Preparation and characterization of recombinant human bone morphogenetic protein-2/poly lactic acid sustained release microspheres / 中国组织工程研究

ABSTRACT

BACKGROUND:Poly lactic acid as an excellent delivery has good biocompatibility. OBJECTIVE:To prepare recombinant human bone morphogenetic protein-2 (rhBMP-2)/poly lactic acid (PLA) sustained release microspheres, and to study its physical and chemical properties. METHODS:The rhBMP-2/PLA sustained release microspheres were prepared using w/o/w solvent evaporation method. Scanning electron microscopy, laser particle size, zeta potential, and swel ing properties were detected. ELISA kit was utilized for measurement of encapsulation efficiency, drug-loading rate and in vitro drug release rate. RESULTS AND CONCLUSION:Under the scanning electron microscope, rhBMP-2/PLA sustained release microspheres were approximately circle with excellent dispersion. The uniform spheres were visible with a mean particle size of 839.6 nm. The zeta potential were (-32.93±3.74) mV. The swel ing coefficient was 1.157±0.059. The drug-loading rate and encapsulation efficiency of rhBMP-2/PLA sustained release microspheres were (88.943±2.878)%and (0.026±0.001)%respectively. The drug release rate at 1 day was about 10.199%, then the drug release was relatively constant, and til 19 days, the cumulative drug release rate was 54.643%. These findings indicate that the constructed rhBMP-2/PLA sustained release microspheres meet the requirement of the Chinese Pharmacopoeia (10th edition) that the encapsulation efficiency is not less than 80%and the microspheres have a good slow-release function in vitro.