Antibacterial and Osteogenic Activity of Titania Nanotubes Modified with Electrospray-Deposited Tetracycline Nanoparticles

TiO2 nanotubes as an antibacterial nanotextured surface for dental implants: Systematic review and meta-analysis

OBJECTIVES

Nanotechnology is constantly advancing in dental science, progressing several features aimed at improving dental implants. An alternative for surface treatment of dental implants is electrochemical anodization, which may generate a nanotubular surface (TiO2 nanotubes) with antibacterial potential and osteoinductive features. This systematic review and meta-analysis aims to elucidate the possible antibacterial properties of the surface in question compared to the untreated titanium surface.

SOURCES

For that purpose, was performed a systematic search on the bases PubMed, Lilacs, Embase, Web Of Science, Cinahl, and Cochrane Central, as well as, manual searches and gray literature.

STUDY SELECTION

The searches resulted in 742 articles, of which 156 followed for full-text reading. Then, 37 were included in the systematic review and 8 were included in meta-analysis.

RESULTS

Fifteen studies revealed significant antibacterial protection using TiO2 nanotube surfaces, while 15 studies found no statistical difference between control and nanotextured surfaces. Meta-analysis of in vitro studies demonstrated relevant bacterial reduction only for studies investigating Staphylococcus aureus in a period of 6 h. Meta-analysis of in vivo studies revealed three times lower bacterial adhesion and proliferation on TiO2 nanotube surfaces.

CONCLUSIONS

TiO2 nanotube topography as a surface for dental implants in preclinical research has demonstrated a positive relationship with antibacterial properties, nevertheless, factors such as anodization protocols, bacteria strains, and mono-culture methods should be taken into consideration, consequently, further studies are necessary to promote clinical translatability.

Antibacterial properties of laser-encapsulated titanium oxide nanotubes decorated with nanosilver and covered with chitosan/Eudragit polymers

To provide antibacterial properties, the titanium samples were subjected to electrochemical oxidation in the fluoride-containing diethylene glycol-based electrolyte to create a titanium oxide nanotubular surface. Afterward, the surface was covered by sputtering with silver 5 nm film, and the tops of the nanotubes were capped using laser treatment, resulting in an appearance of silver nanoparticles (AgNPs) of around 30 nm in diameter on such a modified surface. To ensure a controlled release of the bactericidal substance, the samples were additionally coated with a pH-sensitive chitosan/Eudragit 100 coating, also exhibiting bactericidal properties. The modified titanium samples were characterized using SEM, EDS, AFM, Raman, and XPS techniques. The wettability, corrosion properties, adhesion of the coating to the substrate, the release of AgNPs into solutions simulating body fluids at different pH, and antibacterial properties were further investigated. The obtained composite coatings were hydrophilic, adjacent to the surface, and corrosion-resistant. An increase in the amount of silver released as ions or metallic particles into a simulated body fluid solution at acidic pH was observed for modified samples with the biopolymer coating after three days of exposure avoiding burst effect. The proposed modification was effective against both Gram-positive and Gram-negative bacteria.

Engineered titania nanomaterials in advanced clinical applications

Significant advancement in the field of nanotechnology has raised the possibility of applying potent engineered biocompatible nanomaterials within biological systems for theranostic purposes. Titanium dioxide (titanium(IV) oxide/titania/TiO2) has garnered considerable attention as one of the most extensively studied metal oxides in clinical applications. Owing to the unique properties of titania, such as photocatalytic activity, excellent biocompatibility, corrosion resistance, and low toxicity, titania nanomaterials have revolutionized therapeutic approaches. Additionally, titania provides an exceptional choice for developing innovative medical devices and the integration of functional moieties that can modulate the biological responses. Thus, the current review aims to present a comprehensive and up-to-date overview of TiO2-based nanotherapeutics and the corresponding future challenges.

Surface Engineering Strategies to Enhance the In Situ Performance of Medical Devices Including Atomic Scale Engineering

Decades of intense scientific research investigations clearly suggest that only a subset of a large number of metals, ceramics, polymers, composites, and nanomaterials are suitable as biomaterials for a growing number of biomedical devices and biomedical uses. However, biomaterials are prone to microbial infection due to Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), hepatitis, tuberculosis, human immunodeficiency virus (HIV), and many more. Hence, a range of surface engineering strategies are devised in order to achieve desired biocompatibility and antimicrobial performance in situ. Surface engineering strategies are a group of techniques that alter or modify the surface properties of the material in order to obtain a product with desired functionalities. There are two categories of surface engineering methods: conventional surface engineering methods (such as coating, bioactive coating, plasma spray coating, hydrothermal, lithography, shot peening, and electrophoretic deposition) and emerging surface engineering methods (laser treatment, robot laser treatment, electrospinning, electrospray, additive manufacturing, and radio frequency magnetron sputtering technique). Atomic-scale engineering, such as chemical vapor deposition, atomic layer etching, plasma immersion ion deposition, and atomic layer deposition, is a subsection of emerging technology that has demonstrated improved control and flexibility at finer length scales than compared to the conventional methods. With the advancements in technologies and the demand for even better control of biomaterial surfaces, research efforts in recent years are aimed at the atomic scale and molecular scale while incorporating functional agents in order to elicit optimal in situ performance. The functional agents include synthetic materials (monolithic ZnO, quaternary ammonium salts, silver nano-clusters, titanium dioxide, and graphene) and natural materials (chitosan, totarol, botanical extracts, and nisin). This review highlights the various strategies of surface engineering of biomaterial including their functional mechanism, applications, and shortcomings. Additionally, this review article emphasizes atomic scale engineering of biomaterials for fabricating antimicrobial biomaterials and explores their challenges.

Influence of Titania Nanotubes Diameter on Its Antibacterial Efficacy against Periodontal Pathogens: An In vitro Analysis

Background

Peri implant infection in dental implantology is a frequently encountered clinical problem. Titania nanotubes (TNTs) are recent improvement in surface characterization, showing promising results.

Aim

The nanosurface parameter tweaking has been implicated with profound change in the microbiological and biological response. Hence, it was proposed that alteration in the nanotube diameter could have positive influence in its antibacterial activity against salient periodontal pathogens.

Materials and Methods

Commercially, pure titanium discs of 8-mm diameter and 1.5-mm thickness were prepared. Polished titanium discs were used as control (Group A). Vertically oriented, structured TNTs were fabricated by anodization technique and grouped as B and C, having nanotube diameter, 40 and 80 nm subsequently. The surface characterizations of the samples were done by scanning electron microscope analysis. The antibacterial activity was evaluated with the bacterial colony counting method, at 24 h, 72 h, and 1-week intervals.

Statistical Analysis

The one-way analysis of variance and Tukey's honest significance post hoc test were employed to assess the statistical significance.

Results

The 80 nm nanotubes showed better antibacterial activity comparatively, at all three-time intervals investigated.

Conclusion

The optimal TNT diameter of 80 nm was the most effective from an antimicrobial stand point of view.

Nanostructured Surfaces to Promote Osteoblast Proliferation and Minimize Bacterial Adhesion on Titanium

The objective of this study was to investigate the potential of titanium nanotubes to promote the proliferation of human osteoblasts and to reduce monomicrobial biofilm adhesion. A secondary objective was to determine the effect of silicon carbide (SiC) on these nanostructured surfaces. Anodized titanium sheets with 100-150 nm nanotubes were either coated or not coated with SiC. After 24 h of osteoblast cultivation on the samples, cells were observed on all titanium sheets by SEM. In addition, the cytotoxicity was evaluated by CellTiter-BlueCell assay after 1, 3, and 7 days. The samples were also cultivated in culture medium with microorganisms incubated anaerobically with respective predominant periodontal bacteria viz. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia as monoinfection at 37 °C for 30 days. The biofilm adhesion and coverage were evaluated through surface observation using Scanning Electron Microscopy (SEM). The results demonstrate that Ti nanostructured surfaces induced more cell proliferation after seven days. All groups presented no cytotoxic effects on human osteoblasts. In addition, SEM images illustrate that Ti nanostructured surfaces exhibited lower biofilm coverage compared to the reference samples. These results indicate that Ti nanotubes promoted osteoblasts proliferation and induced cell proliferation on the surface, compared with the controls. Ti nanotubes also reduced biofilm adhesion on titanium implant surfaces.

Toward Bactericidal Enhancement of Additively Manufactured Titanium Implants

Implant-associated infections (IAIs) are among the most intractable and costly complications in implant surgery. They can lead to surgery failure, a high economic burden, and a decrease in patient quality of life. This manuscript is devoted to introducing current antimicrobial strategies for additively manufactured (AM) titanium (Ti) implants and fostering a better understanding in order to pave the way for potential modern high-throughput technologies. Most bactericidal strategies rely on implant structure design and surface modification. By means of rational structural design, the performance of AM Ti implants can be improved by maintaining a favorable balance between the mechanical, osteogenic, and antibacterial properties. This subject becomes even more important when working with complex geometries; therefore, it is necessary to select appropriate surface modification techniques, including both topological and chemical modification. Antibacterial active metal and antibiotic coatings are among the most commonly used chemical modifications in AM Ti implants. These surface modifications can successfully inhibit bacterial adhesion and biofilm formation, and bacterial apoptosis, leading to improved antibacterial properties. As a result of certain issues such as drug resistance and cytotoxicity, the development of novel and alternative antimicrobial strategies is urgently required. In this regard, the present review paper provides insights into the enhancement of bactericidal properties in AM Ti implants.