Mussel-Inspired In Situ Photodynamic Antibacterial Coating for Postoperative Management of Artificial Corneas

Artificial corneal (AC) implants offer hope to millions with corneal blindness, including 5 million in China. Titanium is one of the materials commonly used in the fabrication of artificial corneal scaffolders because of its light texture, high mechanical properties, and high biosafety. However, postoperative bacterial infections, especially from Pseudomonas aeruginosa and Staphylococcus aureus (S. aureus), remain a significant challenge due to the bioinert nature of titanium materials, leading to high infection rates. In this study, we introduce an innovative in situ photodynamic coating technology designed to manage postoperative infections in artificial corneas. Inspired by mussel adhesive proteins, this coating employs a composite of APTES-TA formed by Schiff base and Michael addition reactions between 3-aminopropyltriethoxysilane (APTES) and tannic acid (TA), integrated with the bacterial targeting capabilities of 4-carboxyphenylboronic acid (CPBA) and the photo-Fenton activity of FeOOH (iron(III) hydroxide). The design of the AC@APTES-TA-CPBA-FeOOH coating leverages the dynamic boronate ester bonds, which interact specifically with bacteria in tears, effectively capturing them on the surface of the artificial cornea. The coating exhibits a photocatalytic Fenton-like effect, which confers it with an exceptional bactericidal efficiency of over 99% in vitro. Furthermore, it demonstrates excellent protective functionality for mouse corneas in vivo experiments.