A Quick and Efficient Method for the Generation of Immunomodulatory MSC from Human iPSC

Mesenchymal stromal cells (MSC) have been widely investigated for their regenerative capacity, anti-inflammatory properties and beneficial immunomodulatory effects across multiple clinical indications. Nevertheless, their widespread clinical utilization is limited by the variability in MSC quality, impacted by donor age, metabolism and disease. Human induced pluripotent stem cells (hiPSC) generated from readily accessible donor tissues, are a promising source of stable and rejuvenated MSC but differentiation methods generally require prolonged culture and result in low frequencies of stable MSC. To overcome this limitation, we have optimized a quick and efficient method for hiPSC differentiation into foot-print free MSC (hiMSC) in this study. This method capitalizes on the synergistic action of growth factors Wnt3a and Activin A with BMP4, leading to an enrichment of MSC after only 4 days of treatment. These hiMSC demonstrate a significant upregulation of mesenchymal stromal markers (CD105+, CD90+, CD73 and CDH) comparable to bone marrow-derived MSC, with reduced expression of the pluripotency genes (Oct-4, c-Myc, Klf4 and Nanog) compared to hiPSC. Moreover, they show improved proliferation capacity in culture without inducing any teratoma formation in vivo. Osteogenesis, chondrogenesis and adipogenesis assays confirmed the ability of hiMSC to differentiate into the three different lineages. Secretome analyses showed cytokine profiles comparable to bone marrow-derived MSC. Encapsulated hiMSC in alginate beads co-cultured with osteoarthritic (OA) cartilage explants showed robust immunomodulation, with stimulation of cell growth and proteoglycan production in OA cartilage. Our quick and efficient protocol for derivation of hiMSC from hiPSC, and their encapsulation in microbeads therefore, presents a reliable and reproducible method to boost the clinical applications of MSC.