Preparation of chitosan microcarriers by high voltage electrostatic field and freeze drying

In this paper, a biocompatible, non-toxic porous chitosan microcarrier was prepared by high voltage electrostatic field and freeze drying technology. The chitosan solution was pushed from the syringe drop into the sodium polyphosphate solution using a booster pump. The droplet diameter of the chitosan solution was adjusted by the voltage of the electrostatic field formed between the syringe and the sodium polyphosphate solution. The droplets were dropped into a sodium polyphosphate solution to form microspheres. The microspheres were subsequently immersed in 25% (v/v) glutaraldehyde for crosslinking to enhance the mechanical strength of the microspheres. These microspheres were then frozen and lyophilized to form a microcarrier. By performance characterization, these microcarriers had a particle size of 400-500 μm, a pore size of 15-20 μm, and a porosity of 90%. Under simulated human environmental conditions, the 21-day degradation rate was about 30%, indicating that the microcarriers have potential clinical value.