Technologies for bionic simulation of osteocyte microenvironment

Osteocyte is the most important functional cell type in osseous tissue, which is vital in response to mechanical stimuli, bone remodeling, mineral metabolism and homeostasis. Lacuna-canalicular networks serve as the fundamental structural microenvironment for osteocyte residing in and functioning. The rigid bone matrix mainly composed of type- I collagen and hydroxyapatite provides the biochemical microenvironment for osteocyte adhesion and interaction with other cells and extracellular matrix. It is also accepted that the surrounding mechanical microenvironment is vital for osteocyte. Furthermore, due to the sensitive dependence on the surrounding environment, osteocyte will be greatly influenced by the changes of surrounding microstructures, biochemical components and mechanical stimulations. The microenvironment surrounding osteocyte is therefore of crucial importance to both elucidating the mechanism of mechanical perception and discovery of new biological functions. However, the complicated lacuna-canalicular network surrounded by rigid bone matrix makes the study of osteocyte in vivo technically difficult. It can be of great significance to reconstruct bionic microenvironment in vitro for further revealing the functions of osteocyte. The systematic introduction of structural, biochemical and mechanical microenvironment surrounding osteocyte was presented here, and the recent technologies for simulation of bionic microenvironment in vitro were also reviewed. This review will provide a useful reference for researchers who are interested in osteology, tissue engineering and regenerative medicine.