Compressive stress improves mechanical properties of mineralized collagen by dynamically regulating its mineralization - a closed-loop regulation mechanism

Abstract

Mineralized collagen scaffold is one of the best choices for bone defects treatment, but weak mechanical strength is the main factor restricting its development. Recent studies demonstrated that despite being a fundamental form of mechanical stimulation in human activities, the impact of cyclic compressive stress on collagen mineralization remains unclear, with even less known about the dynamic mechanical mechanism. This study employed cyclic compressive stress to investigate its effect on collagen mineralization. The findings revealed that cyclic compressive strain promotes collagen mineralization by facilitating increased mineral penetration into the collagen and altering mineral morphology on the collagen surface. As the mineral volume fraction of mineralized collagen rises, its elastic modulus also increases. Additionally, the finite element simulation results proved that cyclic compressive stress can impact mineral distribution by affecting their transport and deposition, consequently influencing the stress distribution and regulating mechanical properties of mineralized collagen. Alterations in mechanical properties provide feedback on internal stress distribution, subsequently impacting mineral mineralization. This study achieves a closed-loop study on the mechanical regulated collagen mineralization, offers insight into the mechanism of collagen mineralization, paving the way for further exploration of biomineralization mechanisms and potentially inspiring novel approaches for the fabrication of mineralized collagen scaffolds.