Stimulus-Responsive Cellulose-Based Hydrogels for Drug Delivery
Stimulus-responsive cellulose-based hydrogels combine the advantages of being widely sourced, renewable, biocompatible, and biodegradable. With their three-dimensional porous networks and high water content, they provide an ideal environment for drug loading, diffusion, and cell growth. Through chemical modification, physical crosslinking, chemical crosslinking, or composite network design, cellulose-based hydrogels can respond to pH, temperature, light, and multi-stimuli, and achieve controlled drug release by adjusting network pore size, swelling behavior, crosslinking density, or degradation rate. This review summarizes the structural characteristics of cellulose and its derivatives, the main preparation methods of cellulose-based hydrogels, their stimulus-responsive mechanisms, and recent advances in their application for drug delivery. It focuses on their potential applications in anticancer drug delivery, wound dressings and antimicrobial delivery, ophthalmic drug delivery, oral-intestinal drug delivery, as well as tissue engineering and regenerative medicine. Finally, this paper summarizes the challenges facing these materials in terms of mechanical properties, release behavior stability, in vivo compatibility, and large-scale application, and outlines future directions for their development.