Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Tissue Engineering, 639 Zhi Zao Ju Road, Shanghai 200011, PR China.
Biomaterials. 2010 Mar;31(8):2176-83. doi: 10.1016/j.biomaterials.2009.11.080. Epub 2009 Dec 21.
Due to the lack of appropriate scaffolds, the in vitro engineering of cartilage tissue with a sophisticated structure, such as a human ear, remains a great challenge. Although polyglycolic acid (PGA) has become one of the most successful scaffolds for cartilage regeneration, how to overcome its limitations in achieving desirable mechanical strength and accurate control over shape remains an unsolved problem. In this study, the mechanical strength of PGA scaffold was enhanced by coating with polylactic acid (PLA). The content of PLA was optimized by balancing the scaffold's biocompatibility and mechanical strength. The PLA/PGA scaffold was then fabricated into a human ear-shape mirror-symmetrical to a normal ear by pressing the scaffold in the ear negative molds, which were fabricated by the computer aided design and manufacturing (CAD/CAM) technique according to the CT scan data from the normal ear. The ear-shaped scaffold reached a similarity level of over 97% compared to the positive ear mold by the shape analysis using a 3D laser scan system. Most importantly, after chondrocyte seeding, the constructs largely retained the original shape during culture with a similarity level of over 84%. Furthermore, the constructs formed ear-shaped cartilage-like tissues at 12 weeks, which revealed a tissue structure with abundant cartilage extracellular matrices and mature lacuna. Additionally, the ear-shaped cartilage at 12 weeks also exhibited fine elasticity and good mechanical strength. These results may provide a useful strategy for reconstructing cartilage tissue with complicated shapes such as a human ear by an in vitro engineering approach.
由于缺乏合适的支架，体外工程化具有复杂结构的软骨组织，例如人耳，仍然是一个巨大的挑战。尽管聚乙醇酸（PGA）已成为软骨再生最成功的支架之一，但如何克服其在实现理想机械强度和形状精确控制方面的局限性仍然是一个未解决的问题。在这项研究中，通过涂覆聚乳酸（PLA）来增强 PGA 支架的机械强度。通过平衡支架的生物相容性和机械强度来优化 PLA 的含量。然后，通过将支架压入根据正常耳的 CT 扫描数据通过计算机辅助设计和制造（CAD/CAM）技术制造的耳负模中，将 PLA/PGA 支架制成与人耳镜像对称的耳形。通过使用 3D 激光扫描系统进行的形状分析，耳形支架与阳性耳模具的相似度达到 97%以上。最重要的是，在接种软骨细胞后，构建体在培养过程中基本保持了原始形状，相似度超过 84%。此外，构建体在 12 周时形成了耳状软骨样组织，其组织结构具有丰富的软骨细胞外基质和成熟的陷窝。此外，12 周的耳状软骨还表现出良好的弹性和机械强度。这些结果可能为通过体外工程方法构建具有复杂形状的软骨组织，例如人耳，提供了一种有用的策略。
