Alendronate and polyelectrolyte synergically induce biomimetic mineralization of collagen and demineralized dentin

Alendronate (ALN), a potent bisphosphonate, plays a significant role in both bone formation and osteoporosis therapy. However, its potential to promote biomimetic mineralization of type I collagen fibrils and demineralized dentin remains unclear. This study reveals that ALN-pretreated collagen fibrils form ester bonds between the hydroxyl groups of ALN and the carboxyl groups of collagen, accompanied by a reduction in collagen surface potential. Additionally, an adsorption equilibrium of ALN to collagen was achieved at 25 mM ALN. ALN pretreatment facilitates intrafibrillar mineralization of type I collagen fibrils in a dose-dependent manner, as well as mineralization of demineralized dentin in synergy with polyelectrolyte-stabilized Amorphous Calcium Phosphate (ACP) nanoparticles. This process effectively restores the mechanical properties of demineralized dentin to levels comparable to natural dentin. Thus, ALN holds potential for localized applications aimed at promoting remineralization of demineralized dentin.