Isolation and culture of human keloid-derived mesenchymal stem cells and their growth curve

Objective To investigate the method to culture high-purity keloid-derived mesenchymal stem cells(MSCs).Methods The keloid tissue samples were collected from the skin of 4 patients hospitalized in our department.The lesioned areas were the chest and the back.The human keloid cells were cultured with the serial culture medium in the following order:DMEM∶F12/(100 mL/L)fetal bovine serum(FBS),then low-glucose DMEM/(100 mL/L)FBS,low glucose DMEM/(10 mL/L)FBS,and last serum-free stem cell medium.Then we observed cell morphology and identified cell surface markers by flow cytometry method.Results We obtained high-purity fiber-like cells of long spindle and uniform shape by the serum gradient culture method.The expression of cell surface markers detected by flow cytometry was 99.99%for CD29,99.7%for CD44,0.69%for CD45,and99.96%for CD73.Conclusion High-purity keloid-derived mesenchymal stem cells can be obtained by the culture method of decreasing serum concentration gradient.