Xeno-Free Human Wharton’s Jelly Mesenchymal Stromal Cells Maintain Their Characteristic Properties after Long-Term Cryopreservation

OBJECTIVE: The past decade has witnessed a rapid growth in harnessing the potential of adult stem cells for regenerative medicine. An investigational new drug (IND) or a regenerative medicine advanced therapy (RMAT) product must fulfil many requirements, such as stability studies, after cryopreservation. Such studies are important to ascertain the utility of off-the-shelf allogeneic cells for clinical applications. The present work describes a complete characterisation of xeno- free human Wharton’s Jelly mesenchymal stromal cells (hWJ-MSCs) before and up to 28 months post-cryopreservation. MATERIALS AND METHODS: In this experimental study, culture methods that involved plasma derived human serum and recombinant trypsin were used to develop clinical grade cells. Complete cell characterisation involved flow cytometry studies for viability, positive and negative markers, colony forming unit (CFU) potential, population doubling time (PDT), soft agar assay to evaluate in vitro tumourigenicity, karyotype analysis and differentiation studies which were performed before and at 6, 12, 18 and 28 months post-cryopreservation. RESULTS: Our data showed consistency in the flow cytometry, CFU assay, PDT, soft agar assay, karyotyping and differentiation studies. CONCLUSION: Using our protocols for extended xeno-free culture and cryopreservation of hWJ-MSCs, we could establish the shelf life of the cell-based product for up to 28 months.