Repair of Damaged Hair Protein Fiber by Jointly Using Transglutaminase and Keratin

In the 2021 study, researchers investigated the effectiveness of a combined treatment using transglutaminase (TG enzyme) and keratin to repair damaged hair. They prepared a TG-keratin repair solution and applied it to hair samples, measuring various properties before and after treatment. The results showed significant improvements: alkali solubility decreased from 16.14% to 4.92%, fracture stress increased from 0.832 N to 1.668 N, fracture strain rose from 8.81 mm to 10.17 mm, and swelling rate dropped from 38.34% to 2.34%. Additionally, spectroscopic analyses indicated that the treatment led to more amide bonds, higher crystallinity, and stronger crosslink activities in the hair proteins. Microscopic observations revealed a smoother hair surface with fewer warped scales. This study was the first to apply enzyme technology to hair repair, suggesting a new direction for environmentally friendly and efficient biological hair care and the application of protein-based materials.