藻酸包埋异体关节软骨细胞修复兔膝关节软骨缺损

目的 探讨异体关节软骨细胞作为软骨种子细胞修复关节软骨缺损的可行性。方法 无菌取成年新西兰大白兔四肢关节软骨，酶消化法分离细胞，条件培养基体外培养扩增，藻酸钙凝胶包埋培养1周，植入兔膝关节股骨髁间软骨缺损，对照组缺损旷置。术后3、6个月分别取材，观察缺损修复情况；切片特染和免疫组化观察修复组织病理，并Wakitnni评分评估修复质量。结果 7／8缺损为成熟透明软骨组织修复，1／8为纤维软骨修复；Wakitani平均评1．75分；空白对照组评7．65分。实验组3个月组标本未见淋巴细胞或白细胞浸润，6个月组标本未见明显退变；所有标本均未见藻酸残留。结论 用藻酸包埋异体关节软骨细胞修复兔膝关节软骨缺损的方法是可行的，异体关节软骨细胞在适当的处理后可成为关节软骨组织工程种子细胞。

Joint resurfacing using allograft chondrocytes embedded in alginate gel

OBJECTIVE: To explore the feasibility of repairing the articular cartilage with allo-articular chondrocytes embedded in alginate gel. METHODS: Allo-articular chondrocytes were isolated from three adult New zealand rabbits. The cells were cultured in DMEM/F-12 supplemented with 20% fetal bovine serum (FBS). Chondrocytes of 2nd - 3rd passage were harvested and were diluted to 5.0 x 10(7) cells/ml with 1.2% alginate. Then alginate gel was formed by 102 mM CaCl(2). The gels were cultured subsequently for 1 week and then transferred to the full-thickness defects in the femoral condyles of adult rabbits. In control group the defects were left untreated. The animals were sacrificed in the 3rd and 6th month after operation respectively. The specimens were decalcified with 50% formic acid. The histologic sections were stained with safranin O-fast green, hematoxylin-eosin (H&E) and picric acid-Sirius red and immunohisto-stained for type II collagen and aggrecan. The repairing efficiency was evaluated according to Wakitani scoring. RESULT: In the experiment group all 8 defects acquired repair, 7/8 were repaired with mature hyaline cartilage tissue, and 1/8 was with fibrocartilage tissue for less cell-gel inputted. The thick of repaired tissues were closed to the normal and the tissue integrated smoothly with cartilage around the defects. Safranin O staining of the matrix acted in accordance with the normal and immunostaining for type II collagen and aggrecan showed positive. Picric acid-Sirius red staining showed that the chondrocytes lined in lines and the collagen aligned like Gothic architecture structure by polarization microscopy. There was no evidence of residue of alginate and inflammation in 3rd month specimens and no obvious deterioration at 6th month. But in control group, only a small amount of fibrous, fibrocartilage, or hyaline-like tissue was seen on the surface of the defects. Wakitani scoring showed 1.75 points for the experiment group and 7.65 for the control group. CONCLUSION: It is a promising way to repair the articular cartilage with homogeneous articular chondrocytes embedded in alginate gel.