下颌骨髁突仿生复合支架的制备与表征

Synthesis and characteristics of integrated bionic mandibular condylar scaffold

目的构建下颌骨髁突一体化壳聚糖（CS）-聚己酸内酯（PCL）．羟磷灰石（HA）（HA／PCL-CS）仿生复合支架，并探讨其在髁突组织工程中应用的可行性。方法应用快速成形技术形成下颌骨髁突模具，利用溶液浇铸．冰沥方法制备下颌骨髁突一体化仿生复合支架模型，PCL：CS按4：1的比例混合，分别加入质量比为40％、50％、60％、70％的HA，分为a、b、c、d组，观察支架的微观形貌、孔隙率、红外光谱、x线衍射、力学性能等特性。结果支架与下颌骨髁突形状相吻合，外观黄白色，坚硬，分上层及下层两部分。扫描电子显微镜显示该复合支架具有三维网络空间结构，孔隙率70％～85％，孔径大小10—200μm。红外光谱显示随着HA的含量减少，其波峰强度降低。x线衍射结果显示随着HA含量的增加，其衍射峰强度相对降低。HA含量为50％时支架具有适宜的抗拉伸强度及抗压、抗弯强度。结论溶液浇铸-冰沥方法制得的支架具有良好的综合材料性能，有望成为一种髁突自体组织工程用支架材料。

Objective This study aims to construct a chitosan （CS）-polycaprolactone （PCL）-hydroxyapatite （HA） com- posite biomimetic scaffold to replace condyle and to explore the tissue engineering applications of condylar. Methods A resin mold of the mandibular condyle was prepared by using rapid prototyping techniques. A mandibular condylar integrated biomirnetic scaffold model was prepared by solution casting-ice Lek. PCL and CS were mixed at a ratio of 4 ： 1. HA at quality ratios of 40%, 50%, 60%, and 70% was added to groups a, b, c, and d, respectively. The microscopic morphology, porosity, infrared spectra, X-ray diffraction pattern, and mechanical properties of the scaffold were observed. Results The scaffold that includes both upper and lower parts displayed the same features （i.e., shape, yellow-white appearance, and hard texture） as the mandibular condyle. Scanning electron microscopy showed that the composite scaffold had a 3D network spatial struc- ture, 70%-85% porosity, and 10-200 μm pore size. Infrared spectra showed that the peak intensity reduced with decreasing HA content. X-ray diffraction showed that the diffraction peak decreased with increasing HA content. Suitable tensile and compressive and flexural strength were discovered in the presence of 50% HA. Conclusion The scaffold prepared by solu- tion casting-ice Lek shows favorable comprehensive features and is expected to replace human condylar.