Various tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has yet succeeded in devising an optimal system to restore damaged articular cartilage. Here, the design, assembly, and biological testing of a porous, chitosan/collagen-based scaffold as an implant to repair damaged articular cartilage is reported. Its gradient composition and trilayer structure mimic variations in natural cartilage tissue. One of its layers includes hydroxyapatite, a bioactive component that facilitates the integration of growing tissue on local bone in the target area after scaffold implantation. The scaffold was evaluated for surface morphology; rheological performance (storage, loss, complex, and time-relaxation moduli at 1 kHz); physiological stability; in vitro activity and cytotoxicity (on a human chondrocyte C28 cell line); and in vivo performance (tissue growth and biodegradability), in a murine model of osteoarthritis. The scaffold was shown to be mechanically resistant and noncytotoxic, favored tissue growth in vivo, and remained stable for 35 days postimplantation in mice. These encouraging results highlight the potential of this porous chitosan/collagen scaffold for clinical applications in cartilage tissue engineering.

中文翻译：

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用于修复骨关节炎的可植入多孔三层支架的设计，构造和生物学测试。

在过去的二十年中，已经设计并测试了各种用于软骨修复的组织工程系统，从而导致了许多有前途的软骨移植物的发展。然而，还没有人成功地设计出一种最佳的系统来修复受损的关节软骨。在此，报道了基于壳聚糖/胶原蛋白的多孔支架作为修复受损关节软骨的植入物的设计，组装和生物学测试。它的梯度组成和三层结构模仿天然软骨组织中的变化。它的一层包括羟基磷灰石，羟基磷灰石是一种生物活性成分，可在支架植入后促进生长组织整合到目标区域内局部骨骼上。评价支架的表面形态。流变性能（在1 kHz时的存储，损耗，复数和时间松弛模量）；生理稳定性；体外活性和细胞毒性（对人软骨细胞C28细胞系）；骨关节炎的小鼠模型中的体内表现（组织生长和生物降解性）。该支架显示出机械抗性和无细胞毒性，有利于体内组织生长，并且在小鼠植入后35天保持稳定。这些令人鼓舞的结果突出了这种多孔壳聚糖/胶原蛋白支架在软骨组织工程中临床应用的潜力。