Impact of Surface Properties — Including Pore Size — of Porous Structures on Anticancer Drug Delivery Efficiency in Colon Cancer: A Systematic Review

Porous materials with micro-, meso-, and macroporous structures receive increasing attention as multifunctional platforms for targeted drug delivery in colon cancer therapy. Their adjustable pore sizes, tunable surface chemistry, and adaptable structural frameworks enable controlled drug loading and release. Pore size distribution's impact on treatment efficacy is under-investigated. In line with PRISMA 2020 guidelines, this review systematically examined more than 3,000 studies and, based on performance criteria, identified 203 articles for inclusion. The IUPAC pore classification elucidates the impact of pore diameters on drug diffusion, cellular uptake, and cytotoxicity, highlighting their essential function in multi-modal treatment techniques. Recent advancements in pH-responsive systems, aptamer-mediated targeting, and hierarchical porosity engineering illustrate how these integrated mechanisms augment site-specific drug delivery and enhance therapeutic selectivity. The review emphasizes essential design principles and future outlooks for creating next-generation porous carriers, whereby pore size, surface functionality, and biological responsiveness work in concert to enhance colon cancer therapy.