Recent advances and therapeutic applications of mesoporous silica nanoparticles in oncology

Abstract

Mesoporous silica nanoparticles (MSNs) have been recognized as efficient, all-around nanocarriers for cancer therapy. This review highlights recent improvements in MSN design, synthesis, functionalization, and biomedical applications, as reflected in their individual textural characteristics of high surface area, pore size (2–50 nm), and high density of silanol groups, which allow high drug loading, controlled release, and multifunctionality. Researchers use advanced synthetic methods (sol–gel/Stöber, templated surfactant self-assembly, hydrothermal/solvothermal) and structural variations (hollow, core–shell, large-pore MSNs) to achieve precise control over particle size, morphology, and pore structure, enabling loading of a range of cargos (from small chemotherapeutics to nucleic acids). Active targeting, appendage of on-demand release. Surface engineering methods are discussed: PEGylation, ligand conjugation (folate, peptides, antibodies, aptamers), and stimuli-responsive gatekeepers (pH, redox, enzyme, light). This review presents up-to-date methods for MSN-based combination therapies and theranostic systems with real-time imaging agent monitoring in preclinical models. Preclinical work has been done in breast and lung cancers, and metastatic cancer models demonstrate improved tumor accumulation, cellular uptake, and therapeutic efficacy compared to free drugs. However, biodistribution studies have shown that uptake occurs via the mononuclear phagocyte system organs (liver, spleen), with size- and surface-dependent profiles. Translational issues are discussed with reference to scale-up and batch reproducibility, regulatory barriers, long-term safety concerns, and immunogenicity. Researchers identify opportunities underway, such as biomimetic coatings, nanomotors, customized MSN formulations, and combinations with gene and immune therapies, which have the potential to bridge the bench-to-bedside gap. Strategies for drug encapsulation (physical adsorption, electrostatic binding, covalent grafting) and secrecy (passive diffusion, stimulus-gated opening of gates) are considered, as are success stories of high-loading formulations. Though these results are encouraging in preclinical studies, clinical translation has not been aggressively pursued. The repertoire of silica platforms in clinical studies is mostly dense, not mesoporous, indicating that careful chronic toxicity research, along with standard manufacturing and early regulatory discussions, is necessary to accelerate safe use in clinical trials. In conclusion, although MSNs have significant potential for precision oncology due to their modularity and many functionalities, to realize their clinical potential, manufacturing, safety, and regulatory challenges should be addressed through standardized characterization and collaborative work across disciplines that are urgent priorities.