Small indium (In) additions up to 5 wt % to the beta-type Ti-40Nb alloy effectively improve its mechanical biofunctionality. The impact on its biocompatibility is addressed in this work. Comparative electrochemical polarization studies and inductively coupled plasma optical emission spectrometry analyses were conducted in Tris-buffered saline (on the basis of 150 mM NaCl) with pH 7.6 and 2.0 at 310 ± 1 K with Ti-6Al-4V as reference. The metal ion releases from beta-type alloys were generally very low, for example, those of In ions from (Ti-40Nb)-4In specimens were below 6 × 10 mmol/cm . X-ray photoelectron spectroscopy revealed the passivation mainly by Ti- and Nb-oxides with traces of In-oxides as the dominating surface process. In vitro studies demonstrate a better human bone marrow stromal cells (hBMSC) activity on the beta-type alloys in comparison to CP-Ti (grade 2), which is mainly due to their high Nb content. At 24 h after seeding on (Ti-40Nb)-4In the metabolic activity of hBMSC was 1.5-fold higher and after 11 days, the tissue non-specific alkaline phosphatase activity was 1.8-fold higher relative to values for CP-Ti. Surface treatments, like chemical etching or plasma oxidation, change the surface topography and the thickness and composition of the oxide layers, but they are not effective in further improving the cell response. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1686-1697, 2018.

A strategy is presented to deposit defined layers of TiO 2 onto the pore surface within ordered mesoporous, crystalline CeO 2 -ZrO 2 thin films using atomic layer deposition (ALD). As structure-directing agent, a special diblock copolymer, poly(isobutylene)-block-poly-(ethylene oxide), was used, resulting in a three-dimensional arrangement of spherical pores with diameter around 13 nm. High resolution transmission electron microscopy investigations evidence the presence of anatase TiO 2 coatings within the mesopores, while ellipsometric porosimetry studies together with time-of-flight secondary-ion mass spectrometry depth profiles indicate the deposition inside the mesopores up to 50 ALD cycles. Afterward, the interconnecting channels between the mesopores are filled completely prohibiting further transport of the gaseous TiO 2 precursor into the ordered structure of mesopores and hence, limit the layer growth on the surfaces of the pores. Therefore, the size of the mesopores and their connections are decisive when growing transition-metal oxide layers on the surface of porous substrates and need to be considered for future depositions using ALD. The hybrid TiO 2 /CeO 2 -ZrO 2 materials are studied by several complementary analytical techniques, to validate the deposition process and also the applicability of these techniques for such materials in general.

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