Titania Nanotubes/Hydroxyapatite Nanocomposites Produced with the Use of the Atomic Layer Deposition Technique: Estimation of Bioactivity and Nanomechanical Properties

Abstract

Titanium dioxide nanotubes/hydroxyapatite nanocomposites were produced on a titanium alloy (Ti6Al4V/TNT/HA) and studied as a biocompatible coating for an implant surface modification. As a novel approach for this type of nanocomposite fabrication, the atomic layer deposition (ALD) method with an extremely low number of cycles was used to enrich titania nanotubes (TNT) with a very thin hydroxyapatite coating. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for determination of the structure and the surface morphology of the fabricated nanocoatings. The biointegration activity of the layers was estimated based on fibroblasts’ proliferation on the TNT/HA surface. The antibacterial activity was determined by analyzing the ability of the layers to inhibit bacterial colonization and biofilm formation. Mechanical properties of the Ti6Al4V/TNT/HA samples were estimated by measuring the hardness, Young’s module, and susceptibility to scratching. The results revealed that the nanoporous titanium alloy coatings enriched with a very thin hydroxyapatite layer may be a promising way to achieve the desired balance between biofunctional and biomechanical properties of modern implants.

In Vitro Studies on Nanoporous, Nanotubular and Nanosponge-Like Titania Coatings, with the Use of Adipose-Derived Stem Cells

“…However, optimal properties should be sought, and our research allows us to conclude about the high usefulness of TNT5 coatings. Furthermore, it confirms our extensive previous research, indicating this coating as the most biocompatible, not causing cytotoxic and genotoxic effects and bioactive microbiocidal [20][21][22][23][24][25][26][27][28][29][30]83]. The fact, that TNT5 possessed the most similar value of Young's modulus to bone, and that on this coating the number of osteoblasts seeded and co-cultured with ADSCs rose after 72 h culture almost twice when compared with unmodified scaffold and by 30% when compared with MG-63 cells growing alone, together with the ability to provoke a higher ALP activity, allows to state that this system has high application potential in modern implantology.…”

“…Due to the similar topography to natural bone, such modified surfaces promote direct contact with bone cells and the formation of apatite, which is the main component of bone tissue [8,18,19]. Homogeneous nanotubular, but also nanoporous and nanosponge-like coatings, on the surface of a titanium/titanium alloy implant can be easily and quickly produced by controlled electrochemical anodization procedure, which has been meticulously optimized and described in our earlier reports [20][21][22][23][24][25][26][27][28][29][30].…”

“…Our earlier studies, which were carried out using nanofibrous titania coatings [51], as one of the few, showed that ADSC functionalizing the initially unfavorable surface prepare it for more demanding cells, and make it suitable for the cell growth. Obtained results mobilized us to look again at nanoporous, nanotubular, and nanosponge-like titania systems, which were characterized in details in terms of the structure, morphology and biointegrity with fibroblasts and osteoblasts [20][21][22][23][24][25][26][27][28][29][30], but this time in terms of their predisposition towards adhesion, proliferation, and differentiation of mesenchymal stem cells of adipose origin. In our works, we have also tried to draw attention to the influence of surface coating architecture and its physicochemical properties on the effects mentioned above.…”

Photocatalytic Activity of Nanostructured Titania Films Obtained by Electrochemical, Chemical, and Thermal Oxidation of Ti6Al4V Alloy—Comparative Analysis

“…The wettability and surface free energy of the produced titania nanocoatings were determined using the earlier described method [74,75]. The contact angle of water and diiodomethane was measured using a goniometer with drop shape analysis software (DSA 10 Krüss GmbH, Hamburg, Germany).…”

Bismuth-Doped Nanohydroxyapatite Coatings on Titanium Implants for Improved Radiopacity and Antimicrobial Activity

“…Many studies indicate that Ti implants can be coated with calcium phosphate (e.g., hydroxyapatite) layers by various deposition methods such as electrodeposition, plasma spray, high-frequency magnetron sputtering, biomimetic precipitation, etc. [4][5][6][7][8]. In this way, the bioactivity, biocompatibility, and corrosion resistance of the Ti-based implants are improved.…”