Abstract: Objective: To prepare biodegradable and easily entrapped gelatin/genistein nanocomplex for promote alveolar bone formation. Methods: Gelatin nanoparticles (GNPs) were prepared by two-step desolvation method, after then genistein (GEN) was adsorbed on the surface of GNPs to formulate nanocomplexes. The diameter, surface morphology, adsorption conditions, and capacity were measured and calculated. The loading of GEN on the GNPs was measured at different concentration of the GNPs, times, temperatures, and pH values by HPLC at 262nm. The concentration of genistein was calculated by standard curve equation, and the effect of various parameters on the amount of adsorption was quantified. Results: The surface of GNPs was smooth and round, and the particle diameter distribution range was from 150 to 200nm. The highest drug loading was about 34.7%, and the entrapment efficiency was over 90% under the optimized conditions. With the degradation of nanocomplexes, the release of genistein was reversible, and the lyophilized nanocomplex had stable nanostructure and drug content. Conclusion: Two-step desolvation method is an ideal way to prepare gelatin/genistein nanocomplex. Besides, the excellent structural stability enables it to be stored at room temperature for more than half a year.

Key words: Gelatin, Genistein, Nanocomplex