Fig. 4. (a) Cumulative release curves at 25 °C, (b) Cumulative release curves at 37 °C, and (c) DSC curves of the microfibers. (d) The IR spectra and IR images illustrate the distribution of the carboxyl groups and hydroxyl groups before and after KGM addition of microfibers. (e) Schematic representation of sustained drug release via hydrogen bonding.