PREPARATION AND CHARACTERIZATION OF CHITOSAN/REGENERATED SILK FIBROIN (CS/RSF) FILMS AS A BIOMATERIAL FOR CONTACT LENSES-BASED OPHTHALMIC DRUG DELIVERY SYSTEM

Abstract

Objective: The aim of this study was to develop chitosan/regenerated silk fibroin (CS/RSF) films as a biomaterial for contact lenses-based ophthalmic drug delivery system. Methods: CS/RSF films were prepared with polyethylene glycol 400 as a plasticizer by using a film casting technique. Their physicochemical properties were investigated by measuring various properties such as thickness, morphology, chemical interaction, light transparency, mechanical properties, water content, oxygen permeability, thermal properties and enzyme degradation. In addition, cytotoxicity was also studied. Results: At optimal preparation conditions, CS/RSF films showed smooth surfaces with highly visible light transparency of >90%, which meet the visual requirement. CS/RSF films showed high water content, 59-65% by weight, and their Young’s modulus and elongation at break was in the range of 3.8-6 N/mm2 and 113-135%, respectively. The CS/RSF films also could be sterilized by autoclave method as they possessed high thermal decomposition temperature of >260 °C which can be confirmed by both differential scanning calorimetry and thermogravimetric analysis. In addition, CS/RSF films showed no degradation in stimulated tear fluid containing lysozyme for 7 d and showed no cytotoxicity by MTT assay. Conclusion: CS/RSF films showed excellent physicochemical properties and non-cytotoxicity indicating their promising potential use as a biomaterial for contact lenses-based ophthalmic drug delivery system.