocatalytic activity under solar irradiation. Furthermore, the study demonstrated excellent cytocompatibility, a characteristic of particular importance for biomedical devices and smart textile applications. Although the primary objective of the work was environmental remediation, its findings considerably expand the understanding of the optical, structural, and biological properties of Spirulina-derived carbon dots, reinforcing their potential for fluorescent sensing, bioimaging, wearable optical systems, and other intelligent textile-based technologies (Palanimuthu et al., 2023).

Another emerging trend involves the direct incorporation of Spirulina biomass into structural materials designed for additive manufacturing. Recently, biodegradable biocomposites based on photopolymerizable polylactic acid (PLA) resins, reinforced with low concentrations of Spirulina biomass, were successfully fabricated via three-dimensional (3D) printing for textile accessory applications. The incorporation of microalgal biomass significantly increased the elastic modulus, improved thermal stability, and modified the aesthetic characteristics of the printed materials, while maintaining a manufacturing process that relies exclusively on environmentally safe components. Beyond the mechanical improvements achieved, the incorporation of Spirulina enabled the production of biodegradable composites through low-impact manufacturing routes that are readily customizable using additive manufacturing technologies. These findings demonstrate that Spirulina can serve not only as a surface-active ingredient but also as a structural component in advanced biomaterials for textile manufacturing, thereby considerably expanding opportunities for sustainable design, product customization, and functional engineering within the fashion and technical textile industries (Bowman et al., 2025).

Beyond optical and structural applications, Spirulina has also been investigated as a functional component in electrospun nanofiber mats to develop technical textiles with tailored performance. A recent study evaluated bilayer textile structures composed of cotton fabrics combined with poly(vinyl alcohol) (PVA) electrospun nanofibers containing Spirulina, comparing their thermal behavior with formulations incorporating beeswax and Chlorella. Although the beeswax-containing formulation exhibited the highest thermal insulation performance, the results demonstrated that incorporating microalgal biomass into electrospun nanofibers is technically feasible while preserving structural characteristics compatible with multilayer textile architectures. This approach substantially broadens the spectrum of Spirulina applications by demonstrating that its constituents can contribute not only to bioactivity but also to the design of multifunctional textile architectures intended for thermal regulation, physiological comfort, and smart nanofiber-based systems (Gospodinova et al., 2024).

Although both purified phycocyanin and whole Spirulina biomass have proven to be suitable precursors for the production of fluorescent carbon dots, each approach presents distinct advantages and challenges. The use of purified phycocyanin offers greater compositional consistency and may facilitate the production of nanomaterials with more reproducible optical properties, whereas whole biomass represents a more cost-effective and sustainable alternative by eliminating purification steps and promoting the complete utilization of the microalgal biomass. However, direct comparisons between these two strategies remain scarce, making it difficult to determine whether the potential improvements in fluorescence performance, optical stability, and biocompatibility provided by purified phycocyanin justify the additional processing complexity and production costs required for its isolation. From a commercial perspective, selecting the precursor should consider not only the performance of the resulting carbon dots but also raw material availability, processing costs, and the requirements of the intended biomedical application.

In studies involving smart and advanced textiles, Spirulina assumes a different role, acting as a complementary functional additive rather than the primary structural component of the material. Its successful incorporation into polymeric matrices such as PLA and PVA demonstrates good compatibility and confirms the technical feasibility of producing more sustainable multifunctional materials. Nevertheless, current studies remain largely focused on demonstrating the feasibility of biomass incorporation, generally employing relatively low Spirulina concentrations. Consequently, it remains unclear to what extent increasing the biomass content could further enhance the mechanical, thermal, optical, or biological properties of these materials without compromising their processability or structural performance. Addressing this question represents an important direction for future research and may contribute to maximizing the functional potential of Spirulina in advanced textile applications (Sellaoui et al., 2024; Bowman et al., 2025).

4.5 Sustainable biomaterials and biocomposites

The growing demand for sustainable textile materials has accelerated the gradual replacement of fossil-based polymers with renewable, biodegradable biomaterials derived from natural resources. Within this context, Spirulina has attracted increasing attention not only for its rich content of bioactive compounds but also for its ability to serve as a structural component in polymeric matrices, contributing to the development of multifunctional biomaterials. Unlike the applications discussed in the previous sections, where biomass primarily serves as a source of natural pigments or functional additives, recent studies have shown a clear trend toward its direct incorporation into the architecture of polymeric materials, thereby expanding the possibilities for developing biocomposites for textile applications. This strategy is fully aligned with the principles of the circular bioeconomy and sustainable chemistry, which emphasize the use of renewable feedstocks, reduced dependence on fossil resources, and the development of environmentally responsible materials.

One of the most promising strategies for expanding the use of Spirulina in textile engineering is combining it with biodegradable biopolymers to produce multifunctional biomaterials. Sellaoui et al. developed films composed entirely of Spirulina biomass, as well as hybrid films containing Spirulina and chitosan, demonstrating that incorporating chitosan significantly improved tensile strength, elongation at break, and the structural organization of the polymeric matrix. Morphological analyses revealed noticeable modifications in the film’s surface topography, while X-ray diffraction indicated the formation of a partially semicrystalline structure attributable to the presence of chitosan. Although the primary objective of the study was the production of adsorptive films for textile dye removal, the results clearly demonstrate that microalgal biomass can serve as an effective component of processable biomaterials with mechanical properties suitable for future applications in coatings, membranes, and other polymeric materials in the textile sector. Similarly, incorporating Spirulina into polylactic acid (PLA) matrices resulted in biocomposites with enhanced mechanical performance and improved thermal stability, demonstrating the biomass’s excellent compatibility with biodegradable polymeric systems and highlighting its potential as a structural component in high-value materials. Collectively, these studies indicate that the role of Spirulina extends well beyond its biological functions, establishing this microalga as a promising building block for the development of sustainable biomaterials intended for textile engineering (Sellaoui et al., 2024; Bowman et al., 2025).

Another important aspect concerns the environmental fate of these biomaterials after their service life. Replacing conventional polymers with biodegradable alternatives is an important strategy to mitigate microplastic generation in the textile sector, which is currently recognized as a major source of synthetic fibers released into the environment during garment use and laundering. Within this context, Sharma and Vuppu (2023) emphasized that biomaterials derived from renewable resources, including microalgae such as A. platensis, exhibit considerable potential for integration into circular economy systems owing to their susceptibility to enzymatic biodegradation and their reduced contribution to the accumulation of persistent plastic waste. In addition to discussing different degradation pathways for bioplastics, the authors highlighted that enzymes produced by Spirulina, including laccases and catalases, may eventually contribute to the biodegradation of polymeric materials, further expanding the environmental relevance of this biomass.

From a broader perspective, studies investigating the biodegradation of naturally derived polymers further reinforce the potential of algal biomass as a sustainable feedstock for advanced materials. Shi et al. demonstrated that algae-derived polymers exhibit high biodegradability under anaerobic conditions, identifying Spirulina as one of the microalgal biomasses with the greatest degradation potential among the species evaluated. The authors argued that materials produced from renewable biological resources help reduce fossil carbon emissions by returning recently fixed carbon to the natural carbon cycle, a characteristic that is particularly relevant to short-life products and frequently discarded items, such as numerous textile products and accessories. Although this study was not specifically designed for textile applications, its findings provide valuable scientific support for the use of Spirulina-based biomaterials within the circular bioeconomy and sustainable carbon management (Shi et al., 2010).

Despite these encouraging advances, the use of Spirulina as a structural component of textile biomaterials remains at a relatively early stage compared with its applications in natural dyeing and functional textile finishing. The available literature demonstrates that the biomass exhibits excellent compatibility with a variety of natural and biodegradable polymeric matrices, enabling it to serve as a structural reinforcement, a renewable feedstock, and a reservoir of bioactive compounds. Nevertheless, studies specifically focused on developing textile fibers containing Spirulina, as well as comprehensive investigations addressing long-term mechanical performance, industrial processability, durability, and end-of-life behavior, remain scarce. Furthermore, translating these laboratory-scale materials into commercial products will require manufacturing processes that are compatible with existing polymer processing technologies while maintaining the mechanical performance, biodegradability, and functional properties required for textile applications at an economically viable cost. Consequently, the greatest opportunity in this field lies not merely in replacing conventional raw materials, but in designing a new generation of multifunctional biomaterials capable of integrating environmental sustainability, technological performance, biological functionality, and industrial manufacturability within a single materials engineering platform (Shi et al., 2010; Sharma and Vuppu, 2023; Sellaoui et al., 2024).

5 Processing technologies and performance evaluation

The successful application of Spirulina as a functional material for the textile industry relies on a sequence of technological processes that directly influence the performance, stability, and industrial feasibility of the resulting products. Although the microalgal biomass is naturally rich in pigments, proteins, and other high-value metabolites, its technological exploitation still faces significant challenges, including the pronounced sensitivity of phycocyanin to temperature, light irradiation, and pH variations, as well as the natural variability in biomass composition resulting from cultivation conditions. Consequently, processing technologies have become a key factor in advancing Spirulina-based textile applications, not only by preserving its bioactive compounds but also by improving their stability, reproducibility, and compatibility with different manufacturing routes (Dufossé, 2024).

The first technological challenge concerns producing biomass with sufficiently standardized quality and chemical composition while maintaining the scalability and economic feasibility required for industrial applications. The concentration of pigments such as phycocyanin, as well as overall biomass productivity, is strongly influenced by factors including light intensity, nutrient availability, temperature, aeration, and cultivation system design. In this context, closed photobioreactors have been identified as an important strategy for minimizing contamination, maintaining precise control over cultivation parameters, and improving the reproducibility of natural pigment production. Although open cultivation systems remain economically attractive todue of their lower installation costs, microalgal species intended for natural colorant production often require more controlled cultivation conditions to maximize both biomass productivity and metabolite quality (Dufossé, 2024).

Following cultivation, the recovery of bioactive compounds represents one of the most critical stages of the entire processing chain. The highly resistant cellular aggregates of Spirulina hinder the extraction of phycocyanin, often resulting in reduced extraction yields and pigment degradation when conventional methods are employed. In this context, green extraction technologies have emerged as promising alternatives that improve phycocyanin recovery efficiency while reducing processing time and solvent consumption. Besides producing extracts with higher purity, these approaches better preserve the pigment’s biological activity, an aspect that is particularly important for applications that simultaneously rely on its chromatic and functional properties, such as smart textiles and cosmetotextiles (Fratelli et al., 2021; Naviglio et al., 2022).

Even after extraction, obtaining highly purified fractions remains a major challenge for high-value applications. Conventional purification protocols often require multiple downstream processing steps, increasing production costs while reducing overall recovery yields. As an alternative, continuous-flow electrophoretic separation technologies have been developed to enable the efficient purification of compounds present in Spirulina extracts. By employing carefully controlled pH gradients, this system enabled rapid separation of fractions from the microalgal supernatant without intermediate purification steps, yielding samples suitable for biological applications while significantly reducing processing time. Although originally proposed for biomolecule purification, this technology exemplifies the continuous evolution of downstream processing strategies aimed at obtaining highly purified ingredients, an increasingly important requirement for textile applications demanding high reproducibility and long-term performance stability (Stastna and Slais, 2021).

The subsequent stage involves incorporating these functional compounds into textile materials, a process that varies according to the intended application. The current literature describes a wide range of technological approaches, including exhaustion dyeing, screen printing, electrospinning, green synthesis of nanoparticles, fabrication of biopolymeric films, and three-dimensional (3D) printing. In these processing routes, Spirulina or its derivatives can be incorporated through distinct mechanisms depending on the selected technology. During dyeing processes, pigments are directly adsorbed onto textile fibers; in printing and coating technologies, bioactive compounds and nanoparticles are deposited onto the fabric surface through specifically formulated pastes or coating formulations; electrospinning immobilizes Spirulina-derived compounds within polymeric nanofibers; whereas in biopolymeric films and three-dimensional printed biocomposites, the biomass becomes an integral structural component of the material itself. Each of these processing strategies directly influences the stability of bioactive compounds, their distribution throughout the textile matrix, and the long-term durability of the resulting functional properties (Moldovan et al., 2022; Abdelgawad et al., 2025; Bowman et al., 2025; Rathinamoorthy and Rajesh Kumar, 2025; Hou et al., 2026). Despite their differences, all these technologies pursue a common objective: overcoming the intrinsic limitations of biomass, including limited affinity for certain textile fibers, poor wash durability, photochemical instability, and the need to improve the homogeneous distribution of active compounds within textile substrates. Consequently, the selection of an appropriate processing technology has evolved from merely a manufacturing step to a determining factor in preserving Spirulina functionality throughout the textile material’s service life.

Overall, the evolution of Spirulina-based textile applications depends not only on the discovery of new biological functionalities but also on the continuous advancement of processing technologies. Progress in controlled cultivation systems, more efficient extraction and purification methods, sustainable incorporation strategies, and increasingly robust characterization protocols has progressively overcome historical limitations associated with biomass stability, reproducibility, and functional performance. Despite these technological advances, large-scale implementation remains one of the major challenges for Spirulina-based textile technologies. Successfully translating laboratory-scale processes into industrial manufacturing will require not only scalable cultivation systems and cost-effective downstream processing but also manufacturing routes compatible with existing textile production infrastructure. Achieving this balance between product performance, process efficiency, and economic viability will be essential for the widespread industrial adoption of Spirulina-derived textile materials. Future studies should prioritize developing scalable, economically viable processing routes that maintain the functional properties of Spirulina-derived compounds while ensuring compatibility with existing industrial textile manufacturing processes. Consequently, the integration of biotechnology, materials science, and textile engineering has emerged as one of the principal driving forces behind the consolidation of Spirulina as a promising platform for the development of high-value functional textile materials.

6 Sustainability, circular economy and current challenges

The growing demand for more sustainable textile production has promoted a gradual paradigm shift in which industrial residues are no longer regarded merely as environmental liabilities but rather as valuable resources capable of generating new products and production pathways. In this context, Spirulina offers a unique advantage over most renewable feedstocks currently explored in the textile industry. Beyond supplying natural pigments, bioactive compounds, and biomass for a wide range of textile applications, its cultivation can also be integrated into industrial wastewater treatment processes. This unique capability enables a single biological resource to simultaneously perform environmental remediation, nutrient recovery, and renewable biomass production, bringing the concept of microalgal biorefineries closer to the principles of the circular bioeconomy. In contrast to the traditional linear production model—based on resource extraction, manufacturing, consumption, and disposal—the integrated use of Spirulina enables the continuous recirculation of resources within the production chain, reducing the demand for freshwater, chemical inputs, and fossil-derived raw materials (Dario et al., 2018; Hanifa et al., 2025).

In recent years, numerous studies have demonstrated that textile wastewater can be transformed from an environmental burden into an alternative cultivation medium for microalgae. The cultivation of Spirulina in textile effluents has shown growth performance comparable to that observed in conventional culture media, while simultaneously achieving substantial reductions in chemical oxygen demand (COD), nitrogen, and phosphorus concentrations. Besides mitigating the pollutant load, cultivation in textile wastewater generated biomass suitable for subsequent valorization, demonstrating that biological wastewater treatment can occur simultaneously with renewable biomass production. This integrated approach represents an important departure from conventional wastewater treatment technologies, which generally require high energy inputs while generating secondary residues with little or no added value (Selvaraj and Arivazhagan, 2024; 2025a).

The valorization of the resulting biomass is one of the most promising aspects of applying Spirulina within the circular bioeconomy. Figure 2 summarizes the current challenges and future perspectives of Spirulina and its components in textile innovations and applications. Cultivation in textile wastewater not only preserved the microalga’s growth capacity but also induced favorable metabolic changes, including increased accumulation of lipids and carbohydrates, thereby expanding its potential for subsequent applications such as biofuel production and the manufacture of advanced biomaterials. Similar observations have been reported for other cyanobacteria cultivated in textile effluents, where the resulting biomass exhibited high lipid contents, favorable fatty acid profiles for biodiesel production, and significant reductions in the phytotoxicity of treated wastewater. Consequently, the process generates not only a remediated effluent but also value-added biomass, thereby establishing a substantially more efficient resource-utilization pathway (Dario et al., 2018; Bandara et al., 2026).

This integrated resource utilization strategy embodies the modern concept of the microalgal biorefinery, in which each biomass fraction can be converted into products of different added value according to its chemical composition. Phycocyanin may be directed toward sustainable textile coloration or functional materials; lipids can be converted into biofuels; proteins may serve multiple biotechnological applications; and the residual biomass can be transformed into biosorbents, biocomposites, or agricultural fertilizers. Recent reviews emphasize that this cascade utilization strategy represents one of the most promising approaches for improving the economic viability of microalgal technologies in the textile sector by minimizing waste generation while maximizing the utilization of the entire biomass. From this perspective, Spirulina should no longer be regarded merely as a source of natural pigments but rather as a multifunctional biotechnological platform capable of integrating wastewater treatment, resource recovery, and the production of high-value materials within a single production system (Hanifa et al., 2025).

Another important aspect concerns the distinct biological mechanisms by which microalgae contribute to the remediation of textile wastewater. Beyond simple biosorption of textile dyes, processes such as bioaccumulation, biodegradation, and biotransformation also contribute to the removal of organic contaminants, nutrients, and potentially toxic metals. In some cases, the production of oxidative enzymes, including laccases and peroxidases, further enhances the degradation of complex dye molecules, thereby increasing the efficiency of biological treatment systems. Although comparative studies indicate that other microalgal species may exhibit higher enzymatic activity toward specific dyes, the results obtained with Spirulina demonstrate that its remarkable metabolic adaptability and ability to thrive in real industrial effluents remain significant advantages when environmental remediation and subsequent biomass valorization are considered as integrated objectives (Abd Ellatif et al., 2021; Selvaraj and Arivazhagan, 2025a).

In addition to biological treatment itself, several engineering strategies have been proposed to further improve process efficiency at the industrial scale. Continuous fixed-bed systems employing Spirulina biomass have demonstrated high adsorption capacities for reactive dyes, while hybrid processes combining electrocoagulation with adsorption using Spirulina-derived activated carbon achieved superior removal of both organic matter and color from real textile wastewater. These approaches demonstrate that microalgal biomass can serve multiple functions throughout the production chain: initially as a living organism responsible for wastewater remediation, and subsequently as processed biomass converted into highly efficient biosorbents and adsorbents. This sequential reuse of the same biological resource represents a practical example of circular bioeconomy principles, in which a single biomass fulfills multiple functions before its final disposal (Selvaraj and Arivazhagan, 2025b).

Overall, the available evidence demonstrates that Spirulina’s greatest contribution to sustainable textile manufacturing lies not in any single application, but in its ability to integrate multiple stages of the production chain into a unified biotechnological system. The biomass can be cultivated using industrial effluents as a nutrient source, contribute to wastewater remediation, provide natural pigments for textile coloration, supply bioactive compounds for functional finishing, and, after processing, still be valorized to produce biosorbents, biomaterials, or biofuels. This cascade utilization strategy is among the most comprehensive examples of circular bioeconomy currently described for microalgal systems and constitutes one of the strongest arguments supporting the growing interest in Spirulina as a technological platform capable of accelerating the textile industry’s transition toward more sustainable production models.

Despite the remarkable advances achieved in recent years, the consolidation of Spirulina as a feedstock for the textile industry still depends on overcoming several scientific, technological, and industrial challenges. From an environmental perspective, one aspect that remains frequently overlooked concerns the interaction between Spirulina itself and the contaminants present in textile effluents. Although numerous studies have demonstrated the high efficiency of this microalga in removing dyes, nutrients, and heavy metals, several textile dyes have also been shown to exert toxic effects on its metabolism, impairing cell growth, photosynthetic activity, biochemical composition, and overall biomass productivity. These observations indicate that the efficiency of phycoremediation depends not only on the physiological characteristics of the microalga but also on the chemical composition of the treated wastewater. Consequently, strategies such as controlled wastewater dilution, gradual acclimation of microalgal cultures, selection of more tolerant strains, and integration with complementary physicochemical treatments may be required to simultaneously ensure effective wastewater remediation and the production of biomass suitable for subsequent valorization (Gita et al., 2021; Krishna Moorthy et al., 2021; Moorthy et al., 2022).

Another important limitation concerns the relatively limited knowledge regarding the long-term performance of Spirulina-based textile materials. Most available studies focus primarily on the initial characterization of fabrics or biomaterials, whereas issues related to long-term durability, resistance to repeated laundering, aging under service conditions, long-term storage stability, and end-of-life behavior remain largely unexplored. Likewise, comprehensive life cycle assessment (LCA), techno-economic analysis, and industrial scale-up studies remain scarce, making it difficult to compare Spirulina-based technologies with conventional textile manufacturing processes currently used in industry. Future studies should also consider the growing competition for Spirulina biomass among different industrial sectors, including food, cosmetics, pharmaceuticals, and biomaterials, since the large-scale expansion of textile applications will ultimately depend on the availability of sustainable and economically competitive biomass production systems. Addressing these knowledge gaps is essential, since successful industrial implementation depends not only on technical performance but also on economic feasibility and environmental sustainability throughout the entire product life cycle.

Another challenge lies in the need for stronger integration among multiple scientific and engineering disciplines. Developing Spirulina-based textile materials requires expertise spanning microalgal cultivation, biotechnology, polymer chemistry, textile engineering, nanotechnology, materials science, and environmental engineering. Nevertheless, current research remains relatively fragmented, with most studies addressing only isolated stages of the technological value chain. More significant advances will depend on truly interdisciplinary approaches that integrate biomass production, bioactive compound recovery, materials processing, functional performance evaluation, and biomass valorization strategies within a unified development framework. Such integration will be fundamental for establishing production systems that are not only environmentally sustainable but also economically competitive (Dufossé, 2024; Bowman et al., 2025; Hanifa et al., 2025).

Looking ahead, Spirulina’s greatest potential for the textile industry lies not in any single application but in its ability to connect multiple stages of an integrated value chain. A single biomass can be cultivated using textile wastewater as a nutrient source, provide natural pigments for sustainable textile coloration, supply bioactive compounds for functional finishes and cosmetotextiles, serve as a precursor for advanced biomaterials, and finally be valorized to produce biosorbents, biofuels, or new biocomposites. This cascade utilization strategy is among the most comprehensive examples of circular bioeconomy currently reported for microalgal systems and positions Spirulina as a multifunctional biotechnological platform capable of integrating environmental remediation, waste valorization, and innovation in sustainable textile materials. Ultimately, the future success of Spirulina in the textile industry will depend less on the discovery of new biological functionalities—which are already well established—and more on the ability to integrate cultivation, downstream processing, materials engineering, and industrial manufacturing into economically viable and scalable production systems.

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Footnotes

Edited by: Prabhuraj D. Venkatraman, Manchester Metropolitan University, United Kingdom

Reviewed by: Muazzez Gurgan, Namik Kemal University, Türkiye

Hirak Parikh, Indiana State University, United States