The influences of 3,4-dihydroxybenzaldehyde on the microstructure and stability of collagen fibrils

Abstract

3,4-dihydroxybenzaldehyde (DB), a derivative of catechol, were applied to improve the physicochemical properties of collagen fibrils, prepared via the self-assembly of collagen molecules. The aldehyde group of DB interacted with ε-amino group of collagen, and then the catechol group of DB was oxidized and self-polymerized, resulting in the formation of cross-links among collagen. The results of spectral experiment showed that the triple helix structure of collagen were integrated and the Tyr residues of collagen might react after cross-linking. Collagen fibrils became dark brown and the yellowness (Δb*) ascended from 0 to 3.24 when the [CHO]/[NH2] ratio rose from 0:1 to 40:1. Due to the effects of DB, the adjacent collagen fibrils agglomerated without particular orientation and the pore size of collagen fibril network decreased. The thermal stability of collagen fibrils had been improved about 15 °C while the elastic modulus obviously increased from 19 to 834 Pa after cross-linking. Moreover, the presence of DB also caused the dramatically enhancement in the enzymatic resistance of collagen fibrils while the biocompatibility of collagen fibrils was still desirable. These promising data suggested biomedical materials based on collagen fibrils with requisite properties can be obtained via adjusting the dose of DB.