Preparation of Silk Fibroin Microspheres and Its Application to Protein Adsorption

Silk fibroin (SF) microspheres were prepared by a water-in-oil emulsion solvent evaporation method without any surfactants. The water and oil phases were SF aqueous solution and paraffin, respectively. The SF microspheres with spherical shape and smooth surface were separated into the size ranges of 80 m, 80-150 m and 150 m. SF conformation of the microspheres was investigated by Fourier transform infrared spectroscopy while scanning electron microscopy used for morphological observation. After being treated with methanol, the SF conformation was changed from random coil to -sheet form. Finally, the influence of particle size on protein adsorption efficiency was studied. Bovine serum albumin (BSA) was chosen as a model protein to carry out an immobilization test onto the SF microspheres by non-covalent adsorption. Efficiency of BSA adsorption was significantly increased with decreasing the SF microsphere size.