软骨组织工程研究中的干细胞

近来，干细胞作为一种自体软骨细胞的替代物，在软骨组织工程中日益得到重视。骨髓源性干细胞在多种条件下均能表现出软骨形成的潜能。脂肪源性干细胞是一种从脂肪组织中分离获得成的纤维细胞样干细胞群，经体外一段时间培养后，获得稳定的扩增，其衰老的水平较低，在三维培养环境下可分化为软骨细胞。肌肉、滑膜和骨膜是骨髓和脂肪组织之外的用于软骨修复的其他干细胞源。人类胚胎干细胞和原代软骨细胞共培养，可以诱导软骨形成，但对其选择纯化较为困难，且胚胎干细胞具有致瘤性，临床使用尚存在伦理学问题。

Stem cell in cartilage tissue engineering

Recently, stem cells attract significant attention in cartilage tissue engineering as an alternative to autologous chondrocytes. Bone marrow-derived stem cells showed potency to chondrogenesis in various culture conditions. Adipose-derived stem cells are a kind of fibroblast-like stem cells population which can be isolated from adipose tissue and cultured in vitro, can differentiate into chondrocyte after an extended period with stable expansion and low levels of senescence in 3D culture environment. Besides bone marrow and adipose tissue, muscle, synovium, and periosteum are other sources of adult stem cells being explored for applications in cartilage repairment. Furthermore, co-culture of human embryonic stem cells with primary chondrocytes can induce the chondrogenesis differentiation, however, the difficulties in ESC selective purification, as well as oncogenicity and ethical issues, may limited the use in clinic.