Joint resurfacing using allograft chondrocytes embedded in alginate gel

摘要

OBJECTIVErnTo excplore the feasibility of repairing the articular cartilage with homogeneous articular chondrocytes enbedded in alginate gel.rnMETHODSrnHomogenous articular chondrocytes were isolated from two adult rabbits. The cells were cultured in DMEM/F-12 supplemented with 20% fetal bovine serum (FBS), 50ug/ml ascorbic acid-2-phosphate, 0.4mM proline, 5ug/ml insulin and lmM non-essential amino acids (NEAA) in flasks in vitro. Chondrocytes of 2nd-3rd passage were harvested with trypsin and were diluted to 5.0×107cells/ml with 1.2% alginate. Then alginate gel formed by 102mM CaCl2. The gels were cultured subsequently for 1 week and then transferred to the full-thickness defects in 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 decalcifying with 50% formic acid. The histologic sections were stained with safranin O-fast green, hematoxylin-eosin(H&E) and picric acid-Sirius red and immunostained for type II collagen and aggrecan. Repairing efficiency was evaluated according to Wakaniti scoring.rnRESULTrnIn 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 residua of alginate and inflammation in 3rd month specimens and no obvious deteriorated at 6th month. But in control group, only a small amount of fibrous, fibrocartilage, or hyaline-like tissue was seen on the surface of defects. Wakaniti scoring showed 1.75 points for experiment group and 9.75 for control group.rnCONCLUSIONrnIt is a promising way of repairing the articular cartilage with homogeneous articular chondrocytes enbedded in alginate gel.