pH-sensitive keratin-based polymer hydrogel and its controllable drug-release behavior

Using feather keratin as biocompatible and inexpensive natural biopolymer and methacrylic acid as a functional monomer, we prepared a pH-sensitive feather-keratin-based polymer hydrogel (FKPGel) with grafted copolymerization. The obtained FKPGel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The swelling behavior and pH sensitivity of the FKPGel were investigated. When the small molecule (rhodamine B) and macromolecule (bovine serum albumin) were used as model drug molecules, the FKPGel exhibited controllable release behavior in vitro, and the hydrogels had pH sensitivity. For a small molecular drug, the cumulative release rate was 97% in 24 h at pH 8.4. For macromolecular drug, the cumulative release rate reached 89% at pH 7.4. Its release behavior could be controlled by the pH value. In summary, a simple method was found to reuse disused feathers. It is a kind of pH-sensitive hydrogels to be applied in drug-delivery systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41572.