Mucoadhesive nanofibers for ocular drug delivery: mechanisms, design strategies, and applications

Delivering drugs effectively to the ocular surface is challenging due to rapid clearance mechanisms, including blinking, tear turnover, and protective barriers of the conjunctival and corneal epithelium. As a result, conventional options such as eye drops often fail to provide sustained therapeutic effects and require frequent dosing, leading to reduced patient compliance. Mucoadhesive nanofiber systems offer a promising solution by enhancing drug retention and enabling controlled release at the ocular surface. These nanofibers, produced primarily through electrospinning, provide a high surface area, tunable mechanical properties, and compatibility with mucoadhesive polymers, collectively improving drug bioavailability, extending residence times, and minimizing systemic side effects. This review comprehensively explores the fundamentals of mucoadhesion, including the structural and compositional characteristics of ocular mucosal surfaces and the molecular interactions essential for optimized drug delivery. It examines advanced strategies for incorporating mucoadhesive features into nanofibers, such as polymer blending, surface modification, and molecular imprinting, and assesses their influence on therapeutic outcomes. Finally, recent advancements and their potential for clinical translation are discussed. By presenting a thorough analysis of current techniques and emerging innovations, this review aims to guide researchers in developing next-generation mucoadhesive nanofiber platforms that improve therapeutic efficacy and patient compliance in ocular drug delivery.