Characterization and chondrogenic differentiation of menstrual blood-derived stem cells on a nanofibrous scaffold

Introduction: The recent identification of menstrual blood-derived stem cells (MenSCs) as a unique population of stem cells has created enormous promise for tissue engineering. In this study, after characterization of MenSCs in comparison with bone marrow-derived stem cells (BMSCs), the potential of MenSCs seeded into electrospun, biodegradable, nano fibrous scaffolds in order to engineer cartilage was evaluated. Methods: MenSCs and BMSCs were isolated by discontinuous density gradient centrifugation and plastic adherence. After characterization of MenSCs compared with BMSCs, MenSC differentiation into chondrocytes was investigated on a nano fibrous scaffold with specific growth and differentiation factors. The scaffold was prepared from polycaprolactone (PCL) and its surface was modified by plasma treatment. Results: Flow cytometric analysis of expanded cells showed that MenSCs typically express some surface and intracellular markers associated with BMSCs. But marked expression of OCT-4 and the absence of STRO1 distinguished them from mesenchymal stem cells obtained from bone marrow. Based on scanning electron microscope images, the MenSCs were strongly anchored to the highly porous scaffold, which they penetrated and proliferated on. The scaffold contained an extensive cartilage-like extracellular matrix with about 50% greater glycosaminoglycan content than control MenSCs differentiated in a two-dimensional (2D) culture system (p<0.05). Considerable amounts of proteoglycan were produced by the cells differentiated on the scaffold, as demonstrated by Alcian blue staining. Unlike undifferentiated MenSCs, cells differentiated on the scaffold had strong immunoreactivity with monoclonal antibody against collagen type II. Conclusions: The evidence presented in this study introduces MenSCs as a suitable stem cell population candidate for cartilage tissue engineering.