Improving Biocompatibility of Implantable Metals by Nanoscale Modification of Surfaces: An Overview of Strategies, Fabrication Methods, and Challenges

Abstract

The human body is an intricate biochemical-mechanical system, with an exceedingly precise hierarchical organization in which all components work together in harmony across a wide range of dimensions. Many fundamental biological processes take place at surfaces and interfaces (e.g., cell-matrix interactions), and these occur on the nanoscale. For this reason, current health-related research is actively following a biomimetic approach in learning how to create new biocompatible materials with nanostructured features. The ultimate aim is to reproduce and enhance the natural nanoscale elements present in the human body and to thereby develop new materials with improved biological activities. Progress in this area requires a multidisciplinary effort at the interface of biology, physics, and chemistry. In this Review, the major techniques that have been adopted to yield novel nanostructured versions of familiar biomaterials, focusing particularly on metals, are presented and the way in which nanometric surface cues can beneficially guide biological processes, exerting influence on cellular behavior, is illustrated.

The Role of Titanium Surface Nanostructuring on Preosteoblast Morphology, Adhesion, and Migration

“…[19] A variety of surface modification strategies can be employed to titaniumbased implants to enhance osseointegration. [20][21][22][23] Straightforward surface treatments of titanium and its alloys can be divided into three main groups: mechanical, chemical, and physical methods. [8,20] These methods are used either individually or in combination, and cause the formation of different nanotopographies.…”

The role of well-defined nanotopography of titanium implants on osseointegration: cellular and molecular events in vivo

“…Previous in vitro studies show that nanofeatures stimulate osteoblasts and their progenitors, including the osteogenic differentiation of MSCs. 10,[19][20][21]25,26,[44][45][46] However, many of these studies use osteogenic differentiation media in the culture, and so the effect of nanotopography would be considered as an adjunctive effect. It is therefore interesting that in absence of differentiation media, surface nanotopography did neither induce differentiation nor lineage-specific gene expression changes of MSCs.…”

Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

“…thermal or plasma spraying, sparking, or anodic oxidation [2,9]. For glassy Ti alloys, those studies are still rather scarce.…”