具有连续梯度过渡层结构细菌纤维素支架的构建与腱-骨界面再生行为的研究

It is very promising to heal the injured tendon-bone interface through tendon-bone interface layer repair and regeneration via tissue engineering method. Whereas, it is key role in realizing the regeneration of the gradient structure between the tendon and bone by preparing tissue engineering scaffolds with an effective interface transition layer. In this project, the bacterial cellulose (BC) hydrogels with tailored pore structure are prepared by membrane-liquid interface culture method. Moreover, through stretching method combined with liquid flowing controlling technology, the BC hydrogels were induced to form integrated multilayer tissue engineering scaffold with continuous gradient transition structure, in which the gradient oriented nanobacteria cellulose were successively transformed to gradient mineralized nanobacteria cellulose, and then to mineralized nanobacteria cellulose. Here we will mainly focus on the study about the interactions between gradient transition layer and cells by tailoring the gradient transition feature parameters of the scaffolds. The healing of bone-tendon junction and the integration between tendon and bone in vivo will also be investigated. The results obtained here could be served for the design and preparation of biomimetic scaffolds for tendon-bone.

通过组织工程方法实现肌腱-骨界面修复与再生是治疗骨腱连接点损伤的新希望，构建有效肌腱-骨界面层实现骨腱连接点损伤后梯度结构的再生是当前亟待解决的关键科学问题之一。本项目拟采用膜液界面培养技术制备孔结构可控的细菌纤维素（BC）支架，在此基础上，采用拉伸技术和液流控制技术，诱导BC支架形成一个由连续梯度过渡结构组成的融合一体化肌腱-骨组织工程支架，该梯度过渡层由梯度纤维取向纳米细菌纤维素到梯度矿化纳米细菌纤维素，再到矿化纳米细菌纤维素渐变。通过对支架内过渡层中梯度特性参数的调控，重点研究过渡层与细胞的相互作用，考察骨腱连接点损伤修复以及腱-骨整合效果，揭示过渡层梯度特性对肌腱-骨界面再生过程的调控规律。本项目有望为仿生肌腱-骨支架的设计与制备提供可靠的理论依据和新的技术途径。

通过组织工程方法实现肌腱-骨界面修复与再生是治疗骨腱连接点损伤的新希望，构建有效肌腱-骨界面层实现骨腱连接点损伤后梯度结构的再生是当前亟待解决的关键科学问题之一。本项目采用了膜液界面培养技术制备了孔结构可控的细菌纤维素（BC）支架，在此基础上，采用拉伸技术和液流控制技术，制备了由梯度纤维取向纳米细菌纤维素到梯度矿化纳米细菌纤维素，再到矿化纳米细菌纤维素渐变的融合一体化肌腱-骨组织工程支架。研究了微球对BC网络结构中大孔构建以及孔的构建对细胞渗入支架的影响，探讨了拉伸力对纤维取向以及液流控制参数对矿化梯度的调控作用，考察了构建的一体化支架对骨腱连接点损伤修复以及腱-骨整合效果。本项目的主要结论如下：1.采用膜液界面培养法制备了具有大孔结构的BC支架。2.采用湿法拉伸技术制备了具有高度排列的纳米纤维BC，通过控制拉伸速度为2r/min和拉伸应变为0-20%制备了具有纤维取向梯度的BC支架。3.采用CaCl2活化和SBF浸泡法制备了矿化BC，通过0.1M的CaCl2溶液活化3d后的BC凝胶，通过液流控技术，控制其在1.5×SBF溶液中浸泡1-7d制备了具有矿化梯度的BC支架。4.基于获得的拉伸参数和矿化参数，成功构建了对于腱骨界面修复具有增强效应的具有连续梯度过渡层的融合一体化支架，对于其他具有分级结构的界面组织的仿生构建提供广泛基础和借鉴，在界面组织工程中具有重要意义和极大的应用前景。