Abstract
Acid-soluble and pepsin-soluble collagens with triple helical structures were successfully extracted from the rabbit epidermal skin by two different extraction approaches. The kinetics of collagen self-assembly process modulated by concentration, pH value and temperature during fibril formation to form collagen hydrogels were investigated. The present study determined the relationship among fibril formation, microstructure and rheological properties of collagen hydrogels. Moreover, collagen hydrogels, where the mechanical properties are tuned by different extraction methods and conditions of fibril formation were used for biological evaluation. Using these collagen hydrogels, our results demonstrate the ability to de-couple matrix stiffness from matrix density and structure in collagen gels, and that increased matrix stiffness results in decreased sprouting and outgrowth of blood-derived endothelial colony-forming cells in vitro.