Transglutaminase‐modified wool keratin film and its potential application in tissue engineering

Abstract

Transglutaminase (TGase) catalyzes the cross‐linking of many proteins and has been widely used to improve the properties of certain protein‐based materials. Keratin is considered as a promising biomaterial candidate following traditional chemical modification. In this study, the effect of TGase on the properties of a wool keratin film was investigated. The TGase‐modified film was applied to drug release and cell proliferation. Treatment with TGase (30 U/g keratin) for 18 h at 40°C increased the tensile strength of the film from 5.18 ± 0.15 MPa to 6.22 ± 0.11 MPa and decreased the elongation at break from 83.47 ± 1.79% to 72.12 ± 3.02%. The stability of the film in PBS and in artificial gastric juice was also improved. A rougher surface and a more compact cross‐section were observed by scanning electron microscopy photographs of the TGase‐treated film. SDS‐PAGE analysis confirmed that higher molecular weight proteins were formed in the TGase‐modified keratin solution and film. The results of the drug release assay using diclofenac indicated that both films with and without TGase treatment led to a high initial release in PBS, which was more constant in artificial gastric juice. The enzyme treatment led to a lower drug release rate from the film. Cell culture experiments suggested that the TGase‐mediated cross‐linked keratin film shows a good biocompatibility and that it can be used for tissue engineering applications.