The Structure and the Release Performance of Silk Fibroin-hydroxypropyl Chitosan Microspheres

Insulin was used as the targeting drugs and silk protein and hydroxypropyl chitosan as the drugs package material,to prepare the SF-HPCS microspheres using the complex coacervation.Scanning electron microscopy(SEM)was applied to observe the appearance of microspheres.The infrared spectroscopy(FTIR),scanning electron microscopy(SEM),X-ray diffraction(XRD)and thermogravimetric analysis(TGA)were used to characterize the microspheres containing the drug structure,the external morphology and thermal properties.The results showed that microspheres were spherical,dense surface,and average particle size of 22.4 μm,normal distribution.There is an interaction between silk fibroin and hydroxypropyl chitosan.XRD showed that crystallization increased and the drug-loaded SF-HPCS microspheres embedded rate was 73.6%,larger than the drug-loaded HPCS microspheres(64.3%)and the drug-loaded CS microspheres(57.1%).The drug-loaded SF-HPCS microsphere release of 21.3% in an artificial gastric juice,released 81.2% in 24 h.The release reached 92.2% in 48 h in an artificial intestinal fluid.The process of drug release was slow.