Novel pH-Sensitive Lactic Acid Oligomer Grafted Chitosan Hydrogel for Controlled Drug Release

摘要

A pH-sensitive hydrogel, using chitosan as hydrophilic segment and lactic acid oligomer (LAO) as hydrophobic segment, was successfully synthesized through a dehydration reaction between amino and carboxyl groups. Scanning electron microscope (SEM) images revealed that the channel-like network structure of the as-prepared hydrogels, which plays an important role in controllable drug release behavior, was gradually collapsed with increasing content of lactic acid. Fourier-transform infrared (FTIR) spectra were obtained to demonstrate the occurrence of the dehydration reaction. Furthermore, the swelling ratio measurement and release study were performed, and the results showed that the chitosan/LAO hydrogel had an outstanding pH-sensitive property, and thus has high potential for usage in controlled-drug release.