Zwitterionic Graft Coatings for Enhanced Orthopedics

描述（由申请人提供）：项目总结该I期SBIR项目旨在为具有增强耐久性的骨科表面开发新的两性离子移植物方法。随着美国人寿命的延长和生活的活跃，全关节置换术变得越来越普遍。目前骨科关节的平均寿命约为20年。此时，关节磨损导致颗粒形成，随后出现疼痛和炎症，最终需要翻修。与初次关节置换术相比，置换关节植入物的翻修手术更加困难、痛苦和昂贵。该工作扩展了仿生磷酰胆碱（PC）单体光化学接枝到高分子量聚乙烯（UHWMPE）的学术研究。接枝PC单体产生100-200 nm的聚合物涂层，其显著减少磨损，同时还减少体内促炎细胞因子释放和巨噬细胞募集。然而，接枝工艺时间对于大批量制造是不方便的。该提案的重点是使用我们专有的光交联剂TriLite（R）形成一个中间层，该中间层与聚乙烯表面结合，使表面交联，并引发接枝聚合。TriLite（R）层在接枝条件下不会从表面脱附，从而导致更均匀和更快的接枝。该提案的新奇在于使用新的光交联剂来加速接枝时间、增加交联和改善均匀性，以及使用几种不同的两性离子单体和共聚物涂覆方法。所得涂层将针对润滑性、均匀性、厚度和耐磨性进行优化。这项工作中开发的移植过程将为许多美国人培育更持久，更生物相容的植入材料。 公共卫生相关性：项目叙述在美国，每年约有60万美国人接受膝关节和髋关节植入，全球超过100万人。这些植入物的寿命约为20年，对于更活跃的接受者来说更短。本提案旨在延长骨科植入物的产品寿命。这个市场已经很大，2006年超过54亿美元，预计在未来20年内，关节置换总数将增加五倍以上。具有更好磨损特性的改进骨科材料不仅有助于美国经济，而且通过消除晚年痛苦的翻修手术来改善许多美国人的生活。

DESCRIPTION (provided by applicant): Project Summary This Phase I SBIR project is designed to develop new zwitterionic graft methodology for orthopedic surfaces with enhanced durability. As Americans live longer and more active lives, total joint replacement is becoming more common. Current orthopedic joints have average lifespans of approximately 20 years. By that point wear on the joint causes particulate formation, with subsequent pain and inflammation, requiring eventual revision. Revision surgeries to replace joint implants are more difficult, painful, and expensive than initial joint replacement. The work proposed extends academic research on photochemically grafting biomimetic phosphoryl choline (PC) monomers to ultrahigh molecular weight polyethylene (UHWMPE). Grafting PC monomers creates 100-200 nm polymer coatings which reduce wear significantly while also decreasing pro-inflammatory cytokine release and macrophage recruitment in vivo. However, grafting process times are unwieldy for high volume manufacturing. This proposal focuses on using our proprietary photocrosslinker TriLite(R) to form an intermediate layer which bonds to the polyethylene surface, crosslinks the surface, and initiates graft polymerization. The TriLite(R) layer will not desorb from the surface under the graft conditions, leading to a more uniform and faster graft. The novelty of the proposal is the use of a new photocrosslinker to speed graft time, increase crosslinking, and improve uniformity, as well as use of several different zwitterionic monomers and copolymer coating methodologies. The resulting coating will be optimized for lubricity, uniformity, thickness and wear durability. The graft processes developed in this work will foster longer lasting, more biocompatible implant materials for many Americans. PUBLIC HEALTH RELEVANCE: Project Narrative Approximately 600,000 Americans receive knee and hip implants annually in the US, over 1 million worldwide. These implants have a lifetime of approximately 20 years, less for more active recipients. This proposal is designed to increase the product lifetime of orthopedic implants. This market is already large, over $5.4 billion in 2006, and more than a fivefold increase in the number of total joint replacements is expected in the next 20 years. Improved orthopedic materials with better wear characteristics would not only contribute to the US economy, but also improve the lives of many Americans by eliminating the need for painful revision surgeries in their later years.