Many microcarriers were reported that only achieved cell growth on their outer surface. Some porous microcarriers have some problems such as cytotoxicity due to the use of toxic crosslinking agents and chemical pore-forming agents. The gap is not large enough to accommodate cell growth and so on.
Herein, Lixia Huang et al used emulsion-based thermally induced phase separation (TIPS) to prepare highly porous chitosan microspheres (CSM) without using toxic crosslinkers and chemical porogenic agents other than ice. The CSM had an average diameter of ∼150μm with interconnected pores varying from 20∼50μm in size. Due to their excellent biocompatibility and unique porous structure, high-performance hepatocyte culture in three-dimensional (3D) space was achieved using the CSM as microcarriers, as cell growth also took place within the internal pores of the CSM, besides their external surface, and multidirectional cell–cell interactions were observed. Enhanced cellular activity and functions were obtained with the CSM microcarriers as compared with 2D cell culture. It is believed that these CSM microcarriers provide a promising platform for 3D cell culture in vitro.