Metal- and Metal-Oxide Nanotheranostics for Solid Tumors: Imaging, Delivery, and Therapeutic Response

Solid tumors remain among the most treatment-resistant malignancies, defined by dense stromal barriers, heterogeneous vasculature, immunosuppressive microenvironments, and mechanisms of therapeutic escape that collectively limit the efficacy of conventional approaches. The convergence of nanotechnology and oncology has opened a fundamentally different paradigm — one in which a single engineered platform can simultaneously image the tumor, deliver a therapeutic payload with precision, and monitor the biological response in real time. Metal- and metal-oxide nanoparticles are uniquely positioned at the center of this convergence.Gold, silver, copper, zinc oxide, iron oxide, titanium dioxide, and cerium oxide nanoparticles — among others — offer an exceptional combination of tunable physicochemical properties, intrinsic imaging contrast, surface versatility, and multifunctional therapeutic capacity. Their size-dependent optical, magnetic, and electronic behaviors make them inherently adaptable to the demands of modern theranostic design. When engineered with appropriate surface chemistries, targeting ligands, and stimuli-responsive release mechanisms, these platforms can exploit features of the solid tumor microenvironment — including acidic pH, elevated reactive oxygen species, hypoxia, and overexpressed surface receptors — to achieve selective accumulation and context-dependent activity.This Research Topic focuses on the full translational arc of metal- and metal-oxide nanotheranostics: from rational platform design and synthesis, through mechanistic interrogation in tumor models, to assessment of therapeutic response in vivo. Central themes include the integration of these agents with clinically relevant imaging modalities such as MRI, computed tomography, photoacoustic imaging, and PET; their deployment as vehicles for chemotherapeutic, nucleic acid, and immunomodulatory payloads; and their application in photothermal, photodynamic, and radiation-sensitizing therapeutic strategies. Equally important are investigations into nanoparticle behavior within the tumor microenvironment — including interactions with stromal cells, immune populations, and the extracellular matrix — as well as questions of biocompatibility, biodistribution, and systemic toxicity that bear directly on clinical translatability.Research addressing the intersection of nanotheranostic platforms with immunotherapy, including checkpoint blockade sensitization, abscopal effect induction, and innate immune activation, is of particular interest, as is work exploring combination strategies that harness the synergy between nanomedicine and established or emerging oncological treatments. Studies that leverage advanced tumor models, including three-dimensional cultures, organoids, and in vivo systems, to rigorously evaluate platform performance and therapeutic outcomes are especially encouraged.This collection welcomes contributions from researchers working at the interface of materials science, cancer biology, imaging physics, pharmacology, and translational oncology. The goal is to consolidate the current state of the field, surface emerging mechanistic insights, and define the critical challenges that must be addressed to move metal- and metal-oxide nanotheranostics from the bench toward clinical adoption in the treatment of solid malignancies.Please note: Manuscripts consisting solely of bioinformatics, computational analysis, or predictions of public databases which are not accompanied by validation (independent clinical or patient cohort, or biological validation in vitro or in vivo, which are not based on public databases) are not suitable for publication in this journal. Topic editors: Donald Fernandes, Natalie Julie Serkova, Rahul Gupta Source: https://www.frontiersin.org/research-topics/83664/metal--and-metal-oxide-nanotheranostics-for-solid-tumors-imaging-delivery-and-therapeutic-response