Preparation, Mass Diffusion, and Biocompatibility Analysis of Porous-channel Controlled Calcium-alginate-gelatin Hybrid Microbeads for in Vitro Culture of NSCs

The Ca-alginate/gelatin (CAG) microbeads were prepared and evaluated through assays for their mechanical strength, permeability, and the feasibility as a cell carrier for in vitro culture of neural stem cells. The effects of different concentrations of sodium alginate, gelatin, and calcium chloride on the mechanical strength of CAG microbeads were determined using a self-made puncture force tester. Following this, the microbeads were immersed in DMEM media for a specified period to test its decay resistance. A diffusion model including a calculation formula of diffusion coefficient was built to investigate the diffusion of glucose and bovine serum albumin (BSA) through the wall of the microbeads. Furthermore, the feasibility of the microbeads for in vitro culture was identified using neural stem cells from Kunming mouse. Through a systematic approach and comprehensive analysis, the optimal gelatin conditions for microbead preparation were determined; the final combination of parameters of 1.5 % (wt%) sodium alginate (SA), 0.5 % (wt%) gelatin, and 4 % (wt%) CaCl2 were the best conditions for NSC cultures. This experiment demonstrated that CAG microbeads had good cytocompatibility that made it suitable for the culture and successfully maintained stemness of neural stem cells.