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

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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.

Section snippets

Strategy of experimentation

Both artificial liver and liver transplantation require a large amount of hepatocyte source. Compared with traditional single-layer plates, microcarriers have good mass transfer ability and mechanical stability, and can provide a larger specific surface area for hepatocyte culture. In addition, the microcarriers provides a three-dimensional growth space for the cells, which are more conducive to protecting the normal function of the cells and facilitating high-quality, high-density culture of

Preparation of chitosan microcarriers

Through experience summarization and single factor experiments, the factors affecting the preparation of microspheres are voltage, frequency, propulsion speed, pulse, liquid-surface distance and solution concentration. According to the experimental results, a voltage of 55 kV, a frequency of 90 Hz, a propulsion speed of 90 mm/h, a pulse width of 6 ms, and a liquid surface distance of 25 mm were selected for the preparation of microcarriers. Orthogonal experiments were carried out on the

Discussion

Liver is a highly organized structure. Once the primary hepatocytes are removed from an organism, tissue-specific functions are rapidly lost. Artificial liver is important for the treatment of fulminant hepatic failure. High-density culture of hepatocytes is vital for the development of artificial liver. The emergence of various microcarriers has made it possible to culture large numbers of hepatocytes. Piskin et al. (14) prepared poly-hydroxymethylsiloxanes (PDMS-OH) microcarriers by

Acknowledgments

This work was supported by the National Natural Science Foundation of China, No. 51776130.

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