Directional Copper Decoration of Spaced TiO2Nanotubes Enables Geometry-Controlled Ion Release and Antibacterial Response

Pach M, Böhringer D, Fomicheva I, Sarau G, Taccardi N, Kamaleev M, Christiansen SH, Goldmann W, Tesler A, Mazare AV (2026)

Publication Type: Journal article

Publication year: 2026

Journal

ACS Applied Materials and Interfaces American Chemical Society

Book Volume: 18

Pages Range: 6157-6165

Journal Issue: 3

DOI: 10.1021/acsami.5c20633

Abstract

Anodic titanium dioxide (TiO2) nanotubes (NTs) are well-established implant coatings owing to their nanoscale tunability, osteogenic support, and long-term biocompatibility. However, reproducible approaches that directly link NT geometry with controlled antibacterial functionality and tunable ion release remain limited. Here, we present a spatially selective, geometry-defined copper (Cu) decoration strategy for morphology-defined spaced NTs with an intertube spacing of 70–214 nm and a diameter of ∼145 nm. These NTs were fabricated via fluoride-containing diethylene glycol-based anodization. Directional sputtering was used to deposit Cu as either conformal wall coatings, the common physical vapor deposition configuration, or as discrete top caps, perpendicular to the sputtering target configuration, thus enabling precise control of the Cu metal localization on/in the spaced NTs. Morphology–composition correlations, confirmed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and focused ion beam scanning electron microscopy (FIB-SEM), revealed a clear depth confinement for the cap-decorated NTs versus an extended distribution in the case of the conformal coatings. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) showed that ∼1 atom % Cu, the antibacterial/cytocompatibility threshold in the literature, generated sustained ion release with early bacterial suppression. Higher loadings accelerated Cu2+ release but produced variable long-term inhibition, which can be correlated with the Cu configuration type. This geometry-directed sputtering approach provides a reproducible route for spatially controlled Cu placement, with a link between NT geometry, Cu localization, and antibacterial behavior, thus applicable for designing future multifunctional implant surfaces with controlled therapeutic release. It also provides a reproducible strategy for designing future multifunctional, release-tunable implant surfaces.

Authors with CRIS profile

David Böhringer Lehrstuhl für Biophysik Iana Fomicheva Lehrstuhl für Biophysik Nicola Taccardi Lehrstuhl für Chemische Reaktionstechnik (CRT) Maksim Kamaleev Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO) Wolfgang Goldmann Lehrstuhl für Biophysik Alexander Tesler Lehrstuhl für Biophysik Anca Valentina Mazare Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO)

Involved external institutions

Fraunhofer-Institut für Keramische Technologien und Systeme (IKTS) DE Germany (DE)

How to cite

APA:

Pach, M., Böhringer, D., Fomicheva, I., Sarau, G., Taccardi, N., Kamaleev, M.,... Mazare, A.V. (2026). Directional Copper Decoration of Spaced TiO2Nanotubes Enables Geometry-Controlled Ion Release and Antibacterial Response. ACS Applied Materials and Interfaces, 18(3), 6157-6165. https://doi.org/10.1021/acsami.5c20633

MLA:

Pach, Markus, et al. "Directional Copper Decoration of Spaced TiO2Nanotubes Enables Geometry-Controlled Ion Release and Antibacterial Response." ACS Applied Materials and Interfaces 18.3 (2026): 6157-6165.

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