Development of an in-situ forming collagen-based hydrogel as a regenerative bioadhesive for corneal perforations

Corneal injuries play a significant role in global visual impairment, underscoring the demand for innovative biomaterials with specific attributes such as adhesion, cohesion, and regenerative potential. In this study, we have developed a biocompatible bioadhesive for corneal reconstruction. Derived from Collagen type I, naturally present in human corneal stromal tissue, the bioadhesive was cross-linked with modified polyethylene glycol diacrylate (PEGDA-DOPA), rendering it curable through visible light exposure and exhibiting superior adhesion to biological tissues even in wet conditions. The physicochemical characteristics of the proposed bioadhesive were customized by manipulating the concentration of its precursor polymers and adjusting the duration of photocrosslinking. To identify the optimal sample with maximum adhesion, mechanical strength, and biocompatibility, characterization tests were conducted. The optimal specimen, consisting of 30 % (w/v) PEGDA-DOPA and cured with visible light for 5 min, exhibited commendable adhesive strength of 783.6 kPa and shear strength of 53.7 kPa, surpassing that of commercialized eye adhesives.Additionally, biocompatibility test results indicated a notably high survival rate (>100 %) of keratocytes seeded on the hydrogel adhesive after 7 days of incubation. Consequently, this designed bioadhesive, characterized by high adhesion strength, robust mechanical strength, and excellent biocompatibility, is anticipated to enhance the spontaneous repair process of damaged corneal stromal tissue.