Oxidized pectin cross-linked carboxymethyl chitosan: a new class of hydrogels.

Oxidation of pectin was performed with sodium periodate to prepare pectin dialdehyde (PD). In this study we used the cross-linking reaction of the active aldehyde of PD and the amino of carboxymethyl chitosan (CMC) to prepare the hydrogels. By controlling the proportion of pectin dialdehyde and CMC we made different kinds of hydrogels. We systematically studied the characters of the hydrogels using Fourier transform infrared spectroscopy analysis of the pectin dialdehyde, CMC and the hydrogels, and also X-ray diffractometry and scanning electron microscopy analysis of the instrument of the hydrogels. Equilibrium swelling showed that the gels retained about 88-93% water. The water vapor transmission rate (WVTR) and the evaporation of water from gels showed that such hydrogels were optimal for maintaining a moist environment conducive for wound healing. Examination of the hemolytic potential showed that the hydrogels were nonhemolytic in nature. The hydrogels were non-toxic and blood-compatible. This hydrogel prepared from oxidized pectin and CMC without employing any extraneous cross-linking agents is expected to have potential as wound-dressing material.