Gulati Karan, Hamlet Stephen M, Ivanovski Sašo
School of Dentistry, The University of Queensland, 288 Herston Road, Herston, QLD 4006, Australia.
J Mater Chem B. 2018 May 14;6(18):2677-2689. doi: 10.1039/c8tb00450a. Epub 2018 Apr 19.
Owing to its biocompatibility and corrosion resistance, titanium is one of the most commonly used implantable biomaterials. Numerous in vitro and in vivo investigations have established that titanium surfaces with a nanoscale topography outperform conventional smooth or micro-rough surfaces in terms of achieving desirable bonding with bone (i.e. enhanced bioactivity). Among these nanoscale topographical modifications, ordered nanostructures fabricated via electrochemical anodization, especially titania nanotubes (TNTs), are particularly attractive. This is due to their ability to augment bioactivity, deliver drugs and the potential for easy/cost-effective translation into the current implant market. However, the potential of TNT-modified implants to modulate the host immune-inflammatory response, which is critical for achieving timely osseointegration, remains relatively unexplored. Such immunomodulatory effects may be achieved by modifying the physical and chemical properties of the TNTs. Furthermore, therapeutic/bioactive enhancements performed on these nano-engineered implants (such as antibacterial or osteogenic functions) are likely to illicit an immune response which needs to be appropriately controlled. The lack of sufficient in-depth studies with respect to immune cell responses to TNTs has created research gaps that must be addressed in order to facilitate the design of the next generation of immuno-modulatory titanium implants. This review article focuses on the chemical, topographical and mechanical features of TNT-modified implants that can be manipulated in order to achieve immuno-modulation, as well as providing an insight into how modulating the immune response can augment implant performance.
由于其生物相容性和耐腐蚀性，钛是最常用的可植入生物材料之一。大量的体外和体内研究已经证实，具有纳米级形貌的钛表面在与骨实现理想结合（即增强生物活性）方面优于传统的光滑或微粗糙表面。在这些纳米级形貌修饰中，通过电化学阳极氧化制备的有序纳米结构，特别是二氧化钛纳米管（TNTs），尤其具有吸引力。这是因为它们能够增强生物活性、递送药物，并且有可能轻松/经济高效地转化为当前的植入市场。然而，TNT修饰的植入物调节宿主免疫炎症反应的潜力，这对于及时实现骨整合至关重要，仍相对未被探索。这种免疫调节作用可以通过改变TNTs的物理和化学性质来实现。此外，在这些纳米工程植入物上进行的治疗/生物活性增强（如抗菌或成骨功能）可能会引发需要适当控制的免疫反应。关于免疫细胞对TNTs反应的深入研究不足，产生了必须解决的研究空白，以便促进下一代免疫调节钛植入物的设计。本文综述聚焦于TNT修饰植入物的化学、形貌和机械特性，这些特性可被操控以实现免疫调节，同时深入探讨调节免疫反应如何增强植入物性能。
