The Effect of Cross-Linking Agents and Collagen Concentrations on Properties of Collagen Scaffolds

Collagen-based scaffolds are appealing products for various applications in pharmaceutics and tissue engineering and military applications like wound healing. This study was conducted to extract acid soluble collagen protein from calf skin tissue and cross-linked it using cross-linking agents. The collagen scaffolds with different 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) / N-hydroxysuccinimide (NHS) molar ratios as cross-linking agents were investigated. The type I extracted collagen was used as a raw material for making collagen based scaffolds. Different EDC/NHS molar ratios as cross-linking agents were used. Matrix morphology and mechanical strength of the scaffolds were determined to evaluate the physicochemical properties of the collagen matrices with different cross-linker molar ratios. Furthermore collagen and cross-linked collagen were characterized using standard methods like SDS- page, FT-IR and SEM analysis. The results confirmed that the extracted collagen is pure and free of any non-collagen protein contamination. Furthermore, the results showed that average pore size of the scaffolds from EDC/NHS cross-linker with molar ratio of 1:1 (I) was less than the scaffolds that were made using EDC/NHS cross-linker with molar ratio of 2:1 (II). Moreover, collagen samples that were cross-linked using 1:1 EDC/NHS molar ratios showed increased mechanical strength comparing to 2:1 EDC/NHS molar ratio. The applied protocol is a convenient method for extraction of collagen and obtaining pure calf skin collage type I. Furthermore the best molar ratio of EDC/NHS cross-linking agents to cross-link collagen is 1:1 for obtaining stronger collagen structure.