Amyloid-like oligomeric nanospheres modify type I collagen to promote intrafibrillar mineralization

Abstract

Mineralized collagen fibrils are the basic building block of bone, dentin and cementum. Great efforts have been made to achieve biomimetic mineralization of collagen fibrils in vitro to treat hard tissue damage, but there is a key challenge to obtain remineralized collagen with mineral contents and mechanical properties comparable to those of natural hard tissues. Meanwhile, the low efficiency and time-consuming period of mineralization should not be neglected. Therefore, we propose a novel strategy of biomimetic collagen mineralization that uses biocompatible and versatile amyloid-like oligomeric nanospheres (ALONs) to modify and cross-link collagen fibrils to promote intrafibrillar collagen mineralization. ALONs can adhere to collagen fibrils, and the inherent abundant functional groups of ALONs attract calcium ions and phosphate ions to form the ALONs-CaP complex, which increases the pool of mineralization precursors available for intrafibrillar mineralization. Higher-quality mineralized collagen with better biomechanical properties is achieved in 3 h compared with mineralization of unmodified collagen. The ALONs-CaP complex may provide a new collagen mineralization strategy to promote intrafibrillar mineralization and serve as a reference for understanding the mechanism of intrafibrillar mineralization.