Effect of a subset of adipose-derived stem cells isolated with liposome magnetic beads to promote cartilage repair

This study aimed to investigate the ability of CD146⁺ subset of ADSCs to repair cartilage defects. In this study, we prepared CD146⁺ liposome magnetic beads (CD146⁺LMB) to isolate CD146⁺ADSCs. The cells were induced for chondrogenic differentiation and verified by cartilage-specific mRNA and protein expression. Then a mouse model of cartilage defect was constructed and treated by filling the induced cartilage cells into the damaged joint, to evaluate the function of such cells in the cartilage microenvironment. Our results demonstrated that the CD146⁺LMBs we prepared were uniform, small and highly stable, and cell experiments showed that the CD146⁺LMB has low cytotoxicity to the ADSCs. ADSCs isolated with CD146⁺LMB were all CD146⁺, CD105⁺, CD166⁺ and CD73⁺. After chondrogenic induction, the cells showed significantly increased expression of cartilage markers Sox9, collagen Ⅱ and aggrecan at protein level and significantly increased Sox9, collagen Ⅱ and aggrecan at mRNA level, and the protein expression and mRNA expression of CD146⁺ADSCs group were higher than those of ADSCs group. The CD146⁺ADSCs group showed superior tissue repair ability than the ADSCs group and blank control group in the animal experiment, as judged by gross observation, histological observation and histological scoring. The above results proved that CD146⁺LMB can successfully isolate the CD146⁺ADSCs, and after chondrogenic induction, these cells successfully promoted repair of articular cartilage defects, which may be a new direction of tissue engineering.