Mechanistic study of silica nanohybrids in cancer drug delivery: Current techniques, limitations, and future prospects

Because of their high cargo-loading capacity, tunable porosity, ease of surface functionalization, and compatibility with stimuli-responsive and multimodal therapeutic strategies, silica nanohybrids especially mesoporous silica nanoparticles (MSNs) and their organic–inorganic composites have emerged as flexible platforms for cancer drug delivery. Clinical translation is nevertheless constrained by an inadequate mechanistic knowledge of their interactions with biological systems, despite encouraging preclinical effectiveness. The key mechanisms in silica nanohybrid-mediated cancer drug delivery, such as cellular uptake pathways (dominated by clathrin, caveolae, and macropinocytosis), endosomal escape strategies (proton sponge, membrane destabilization, ROS-mediated disruption), stimuli-responsive release (pH, redox, enzyme, light, magnetic, and ultrasound), tumor microenvironment (TME) penetration, and in vivo biodistribution are all critically examined. This review highlight persistent limitations, including an overreliance on simplified 2D/early 3D models, a lack of standardized validation protocols, a poor correlation between uptake and therapeutic outcome, insufficient long-term degradation and toxicity profiling, and inadequate characterization of nano-immune interactions. Emerging directions patient-derived tumor organoids, vascularized microfluidic tumor-on-chip systems, humanized mouse models, multi-omics interrogation of protein corona and cellular responses, AI-driven predictive modeling and inverse design, and safety-by-design principles aligned with regulatory expectations provide promising pathways to address these gaps. By combining sophisticated, physiologically applicable platforms with quantitative systems level analysis and translational vision, the field may develop silica nanohybrids from laboratory synthesis to safe, efficacious, and clinically feasible precision cancer therapies.