Collagen/kerateine multi-protein hydrogels as a thermally stable extracellular matrix for 3D <i>in vitro</i> models
Kameel Zuniga, Manasa Gadde, Jacob Scheftel, Kris Senecal, Erik N. K. Cressman, Mark Van Dyke, Marissa Nichole Rylander
Abstract
Objective To determine whether the addition of kerateine (reduced keratin) in rat tail collagen type I hydrogels increases thermal stability and changes material properties and supports cell growth for use in cellular hyperthermia studies for tumor treatment.Methods Collagen type I extracted from rat tail tendon was combined with kerateine extracted from human hair fibers. Thermal, mechanical, and biocompatibility properties and cell behavior was assessed and compared to 100% collagen type I hydrogels to demonstrate their utility as a tissue model for 3D in vitro testing.Results A combination (i.e., containing both collagen ‘C/KNT’) hydrogel was more thermally stable than pure collagen hydrogels and resisted thermal degradation when incubated at a hyperthermic temperature of 47°C for heating durations up to 60 min with a higher melting temperature measured by DSC. An increase in the storage modulus was only observed with an increased collagen concentration rather than an increased KTN concentration; however, a change in ECM structure was observed with greater fiber alignment and width with an increase in KTN concentration. The C/KTN hydrogels, specifically 50/50 C/KTN hydrogels, also supported the growth and of fibroblasts and MDA-MB-231 breast cancer cells similar to those seeded in 100% collagen hydrogels.Conclusion This multi-protein C/KTN hydrogel shows promise for future studies involving thermal stress studies without compromising the 3D ECM environment or cell growth.