Photocurable antimicrobial silk-based hydrogels for corneal repair

Area of Science:

• Biomaterials Science
• Ophthalmology
• Regenerative Medicine

Background:

• Corneal transplantation is limited by donor tissue scarcity.
• Antibiotic eye drop delivery is challenging in ocular surgery, risking implant success.
• A need exists for advanced corneal equivalents and antimicrobial delivery systems.

Purpose of the Study:

• To develop photoactivatable, antimicrobial silk-based hydrogels (SilkMA) as a corneal equivalent.
• To assess the physical, mechanical, and biological properties of SilkMA hydrogels.
• To evaluate the antimicrobial efficacy of SilkMA hydrogels against common ocular pathogens.

Main Methods:

• Methacrylated silk (SilkMA) hydrogels were synthesized via photopolymerization with gentamicin.
• Physical properties (Young's modulus, water content, light transmittance) were characterized.
• In vitro degradation, fibroblast biocompatibility, and agar diffusion tests for bacterial inhibition were performed.

Main Results:

• SilkMA hydrogels exhibited Young's modulus (21–79 kPa), water content (83–90%), and light transmittance similar to the human cornea.
• Methacrylation did not compromise in vitro degradation or fibroblast adhesion/proliferation.
• Hydrogels successfully inhibited Staphylococcus aureus and Pseudomonas aeruginosa growth for 72 hours.

Conclusions:

• Photocurable antimicrobial SilkMA hydrogels show promise as a novel biomaterial for corneal regeneration.
• These hydrogels offer tunable physical properties and effective antimicrobial activity.
• SilkMA hydrogels present a potential solution to donor tissue shortage and infection risks in ophthalmology.