Effects of branched polyethylene glycol derivative crosslinking on the structure and conformation stability of bovine tendon type I collagen

Abstract

Objective The triple helix of collagen is the basis of its biological function, such as cell adhesion and tissue remodeling. Crosslinking of collagen with chemical agent will improve the biomechanical properties. However, the effects of differernt crosslinking agents on the structure and conformation stability of type Ⅰ collagen are rarely investigated. Methods The branched polyethylene glycol ( PEG)derivative ( MW 12 kD) was used as crosslinking agent, and allowed to react with bovine achilles' s tendon type Ⅰ collagen modified by succinimidylacetylthioacetate (SATA). The ability of resistance of crosslinked collagen to enzymatic degradation was investigated by measuring the release of hydroxyproline, and differential scanning calorimeter ( DSC ) was taken to determine the thermal denaturation temperature. The effect of PEG on the riple helix of collagen was studied by circular dichroism ( CD) . Results The resistance ability of PEG crosslinked collagen was strongly enhanced when compared with that of control group ( P ＜0. 05 ) , and the thermal denaturation temperature was also significantly rised. CD demonstrated that PEG crosslinking did not result in the destruction of the triple helix conformation of type Ⅰ collagen. Conclusion Branched PEG derivative used in this study is a promising polymer crosslinking agent that may be utilized in the modification of type Ⅰ collagen. Key words: Type Ⅰ collagen; Polyethylene glycol; Thermal denaturation temperature