课题背景：目前，利用组织工程学方法构建透明软骨来修复关节软骨缺损是骨科领域的热点。可注射性水凝胶-几丁质是一种符合软骨组织工程载体要求的生物材料，能够为软骨细胞提供三维的生长空间，使其在其中不断增殖的同时，还能够保持固有的表型，与其进行体外联合培养，能克服自体组织来源有限、移植的骨软骨柱之间整合不佳等缺陷。

相关链接：几丁质凝胶在软骨组织工程领域的研究尚处于起步阶段，还有许多问题需要进一步的研究。比如，如何将几丁质凝胶与刺激软骨细胞增殖的生长因子相结合的问题，尤其是对于那些老化软骨的软骨细胞更显得尤为重要；由几丁质凝胶复合软骨细胞所修复的关节软骨的生物力学特性如何？植入后有无刺激临近细胞恶变的潜在可能；软骨中远期是否退变，远期疗效是否确切等等。

术语解析：几丁质又名甲壳素、甲壳质，分布于虾蟹等动物外壳及真菌的细胞壁，是一种天然生物高分子多聚糖（聚1，4-葡糖氨），具有明显的碱性、良好的生物相容性和生物降解，所有降解产物对人体均无毒性、无刺激、无免疫原性和无致突变性，且具有广谱抑制细菌、霉菌的作用，是一种新颖的软骨组织工程材料。

摘要
背景：可注射性水凝胶-几丁质是国际上最新兴起的软骨组织工程材料，它提供了一类新的细胞固定机制。
目的：实验拟观察采用同种异体软骨细胞复合几丁质凝胶修复关节软骨缺损的效果。
设计、时间及地点：随机对照动物实验，于2004-11/2006-03在中国医科大学中心实验室完成。
材料：2周龄新西兰白兔30只，体质量0.3 kg 左右，制备关节软骨缺损模型。
方法：30只兔随机分为实验组：将体外培养的第2代软骨细胞与几丁质凝胶混合，最终细胞浓度为2.5×1011 L-1，注射入所建立动物模型的关节囊内；软骨细胞悬液组：细胞浓度为2.5×1011 L-1；对照组：不做任何处理。
主要观察指标：分别于第4，8，12周取材，取膝关节外侧髁观察修复情况。苏木精-伊红染色后行大体、组织学及电镜检查。
结果：①大体观察：各组动物膝关节未出现明显红肿等炎症迹象。②组织学观察：实验组术后12周时，缺损区可见新生透明样软骨组织，表面光滑，与周围软骨界面难以辨认。软骨细胞悬液组和空白对照组均未见明显修复。③透射电镜观察：实验组新生组织内软骨细胞呈圆形或椭圆形，胞质内含有丰富的粗面内质网、核糖体、高尔基复合体等细胞器；软骨细胞悬液组8~12周后新生组织以胶原纤维为主。空白对照组表现为大量胶原纤维。
结论：同种异体软骨细胞复合几丁质凝胶修复关节软骨缺损效果明显，将几丁质凝胶作为移植载体是可行的。
关键词：关节软骨；异体软骨细胞；几丁质凝胶

肖万军，范广宇.几丁质凝胶与同种异体软骨细胞复合修复关节软骨缺损[J].中国组织工程研究与临床康复，2008，12(19):3633-3636 [www.zglckf.com/zglckf/ejournal/upfiles/08-19/19k-3633(ps).pdf]

Homologous chondrocytes in combination with chitosan to repair articular cartilage defects

Abstract
BACKGROUND: Injectable hydrogel-chitosan is the latest developed material for cartilage tissue engineering. It provides a novel cell attachment mechanism.　
OBJECTIVE: To investigate the effect of allologous chondrocytes in combination with chitosan in repairing cartilage defects.
DESIGN, TIME AND SETTING: Randomized controlled animal trial was performed at the Central Laboratory of China Medical University from November 2004 to March 2006.
MATERIALS: Thirty 2-week-old New Zealand rabbits weighing 0.3 kg were selected to model cartilage defect.
METHODS: Thirty rabbits were randomly divided into three groups. In the experimental group, the defects were repaired by the injection of second passage of chondrocytes (2.5×1011 L-1) combined with chitosan into articular capsule; the cell suspension group was only injected with chondrocyte suspension (2.5×1011 L-1); the control group was not given any treatment.
MAIN OUTCOME MEASURES: The animals were sacrificed at the 4th, 8th, and 12th weeks after operation, respectively to harvest the lateral condyle of knee joint. Hematine-eosine staining, gross and histological examinations, and electron microscopic evaluations were performed to observe the repair condition.
RESULTS: The gross observation showed that there was no obvious swelling or other inflammatory responses in each rabbits. Histological examination suggested that in the experimental group, the cartilage defects were repaired by the hyaline cartilage tissue with smooth surface, which integrated smoothly with articular cartilage at 12 weeks after operation. No obvious defect repair was observed in the other groups. The transmission electron microscopic observation showed that in the new-formation tissues of the experimental group, there were round or oval chondrocytes, and abundant rough endoplasmic reticulum, ribosome and Golgi complex in cytoplasm. At 8 to 12 weeks, plenty of collagen fibers were found in cell suspension group. In the control group, only fibrous tissues were seen on the surface of defects.
CONCLUSION: The articular cartilage defects of rabbits are repaired with allograft of chondrocytes seeded onto chitosan, indicating chitosan can serve as carrier in cell transplantation.

Xiao WJ, Fan GY.Homologous chondrocytes in combination with chitosan to repair articular cartilage defects.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(19):3633-3636(China)
[www.zglckf.com/zglckf/ejournal/upfiles/08-19/19k-3633(ps).pdf]