中文摘要：

目的用选择性激光烧结（selective laser sintering,SLS）技术构建纳米羟基磷灰石（nano-hydroxyapatite,Nano-HA）/聚己内酯（poly-ε-caprolactone,PCL）人工骨支架并探索其力学特性、生物相容性和生物活性。方法配制NanoHA质量分数分别为5%、10%、15%的Nano-HA/PCL混合材料粉末,采用SLS技术制备出PCL与Nano-HA/PCL（5%、10%、15%）人工骨支架,并测定其孔隙率及抗压强度。将分离培养的兔骨髓间充质干细胞（MSCs）接种至上述2种支架中,观察细胞黏附及增殖情况,并通过碱性磷酸酶（ALP）表达测定、茜素红法钙结节染色比较其成骨分化情况。结果各组支架均具有良好的力学强度和细胞黏附性,且未见明显的细胞毒性;接种后第1天各组的ALP表达差异无统计学意义,但随着培养时间的延长,Nano-HA/PCL组的ALP表达逐渐高于PCL组与空白对照组（P〈0.05）,且Nano-HA比例越高,ALP的表达也越强（P〈0.05）;Nano-HA/PCL组茜素红染色的阳性强度高于PCL组与空白对照组,且随着Nano-HA含量增高,其钙结节数量增多,染色的阳性强度也随之增加。结论本研究通过SLS技术所构建出的Nano-HA/PCL人工骨支架具有良好的生物力学强度、生物相容性及骨诱导性,有望成为一种新型骨修复替代材料。

英文摘要：

Objective To fabricate nano-hydroxyapatite（Nano-HA）/poly-ε-caprolactone（PCL）scaffolds with the selective laser sintering（SLS）technique and to study the mechanical strength,biocompatibility and bioactivity of the prepared scaffolds.Methods Nano-HA and PCL powders with Nano-HA weight ratio accounting for 0%,5%,10%,and 15% were mixed,and PCL and Nano-HA/PCL scaffolds（5%,10% and 15%）were fabricated using SLS technique.The porosity and mechanical strength of scaffolds were determined.Isolated rabbit bone marrow stromal cells were seeded onto the Nano-HA/PCL or PCL scaffolds and cultured in vitro.Cell adhesion and proliferation were observed.The osteogenesis for pure PCL and nano-HA/PCL scaffolds were compared by detecting alkaline phosphatase（ALP）expression and Alizarin Red S staining.Results Both the pure PCL and Nano-HA/PCL composite scaffolds showed good mechanical strength and cell adhesion without obvious cell toxicity.The expression of ALP in all groups showed no significant difference on the first day of seeding,but with the extension of culture time,ALP expression in Nano-HA/PCL group was significantly increased compared with PCL group and blank group（P〈0.05）.The expression of ALP increased with the increase of Nano-HA ratio（P〈0.05）.The positive intensity of Alizarin Red S staining in Nano-HA/PCL group was higher than those in PCL group and blank group;moreover,the number of calcium nodules and positive intensity of staining were inceased with the increase of nano-HA the ratio.Conclusion The nano-HA/PCL composite scaffold fabricated with SLS technique in the present study has good mechanical strength,biocompatibility and osteoinduction,and it may serve as an alternative material for bone repair.