Titanium Surface Chemical Composition Interferes in the Pseudomonas aeruginosa Biofilm Formation

Enhancing Titanium Disk Performance through In-Pack Cold Atmospheric Plasma Treatment

While titanium dental implants have already been clinically established, ongoing research is continuously being conducted to advance the fields of osseointegration and bacterial resistance, seeking further improvements in these areas. In this study, we introduce an innovative method for treating titanium surfaces within tightly sealed packaging. Specifically, titanium discs, enclosed in surgical-grade packaging, underwent treatment using cold atmospheric plasma (CAP). The surfaces were thoroughly characterized in terms of wettability, crystalline structure, and chemical composition. Hemocompatibility analyses were conducted using blood diluted in sodium citrate (1:9) exposed to titanium discs for 30 min inside a CO2 incubator at 37 °C. Subsequently, various blood parameters were evaluated, including prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet adhesion. Microbiological analyses were also performed using Pseudomonas aeruginosa (ATCC 27853) for 4 h at 37 °C. The treatment with CAP Jet resulted in a reduction in contact angle without causing any changes in the crystalline structure. No statistically significant differences were observed in the blood parameters. The plasma-treated samples exhibited lower PT and APTT values compared to those of the control group. The surfaces treated with CAP Jet showed increased platelet activation, platelet density, and thrombus formation when compared with the untreated samples. Moreover, the treated surfaces demonstrated lower bacterial colony formation compared with other surfaces.

Influence of surface treatment by laser irradiation on bacterial adhesion on surfaces of titanium implants and their alloys: Systematic review

Objective

The aim of this systematic review was to present the current knowledge on the influence of laser surface treatment on the adhesion of bacteria to titanium and its alloys.

Design

This review was structured according to PRISMA guidelines for systematic reviews and meta-analyses, and registered on the Open Science Framework platform (https://doi.org/10.17605/OSF.IO/FTA3W). Article searches were performed in 4 databases: PubMed, Scopus, Embase, and Science Direct. In addition, a manual search was performed in the reference lists of the selected articles. The selection of articles was performed by two reviewers. The articles found were screened for eligibility using the previously established inclusion and exclusion criteria. The methodological quality of the studies was assessed using the Joanna Briggs Institute (JBI) Critical Assessment Checklist for Quasi-Experimental Studies (non-randomized experimental studies).

Results

Most of the studies evaluated showed that surface treatment by laser irradiation can affect the adhesion of bacteria to titanium surfaces and that this is directly related to changes in surface properties such as chemical composition, morphology, roughness, and wettability, as well as the type of bacterial species involved.

Conclusions

The studies considered in this systematic review have shown that surface treatment by laser irradiation is a promising technique to reduce the adhesion of bacteria on the surface of titanium implants.

Advances in the superhydrophilicity-modified titanium surfaces with antibacterial and pro-osteogenesis properties: A review

In recent years, the rate of implant failure has been increasing. Microbial infection was the primary cause, and the main stages included bacterial adhesion, biofilm formation, and severe inhibition of implant osseointegration. Various biomaterials and their preparation methods have emerged to produce specific implants with antimicrobial or bactericidal properties to reduce implant infection caused by bacterial adhesion and effectively promote bone and implant integration. In this study, we reviewed the research progress of bone integration promotion and antibacterial action of superhydrophilic surfaces based on titanium alloys. First, the adverse reactions caused by bacterial adhesion to the implant surface, including infection and bone integration deficiency, are briefly introduced. Several commonly used antibacterial methods of titanium alloys are introduced. Secondly, we discuss the antibacterial properties of superhydrophilic surfaces based on ultraviolet photo-functionalization and plasma treatment, in contrast to the antibacterial principle of superhydrophobic surface morphology. Thirdly, the osteogenic effects of superhydrophilic surfaces are described, according to the processes of osseointegration: osteogenic immunity, angiogenesis, and osteogenic related cells. Finally, we discuss the challenges and prospects for the development of this superhydrophilic surface in clinical applications, as well as the prominent strategies and directions for future research.

Inhibition of bacterial adherence to biomaterials by coating antimicrobial peptides with anionic surfactant

Medical devices are widely used in modern medicine, but their utilities are often limited by the biofilm formation of bacteria that are tolerant to most antibiotics. In this report, antimicrobial peptides (AMPs) were coated onto biomaterials by the aid of surfactant through hydrophobic interactions. To increase the coating efficiency, stability of AMPs in body fluids and spectrum of antimicrobial activity, pairs of AMPs were coated simultaneously onto various substrates, such as silicone, polyurethane and titanium, which are commonly used components of biomedical devices. These coated AMPs exhibited very low cytotoxicity and hemolytic activities because they were gradually released into urine or serum. The AMP pairs, such as T9W + SAAP159 and T9W + RRIKA, coated onto the silicone discs were able to inhibit in vitro bacterial adherence in urine. Most importantly, AMP pairs coated onto the silicone tubing by surfactant SDBS could prevent bacterial adherence to mouse bladder and the silicone tubing implanted within it. These results provide a promising approach towards circumventing urinary catheter-associated infections caused by bacterial adherence.

Live endothelial cells on plasma-nitrided and oxidized titanium: An approach for evaluating biocompatibility

We evaluated the effects of titanium plasma nitriding and oxidation on live endothelial cell viscoelasticity. For this, mechanically polished titanium surfaces and two surfaces treated by planar cathode discharge in nitriding (36N₂ and 24H₂) and oxidant (36O₂ and 24H₂). Surfaces were characterized regarding wettability, roughness and chemical composition. Rabbit aortic endothelial cells (RAECs) were cultured on the titanium surfaces. Cell morphology, viability and viscoelasticity were evaluated by scanning electron microscopy (SEM), methyl thiazolyl tetrazolium (MTT) assay and atomic force microscopy (AFM), respectively. Grazing Incidence X-ray Diffraction confirmed the presence of TiN_0,26 on the surface (grazing angle theta 1°) of the nitrided samples, decreasing with depth. On the oxidized surface had the formation of TiO₃ on the material surface (Theta 1°) and in the deeper layers was noted, with a marked presence of Ti (Theta 3°). Both plasma treatments increased surface roughness and they are hydrophilic (angle <90°). However, oxidation led to a more hydrophilic titanium surface (66.59° ± 3.65 vs. 76.88° ± 2.68; p = 0.001) due to titanium oxide films in their stoichiometric varieties (Ti₃O, TiO₂, Ti₆O), especially Ti₃O. Despite focal adhesion on the surfaces, viability was different after 24 h, as cell viability on the oxidized surface was higher than on the nitrided surface (9.1 × 10³ vs. 4.5 × 10³cells; p < 0.05). This can be explained by analyzing the viscoelastic property of the cellular cytoskeleton (nuclear and peripheral) by AFM. Surface oxidation significantly increased RAECs viscoelasticity at cell periphery, in comparison to the nucleus (2.36 ± 0.3 vs. 1.5 ± 0.4; p < 0.05), and to the RAECs periphery in contact with nitrided surfaces (1.36 ± 0.7; p < 0.05) and polished surfaces (1.55 ± 0.6; p < 0.05). Taken together, our results have shown that titanium plasma treatment directly increased cell viscoelasticity via surface oxidation, and this mechanobiological property subsequently increased biocompatibility.

Plasma nitriding under low temperature improves the endothelial cell biocompatibility of 316L stainless steel

OBJECTIVES

To evaluate the effects of the surface modification of 316L stainless steel (SS) by low-temperature plasma nitriding on endothelial cells for stent applications.

RESULTS

X-ray diffraction (XRD) confirmed the incorporation of nitrogen into the treated steel. The surface treatment significantly increased SS roughness and hydrophilic characteristics. After 4 h the cells adhered to the nitride surfaces and formed clusters. During the 24 h incubation period, cell viability on the nitrided surface was higher compared to the polished surface. Nitriding reduced late apoptosis of rabbit aorta endothelial cell (RAEC) on the SS surface.

CONCLUSION

Low temperature plasma nitriding improved the biocompatible of stainless steel for use in stents.

Artificial Organs 2018: A Year in Review

In this Editor's Review, articles published in 2018 are organized by category and summarized. We provide a brief reflection of the research and progress in artificial organs intended to advance and better human life while providing insight for continued application of these technologies and methods. Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. Peer-reviewed special issues this year included contributions from the 13th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion edited by Dr. Akif Undar, and the 25th Congress of the International Society for Mechanical Circulatory Support edited by Dr. Marvin Slepian. Additionally, many editorials highlighted the worldwide survival differences in hemodialysis and perspectives on mechanical circulatory support and stem cell therapies for cardiac support. We take this time also to express our gratitude to our authors for offering their work to this journal. We offer our very special thanks to our reviewers who give so generously of time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.