Nanostructured and Nanoparticulate Metals: Redefining the Field of Medical Devices

Abstract

Metals have been a crucial part of medical devices since ancient times; for example, ancient civilizations such as the Phoenicians, Etruscans, Greeks, Romans, Chinese, and Aztecs used gold in dental applications as far back as 2700 BC [1]. Metals are vital for various medical device applications from orthopedic implants to vascular stents due to their attractive physical properties, such as mechanical strength, resilience, and flexibility. However, metals are generally regarded as bio-inert, which was suitable several decades ago, but today it is clear that for the field of medical devices to advance, we need bioactive metals which promote desirable cellular responses. To help achieve such bioactive properties without sacrificing mechanical properties (as is done by the selection of ceramics and polymers for certain medical device applications), the use of nanostructured and nanoparticulate metals has emerged. A multitude of research and discovery is currently being done in the field of metallic nanostructures and nanotechnology. Research in the nanotechnology field is growing at rapid speed do to the fact that nanomaterials show promise to improve a vast array of material properties [2]. A nano material can be described as a material having features less than 100 nm [2,3]. Due to greater surface area, the result of this nanoscale is the potential to achieve unique mechanical, optical, electrical, and magnetic properties as well as enhance biological interactions [2,3]. By combining nano-structured metals in medical devices, novel products are being developed that are stronger, lighter, and more biocompatible. This paper seeks to review some of the current uses of metal nanostructures in the medical field, including the treatment of metallic surfaces to create nanoscale surface features and the use of metal nanoparticles to aid drug delivery as well as medical device construction.