Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Department of Physics, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Nat Commun. 2018 Oct 9;9(1):4170. doi: 10.1038/s41467-018-06570-x.
Mineralisation of calcium phosphates in bone has been proposed to proceed via an initial amorphous precursor phase which transforms into nanocrystalline, carbonated hydroxyapatite. While calcium phosphates have been under intense investigation, the exact steps during the crystallisation of spherical amorphous particles to platelet-like bone apatite are unclear. Herein, we demonstrate a detailed transformation mechanism of amorphous calcium phosphate spherical particles to apatite platelet-like crystals, within the confined nanodomains of a bone-inspired nanocomposite. The transformation is initiated under the presence of humidity, where nanocrystalline areas are formed and crystallisation advances via migration of nanometre sized clusters by forming steps at the growth front. We propose that such transformation is a possible crystallisation mechanism and is characteristic of calcium phosphates from a thermodynamic perspective and might be unrelated to the environment. Our observations provide insight into a crucial but unclear stage in bone mineralisation, the origins of the nanostructured, platelet-like bone apatite crystals.
骨中磷酸钙的矿化被认为是通过最初的无定形前体相进行的，该前体相转化为纳米晶碳酸羟基磷灰石。虽然磷酸钙受到了广泛的研究，但球形无定形颗粒向板状骨磷灰石结晶的确切步骤尚不清楚。在此，我们在骨启发型纳米复合材料的受限纳米域内证明了无定形磷酸钙球形颗粒向磷灰石板状晶体的详细转化机制。在湿度的存在下，转化就会开始，在那里形成纳米晶区，并且通过在生长前沿形成台阶，通过纳米级簇的迁移来推进结晶。我们提出，这种转化是一种可能的结晶机制，从热力学的角度来看，这是磷酸钙的特征，并且可能与环境无关。我们的观察结果为骨矿化中一个关键但不明确的阶段提供了深入的了解，即纳米结构、板状骨磷灰石晶体的起源。
