Bioinspired intrafibrillar mineralization of human dentine by PAMAM dendrimer

Great efforts have been made to develop potential substitutes or restorative materials for human hard tissues such as bone and teeth. A general strategy is to mimic the functions of noncollagenous proteins (NCPs), which can modulate the biomineralization process, leading to hierarchical intrafibrillar mineralization and is very important for the properties of biomineralized hard tissues. However, most of the reported biomimetic mineralization strategies could not mimic the full roles of NCPs and reproduce the elegant hierarchy of the biomineralized tissues. In this work, we use 'artificial protein', i.e., PAMAM-COOH dendrimer, to be the analog of NCPs, due to its mono-dispersed molecular weight within the size retention range of collagen and the well-defined steric structure. The bioinspired mineralization process induced by PAMAM-COOH on human dentine was characterized and illustrated both in vitro and in vivo. The design of PAMAM-COOH, especially the 4th generation one (G4-COOH), provides a general strategy to prepare various promising restorative materials for biomineralized hard tissues such as bone and teeth.