Biomedical Implants from Nanostructured Materials
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Over the past nine decades of administering bioimplants to humans, most of the synthetic prostheses consist of material particles and/or grain sizes with conventional dimensions (approximately 1 to 104 µm). Most of these early implants were made out of the following: vanadium steel (in the 1920s), stainless steel, cobalt alloys, titanium (in the 1930s), gold, and amalgams (a metal alloy containing mercury). However, the lack of sufficient bonding of synthetic implants to surrounding body tissues and the inability to obtain mechanical characteristics (such as flexural strength, bending strength, modulus of elasticity, toughness and, ductility) as well as electrical characteristics (such as resistivity and even piezoelectricity) that simulate their human tissue equivalents have, in recent years, led to the investigations of nanomaterials. Consequently, improving the biocompatibility of these implants remains the focus of many research groups around the world. Several nanobiomedical implants are being investigated, and are likely to gain approvals for clinical use. The critical factor for this drive is the increasingly documented, special, nonbiological improved material properties of nanophase materials when compared to conventional grain-size formulations of the same material chemistry.
This entry seeks to add another property of nanophase materials that makes them attractive for use as implants: bio- and cytocompatibility. Active works are focused in the domains of orthopedic, dental, bladder, neurological, vascular, and cardiovascular graft applications. The present level of advances was previously unimaginable with conventional materials possessing large micron-sized particulates. This entry will briefly articulate the seeming revolutionary changes and the potential gains of nanostructured implants in medical technology.