Use of ozone for the preparation of functional silk fibroin-based biomaterial loaded with bioactive compounds for biomedical applications

Silk fibroin (SF) can be used for the preparation of porous functional biomaterials due to its biocompatibility, biodegradability, and minimal inFLammatory reactions. High porosity and homogenous interconnected pore structure is a challenge for the preparation of porous biomaterials. Porous SF foam materials can be formed by bubbling inert gases through aqueous solutions and subsequent freeze drying process. In this study, SF foam structures were prepared by first purging ozone gas and then freeze drying of this ozone-treated aqueous SF solution. Resulting porous materials were efficiently loaded with plant extract for the preparation of functional biomaterials having antimicrobial properties. The interactions of SF with ozone led to chemical modifications that improved both foaming and hydrophobic properties. Intensive ozone treatment caused the crystallinity degree of untreated SF to decrease from 48% to 42%. Ozone treatment also resulted in a significant reduction in surface tyrosine content from 55% to 43%. The use of ozone gas for the preparation of SF foam material enhanced the adsorption capacity of phenolic compounds. The enhancement in the adsorption of phenolic compounds on SF foam structure can be attributed to the oxidation-dependent increase in hydrophobicity.