Chitosan-hydroxypropyl methylcellulose hybrid biomaterials: Structure-function relationships, formulation strategies, and translational challenges in oral and dental applications

The development of innovative biomaterials for oral and dental treatment is growing in emphasis on designing biofunctional systems that can engage proactively with the surrounding biological environment. Although traditional polymeric materials like polymethyl methacrylate (PMMA) have proven clinically effective, they also have drawbacks, including a tendency toward microbial colonization, limited tissue compatibility, and no therapeutic functions. Among Contemporary biopolymers, chitosan (CS) and hydroxypropyl methylcellulose (HPMC) have become notable contenders. CS has antimicrobial properties, is biocompatible, and boosts wound healing, whereas HPMC contributes mucoadhesiveness and hydration. Nevertheless, the individual use of these polymers is limited because they lack adequate mechanical strength and bioactivity. Recent developments in CS-HPMC hybrids have shown promise in combining antimicrobial and wound-healing capabilities by creating a semi-interpenetrating polymer network through intermolecular hydrogen bonding and polymer chain entanglement. Fabrication methods involve hydrogels, films, sponges, and coatings, whose characteristics can be adjusted by varying the polymer ratio, molecular weight, and degree of deacetylation. Although encouraging results have been seen in lab and animal studies, real-world clinical use demands additional research into consistent manufacturing, mechanical properties, and testing in living organisms. This review offers a detailed examination of how structure relates to function, formulation approaches, and challenges in translating CS-HPMC hybrids for use in oral and dental applications.