Osteocyte plays a central role as a commander in the bone to modulate bone remodeling processes. While the osteocyte is known to be differentiated from osteoblasts, understanding in mechanism of the osteocyte differentiation remained still poor. The aim of this study is to elucidate the osteocyte differentiation capability using three-dimensional (3D) cell culture technique. We first fabricated a self-organized spheroid reconstructed by mouse osteoblast-like cells by adjusting the number of subcultured cells in the round-bottom well. Compared to a conventional two-dimensional (2D) monolayer model, the 3D spheroid exerted greater osteocyte gene expressions <i>in vitro</i> within 2 days. As a result of the size-dependent experiment, there might be an appropriate cell-cell and cell-ECM interaction for osteoblast-like cells to induce the osteocytogenesis in the form of 3D spheroid culture. Moreover, the present model showed that the spheroid further exerted the prolonged osteocyte differentiation capability after a long period of incubation, 7 days. In conclusion, we characterized the self-organized osteocytic spheroids reconstructed by osteoblast-like cells and further suggested the potential application of the spheroid as a new <i>in vitro</i> tissue-engineered osteocytic model.

Keywords

Bone, Osteocytes, Differentiation, Osteoblast-like cells, Spheroid, Three-dimensional cell culture

Paper information

Jeonghyun KIM, Hiroyuki KIGAMI, Taiji ADACHI, “Characterization of self-organized osteocytic spheroids using mouse osteoblast-like cells”, Journal of Biomechanical Science and Engineering, Vol.15, No.3 (2020), p.20-00227 doi:10.1299/jbse.20-00227. Final Version Released on July 24, 2020, Advance Publication Released on June 24, 2020.