Di-carboxylic acid cross-linking interactions improves thermal stability and mechanical strength of reconstituted type I collagen. Part I. Oxalic acid

Abstract

This study emphasizes, cross-linking potential of a simple di-carboxylic acid, namely, oxalic acid with type I collagen for the preparation of collagen based biomaterial for clinical applications. Further the study discusses the characteristics features of the cross-linked material in comparison with the standard cross-linker. In addition, the study also demonstrates the role of ionic interactions in providing the thermal stability and tensile strength to the cross-linked biopolymer material. Type I collagen from rat tail tendon treated with oxalic acid at optimized concentrations provided a biopolymer material without changing the triple helical pattern of collagen (CD spectrum) and also with 6-7 fold increase in tensile strength than native collagen. FTIR spectral details demonstrate the ionic interactions between collagen and oxalic acid. Thermal stability analyses of oxalic acid cross-linked biopolymer revealed, high thermal stability compared to materials of glutaraldehyde cross-linked. The results of the study suggest oxalic acid as a suitable cross-linker for collagen and it cross-link with collagen through ionic interactions.