The preparation of silk fibroin microspheres

Silk fibroin microspheres were prepared by oil phase separation coacervation and with silk fibroin as vehicle, dexamethasone sodium phosphate(DSP) as drug model. The emulsion temperature, stirring rate that influence microparticles size and the glutaraldehyde content that influence microspheres structure, drug release properties were investigated. The results showed that when the stirring rate between 350 rpm and 720 rpm, with the increase of stirring rate, the average particles size obviously decreased, it was between 34.7 mu m and 16.2 mu m. And when the emulsion temperature between 37 degrees C and 55 degrees C, with the increase of emulsion temperature, the average particles size decreased; the main structure of pure SF was amorphism, SF microspheres and SF drug-loaded microspheres appeared Silk I and Silk II structures, and there was no obvious change between the SF microspheres and SF drug-loaded microspheres with glutaraldehyde and those without, The drug release rate was faster when the time was between 1 h and 24 h, and the drug release was about the half of the total. After 24 h bad passed, the rate of release decreased. The release rate of SF drug-loaded microspheres with glutaraldehyde was slower than those without, but not obviously. The release rate of SF drug-loaded microspheres with the increase of glutaraldehyde's content decreased, but not obviously.