Preparation of novel pH-sensitive hydrogels of carboxymethyl cellulose acrylates: A comparative study

Novel pH-sensitive hydrogels for drug delivery applications were developed in our laboratory. The hydrogels were made by esterification of sodium carboxymethyl cellulose with acryloyl chloride or methacryloyl chloride. Fourier transform infrared (FTIR) spectra of the hydrogels suggested formation of ester bonds between the hydroxyl groups of sodium carboxymethyl cellulose and carbonyl group of acryloyl chloride or methacryloyl chloride. The hydrogels showed pH-dependent swelling behavior arising from the acidic pendant groups in the polymer network. The permeability of the hydrogel membrane produced, as shown by salicylic acid diffusion, increased in response to increase in pH of the external medium. The pH dependent permeation was found to be reversible. The hydrogel membranes were found to be compatible with the L929 mice fibroblast cell line and mice splenocytes.