Natural protein bioinspired materials for regeneration of hard tissues

The regenerative materials for hard tissues, i.e. tooth (enamel, dentin, and cementum) and bone, require extremely high standards in terms of their mechanical properties, biocompatibility, bioactivity, and multiple-functionality. Among them, the biomedical materials inspired from various natural proteins have attracted increasing research attention. These blueprint proteins include various hard-tissue-related proteins, such as collagen and non-collagenous proteins (e.g. amelogenin, dentin phosphoprotein, bone sialoprotein, and osteopontin), as well as other natural proteins like mussel foot proteins. The current review highlights the structure-function relationship of protein bioinspired biomedical materials (e.g. polymers and polypeptides) and their applications for tooth and bone regeneration. Specifically, the materials bioinspired from salivary acquired pellicle proteins, which have a strong affinity to hydroxyapatite surfaces, are discussed in detail. Finally, the challenges associated with these protein bioinspired materials and their industrialization potentials are discussed.