Preparation and characterization of a multilayer biomimetic scaffold for bone tissue engineering
Preparation and characterization of a multilayer biomimetic scaffold for bone tissue engineering
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骨组织工程多层仿生支架的制备及表征
DOI：
10.1177/0885328206073706
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发表时间：
2007-11-01
影响因子：
2.9
通讯作者：
Zhang, Xiufang
中科院分区：
文献类型：
--
作者：
Kong, Lijun;Ao, Qiang;Zhang, Xiufang
在以支架为基础的骨组织工程中，支架的孔径和力学性能是非常重要的。然而，孔径的增加通常伴随着机械性能的降低。为了获得合适的机械性能和孔隙率，设计了多层支架来模拟松质骨和皮质骨的结构。制备了一种具有多层结构的多孔纳米羟基磷灰石-壳聚糖复合支架，并将其包裹在光滑致密的壳聚糖膜层中，以防止纤维组织向内生长。外管显示出具有小的孔径（直径15-40 μ m）以增强机械性能，而多层支架的芯具有大的孔径（主要是直径70-150 μ m）以用于营养供应和骨形成。与均匀多孔支架相比，具有相同尺寸的多层支架显示出更高的机械强度和更大的中心孔径。在相同的接种条件下，显示出更多的细胞在体外生长到多层支架的中心，而不是生长到均匀的多孔支架中。最后，将支架植入兔腓骨缺损中，以评价支架的骨传导性和支架作为纤维组织向内生长屏障的功效。术后12周，支架中心可见丰富的血管和骨形成，缺损处可见少量纤维组织。
In scaffold based bone tissue engineering, both the pore size and the mechanical properties of the scaffold are of great importance. However, an increase in pore size is generally accompanied by a decrease in mechanical properties. In order to achieve both suitable mechanical properties and porosity, a multilayer scaffold is designed to mimic the structure of cancellous bone and cortical bone. A porous nano-hydroxyapatite-chitosan composite scaffold with a multilayer structure is fabricated and encased in a smooth compact chitosan membrane layer to prevent fibrous tissue ingrowth. The exterior tube is shown to have a small pore size (15-40 mu m in diameter) for the enhancement of mechanical properties, while the core of the multilayer scaffold has a large pore size (predominantly 70-150 mu m in diameter) for nutrition supply and bone formation. Compared with the uniform porous scaffold, the multilayer scaffold with the same size shows an enhanced mechanical strength and larger pore size in the center. More cells are shown to grow into the center of the multilayer scaffold in vitro than into the uniform porous scaffold under the same seeding condition. Finally, the scaffolds are implanted into a rabbit fibula defect to evaluate the osteoconductivity of the scaffold and the efficacy of the scaffold as a barrier to fibrous tissue ingrowth. At 12 weeks post operation, affluent blood vessels and bone formation are found in the center of the scaffold and little fibrous tissue is noted in the defect site.