The Novel Membrane-Type Micro-system to Assess the Bonus Effect of Physiological and Physical Stimuli on Bone Regeneration

The periosteal progenitor cell is suitable for bone tissue regeneration duo to its multipotent differentiation in osteogenesis and chondrogenesis. It was found that both physical and physiological stimuli can induce the differentiation of periosteal progenitor cells. However, the combined-effect of these two stimuli is not clear. The imitation of the nature movement—the cyclic tensile strain stimulation and the multiple growth factors producing cells—adipose-derived stem cells (ADSCs) were used as physical and physiological stimuli to investigate the differentiation of rabbit periosteal cells in this study. For this, a new membrane-type micro-system was invented to provide a simple examination platform for both factors in one single system. The specific rectangular culture chamber not only provided two different types of cells to grow separately but also delivered the single axial tensile strain generated in the micro-system to the cells. It was found that application of either physical or physiological stimuli alone was sufficient to induce the differentiation of periosteal cells. The low tensile strain (4, 5, 6 kPa) led to osteogenesis whereas high tensile strain (7 kPa) induced chondrogenesis. Even though the co-culture of ADSCs only induced osteogenic differentiation of periosteal cells, the co-culture of ADSCs to tensile strain treated periosteal cells further strengthened the osteogenic and chondrogenic differentiation potent in low and high tensile strain, respectively. This study provided the pre-clinical evidence of the stem cell therapy and continuous exercise in cell level bone tissue regeneration.