Engineering functional partial joint replacement: a soft solution to a hard problem

工程功能性部分关节置换：硬问题的软解决方案

• 批准号: 2441039
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2441039
• 关键词: Engineering; functional; partial; joint; replacement

Arthritis is a common problem and typically treatment includes replacing the articular surfaces with hard metal on both sides of the joint with intervening plastic or ceramic. Although successful, with time these fail and further surgery is extensive with unpredictable outcomes. In a significant proportion of cases, the arthritis starts as a focal area on one side of the joint and in such cases, the replacement of one of the contacting articular cartilage surfaces is possible. This is less invasive and allows the patient to return to day to day activities quicker. Currently, these treatment options (known as hemiarthroplasty) include replacing the soft articular cartilage with a hard metallic surface, and are common in the treatment of joint problems secondary to trauma and/or arthritis. Hemiarthroplasty devices for hip, knee, ankle and shoulder currently exist but with somewhat unpredictable results. In vitro studies have shown that replacing the relatively compliant cartilage-covered native surface with a stiff, metallic, axisymmetrical hemiarthroplasty implant can reduce joint contact area by up to two thirds compared with the native joint and cause higher peak contact stress. The abnormal contact mechanics may promote degeneration and erosion of the native cartilage leading to persistent pain, stiffness, and loss of function. Without a doubt, the interactions occurring at the device-cartilage interface are key to successful implantation.At Leeds, we have recently developed a novel two step method for the surface initiated functionalisation of idealised metallic and polymer biomaterials. This exploits soft matter materials concepts to produce a materials system similar in structure and chemistry to a phospholipid bilayer. These gel-type layers have enabled us to produce a relatively thick (~ 3 micrometers) and soft lubricious surface layer (micro < 0.01), although with a single moduli and limited load bearing capacity (effective up to contact pressures of ~ 20 MPa). However with this methods, the properties of these layers can be varied easily through synthesis parameters and are easily translatable to lower moduli biomaterials (ie PEEK). This presents tremendous opportunities for future devices and application where contact of implant interfaces need to be compliant with cartilage or soft tissues. Objectives of this studentship include:1. Develop a robust multi-moduli soft - aqueous based interface capable of withstanding common joint reaction forces observed in the aforementioned applications when slid against articular cartilage. This will be completed on 2D surfaces (PEEK & CoCrMo) and characterised using a range of surface sensitive (FTIR, XPS, cryo-SEM), mechanical (AFM, Nano-indentation) and functional assessments (Tribology, Corrosion).2. Investigate the feasibility of adding therapeutic agents for the targeted treatment of infection or localised arthritis (gentamicin sulphate or glucosamine sulphate, respectively).3. Translate and demonstrate the functionality of the proposed technology on clinically relevant components. The durability of these devices will be determined using the suite of joint simulators.

关节炎是一种常见的问题，通常的治疗方法包括在关节两侧用硬金属替换关节面，并插入塑料或陶瓷。虽然成功了，但随着时间的推移，这些手术失败了，进一步的手术是广泛的，结果不可预测。在很大比例的情况下，关节炎开始于关节一侧的病灶区域，在这种情况下，可以更换其中一个接触的关节软骨表面。这是侵入性较小，并允许患者更快地恢复日常活动。目前，这些治疗选择（称为半关节成形术）包括用硬金属表面替换软关节软骨，并且在继发于创伤和/或关节炎的关节问题的治疗中很常见。目前存在用于髋关节、膝关节、踝关节和肩关节的半关节成形术装置，但其结果有些不可预测。体外研究表明，用刚性、金属、轴对称半关节置换术植入物替换相对柔顺的软骨覆盖的自体表面，与自体关节相比，可将关节接触面积减少多达三分之二，并导致更高的峰值接触应力。异常接触力学可能会促进天然软骨的退化和侵蚀，导致持续疼痛、僵硬和功能丧失。毫无疑问，发生在装置-软骨界面的相互作用是成功植入的关键。在利兹，我们最近开发了一种新的两步法，用于理想化金属和聚合物生物材料的表面引发功能化。这利用软物质材料概念来产生在结构和化学上类似于磷脂双层的材料系统。这些凝胶型层使我们能够生产相对厚（~3微米）和柔软的润滑表面层（微米<0.01），尽管具有单一模量和有限的承载能力（有效接触压力高达~20 MPa）。然而，通过这种方法，这些层的特性可以通过合成参数容易地改变，并且可以容易地转换为较低模量的生物材料（即PEEK）。这为植入物界面的接触需要与软骨或软组织顺应的未来装置和应用提供了巨大的机会。本研究的目的包括：1。开发一种坚固的多模量软质-水基界面，能够承受在上述应用中观察到的关节反作用力（当贴着关节软骨滑动时）。这将在2D表面（PEEK和CoCrMo）上完成，并使用一系列表面敏感（FTIR，XPS，cryo-SEM），机械（AFM，纳米压痕）和功能评估（摩擦学，腐蚀）进行表征。研究添加治疗剂用于感染或局部关节炎靶向治疗的可行性（分别为硫酸庆大霉素或硫酸氨基葡萄糖）。翻译并演示临床相关组件上拟议技术的功能。将使用关节模拟器套件确定这些器械的耐久性。