The Preparation of Silk Fibroin Drug-loading Microspheres

Abstract

Silk fibroin (SF) microspheres were prepared by water-in-oil-in-water double-emulsification with SF as vehicle and dexamethasone sodium phosphate (DSP) as drug model. The surface morphology was observed by SEM, the particle diameter and its distribution were observed with Laser particle sizer. The structure was studied by X-ray diffraction and Fourier transform infrared. The properties of drug release were assessed in vitro. The results showed the drug-loading microspheres average size varied from 6.53 mu m to 68.60 mu m. The structure of SF drug-loading microspheres had an obviously change compared with pure SF, and appeared silk I and silk 11 structures, and its molecular conformation was P-sheet. The average drug-loading varied from 5.32 % to 9.01 %, and the average loading varied from 56.43% to 99.07%. The drug-loading and loading efficiency increased with the increase of SF concentration. The drug-loading and loading efficiency differed when the treated organic solvent differed, their order is: isopropanol