Investigation of acetylated chitosan microspheres as potential chemoembolic agents

The aim was to investigate the potential of chitosan microspheres (CMs) with different acetylation using as a chemoembolic agent. Chitosan microspheres (CMs) were prepared via water-in-oil (W/O) emulsification cross-linking method, and acetylated chitosan microspheres (ACMs) were obtained by acetylation of CMs. Next, we characterized the morphology, size, composition and degrees of deacetylation using scanning electron microscopy (TEM), dynamic laser light scattering (DLS), and Fourier transform infrared spectrometer (FTIR). All microspheres had smooth surfaces and good mechanical flexibility, and all could pass through a 5F catheter. The swelling rate (SR) of CMs decreased significantly with the increase of pH (4.0-10.0) but ACMs did not change under the same conditions. Protein absorption assays suggested that albumin was more greatly adsorbed on CMs than on ACMs. Furthermore, CMs caused more blood clots than ACMs. ACMs caused hemolysis less than CMs (<5% of the time). Data indicated that ACMs had more hemocompatibility. Cytotoxicity tests indicated that ACMs initially had less cell attached proliferation but increased with incubation. In contrast, the relative growth rate of mouse embryo fibroblasts (MEFs) on CMs decreased gradually. The results suggested that ACMs could stimulate the growth of MEFs, and CMs were not cytotoxic to MEFs. Thus, ACMs were more biocompatible with greater potential to be used as chemoembolic material.