Preparation of Recombinant Human Bone Morphogenetic Protein-2 Loaded Gelatin Nanoparticles and Sustained-release Effect in Vitro

Abstract：Objective To prepare rhBMP-2 loaded gelatin nanoparticles and study the sustained-release effect of rhBMP-2 loaded gelatin nanoparticles in vitro. Methods The gelatin nanoparticles were prepared by two-step desolvation method,the surface morphology,inner structure and particle size of the gelatin nanoparticles were observed by Scanning electron microscope ( SEM),Transmission electron microscope( TEM)and Nano-particle size analyzers,the swelling rate of them in water was cal-culated. Then rhBMP-2 were loaded to gelatin nanoparticles,it′s envelopment rate and drug loadings were calculated and the sustained-release effect were detected in vitro. Results The gelatin nanoparticles had a good surface morphology,the inner structure of which had a lot of pores and channels,the the average particle size was(171. 49 ± 50. 12)nm,dispersed uniform-ly:the envelopment rate and drug loadings of rhBMP-2 loaded gelatin nanoparticles were(98. 13 ± 0. 131)% and(58. 89 ± 0. 079)ng/mg respectively,the swelling rate was 1. 83;the release time of rhBMP-2 loaded gelatin nanoparticles was more than one month,the release pattern was“Biphasic release”,on the 1st day was“burst release phase”,drug release amount was a-bout 7%,then drug was slowly released step by step,known as the“slow-release”,about 40% of the drug was released until the 28th day,there were about 60% of the drug released thereafter. Conclusion RhBMP-2 loaded gelatin nanoparticles can be prepared successfully with high entrapment and good sustained-release effect in vitro.