In situ forming hydrogel systems have received a great attention in the biomedical
research fields due to capability of minimally invasive injection, the structural
similarity to the natural extracellular matrix of hydrogel, and multi-tunable
properties. Up to date, various kinds of biomaterials have been utilized to create
injectable hydrogel matrices for therapeutic implants and therapeutic vesicles.
Among them, keratin, derived from hair, has emerged as a fascinating biomaterial
due to high biocompatibility, biodegradability, cellular activity, low immune reaction,
possibility of autologous implantation, and high rich-resource which is suitable for
biomedical applications. While the natural polymer based in situ forming hydrogels
have been widely investigated, there have been no report about in situ cross-linkable
keratin based hydrogel systems so far and poor solubility of keratin in aqueous
solutions is a limitation for use in a broad range of applications too. In this study,
keratin based in situ forming hydrogel system was developed. First we designed a
water soluble keratin by conjugating poly(ethylene glycol) (PEG) molecules and
tethered with tyramine (TA) to exploit the horseradish peroxidase (HRP) mediated
enzymatic reaction. We synthesized three different Keratin-PEG-TA (KPT)
conjugates with different PEG portion and characterized their chemico-physical
properties. The gelation times and mechanical properties can be varied by changing
the concentration of HRP and H2O2 respectively and the surface morphologies of
KPT hydrogels were porous which is suitable for transporting of nutrients and
bioactive molecules to cultivate cells. Finally, in vitro cytotoxicity test was
conducted, exhibiting excellent cytocompatibility. These results demonstrated that
developed KPT hydrogels could be a suitable scaffold for f biomedical applications
in tissue engineering
