[Experimental study of repairing severe ligament injury with transgenetic bone mesenchymal stem cells]

To evaluate the efficacies of transgenetic bone mesenchymal stem cells (BMSCs) carring basic fibroblast growth factor (bFGF) gene on repairing severe ligament injury.

The genes of bFGF and enhanced green fluorescent protein (eGFP) were transfected into BMSCs through adenovirus vector. According to different cell transplantations, the operated rabbits were divided into 3 groups of transgenetic BMSCs, BMSCs and no cells. And group 4 was normal ligament group. The distribution of transgenetic BMSCs in ligament injury area, the expression of bFGF and ligament specific extracellular matrix, i.e. type I collagen, type III collagen, fibronectin, alpha-smooth muscle actin and vimentin, histology and biomechanics of ligament healing were recorded at different timepoints.

The transgenetic BMSCs could be observed in injury area within one month. The expression of bFGF in the transgenetic BMSCs group was significantly higher than that in the control groups at Days 3-14 (P < 0.001) and peaked at Day 7. In the transgenetic BMSCs group, the gene expression of ligament specific extracellular matrix was significantly higher than that in the control groups within one month (P < 0.001). And immunohistochemistry showed strong positive expression. After 3 months, in group 1, hematoxylin and eosin staining showed the arrangement and density of collagen fibers of healing area were better than that in the control groups. And biomechanical testing showed that tensile load were stronger than that in the control groups (P < 0.05).

Transgenetic BMSCs carrying bFGF gene can obviously promote ligament injury healing and increase ligament healing strength.