Objective: Spontaneous cartilage regeneration is poor after a cartilage defect occurs by trauma, surgical, and other reasons. Importance of producing chondrocytes from stem cells and using tissues to repair a defect is getting popular. The aim of this study was to compare the effects of injectable cartilage produced by chondrocytes differentiated from adipose tissue-derived mesenchymal stem cells and chondrocyte cells isolated directly from cartilage tissue.
Methods: Mesenchymal stem cells were isolated from rat adipose tissue and characterized by cell-surface markers. Then, they were differentiated to chondrocyte cells. The function of differentiated chondrocyte cells was compared with chondrocyte cells directly isolated from cartilage tissue in terms of collagen and glycosaminoglycan secretion. Then, both chondrocyte cell types were injected to rats' left ears in liquid and gel form, and histologic evaluation was done 3 weeks after the injection.
Results: Adipose-derived stem cells were strongly positive for the CD44 and CD73 mesenchymal markers. Differentiated chondrocyte cells and chondrocyte cells directly isolated from cartilage tissue had relative collagen and glycosaminoglycan secretion results. However, histologic evaluations did not show any cartilage formation after both chondrocyte cell types were injected to rats.
Conclusions: Strong CD44- and CD73-positive expression indicated that adipose-derived cells had the stem cell characters. Collagen and glycosaminoglycan secretion results demonstrated that adipose-derived stem cells were successfully differentiated to chondrocyte cells.