Bioactive Coatings on Titanium: A Review on Hydroxylation, Self-Assembled Monolayers (SAMs) and Surface Modification Strategies

Abstract

Titanium (Ti) and its alloys have been demonstrated over the last decades to play an important role as inert materials in the field of orthopedic and dental implants. Nevertheless, with the widespread use of Ti, implant-associated rejection issues have arisen. To overcome these problems, antibacterial properties, fast and adequate osseointegration and long-term stability are essential features. Indeed, surface modification is currently presented as a versatile strategy for developing Ti coatings with all these challenging requirements and achieve a successful performance of the implant. Numerous approaches have been investigated to obtain stable and well-organized Ti coatings that promote the tailoring of surface chemical functionalization regardless of the geometry and shape of the implant. However, among all the approaches available in the literature to functionalize the Ti surface, a promising strategy is the combination of surface pre-activation treatments typically followed by the development of intermediate anchoring layers (self-assembled monolayers, SAMs) that serve as the supporting linkage of a final active layer. Therefore, this paper aims to review the latest approaches in the biomedical area to obtain bioactive coatings onto Ti surfaces with a special focus on (i) the most employed methods for Ti surface hydroxylation, (ii) SAMs-mediated active coatings development, and (iii) the latest advances in active agent immobilization and polymeric coatings for controlled release on Ti surfaces.

Nanoarchitectonics of Electrically Activable Phosphonium Self-Assembled Monolayers to Efficiently Kill and Tackle Bacterial Infections on Demand

“…To this aim, self-assembled monolayers (SAMs) have proven to be an efficient approach to coherently www.videleaf.com improve metallic surfaces properties including those of Ti. [34] Indeed, through careful engineering, SAMs act as dense, compact, and versatile layers that allow the modification and fine tuning of the surfaces with advanced and specific properties even on complex geometries.…”

Sustained Drug Release from Biopolymer-Based Hydrogels and Hydrogel Coatings

“…This way, therapeutic effect of bioactive substances is extended, and the over-excessed concentration peaks of conventional methods are diminished. These features endow hydrogel coatings with privileged pharmacokinetic profiles, which can be modulated for personalized therapies [78]. Further, hydrogel coatings do not need to modulate specific linkages to release bioactive agents since their release mechanisms are mainly governed by simple diffusion, swelling, and degradation processes [79].…”

Bioactive Titanium Surfaces Enriched with Silver Nanoparticles Through an In Situ Reduction: Looking for a Balance Between Cytocompatibility and Antibacterial Activity

“…[13] A high density of ÀOH groups can be also beneficial for the cytocompatibility and cell response of the titanium surface. [25] In Figure 3, the spectra of the silver region are visible. The profile fitting of CT was not performed in this region because no Ag was detected on this sample, as expected.…”