摘要：The repair of osteochondral defects is one of the major clinical challenges in ***-established osteochondral tissue engineering methods have shown promising results for the early treatment of small ***,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the *** this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion *** developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite *** microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle *** 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage *** histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control *** genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control *** findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.

摘要：为提高骨缺损修复的治疗效果,设计孔隙率为78.8%、70.8%、62.6%和54.4%的梯度多孔钛支架(分别表示为P1,P2,P3和P4),并通过选择性激光熔化技术进行制备。通过模拟和实验方法研究支架的成形性、显微组织、力学性能和渗透性能。模拟结果表明,4种梯度结构的最大等效应力和渗透性分别在569.1~1469.0MPa和(21.7~54.6)×10^(−9)m^(2)范围内,并且P3和P4具有更小的最大等效应力,表明P3和P4具有更高的强度。P3和P4结构支架的显微组织为α'马氏体,屈服强度和弹性模量分别为185.3~250.8MPa和6.1~9.7GPa。相比于P3结构支架,P4结构支架展现出更高的强度和与皮质骨更加匹配的弹性模量,并且其渗透性(18.6×10^(−9)m^(2))在人体骨组织渗透性范围内。因此,具有P4结构支架有望被应用于骨科植入领域。

摘要：Osteoarthritis (OA), identified as one of the priorities for the Bone and Joint Decade, is one of the most prevalent joint diseases, which causes pain and disability of joints in the adult population. Secondary OA usually stems from repetitive overloading to the osteochondral (OC) unit, which could result in cartilage damage and changes in the subchondral bone, leading to mechanical instability of the joint and loss of joint function. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bone in the early stages of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available OC scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, none of these scaffolds has shown satisfactory clinical results. This article reviews the OC tissue structure and the design, manufacturing and performance of current OC scaffolds in treatment of OA. The findings demonstrate the importance of biological and biomechanical fixations of OC scaffolds to the host tissue in achieving an improved cartilage fill and a hyaline-like tissue formation. Achieving a strong and stable subchondral bone support that helps the regeneration of overlying cartilage seems to be still a grand challenge for the early treatment of OA.

摘要：在骨科植入物和再生医学研究领域,为了得到合适的产品需要经过反复实验分析优化材料、结构、机械性能等指标,从细胞实验到临床试验的整个过程既昂贵又耗时。计算模拟方法是组织工程产品开发的设计工具,可以有效降低开发成本和时耗。本文综述了一系列组织工程模型,他们能模拟从细胞附着到组织再生的全过程。从细胞黏附到组织再生的一体化模型的建立能优化组织工程产品设计和评价过程。然而,目前模拟组织工程过程的模型均各自独立。本文重点介绍了组织工程中细胞黏附、营养物质运输和细胞增殖、分化、迁移的模型,试图将所有独立模型串联在一起以供读者使用。在细胞黏附模型中,离散相模型能最精确地模拟控制细胞运动过程,Stanton-Rutland模型能模拟细胞黏附过程。营养盐运输模型能是一种能将流体体积模型和组分传输模型耦合的数值模型,在组织工程中被应用于营养盐运移过程的预测。有限元以及随机游走算法被用于细胞增殖、分化和迁移的模拟。大多数模型的准确性和有效性还有待进一步研究证实。由于尚缺乏检测营养物质扩散速率的技术,在凝血领域模型分析方法的研究尤其少。因此,组织工程全过程建模方法的研究还有很多工作要做。在未来,数值模型将被视为研究组织工程产品生物性能的最佳方法,并能够优化组织工程产品的参数和材料类型。