新型纳米生物材料修复胫骨大面积缺损的实验研究

Repair of massive tibial defects by nano-hydroxyapatite collagen/chitin fibres in goats

目的通过组织工程方法研究纤维增强纳米相羟基磷灰石胶原复合材料（nanohydroxyapatite collagen／chitin fibres，n—HAC／CF）的细胞相容性及其修复大面积骨缺损的情况，探讨其临床应用的可能性。方法采用纳米技术制备n—HAC／CF，在体外与羊骨髓基质干细胞（bone mesenchymal stem cells，BMSCs）复合培养，观察BMSCs在材料上的生长、增殖情况；取24只山羊，制备羊胫骨40mm骨缺损模型，随机分为3组：A组为BMSCs复合n-HAC／CF；B组为单纯n—HAC／CF；c组为空白对照组。分期行X线、组织学、生物力学测定观察各组成骨情况。结果BMSCs能在n—HAC／CF材料上良好地黏附、增殖和生长。12周时X线、组织学检查显示A组完全修复了骨缺损区，B组部分修复了骨缺损区，A组的新生骨小梁多于B组（P〈0．01），C组未见骨修复。生物力学测定显示最大应力值A组大于B组（P〈0．01）。结论n—HAC／CF具有良好的细胞相容性，并能成功地修复山羊大面积骨缺损，有望成为骨组织工程理想的细胞外基质和骨移植的替代材料。

Objective To investigate the cellular compatibility and efficacy of nano-hydroxyapatite collagen/chitin fibres （n-HAC/CF）in repairing massive tibial defects and explore the possibility of its clinical application. Methods n-HAC/CF was made by nano technology and cocultured with bone mesenchymal stem cells （BMSCs） to observe growth and proliferation of BMSCs. The tibial defects （40 mm） of 2d goats were established and divided into three groups, ie, group A （BMSCs ＋ n-HAC/ CF）, group B （n-HAC/CF） and group C （untreated group）. Bone formation was investigated by gross observation, X-ray examination, histology of HE and biomechanics at 4, 8 and 12 weeks respectively after operation. Results Normal adhenrence, proliferation and growth of BMSCs on the n-HAC/CF could be seen. The examination of X-ray and histology showed that the bone defects were repaired entirely in group A and partly in group B. The quantity of the newly formed bone in group A was more than that in group B （P 〈 0.01 ）. Repair showed no effect in group C. Biomechanical strength of group A was superior to that of group B. Conclusion n-HAC/CF has good cellular compatibility, can successfully repair massive bone defects and can be used as the ideal alternative biomaterial for bone tissue engineering.