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。我们中的许多人将通过例如关节炎而超过我们骨骼部分的有用寿命。目前，例如，髋关节置换术在10-15年之间具有良好的存活率，但随后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（它比初次手术复杂得多），并且对老年和虚弱的患者进行，例如使用全身麻醉是一个问题。外科医生对当前骨科植入物有两个主要担忧。首先，所使用的材料是惰性的。这意味着身体对材料的反应很低。这是一个优点，因为没有免疫反应（炎症），也是一个缺点，因为没有骨反应。如果可以产生选择性生物活性（即没有免疫反应，但增加了骨反应），则可以通过生长骨和植入物来将植入物锁定在适当位置。这种骨反应的缺乏意味着植入物不能很好地固定，并且可以在行走过程中移动。这被称为微动。随着微动程度的增加，这导致随时间的失效。其次，他们担心感染控制。即使在灭菌后，植入材料上也可能存在少量细菌，或者可能在手术过程中引入。如果感染持续存在，它会对植入物的使用寿命产生重大影响，这可能导致年轻患者接受翻修手术，失败率更高。我们开发了非常小的纳米级图案，可用于调节骨生长并防止细菌粘附。因此，我们将优化这些模式，以实现细菌控制和种植体适当部位的骨形成。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为老龄化人口提前规划迈出的一步。

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.