Multi-doped Calcium-Phosphate Coatings for Resorbable Magnesium Alloy Implant Applications

非永久性骨固定器械通常由钛和不锈钢制成，需要在骨愈合后进行第二次手术以取出器械。移除这些器械所需的二次手术会导致失血，给患者带来进一步的疼痛，并且对于需要额外手术团队时间的医疗保健系统来说成本高昂。使用机械性能远高于周围骨骼的金属也会在愈合部位引起问题，例如应力遮挡。镁的机械性能比钛和不锈钢更接近皮质骨，并且在体内具有天然生物可吸收性。然而，镁的快速腐蚀速度阻碍了其在可吸收骨固定装置中的应用，本工作旨在合成和研究具有生物活性的非晶和多晶磷酸钙和含多种取代离子的羟基磷灰石涂层，用于镁骨固定装置的应用。这些多离子掺杂涂层将允许植入部位的更快愈合时间，并将为镁植入物提供可定制的腐蚀速率，作为涂层厚度和结晶度的函数。将研究锶、锌和银离子的掺入如何影响涂层溶解以及随后的潜在镁腐蚀速率。涂层将沉积在FDA批准的镁合金材料上，并通过表面辐照技术进行快速退火，使涂层结晶为具有不同表面特性的离子取代羟基磷灰石。然后，将对涂层镁样品进行一系列体外和腐蚀研究，以确定特定离子释放与改善的细胞活性之间的关系。

Non-permanent bone fixation devices are often made of Titanium and stainless steel, requiring a second procedure to remove the device after the bone has healed. Secondary surgeries required to remove these devices cause blood loss, further pain to patients and are costly for healthcare systems requiring additional surgical team time. Using metals with mechanical properties much higher than surrounding bone can also cause issues at the healing site such as stress shielding. Magnesium has mechanical properties closer to those of cortical bone than Titanium and Stainless Steel and is naturally bioresorbable in the body. However, the use of Magnesium for resorbable bone fixation devices is hindered by its rapid corrosion rate.This work aims to synthesise and investigate bioactive amorphous and polycrystalline Calcium Phosphate and hydroxyapatite coating containing multiple substituted ions for Magnesium bone fixation device applications. These multi-ion doped coatings will allow for a faster healing time of the implant site and will provide the Magnesium implant with a tailorable corrosion rate as a function of coating thickness and crystallinity. Ions Strontium, Zinc and Silver will be investigated for how their incorporation affects coating dissolution and subsequently underlying Magnesium corrosion rate. Coatings will be deposited onto FDA approved Magnesium alloy materials and be flash annealed via a surface irradiation technique to crystallise coatings into ion-substituted hydroxyapatites with varying surface properties. Coated Magnesium samples will then be subjected to a suite of in vitro and corrosion studies to determine relationships between specific ion release and improved cell activity.