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

该项目的目的是在体内检测性能不佳的金属对金属（MoM）髋关节置换术中产生的磨损颗粒的大小、成分和数量，并研究这些颗粒如何与体外细胞系统相互作用。工作计划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，这可以包括红细胞、成骨细胞（骨制造细胞）、成软骨细胞（软骨制造细胞）和巨噬细胞（用于免疫防御的白色血细胞）。它将侧重于细胞活力，毒性和是否发生凋亡诱导（程序性细胞死亡）。细胞摄取研究将着眼于优先的细胞离子摄取位置（细胞溶质或细胞膜）和这种现象的驱动力。这将使用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）开发用于表征髋关节患者样本中磨损金属颗粒的大小、组成和数量的方法。这将涉及基于使用单颗粒（sp）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。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））对颗粒材料进行进一步表征，以确认spICP-MS结果。通过电子显微镜分析亚微米颗粒将涉及优化SEM系统和应用用于法医目的的软件，允许使用低能线自动分析颗粒。主办超区域分析服务微量元素实验室为该项目配备了专门的研究实验室，仪器和研究人员。该中心在测量人体样本中的微量元素和元素种类方面有相当丰富的经验，并有处理人体病理样本的设施。

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.