ABSTRACT
Objective To establish a model of full-thickness avascular meniscal defect to assess outcome of bone-marrow mesenchymal stem cells (BMSCs) modified with human insulin-like growth factor Ⅰ (hIGF-Ⅰ) gene and compounded with injectable calcium alginate gel in repair of meniscal defect.Methods Models of full-thickness defect were created in the anterior comer of meniscus in goats,an area lacking of blood supply.The trial categorized the models to four groups:gene-ehanced tissue engineering (GETE) group (hIGF-Ⅰ transfected BMSCs were mixed with calcium alginate gel),BMSCs group (BMSCs were mixed with calcium alginate gel),empty group (calcium alginate gel was used alone) and control group (the defect was excluded from repair).Macroscopy was done at 4,8,and 16 weeks after operation.Variation of repair tissue was observed by light and scanning electric microscopy and aggrecan in repair tissue was determined as well.Results Meniscal defect was on the mend at 4-16 weeks after operation in GETE group,with the defect area being thoroughly filled with the white,elastic and tight repair tissue similar to normal meniscal tissue.Macroscopic examination showed a better result in GETE group than that in other groups.Light microscopy showed that repair tissue which was mainly fibrochondrocytes was arranged in line with calcium alginate fibers and that space between the fibers was mostly crammed with the matrix secreted by those cells.At the same time,those cells were tightly arranged and the matrix secreted by those cells was equally distributed according to light microscopy.Electroscopy demonstrated neat and tight arrangement of fibers and tight extracellular matrix in fiber space in GETE group.Aggrecan concentration in GETE group was relatively higher than in other groups,but still had difference from the normal meniscus.Conclusion hIGF-Ⅰ gene-transfected BMSCs combined with injectable calcium alginate gel can improve the effect in repair of full-thickness meniscal defect.