A facile method to fabricate versatile keratin cryogels for tissue engineering applications

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Human hair keratin (HHK) is a promising biomaterial for soft tissue regeneration due to its bioactivity and biocompatibility.
• Conventional keratin hydrogels often have dense structures, limiting cell infiltration and tissue integration.
• Developing keratin-based materials with controlled porosity and enhanced mechanical properties is crucial for effective tissue engineering.

Purpose of the Study:

• To develop a facile method for fabricating mechanically superior HHK-based cryogels with a cell-compatible microarchitecture.
• To investigate the use of oxidized dopamine (ODA) as a crosslinker for HHK at sub-zero temperatures.
• To tune the mechanical properties and pore size of HHK cryogels for soft tissue regeneration.

Main Methods:

• Fabrication of HHK-based cryogels using a freeze-thaw (FT) method.
• Covalent crosslinking of keratin molecules with oxidized dopamine (ODA) at sub-zero temperatures.
• Optimization of ODA content and FT cycles to control mechanical properties and pore size.

Main Results:

• HHK-ODA cryogels with micron-sized pores (100-200 μm) were successfully fabricated.
• Mechanical properties, including compressive strength and stiffness, were significantly enhanced (up to 15-fold increase).
• The cryogels effectively supported human dermal fibroblast spreading and proliferation, demonstrating good biocompatibility.

Conclusions:

• A straightforward method for creating mechanically robust HHK cryogels with tunable properties and a cell-friendly porous structure was established.
• The developed HHK-ODA cryogels offer a promising alternative to conventional hydrogels, avoiding complex chemical modifications and cytotoxic crosslinkers.
• These advanced cryogels hold significant potential for applications in soft tissue regeneration and other biomedical fields.