Particulate toxicology and characterisation relating to metal-on-metal hip replacements

该项目的目的是表征在性能较差的金属对金属（MoM）髋关节置换术中产生的体内磨损颗粒的大小、组成和数量，并研究这些颗粒如何在体外与细胞系统相互作用。工作方案将包括三个相互关联的部分：1)含铬、钴和钼的金属颗粒对不同细胞的影响。例如，这可能包括红细胞、成骨细胞（造骨细胞）、成软骨细胞（造软骨细胞）和巨噬细胞（用于免疫防御的白细胞）。它将集中在细胞活力，毒性和凋亡诱导（程序性细胞死亡）是否发生。细胞摄取研究将着眼于优先的细胞离子摄取位置（细胞质或细胞膜）和这种现象的驱动力。这将使用诸如电感耦合等离子体质谱（ICP-MS）和免疫荧光等技术进行检查，以定位和潜在地量化离子分布。2)发展表征髋关节患者样品中磨损金属颗粒大小、组成和数量的方法。这将涉及基于使用单颗粒ICP-MS的方法的开发，并将涉及使用酶消化和离心从样品基质中分离颗粒的方法的优化。3)粒子成像电子显微镜。进一步表征颗粒材料以确认spICP-MS结果将使用成像方法，如扫描电子显微镜（SEM）或透射电子显微镜（TEM）。通过电子显微镜分析亚微米颗粒将涉及SEM系统的优化和用于法医目的的软件的应用，该软件允许使用低能线自动分析颗粒。主办的超区域分析服务微量元素实验室有一个专门的研究实验室，仪器和研究人员的项目。它在人体样品中微量元素和元素种类的测量方面具有相当的经验，并具有处理人体病理样品的设施。

The aim of the project is to characterise the size, composition and number of wear particles in vivo that are produced in poorly performing metal-on-metal (MoM) hip replacements and to investigate how these particles interact with cellular systems in-vitro.The work programme will consist of three inter-related parts:1) The effect of metal particles containing chromium, cobalt and molybdenum on different cells. For example this could include red blood cells, osteoblasts (bone making cells), chondroblasts (cartilage making cells) and macrophages (white blood cells used for immune defence). It will focus on cellular viability, toxicity and whether apoptosis induction (programmed cell death) takes place. Cellular uptake studies will look at preferential cellular ionic uptake location (cytosol or cellular membrane) and the driving forces for such phenomena. This will be examined using techniques such as inductively coupled plasma mass spectrometry (ICP-MS) and immunofluorescence, to locate and potentially quantify the ionic distribution.2) The development of methods for the characterisation of the size, composition and number of wear-metal particles in hip-patient samples. This will involve the development of methods based on the use of single particle (sp) ICP-MS and will involve the optimisation of methods to isolate the particles from the sample matrix using enzymatic digestion and centrifugation.3) Particle imaging electron microscopy. Further characterisation of particulate material to confirm the spICP-MS results will use imaging methods such as scanning electron microscopy (SEM) or transmission electron microscopy (TEM). The analysis of sub-micron particles by electron microscopy will involve optimisation of the SEM system and the application of software used for forensic purposes, that allows for the automatic analysis of particles using low energy lines.The host Supra-Regional Assay Service Trace Element Laboratory has a dedicated research laboratory, instrumentation and research staff for the project. It has considerable experience in the measurement of trace elements and elemental species in human samples and has the facilities to handle human pathological samples.