Multiscale topographical modulation of cells and bacteria for next generation orthopaedic implants.

英国人口老龄化，我们需要提前计划应对这一问题。我们中的许多人会因为关节炎等疾病而失去部分骨骼的使用寿命。目前，例如，髋关节置换术的存活率在10-15年之间，但许多患者需要翻修手术。这对NHS和纳税人来说是昂贵的，对外科医生来说是耗时的（它比初级手术要复杂得多），而且是在老年人和体弱多病的病人身上进行的，比如使用全身麻醉是一个问题。对于目前的骨科植入物，外科医生有两个主要的担忧。首先，所用的材料是惰性的。这意味着身体对这些物质的反应很低。这是一个优点，因为没有免疫反应（炎症），缺点是没有骨骼反应。如果可以产生选择性生物活性（即没有免疫反应，但增加了骨骼反应），则可以通过生长骨骼和植入物来锁定植入物。这种骨反应的缺乏意味着植入物不能很好地固定，并且在行走时可以移动。这被称为微动。随着时间的推移，随着微动程度的增加，这将导致失败。其次，他们担心感染控制。即使在消毒后，细菌也可能以低数量存在于植入材料上或在手术期间引入。如果感染持续下去，就会对种植体的寿命产生重大影响，这可能会导致年轻患者进行翻修手术，失败率会高得多。我们已经开发出非常小的纳米级模式，可以用来调节骨骼生长和防止细菌粘附。因此，我们将优化这些模式，以在种植体的适当点实现细菌控制和骨形成。一个主要的优势是我们可以用钛来加工这些图案，钛是一种通常用于骨科植入物的材料，因为它的强度很高（即它可以承受我们走路时人体的重量）。这种方法是朝着制造终身植入物和提前为人口老龄化做计划迈出的一步。

The UK has an aging population and we need to plan ahead to deal with this. Many of us will outlive the useful lives of parts of our skeleton through e.g. arthritis. Currently, e.g. hip replacements have a good survival rate between 10-15 years but then many patients require revision surgery. This is costly to the NHS and hence taxpayer, time consuming to the surgeon (it is far more complex than primary surgery) and is performed on elderly and frail patients where e.g. use of general anesthetic is a concern. The surgeons have two major concerns regards current orthopaedic implants. Firstly, the materials used are inert. This means that the body has a low response to the materials. This is an advantage as there is no immune response (inflammation) and a disadvantage as there is no bone response. If selective bioactivity could be produced (i.e. no immune response but increased bone response) then the implant could be locked in place by growing bone and implants for life developed. This lack of bone response means that the implants are not well held and can move about during walking. This is termed micromotion. This leads to failure with time as the extent of micromotion increases. Secondly, they worry about infection control. Even after sterilisation bacteria may be present on the implant materials in low numbers or can be introduced during surgery. If the infection can take hold it has major impact on the implant lifetime and this can result in younger patients having revision surgery and that has much higher failure rates.We have developed very small, nanoscale patterns that can be used to tune bone growth and prevent bacterial adhesion. We will thus optimise these patterns to achieve bacterial control and bone formation at appropriate points of the implant. A major advantage is that we can process these patterns in titanium, a material commonly used for orthopaedic implants due to its high strength (i.e. it can withstand the weight of the human body as we walk).Such an approach is a step towards making implants for life and planning ahead for the aging population.