ELECTROPHORETIC NANO-HYDROXYAPATITE COATING FOR ADHESION

粘附性差是关系到可植入羟基磷灰石涂层长期生存能力的最严重的问题。提出了一种新颖的室温电泳法来制备纳米羟基磷灰石(n“-HAP)涂层，消除了与非晶相形成和分层有关的问题。到目前为止，使用电泳法只沉积了微米级的羟基磷灰石材料。N-HAP涂层将表现出更高的韧性、结合强度和高度的结晶度。这种结合的性质是冶金性质的，与热喷涂涂层中获得的机械结合相比，大大提高了结合强度。电泳法还可以实现多组分的共沉积。该程序包括(1)合成n-HAP粒子，(2)沉积n-HAP涂层，以及(3)涂层评价。虽然n-HAP有望使粘结强度增加几倍，但将与n-HAP一起沉积一种磷酸钙骨水泥(CPC)添加剂，以进一步提高粘结强度。在沉积过程中，n-HAP和钛衬底之间会引入一层致密的梯度二氧化钛粘结层(几微米厚)，这样体液就没有机会攻击和降解钛。Infrmat正在与劳伦斯伯克利国家实验室的Antoni Tomsia博士合作评估纳米结构涂层。拟议的商业应用：潜在的商业应用包括用于人类和动物的髋关节、膝盖和其他假体的先进涂层植入物。仅在美国，每年使用HAP涂层植入物进行的髋关节和膝关节手术的数量估计已经产生了30亿美元的年收入。随着更多人口年龄的增长，估计在不久的将来对植入物的需求将大幅上升。一个可比的欧洲市场使潜在收入翻了一番。

Poor adhesion is the single most severe problem related to the long term viability of implantable hydroxyapatite coatings. An innovative room temperature electrophoretic process is proposed to fabricate nanostructured hydroxyapatite ("n"-HAP) coatings, eliminating problems related to amorphous phase formation and delamination. To date, only micron-sized hydroxyapatite materials have been deposited using electrophoresis. The n-HAP coating will exhibit increased toughness, bond strength, and a high degree of crystallinity. The nature of the bond is metallurgical, resulting in dramatically improved bond strength when compared to mechanical bonds obtained in thermal spray coatings. Electrophoresis also enables multicomponent codeposition. This program consists of (1) synthesizing n-HAP particles, (2) depositing the n-HAP coating, and (3) coating evaluation. while the n-HAP is expected to yield a several4old increase in bond strength, a calcium phosphate cement (CPC) additive will be cc-deposited with the n-HAP to further increase bond strength. A dense graded TiO2 bond coat will be introduced (a few microns thick) between the n-HAP and the titanium substrate in the deposition process, so that body fluids will have no opportunity to attack and degrade the titanium. Inframat is collaborating with Dr. Antoni Tomsia of the Lawrence Berkeley National Lab to evaluate the nanostructured coatings. PROPOSED COMMERCIAL APPLICATIONS: Potential commercial applications include advanced coated implants for hips, knees, and other prostheses in humans and animals. In the US alone,the annual number of hip and knee operations using HAP coated implants is estimated to already produce an annual revenue of $3 billion. With the increasing age of the larger population, the estimated demand for implants will rise significantly in the near future. A comparable European market doubles the potential revenue.