Multifunctional Collagen Corneal Shields Enabling Sustained Drug Delivery and Regeneration for Ocular Surface Therapy

Regenerative medicine in ophthalmology offers a novel approach to overcoming the limited healing capacity of ocular tissues and the challenges of conventional therapies. Ocular drug delivery remains hindered by physiological barriers, including tear turnover and the protective corneal epithelium, resulting in the loss of up to 95% of topically administered therapeutics through conventional eye drops. In this context, collagen-based corneal shields have emerged as a promising multifunctional drug delivery platform biomimetically resembling the native corneal extracellular matrix, capable of providing mechanical protection, hydration, and sustained therapeutic release while supporting tissue healing. The present study investigated the development and physicochemical characterization of therapeutic chemically crosslinked collagen corneal shields using custom-designed 3D-printed molds. This methodology enabled control of shield geometry and surface quality, indispensable for maintaining optical performance. Optical analysis confirmed high transparency, with visible transmittance values between 92% and 98%, exceeding ISO standards for ophthalmic biomaterials. Dissolution studies showed controlled biodegradation, with in vitro dissolution rates between 5% and 25%, expected to increase under in vivo enzymatic conditions. Rheological evaluations showed that collagen concentration and crosslinking density affect viscoelastic properties and mechanical integrity. The shields also effectively incorporated water-soluble drugs, enabling prolonged diffusion, while tobramycin-loaded shields demonstrated sustained antimicrobial activity over 72 hours, validating successful drug loading and controlled release. Overall, the results affirm that collagen corneal shields fabricated using 3D-printed molds achieve a combination of controlled biodegradation, sustained drug delivery, and high optical clarity. These attributes underscore their viability as multifunctional scaffolds for next-generation regenerative ophthalmic therapies.