<p>Atomic Layer Deposition Coating of TiO₂ Nano-Thin Films on Magnesium-Zinc Alloys to Enhance Cytocompatibility for Bioresorbable Vascular Stents</p>

Abstract

Background and purposeA coronary stent is a well-known cardiovascular medical device implanted to resolve disorders of the circulatory system due to bloodstream narrowing. Since the implanted device interacts with surrounding biological environments, the surface properties of a typical implantable stent play a critical role in its success or failure. Endothelial cell adhesion and proliferation are fundamental criteria needed for the success of a medical device. Metallic coronary stents are commonly used as biomaterial platforms in cardiovascular implants. As a new generation of coronary stents, bioresorbable vascular scaffolds have attracted a great deal of attention among researchers and studies on bioresorbable materials (such as magnesium and zinc) remain a target for further optimization. However, additional surface modification is needed to control the biodegradation of the implant material while promoting biological reactions without the use of drug elution.MethodsHerein, precise temperature and thickness controlled atomic layer deposition (ALD) was utilized to provide a unique and conformal nanoscale TiO2 coating on a customized magnesium-zinc stent alloy.ResultsImpressively, results indicated that this TiO2 nano-thin film coating stimulated coronary arterial endothelial cell adhesion and proliferation with additional features acting as a protective barrier. Data revealed that both surface morphology and surface hydrophilicity contributed to the success of the ALD nanoscale coating, which further acted as a protection layer inhibiting the release of harmful degradation products from the magnesium-zinc stent.ConclusionOverall, the outcome of this in vitro study provided a promising ALD stent coating with unique nano-structural surface properties for increased endothelialization, and as a result, ALD should be further studied for numerous biomedical applications.

Titanium Dioxide Nanoparticles: Prospects and Applications in Medicine

“…Coating the surface of titanium endoprostheses with a bioactive titanium dioxide layer was also studied in terms of the efficiency of fibrointegration [94]. Atomic layer deposition coating of TiO 2 nano-thin films on magnesium-zinc alloys was found to enhance cytocompatibility for bioresorbable vascular stents [105].…”

Structure and Corrosion Behavior of TiO2 Thin Films Deposited by ALD on a Biomedical Magnesium Alloy

“…Anatase TiO2 has a tetragonal crystal structure with a space group of I41/amd (space group no. 141) with the following lattice parameters: a ALD can be used to grow anatase TiO 2 at lower temperatures than other techniques [23], and this crystal structure may appear when TiO 2 film growth temperatures exceed 165 • C [24]. Aarik et al studied TiO 2 /ALD films using TiCl 4 as the precursor and water as the oxygen source [25].…”

Titanium Dioxide Nanoparticles &ndash; Prospects and Applications in Medicine

“…Coating the surface of titanium endoprostheses with a bioactive titanium dioxide layer was also studied in terms of the efficiency of fibrointegration [98]. Atomic layer deposition coating of TiO2 nano-thin films on magnesium-zinc alloys was found to enhance cytocompatibility for bioresorbable vascular stents [109].…”