纳米羟基磷灰石／壳聚糖－明胶复合微球的制备及性能

BACKGROUND: Hydroxyapatite/polymer composite materials have been widely reported as tissue engineering materials; however, they are limited in repairing treatment because of the powder or piece in shape. OBJECTIVE: To prepare the nanohydroxyapatite (HAP) /chitosan-gelatin (CG) composite microspheres, and to observe the general drug release in vitro. DESIGN, TIME AND SETTING: Repeated measurement study was performed at Laboratory of Biological Functional Polymer, College of Material Science and Chemical Engineering, Beijing University of Technology between January and October 2008. MATERIALS: Nanohydroxyapatite, chitosan, gelatin, and gentamicin were used in this study. METHODS: Microwave irradiation method was used to synthesize aciform hydroxyapatite (pH=7), and W/O combined with multiple emulsification chemical crosslink technique was used to prepare nanohydroxyapatite/chitosan-gelatin composite microspheres. MAIN OUTCOME MEASURES:① Surface morphology and particle diameter distribution;② drug loading, entrapment efficiency, and cumulative release rate. RESULTS:① The composite microspheres were spherical in shape, and the particle diameter ranged from 10 to 30 μm. Hydroxyapatite was greatly embedded by chitosan-gelatin. ② The average drug loading was 32.97%, the average entrapment efficiency was 49.20%, and the cumulative release rate to gentamincin was near 88% within 3 days. CONCLUSION: The composite microspheres exhibit well-distributed morphology, narrow particle diameter distribution and good redispersibility. They can maintain an therapeutic concentration within 3 days.