Optimization of human myoblasts culture under different media conditions for application in the in vitro studies

Human primary in vitro cell cultures are among the most challenging procedures in cellular biology laboratory practice. Myoblasts-progenitor of skeletal muscle origin represent a promising therapeutic cell source since the procedure of their isolation is not technically demanding, and the in vitro culture is relatively straightforward. Myoblasts could be considered as the candidates for clinical applications due to their regenerative potential, and as the carriers of therapeutic proteins introduced through genetic modifications. The main goal of this prospective study was to evaluate different myoblasts isolation strategies based on the pre-plating technique and cells density characteristics. Moreover, testing of different myoblast media formulations-both commercially available and in-house made was performed. Our goal was to establish the in vitro protocol of myoblasts culture allowing for preservation of the proliferative potential and desired phenotype. Our results revealed that in culture of myoblasts of human muscle origin, the pre-plate technique and cell density differences did not correlate with changes in the proliferative potential, however it was observed that low density cells maintained expression of the CD56 marker up to the higher passages. Assessment of different types of culture media confirmed the best performance for DMEM based media without Chicken Embryo Extract (CEE) addition. Cells cultured in DMEM+FBS medium revealed high expression of CD56 and CD90 antigens, absence of the hematopoietic markers and presented stable proliferation profile. This finding is in line with guidelines of regulatory agencies recommending removal of the xeno-derived reagents from the manufacturing process of Advanced Therapy Medicinal Products (ATMP). In this study, human myoblasts culture was optimized in vitro under different media conditions. The next approach in assessment of myoblasts propagation for potential clinical applications will be testing of the clinical grade human platelet lysate (hPL) instead of the FBS.