Reducing the failure rate of artificial replacement hips and knees by understanding the mechanism of adverse biological reactions that currently cause

研究的主要目的：本研究的目的是了解为什么人工髋关节和膝关节有时会在患者中过早失效。这将通过结合实验室、临床和工程学科来找出导致髋关节和膝关节植入物疼痛和失败的不良反应的原因。当人造髋关节和膝盖在病人体内工作时，它们会释放出磨损碎片颗粒。众所周知，这些颗粒会导致种植体失败，但确切的原因尚不清楚，我们的研究问题是：为什么颗粒磨损碎片会导致种植体失败，我们能否预测现有患者的这种情况，以确保他们的安全？总体方法是使用一种新颖的体外方法来模拟炎症和溶骨反应，更接近现实的体内条件。这是双重的：(1)创建无菌磨损颗粒用于研究几种类型的聚合物，包括下一代种植体聚合物；(2)开发一个真正具有代表性的体外细胞模型来研究患者-种植体区域，以比较不同类型的碎片并研究生物反应。接下来是(3)开发一种简单的床边方法来评估未来患者种植体失败的风险。我们打算回答的研究问题是；(a)临床相关的磨损碎片能否在体外诱导人巨噬细胞模型的促炎表型改变？(b)临床相关的磨损碎片是否能够在体外人成骨细胞模型中引发溶骨反应？(c)是否可以从患者样品中分离出磨损碎片并使用NanoSight颗粒跟踪分析进行表征？(d)修订时采集的人体组织样本是否显示炎症标志物增加？新颖的科学和工程方法：临床相关的磨损碎片将使用安装在II级微生物层流柜中的四站多向板钉机产生。将使用NanoSight颗粒跟踪分析和扫描电子显微镜（SEM）来确定碎片的大小和形态。将进行内毒素和支原体检测，以确保产生的磨损碎片未被污染，并适用于随后的体外实验。两种人类细胞系将用于研究产生的磨损碎片的体外生物学效应，包括炎症和骨溶解。免疫调节和溶骨过程的功能分析将与人类细胞系结合使用，以表征正在进行的生物过程的机制。人体组织样本将在翻修手术时获得，并用于免疫组织化学，以便染色特定的炎症标志物以及结构分析。在翻修手术中收集的患者滑液样本分析将用于碎片分离和蛋白质分泌分析。

Key aims of the research: The aim of this research is to understand why artificial hips and knees sometimes fail prematurely in patients. This will be done by combining laboratory, clinical and engineering disciplines to find out what causes the adverse reactions that results in pain and failure of hip and knee implants. When artificial hips and knees operate in the patient's body, they release particles of wear debris. It is understood that these particles contribute to the implant failing, but exactly why that is unknown and our research question is: Why does particulate wear debris cause implants to fail and can we predict this for existing patients in order to make them safe?The overall approach is to use a novel in vitro methodology to simulate inflammatory and osteolytic responses that more closely matches reality in vivo conditions. This is twofold: (1) create aseptic wear particles for study of several types of polymer including the next generation of implant polymers, and (2) develop a truly representative in vitro cell model to study the patient-implant domain to compare different types of debris and investigate the biological responses. These will be followed by (3) developing a simple bedside method to assess the patient risk of implant failure in the future.The research questions we intend to answer are; (a) Can clinically relevant wear debris induce proinflammatory phenotypic changes in a human macrophage model in vitro? (b) Are clinically relevant wear debris capable of eliciting osteolytic responses in an in vitro human osteoblast cell model? (c) Can wear debris be isolated from patient samples and characterised using NanoSight Particle Tracking analysis? (d) Do human tissue samples taken at the point of revision show an increase in inflammatory markers?Novel science and engineering methodology: Clinically relevant wear debris will be generated using a four-station multi-directional pin-on-plate machine housed in a class II microbiology laminar flow cabinet. Debris will be characterised using NanoSight Particle Tracking analysis and scanning electron microscopy (SEM) to determine size and morphology. Endotoxin and mycoplasma testing will be carried out in order to ensure that the wear debris generated is not contaminated and will be suitable for subsequent in vitro experiments. Two human cell lines will be used to investigate the in vitro biological effects of the generated wear debris including inflammation and osteolysis. Functional analyses of immunomodulatory and osteolytic processes will be used in conjunction with the human cell lines in order to characterise the mechanism of ongoing biological processes. Human tissue samples will be acquired at the point of revision surgery and used for immunohistochemistry in order to stain for specific inflammatory markers as well as structural analysis. Patient sample analysis of synovial fluid collected during revision surgery will be used for debris isolation and protein secretion analysis.