Preparation and characterization of pH sensitive sugar mediated (polyethylene glycol/chitosan) membrane

Novel biodegradable membrane based on chitosan matrix was prepared and characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and swelling test. Native sugar, which is commonly used in human life, was utilized to prepare the crosslinked hydrophilic chitosan-polyethylene glycol (PEG) polyblend. According to TGA and FTIR results, the chemical reaction occurred in imine bonds (C=N) between sugar and amino groups in chitosan. Chitosan blending with high swelling capacity of PEG increased the water affinity and reacted with sugar decreased the water affinity. The equilibrium water content (EWC) value of the sugar mediated membrane is in the sequence of sucrose>D-fructose>glucose and they all present much lower water uptake ability than polyblend. The chitosan was not degraded by lysozyme, but all of the sugar-mediated membranes were susceptible to lysozyme. Scanning electron microscope (SEM) morphology shows that the degradation rate not only was controlled by the chemical complexation between sugar and polyblends, but the surface morphology of membranes also has great influence. Sucrose-mediated membrane supports the attachment and growth of NIH 3T3 fibroblasts. The pH-sensitive and well degradable property of the sucrose-mediated membrane can be applied for biomedical application. (C) 2003 Kluwer Academic Publishers.