Faculty of Materials Engineering, Technion-IIT, Haifa, 32000, Israel.
J Mater Sci Mater Med. 2010 Feb;21(2):515-23. doi: 10.1007/s10856-009-3906-y. Epub 2009 Oct 23.
Biomimetic calcium phosphate (Ca-P) coatings improve the osteoconductivity of orthopedic implants and show promise as slow delivery systems for growth factors. This paper compares the structure and composition of biomimetic coatings on flat titanium coupons and on Ti wires/thin pins that are often used as model implants in small animal in vivo models. Ca-P coatings were grown on alkali-treated Ti substrates using a two-step deposition procedure. The coatings on wires consisted of a surface layer of octacalcium phosphate (OCP) and a layer of Ca-deficient hydroxyapatite (CDHA) underneath. The coating thickness and the proportion of CDHA decreased with increasing wire diameter. The coatings on flat coupons were the thinnest, and were comprised almost entirely of OCP. A mechanism of successive formation of the CDHA and OCP phases based on the interplay between nucleation, growth and hydrolysis of OCP crystals as a function of changing local supersaturation is proposed.
仿生磷酸钙（Ca-P）涂层可提高骨科植入物的骨传导性，并有望成为生长因子的缓慢释放系统。本文比较了平面钛片和 Ti 丝/细针上仿生涂层的结构和组成，Ti 丝/细针通常用作小动物体内模型中的植入物模型。通过两步沉积程序在碱处理后的 Ti 基底上生长 Ca-P 涂层。丝上的涂层由表面的八钙磷酸盐（OCP）层和下面的缺钙羟基磷灰石（CDHA）层组成。涂层厚度和 CDHA 的比例随丝直径的增加而减小。平面试片上的涂层最薄，几乎完全由 OCP 组成。提出了一种基于 OCP 晶体成核、生长和水解相互作用以及局部过饱和度变化的连续形成 CDHA 和 OCP 相的机制。
