Chondrocytes co-cultured with Stromal Vascular Fraction of adipose tissue present more intense chondrogenic characteristics than with Adipose Stem Cells

Partly replacement of chondrocytes by stem cells has been proposed to improve the performance of autologous chondrocytes implantation (ACI). Our previous studies showed that the increased cartilage production in pellet co-cultures of chondrocytes and mesenchymal stem cells (MSCs) is due to a trophic role of the MSC by stimulating chondrocyte proliferation and matrix production rather than MSCs actively undergoing chondrogenic differentiation. The aim of this study is to compare the trophic effects of stromal vascular fraction cells (SVF) and in vitro expanded adipose stem cells (ASC). SVF and culture expanded ASCs (n =9) were co-cultured with primary human chondrocytes in pellets. By glycosaminoglycan (GAG) and DNA assays, we showed that co-culture pellets of SVF and chondrocytes have more GAG deposition than that of ASC and chondrocytes. Results of Short Tandem Repeats analysis indicated that the increase in the chondrocytes proportion in the co-culture pellets is more pronounced in the SVF co-culture group than in the ASC co-culture group. Using flow cytometry and microarray, we demonstrated that SVF and ASC have different characteristics in cell surface markers and gene expression profile. SVF is more heterogeneous than ASC, while ASC is more enriched in cells from the mesenchymal lineage than SVF. By subcutaneous implantation into nude mice, we showed that constructs of SVF and chondrocytes are better in depositing cartilage matrix than the mixture of ASC and chondrocytes. Taken together, SVF is better than ASCs in terms of forming cartilage matrix in pellet co-culture and in co-implantation models omitting the need for prior cell expansion. Our study suggests that the SVF in combination with primary human chondrocytes may be a good cell combination for one stage cartilage repair.