Nonionic polymer cross-linked chitosan hydrogel: preparation and bioevaluation

A straightforward method to prepare nonionic polymer (polyacrylamide, PAM) cross-linked chitosan hydrogel has been developed. The chitosan–polyacrylamide (CS–PAM) hydrogel could be quickly obtained by simply mixing of chitosan and polyacrylamide solutions under very benign condition (room temperature, <30 s). The cytotoxicity and hemocompatibility of the CS–PAM hydrogel were subsequently investigated. Cells retained normal morphology even when the concentration of CS–PAM hydrogel in culture system was as high as 640 μg mL−1, indicating the CS–PAM hydrogel has minimal cytotoxicity to A549 and HeLa cells. Meanwhile, no hemolysis was observed after incubating the CS–PAM hydrogel with red blood cells for 6 h, further suggesting excellent biocompatibility of the hydrogel. Scanning electron microscopy images illustrated that the CS–PAM hydrogel can absorb red blood cells through the interaction between the protonated amine groups on chitosan and the negative charged residues on red blood cell membranes. Given its low cost, simple preparation, and excellent biocompatibility, this CS–PAM hydrogel might be a potential biomaterial for future healthcare and biomedical applications.