Orthopedic Implants: Hypersonic Plasma Particle Deposition nano-porosity coatings

描述（由申请人提供）：拟议的研究旨在评估应用高超音速等离子体颗粒沉积（HPPD）技术在骨科植入物中使用的区域涂层Ti6Al4V中的可行性，使HPPD涂层Ti6Al4V的表面修饰区域能够成为关节表面，而未涂层区域仍然是骨骼和组织生长的理想区域。这是一种新颖的应用，因为HPPD涂层以前没有在Ti6Al4V上使用过，也没有在骨科领域使用过。我们假设在Ti6Al4V上应用HPPD涂层工艺将增加Ti6Al4V植入物的预期寿命，同时由于其优越的纳米级薄膜特性而降低磨损颗粒的风险。长期目标是通过消除或减少与磨损相关的替代手术来提高骨科植入涂层的科学进步。作为评估假设的第一个基本步骤，我们计划在第一阶段进行以下研究：具体目标1：修改HPPD工艺的热特性，使TiN， SiC和Si薄膜纳米涂层在Ti6Al4V上形成适当的分子键合，Ti6Al4V是HPPD工艺迄今尚未适用的衬底材料。具体目标2：评估HPPD涂层Ti6Al4V的耐磨性以及其他摩擦学特性（硬度、模量、断裂韧性、表面光滑度、成分、厚度、结合强度），并将其与文献和Co-Cr-Mo合金进行比较。目的3：评估HPPD包被Ti6Al4V的体外生物相容性/细胞活力，并与Co-Cr-Mo合金进行比较。作为上述评估的延续，我们计划在第二阶段研究更多方面，包括：摩擦系数；耐蚀性;抗疲劳强度;动物模型体内生物相容性；以及磨损颗粒分析。虽然所有这些概述的方面都需要进行彻底的评估，但第一阶段研究的耐磨性和体外生物相容性是第二阶段后续评估的先决条件。

DESCRIPTION (provided by applicant): The proposed study aims to evaluate the feasibility of applying Hypersonic Plasma Particle Deposition (HPPD) technique in regional coating Ti6Al4V used in orthopedic implants such that the surface modified region of HPPD coated Ti6Al4V is capable of being the articulating surface while the uncoated region remains ideal for bone and tissue in-growth. This is a novel application since HPPD coating has not previously been used on Ti6Al4V, nor in the orthopedic field. We hypothesize that the application of the HPPD coating process on Ti6Al4V will increase the life expectancy of Ti6Al4V implants while reducing risk of wear particles due to its superior nano-scale film characteristics. The long-term objective is to bring scientific advances in orthopedic implant coatings that will improve health by eliminating or decreasing wear-related replacement surgeries. As the first fundamental step of evaluating the hypothesis, we plan to conduct the following study in Phase I: Specific Aim 1: To modify the HPPD process thermal characteristics to make proper molecular bonding for application of TiN, SiC, and Si thin film nanocoating on Ti6Al4V, a substrate material that the HPPD process has not heretofore been adapted for. Specific Aim 2: To evaluate wear resistance, along with other tribology characteristics (hardness, modulus, fracture toughness, surface smoothness, composition, thickness, bond strength) of the HPPD coated Ti6Al4V, and compare it to literature and Co-Cr-Mo alloy. Specific Aim 3: To assess the in-vitro biocompatibility/cell viability of the HPPD coated Ti6Al4V and compare it with that of Co-Cr-Mo alloy. As a succession of the above evaluation, we plan to examine more aspects in Phase II, including: coefficient of friction; corrosion resistance; fatigue resistance; in vivo biocompatibility on animal model; and wear particle analysis. While all these outlined aspects are necessary to be thoroughly assessed, the wear resistance, and in vitro biocompatibility in Phase I of the study are the prerequisite for the subsequent assessments in Phase ll. PUBLIC HEALTH RELEVANCE: Superior wear resistance and excellent bone in-growth are both essential requirements for orthopedic cement-less implants, yet with the current techniques it is difficult to achieve both in hip resurfacing and small joints such as temporomandibular joint and carpometacarpal joint because of the limited anatomical or prosthetic space. The superior nano-scale film characteristics of our proposed Hypersonic Plasma Particle Deposition (HPPD) coated Ti6Al4V implants are ideal to achieve both goals in the above applications. The overall goal of this project is to examine the wear, hardness, modulus, fracture toughness, surface smoothness, composition, thickness, bond strength, and biocompatibility on Ti6Al4V, as a means to improve health through improved implant quality and longevity.