Reduced TiO₂ Nanotubes/Silk Fibroin/ZnO as a Promising Hybrid Antibacterial Coating

Abstract

The current research aims to elucidate the influence of reduction process of TiO2 nanostructures on the surface properties of a bioinspired Ti modified implant, considering that the interface between a biomaterial surface and the living tissue plays an important role for this interaction. The production of reduced TiO2 nanotubes (RNT) with lower band gap is optimized and their performance is compared with those of simple TiO2 nanotubes (NT). The more conductive surfaces provided by the presence of RNT on Ti, allow a facile deposition of silk fibroin (SF) film using the electrochemical deposition method. This hybrid film is then functionalized with ZnO nanoparticles, to improve the antibacterial effect of the coating. The modified Ti surface is evaluated in terms of surface chemistry, morphology and roughness, wettability, surface energy, surface charge and antibacterial properties. Surface analysis such as SEM, AFM, FTIR and contact angle measurements were performed to obtain topographical features and wettability.The antibacterial effect is studied for new created surfaces against Staphylococcus aureus and Escherichia coli. Changing the titanium surface morphology with RNT increases the bactericidal effect by 27%, then, after SF deposition, by 45% and for ZnO modified samples, the bactericidal rate increases up to 75%.

Y-Branched Titanium Dioxide Nanotubes as a Potential Antimicrobial Coating for Implants

“…The results are presented in Figure 10. By the titanium surface nanostructuring, an increase in the antibacterial effect of up to 15% is observed, this being also demonstrated in our previous study [4]. This can be influenced by the surface morphology and surface energy, which change when TiO2 nanotubes are deposited on the surface.…”

“…However, titanium lacks intrinsic antibacterial properties, leading to limited osseointegration. Therefore, surface modification becomes essential to stimulate osteogenesis and establish favorable interfacial microenvironments at the implant-bone tissue interface [2][3][4].…”

Highly Efficient and Reproducible Sonochemical Synthesis of ZnO Nanocrystals

“…Consequently, besides the conventional applications, novel ones resulted in optoelectronics, hybrid solar cells, sensors, biomedical field, foods, but it is also broadly used as an additive in several materials or products (plastics, ceramics, glass, cement, lubricants, paints, etc.). [9][10][11][12][13] Over the last few decades, several studies were performed with the aim to control the morphology during crystal growth, confirming its strict correlation with the material final properties. [14] At the same time, a great interest in exploring new synthesis methods to prepare nanomaterials is documented, for example by using hydro or solvo-thermal synthesis, [8] microwave [15] and/or ultrasonic assisted routes.…”