包埋载药微球的羟基磷灰石/聚氨酯复合组织工程支架的研究

Studies on Hydroxyapatite/Polyurethane Scaffold Containing Drug-loaded Microspheres for Bone Tissue Engineering

研制具有药物缓释功能的骨组织工程支架,对载药微球包埋于羟基磷灰石/聚氨酯(HA/PU)支架中的药物缓释体系进行了可行性研究.首先将盐酸环丙沙星作为模型药物,包裹于乙基纤维素(EC)微球中,然后将EC微球与HA/PU材料进行复合,制备了抗生素药物缓释支架.结果显示EC微球均匀地分布在HA/PU支架基质中,未对支架的开孔结构和孔隙形貌构成影响.与单纯将药物载入HA/PU支架中相比,复合载药EC微球的HA/PU支架的初期药物暴释明显降低,药物缓释时间延长.体外药物释放实验和抑菌实验结果表明,该载药微球支架具有良好的药物缓释功能和抑菌性能,是一种集骨修复和治疗于一体的新型组织工程支架材料.

To explore and develop scaffold for bone regeneration or tissue engineering with the capacity of con-trolled drug delivery,the feasibility of hydroxyapatite/polyurethane（HA/PU） scaffold containing drug-loaded mi-crospheres for controlled drug delivery system was demonstrated.Ciprofloxacin hydrochlorid as a model drug was encapsulated in ethyl cellulose（EC） microspheres,which were subsequently incorporated into HA/PU composite scaffold to generate an antibiotic drug delivery system.The results show that EC microspheres are uniformly dis-tributed in the HA/PU scaffold matrix and display no significant effect on the pore structure of the scaffold.Com-pared with incorporating ciprofloxacin hydrochlorid into scaffolds directly,embedding microspheres into scaffolds significantly reduces the initial burst drug release and extends the release time of drug delivery.In vitro drug deliv-ery tests and antibacterial activity tests prove that drug-loaded microsphere/scaffold system has good drug delivery properties and effective antibacterial properties.These results suggest that the novel drug-loaded microsphere/ scaffold composites developed in this study is a good candidate scaffold with the function of bone repair and infec-tion treatment for bone tissue engineering.