Isolation and Cultivation of HF-MSCs

The isolation and identification of HF-MSCs were carried out as in our previous study [15 (link), 20 (link)]. Isolated HF-MSCs were cultured in Dulbecco’s modified Eagle’s medium (Life Technologies, Gaithersburg, MD, USA) containing 10% fetal bovine serum (FBS; Hyclone, Logan, UT, USA), 2 ng/mL of basic fibroblast growth factor (Sino Biological Inc., China) and 100 U/mL penicillin–streptomycin (Hyclone). HEK 293 T cells were cultured in DMEM containing 10% FBS and 100 U/mL penicillin–streptomycin. Cells were cultured at 37 °C and 5% CO₂.When the cells proliferated to an 80%–90% confluence, they were digested and subcultured under similar individual conditions.