Delivery Of Basic Fibroblast Growth Factor From Microspheres And Collagen

In this paper, PLGA was modified by amino grafting for heparin and enhance the adsorption of basic fibroblast growth factor (bFGF). The method of water in oil in water was utilized to prepare bFGF-PLGA microspheres. The experiment of bFGF-PLGA microspheres activity detection and release process in vitro indicated that the feasibility of microspheres which were used to be the carrier of long controlled release.Maleic anhydride was used to react with PLGA to produce maleic anhydride modified PLGA (MPLGA), and react with ethylenediamine to produce ethylenediamine modified PLGA (EMPLGA).EMPLGA adsorpt bFGF by graft heparin. Modify reaction products were analyzed by ninhydrin, FT-IR and DSC.The microspheres morphology, mean diamerer, drug loading, encapsulation efficiency, initial burst release rate, diameter distribution, vitro release were set as evaluative guide line to study the microspheres stability under4℃state. The results indicated that all the properties of microspheres had no evident changes in4℃state. The experiment of bFGF-PLGA microspheres activity detection indicated that there were about60%bFGF from bFGF-PLGA microspheres remained active. At the same time, the bFGF-PLGA microspheres could release active bFGF sustained, which could promote cell division growth.The collagen was manufactured from the skin of porcine with pepsin digestion and neutral salt extractions. By adding acetic into collagen gel extracted freshly, we obtained a homogenic diluted acid dispersion of this insoluble collagen gel. The collagen sponge was prepared by lyophilization after freezing. We carried out method to EDC/NHS crosslinking and one-step simultaneous method to EDC/NHS crosslinking and heparin immobilization for modifying collagen sponge, which could enhance its mechanics performance.So, the technics of bFGF-PLGA microspheres was considered to be well stable. The bFGF initial burst release of microspheres was19.8%, fast release phase was relieved effectively in vitro release process, initial burst release only4%.Finally, it is expected that the bFGF-PLGA microspheres could be an ideal drug controlled release carrier in clinical applications, and that the special collagen sponge embedding bFGF-PLGA microspheres could be an ideal kind of wound dressing or tissue engineering scaffolds for deep thickness injure, regulate microenvironments for accelerate tissue repairin in vivo.