Molecular simulation study of the effects of inorganic anions on the properties of chrome-crosslinked collagen

A molecular dynamics (MD) simulation with a modified CHARMM force field was performed to study the effects of various anions (ClO₄⁻, Cl⁻, HPO₄²⁻, SO₄²⁻, CNS⁻ and HCOO⁻) on the structure, stability and crosslinking properties of chrome-crosslinked collagen. Calculated results clearly indicate that the crosslinking quality can be improved through selecting the right kind of anion. The utilization of polychromiums could be fine tuned by varying the type of anion. Perchlorate ions can further stabilize chrome-tanned collagen by hydrogen-bonding interactions. The considerable numbers of hydrogen bonds formed from the sulfate ions and the hydroxyl bridges of polychromium effectively stabilize the four chromium-olation structure during the crosslinking process. (paper)