应用以“钛笼”为基座的三层一体化支架修复关节软骨缺损的研究

Recently the application of functional biomaterials to construct bone-cartilage composite tissue in cartilage defects repairing has become a research focus. However, with current technology it was difficult to implant two kinds of cells(chondrocytes and osteoblasts) cultured under different conditions into the monolithic scaffold in vitro Moreover, in constructing this kind of composite tissue. technology difficulties regarding complicated procedure, unstable working circumstances and ,high costs of time human labour and funding existed. Inspired by the technology of titanium mesh to graft bone in spine surgery, we imagined to replace the bone layer with “Titanium—Mesh— Cage”. Additionally, we aimed to design an intermediate layer between the tissue-engineered cartilage and bone to avoid the downward overgrowth of tissue-engineered cartilage. We planned to use 3D printing technology to manufacture the foundation of “Titanium—Mesh— Cage” , above which was the intermediate layer which made of silk fibroin in high concentration . The surface cartilage layer was made of silk fibroin in low concentration. Thus, the “ Titanium—Mesh— Cage—based” multilayered biomaterial scaffold was made.“.After that,the scaffold were seeded with autologous chondrocytes on the cartilage layer.Before transplantation, autogenous cancellous bone was planted. At last,the scaffold were embedded into articular defects by press-fitting principle in order to repair and regenerate osteochondral defects.

应用组织工程骨软骨复合组织块修复关节软骨缺损已成为当下的研究热点 。但一体化支架在体外培养过程中，需将两种培养条件不尽相同的细胞（软骨细胞和成骨细胞 ）植入同一支架进行共培养，难以取得理想的效果。从脊柱外科的“ 钛笼”植骨术中获得启发，我们拟采用“钛笼”替代复合支架的骨层结构。另外，在一体化支架的使用过程中人们还发现，软骨细胞易出现向软骨下骨过度生长的现象。为了避免这一现象，我们设想在“钛笼”与软骨层之间设计一层致密的“隔离带”，使其既能防止软骨细胞向下过度生长，又不影响细胞因子的交换。我们拟通过3D打印技术制作“钛笼”作为基座，然后在其上方应用高浓度丝素蛋白制作小孔径的隔离层，表层应用低浓度丝素蛋白制作支架的软骨层。以此来实现以“钛笼”为基座的三层复合支架。然后在复合支架的软骨层接种软骨细胞，在植入体内前于钛笼中植入自体松质骨，最后通过压配原理将复合组织块嵌入动物关节软骨缺

应用模拟正常骨软骨组织多层结构的一体化支架体外构建骨-软骨复合组织块修复关节软骨缺损已成为当下的研究热点。然而在体外构建复合组织块的过程中，往往需要在不同层次植入对应的细胞，过程繁琐，操作复杂。我们从脊柱外科的“ 钛笼植骨术”中获得启发，利用“钛笼”替代一体化支架的骨层部分。通过在“钛笼”中埋植自体松质骨来减少传统一体化支架中骨层种植细胞这一步骤。在之前的研究中，我们应用以“β-TCP”为骨层、高浓度壳聚糖/明胶溶液为致密层、低浓度壳聚糖/明胶溶液为软骨层的三层一体化支架修复关节软骨缺损。在本研究中我们以该三层一体化支架为基础，拟通过3D打印技术制作基座为“钛笼”，中间为小孔径PLAG层，上方为大孔径PLGA层的三层一体化复合支架。然后在复合支架的软骨层中接种软骨细胞，在植入体内前于“钛笼”中埋植入自体松质骨，最后通过压配原理将复合组织块嵌入动物关节软骨缺损区修复软骨缺损。我们将其与上一个研究中所使用的TCP支架和马赛克手术的修复效果进行了对比，我们发现“钛笼”支架在三个月内的修复效果优于TCP支架，接近马赛克手术。