Isolation of chondrocytes from rabbit rib cartilage with three-step enzymatic digestion and their biological characteristic in vitro / 第三军医大学学报

ABSTRACT

Objective To observe the effect of isolating and harvesting the chondrocytes from rabbits rib cartilage with the method of three-step enzymatic digestion, and the biological characteristic of the isolated chondrocytes during cultivation in vitro to evaluate their biological activity. Methods The method of three-step enzymatic digestion was designed that the rib cartilage was digested one by one with 1 g/L trypsin and 1 g/L EDTA, 1 g/L hyaluronidase and 2 g/L collagenaseⅠ in the culture medium to isolate chondrocytes. The harvesting and viability rate of the primary chondrocytes were detected. During the passage cultivation in vitro, the changes of the chondrocyte shape and growth were observed, and the changes of the collagen typeⅠ and Ⅱ and aggrecan in the extracellular matrix were detected. Results ① The extracellular matrix of rib cartilage was completely dissolved by the three-step enzymatic digestion, and the chondrocytes were completely isolated from the solid matrix. The number of the harvested chondrocytes from every gram of wet cartilage was (4 295.7)?10~(4) on average,and their viability rate was 97.2% on average. ②The primary and first passage chondrocytes had triangle or multi-angle shape, and became elliptic shape at the growing confluence with the positive immunohistochemical staining of collagen type Ⅱ and the strong heterochromia to toluidine blue. The content of sulfate glycosaminoglycans(GAG) in the extracellular matrix of the primary passage cells was (80.61?11.40) ?g/cm~(2). The chondrocytes after the third passage gradually became spindle shape with the negative staining of collagen typeⅡ and the weak heterochromia to toluidine blue. The content of sulfate GAG of the fourth passage cells was (44.74?10.18) ?g/cm~(2). Conclusion ① The method of three-step enzymatic digestion can make the extracellular matix of rib cartilage to be completely degraded, and has advantages of the high efficiency of harvesting primary chondrocytes with high cellular viability rate and simple manipulation. ②The primary and first passage chondrocytes have fine biological activity.