Atomic scale modelling of the adhesion of hydroxy-apatite to bio-active glasses

作为骨替代物或用于骨修复的材料的生物活性源于生物材料表面形成的羟基磷灰石层生物玻璃是一种很容易与骨骼和软组织粘合的生物活性玻璃，医生和牙医用它来修复骨骼、关节和牙齿。这项研究的目的是利用最先进的计算机模拟技术来研究生物活性玻璃与主要的天然牙釉质成分羟基磷灰石之间相互作用的结构/化学关系的关键方面，重点研究决定界面性质的主要因素：第一，生物之间的外轴关系。活性玻璃表面和磷灰石材料，即(1)界面结构，(2)结合强度，(2)生物活性玻璃的组成，(4)磷灰石晶体的取向。其次，我们将研究磷灰石在生物活性玻璃表面的成核作用，即(1)成核点，(1)玻璃表面的动力学，(O)磷灰石与部分溶解玻璃的共生。因此，我们打算集中在以下问题上：生物活性玻璃与羟基磷灰石相互作用的模型的建立；玻璃表面改性的研究，例如阳离子组成，表面水化；模拟磷灰石微晶在玻璃表面的取向对结合强度的影响；在模拟体液中磷灰石在生物活性玻璃表面的成核。该项目的成果将是对羟基磷灰石与现实生物活性玻璃相互作用的更好和详细的理解，这具有很高的(1)生物活性玻璃与羟基磷灰石相互作用的模型的发展；(2)玻璃表面改性的研究，例如阳离子组成，表面水化；(3)模拟磷灰石微晶在玻璃表面的取向对粘接强度的影响；(4)模拟体液中磷灰石在生物活性玻璃表面的成核。该项目的成果将是对羟基磷灰石与真实生物活性玻璃相互作用的更深入和详细的了解，这对生物活性玻璃作为外科植入材料的生物医学应用具有很高的相关性。

The bioactivity of materials used as bone replacements, or for bone repair, stems from the formation of a hydroxy-apatite layer on the surface of the biomaterial Bioglass is one of a number of bioactive glasses that have been found readily to bond to bone and soft tissue, and is used by doctors and dentists to repair bones, joints and teeth. The aim of the research is to employ state-of-the-art computer simulation techniques to investigate key aspects of the structure/chemistry relationships of the interactions between bio-active glasses and the major natural rnammalian bone and teeth enamel constituent, hydroxyapatte, with a strong emphasis on the investigation df the major factors determining the nature of the interface: firstly the epiitaxial relationship between the bio. active glass surface and the apatite material, i.e. () structure of the interface, (in) strength of bonding, (ii) composition of the bio-active glass, and (iv) orientation of the apatite crystal. Secondly, we will investigate the nucleation of apatite at the bio-active glass surface, i.e. () nucleation sites, (i) the dynamics of the glass surface, and (o) the intergrowth of the apatite with the partially dissolving glass.Hence, we intend to concentrate on the following issues:Development of models for the interactions between bio-active glasses and hy droxy-apatite; Investigation of glass surface modifications, e.g. cation composition, surface hydration; Modelling the effect of orientation of the apatite crystallite to the glass surface on the strength of adhesion; Nucleation of the apatite at the bio-active glass surface in simulated body fluid.The outcome of the project will be an improved and detailed understanding of the interaction of hydroxy-apattifte with realistic bio-active glasses, which is highly(1) Development of models for the interactions between bio-active glasses and hydroxy-apatite;(2) Investigation of glass surface modifications, e.g. cation composition, surface hydration;(3) Modelling the effect of orientation of the apatite crystallite to the glass surface on the strength of adhesion;(4) Nucleation of the apatite at the bio-active glass surface in simulated body fluid.The outcome of the project will be an improved and detailed understanding of the interaction of hydroxy-apatite with realistic bio-active glasses, which is highly relevant to bio-medical applications of bio-active glasses as surgical implant materials.