Study shows the repair of enamel via a biomimetic growth frontier that is constructed from calcium phosphate ion clusters.

Osteoporosis is an incurable chronic disease characterized by a lack of mineral mass in the bones. Here, the full recovery of osteoporotic bone is achieved by using a calcium phosphate polymer‐induced liquid‐precursor (CaP‐PILP). This free‐flowing CaP‐PILP material displays excellent bone inductivity and is able to readily penetrate into collagen fibrils and form intrafibrillar hydroxyapatite crystals oriented along the c‐axis. This ability is attributed to the microstructure of the material, which consists of homogeneously distributed ultrasmall (≈1 nm) amorphous calcium phosphate clusters. In vitro study shows the strong affinity of CaP‐PILP to osteoporotic bone, which can be uniformly distributed throughout the bone tissue to significantly increase the bone density. In vivo experiments show that the repaired bones exhibit satisfactory mechanical performance comparable with normal ones, following a promising treatment of osteoporosis by using CaP‐PILP. The discovery provides insight into the structure and property of biological nanocluster materials and their potential for hard tissue repair.

Biomimetic mineralization can lead to advanced crystalline composites with common chemicals under ambient conditions. An exceptional example is biomimetic nacre with its superior fracture toughness. The synthesis of the prismatic layer with stiffness and wear resistance nonetheless remains an elusive goal. Herein, we apply a biomimetic mineralization method to grow prismatic-type CaCO₃ thin films, mimicking their biogenic counterparts found in mollusk shells with a three-step pathway: coating a polymer substrate, deposition of a granular transition layer, and mineralization of a prismatic overlayer. The synthetic prismatic overlayers exhibit structural similarity and comparable hardness and Young’s modulus to their biogenic counterparts. Furthermore, employment of a biomacromolecular soluble additive, silk fibroin, in fabrication of the prismatic thin films leads to micro-/nano-textures with enhanced toughness and emerging under-water superoleophobicity. This study highlights the crucial role of the granular transition layer in promoting competition growth of the prismatic layer.