Construction and characterization of Mesona chinensis polysaccharide-chitosan hydrogels, role of chitosan deacetylation degree.

A novel kind of polyelectrolyte complex hydrogels was generated through polymerization of Mesona chinensis polysaccharide (MCP) and chitosan (CH) on the basis of physical crosslinking without the addition of ionic crosslinking agents or heat. Rheological measurement, Fourier transform infrared spectroscopy, X-ray diffraction, thermo-gravimetric analysis, and scanning electron microscopy were used to explore the properties of MCP-CH hydrogels. The effects of CH deacetylation degree (DD) on the gel properties and structural characteristics of MCP-CH hydrogels were also studied. Results showed that 0.5 % MCP and 1% CH could form stable and homogeneous hydrogels with favorable properties via electrostatic interaction. The viscoelasticity, water holding capacity, and thermostability of hydrogels were promoted with the increase in DD. The new crystallization peaks appeared with the formation of MCP-CH hydrogels. Moreover, the honeycomb-liked microstructure of MCP-CH hydrogels improved with the increase in DD. These findings may lay the foundation for the further application of MCP-CH hydrogels.