Development of novel three-dimensional culture system for periosteum-derived progenitor cells

초록

Cell therapy has the potential for providing new way of clinical treatments. Stem cells are able to self-renew and differentiate into various types of cells for therapeutic purposes. Especially, mesenchymal stem cells (MSCs) are important tools for cell therapy because of their immunosuppressive properties. MSCs are commonly cultured in two-dimensional (2D) system, but there are reports demonstrating a loss of differentiation capacity of MSCs with time in 2D culture. In addition, the available surface area for the propagation of cells is limited. Therefore, various three-dimensional (3D) culture technologies have been developed. There are numerous studies on 3D cultures using spheres formed by aggregated cells. Aggregation can activate cell–cell interactions, resulting in enhanced therapeutic potential by stimulating stem-cell-associated genes. In this study, we have developed a 3D culture system for the expansion of periosteum-derived progenitor cells (PDPCs) as spheres. The PDPCs are one of diverse MSCs and they have high proliferation capacity. The spheroid formation of PDPCs was induced by using a rotation platform. The rotation system could provide sufficient nutrient supply and oxygen partial pressure gradients for the growth of the spheres. PDPCs were seeded at a density of 200,000 cells/mL in 35-mm non-adhesive culture dishes. Total volume was 2 mL and the cells were cultivated at a rotation rate of 60 rpm. The 3D culture system could be applied to shaking Erlenmeyer flasks. The spheres maintained their viability, proliferation ability and stemness. Furthermore, the PDPCs in 3D culture showed more expression of stem-cell-associated genes than 2D culture. In conclusion, a simple and economical 3D culture system could be developed. This system has many advantages in the stem cell culture such as short handling time, easy production process and possibility of scale-up. Finally, the 3D culture system can increase the potential of PDPCs for clinical use.