Synthesis of new chitosan-glutaraldehyde scaffolds for tissue engineering using Schiff reactions

Hydrogels of chitosan (CS) and glutaraldehyde (GA) were synthesized for tissue engineering applications by using a Schiff reaction. CS was reacted with GA (a cross-linker) at different concentrations, which were expressed as percentage of weight (2, 4, 6, 8 and 10 wt%). An evaluation was made of the effect of the different wt% of GA on the swelling and rheological properties of the hydrogels. The Schiff crosslinking reaction was monitored by UV–vis spectroscopy (550 nm) to determine the reaction kinetics and reaction order at 60 °C. The hydrogel structures were characterized by NMR, FT-IR, HR-MS and SEM, while the degree of cross-linking was examined with TGA-DA. The smaller pores and greatest swelling were found in hydrogels containing 10 wt% of GA. However, only the hydrogels with GA at 2, 4 and 6 wt% displayed viable cells, indicating their in vitro cytocompatibility. The rheological studies showed that the values of the loss and storage modules in the hydrogels increased with a rise in temperature from 30 to 35 and finally 40 °C. Further research is needed to verify the adequacy of these hydrogels as a scaffold for tissue engineering in vivo.