多层软骨组织工程支架的制备

Fabrication of Layered Scaffold for Cartilage Tissue Engineering

软骨组织工程为关节软骨损伤的治疗提供了一种理想的治疗途径,但体外构建的软骨如何在临床应用时采用适当的方法短期内在体内进行良好地固定仍然没有得到很好的解决,阻碍了采用组织工程方法治疗关节软骨疾病的临床应用。本研究通过冷冻干燥的方法制备出一个上层为胶原,下层逐层过渡到以羟基磷灰石为主的复合一体化软骨组织工程支架,利用复合支架下层羟基磷灰石良好的骨传导作用,将支架整体通过底部的快速固定达到对上层软骨进行固定的目的。本研究对该复合支架的制备及其形态结构特点进行了初步研究。结果表明胶原层的孔径孔隙率可以通过冷冻温度及胶原溶液浓度进行控制;羟基磷灰石粒度及其粒度分布明显影响其在胶原支架内部的分布;SEM照片表明用该方法制备出了三层具有不同羟基磷灰石含量的复合胶原羟基磷灰石软骨组织工程支架,支架总高度为6cm,每层高度约为2cm,三层之间不存在界面形成了一个均匀的整体结构。为软骨组织工程提供了一种新型的支架。

Cartilage tissue engineering is a promising therapy for articular cartilage lesions. But the problem how to quickly fix the constructed cartilage tissue in vitro to the natural tissue is still under research. This would influence the wide application of cartilage tissue engineering production in clinical practice. In this study, a layered articular cartilage tissue engineering scaffold was made by the freeze-dry method. The upmost layer is a pure collagen layer and the downmost layer is a collagen/hydroxyapatite （HA） composite layer. Between the two layers are the layers that the HA contents increased. This structure with the HA contents has the osteoconduction capacity, and makes it possible to achieve the fast fixation function of the engineered cartilage through the interaction between the bone and the HA contents in the scaffold once the scaffold implanted into the tissue. The fabrication method and the structure properties of the layered scaffold were discussed in this paper. The results showed that the pore size and porosity of the collagen layer could be controlled by the frozen temperature and the collagen solution concentration. The HA particle size and distribution of it would influence HA＇s distribution in the collagen scaffold. SEM pictures showed that the fabricated layered collagen/HA composite scaffold was a 6cm cylinder with three different HA content containing layers. Each layer had a height about 2cm. The three layers formed a homogeneous unit without any separation between each layer. The layered scaffold could be a promising candidate for the cartilage tissue engineering.