Ectopic chondrogenesis of composite of enhanced green fluorescent protein gene-modified precartilaginous stem cells and bone matrix gelatin

Abstract

Objective To evaluate the chondrogenesis potential of composite of enhanced green fluorescent protein (EGFP) gene-modified precartilaginous stem cells (PSCs) and bone matrix gelatin (BMG) ectopically. Methods PSCs were transfected with pEGFP by means of lipofectamine. The composite of EGFP gene-modified PSCs and BMG was cultured in vitro, then implanted into the right thigh of athymic mice, and BMG implanted into the left thigh as control group. The harvested implants were weighed, and the number of cells and the expression of GFP were examined. The expression of type Ⅱ collegen was detected by using immunohistochemistry. Results EGFP gene-modified PSCs had high expression of GFP in vitro 6 weeks after purification. The composite had high expression of GFP from 1 to 6 weeks after implantation, and high expression of type Ⅱ collagen from 3 to 6 weeks. The mass of the composite was (0.71±0.07), (1.35±0.32), (1.76±0.48), (1.96±0.54), (1.89±0.13) g from 2 to 6 weeks, respectively, which was significantly greater than that in control group (P<0.01). The total number of cells in the composite was (40.0±2.1)×106, (67.0±5.6)×106, (139.0±11.2)×106, (169.0±2.9)×106, (173.0±13.5)×106, (169.0±6.9)×106 from 1 to 6 weeks, respectively, which was significantly greater than that in control group (P<0.01). Conclusion The composite of EGFP gene-modified PSCs and BMG could generate ectopic cartilaginous tissue. Key words: Precartilainous stem cells; Gene transfectection; Bone matrix; Gelatin