An oxygen-permeable spheroid culture chip (Oxy chip) promotes osteoblastic differentiation of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are being clinically used for bone and cartilage regeneration. However, the preparation of MSCs for implantation is still costly and time consuming, and controlling the differentiation of stem cells remains a challenge. Although much attention has been paid to three-dimensional cultures in the fields of tissue engineering and regenerative medicine, adequate oxygen supply remains a challenge for growing thicker and larger cellular constructs. To solve this problem, we have developed an oxygen-permeable spheroid culture device (Oxy chip) that enables direct oxygen supply to the cells. The aim of this study was to examine the effect of a three-dimensional culture and oxygenation to the cells on the differentiation of mouse MSC strain D1 cells. Our data demonstrated that MSCs grown in the Oxy chip differentiated into osteoblasts more quickly and efficiently than those grown in the conventional non-oxygen permeable chip and monolayer culture. DNA array and energy metabolism analyses revealed that the Oxy chip facilitated osteoblastic differentiation and aerobic glycolysis, rather than chondrogenic differentiation and anaerobic glycolysis. Together, we revealed for the first time that the oxygenation by the Oxy chip was effective on the osteoblastic differentiation and survival of three-dimensional cultured MSCs. This chip is useful for preparing differentiated cells and controlling the direction of differentiation of MSCs. Moreover, this approach may be useful for transitioning spheroid cultures as a therapy in regenerative medicine.