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Commercially available, modification of the surface of the modification of the surface of the Ti CP and Ti-40Nb alloys by plasma electrolytic oxidation in a tricalcium phosphate suspension with silver nitrate has been reported. The determined characteristics of the obtained coatings were related to microstructural studies, chemical composition, wettability, and corrosion tests. The proposed treatment ensured the effective incorporation of bioactive compounds into the oxide coatings. Electrochemical corrosion tests showed superior corrosion resistance for both substrates, with higher corrosion resistance obtained for Ti-40Nb samples in baths containing silver nitrate. The presented research highlighted the potential application of PEO treatment of Ti alloys for the purpose of hard tissue implants. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract In this work, nickel-graphene and nickel-graphene oxide composite electrodes were employed as anodes in the electrocatalytic oxidation of urea in an alkaline solution. These composite electrodes have a higher surface area than the unmodified nickel electrode. As the current density increases during the composite formation process, the roughness of the surface and the adhesion of the coating to the substrate increase. The obtained composites have a higher activity than the nickel electrode in both alkaline solution and alkaline solution supplemented with urea. Furthermore, the nickel-graphene composite electrodes are characterized by a higher electroactivity than nickel-graphene oxide electrodes in the urea oxidation process. Highlights • Ni-G and Ni-GO composites as electroactive anodes for urea oxidation. • Electrocatalytic properties of Ni-G and Ni-GO composites were determined. • Ni-G and Ni-GO anodes have higher surface area than non-modified Ni electrode. [ABSTRACT FROM AUTHOR]

Abstract Vanadium- and aluminium-free biomedical Ti alloys are getting more and more attention because of the harmful character of these alloying elements. For this reason, it was proposed to substitute them with more biocompatible elements such as Ta, Nb and Zr. So-called gum metal alloys (Ti-Nb-Zr-Ta systems) belong to β -type Ti alloys which are characterized by excellent biocompatibility and possess the modulus of elasticity more closely related to that of a human bone. The present study aims at elucidating the process stages during DC plasma electrolytic oxidation (PEO) of gum metal (Ti-36Nb-3Zr-2Ta alloy) in calcium hypophosphite-based electrolyte system. The effect of the stages on the surface characteristics of the obtained oxide coatings was also determined. The coatings were characterized using SEM/EDS, XPS and contact angle measurements. It was found that the process comprised at least five different stages. The initiation of relatively strong B-type sparks in the third stage of the treatment was necessary to induce significant incorporation of electrolyte components into the oxide coatings. As the treatment continued beyond that point, the composition of the oxide films was getting more similar to that of hydroxyapatite as it was determined from the valence band XPS spectra. The surface morphology of the films was also closely related to the process stage at which the further growth of the oxide was halted. The composition of the electrolyte (regarding the salts used and their concentration) had a tremendous influence on the duration of the process stages and the surface characteristics of the obtained films. The process was also tested for its usefulness in coating gum metal dental implants in order to form bioactive interfaces. Keeping the voltage below a certain limit (before the onset of more powerful surface sparks) was crucial to obtaining good-quality coatings. Graphical abstract Image 1005 Highlights • Plasma electrolytic oxidation of β-type Ti-36Nb-3Zr-2Ta alloy was studied. • Ca(H 2 PO 2) 2 -based solutions with the addition of Ca(HCOO) 2 or Mg(CH 3 COO) 2 were used. • Specific steps of the PEO and their effect on surface characteristic were analyzed. • Surface analysis was included SEM/EDS, XPS and contact angle measurements. • Dental implants fashioned from gum metal were also subjected to the PEO process. [ABSTRACT FROM AUTHOR]

Abstract In this study, we develop hydroxyapatite coatings that consist of micrometric hexagonal crystals grown on the Ti/TiO 2 substrate. The coatings are synthesized by a hydrothermal method. The advance of our hydrothermal approach lies in the concomitant use of two reagents: ethylenediamine tetraacetic acid and monoethanolamine. The phase identification, surface morphology, and elemental composition of structures are examined by x-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersive x-ray spectroscopy. We also assess the in vitro bioactivity of hydroxyapatite structure and uncoated materials after incubation in the SBF solution. Simultaneously, we conduct a series of experiments to investigate electrochemical properties of titanium with and without hydroxyapatite by the means of electrochemical impedance and potentiodynamic polarization experiments in the Ringer's solution. Our results show that monoethanolamine-assisted hydrothermal method is an efficient and promising approach to obtain hydroxyapatite coatings with excellent crystal quality and Ca/P ratio close to the stoichiometric value of the Ca 10 (PO 4) 6 (OH) 2 phase. The SBF immersion tests indicate high bioactivity of hydroxyapatite coating after 7 days of incubation. However, the hydroxyapatite coating does not improve the corrosion behavior of the metallic titanium substrate. Electrochemical studies of all structures show the highest corrosion resistance for the Ti/TiO 2 surface as compared to other samples. The lowest value of corrosion current density (j cor = 0.65 ± 0.19 nA cm−2) is found for the Ti/TiO 2 surface. This result could be attributed to the porous morphology of the hydroxyapatite layer which could favor direct flow of electrolyte between the corrosive medium and the titanium substrate or to the adverse effect of hydrothermal synthesis on the barrier properties of the TiO 2 intermediate layer. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the preparation of a functional hybrid coating loaded with a drug (amoxicillin) on a promising titanium alloy – Ti-15Mo alloy is presented. The titanium alloy surface was anodized in solution with bioactive compounds to obtain a porous oxide layer favorable for MG-63 osteoblast-like cell adhesion. Then, a poly(lactide- co -glycolide) (PLGA) loaded with amoxicillin layer was formed using a dip-coating technique to cover the oxide layer, without filling in all of the pores. The morphology of the surface was evaluated using scanning electron microscopy supported by 3D Roughness Reconstruction software. The surface treatment of the Ti-15Mo alloy surface caused the surface roughness to increase up to 1.71 μm. The anodization process caused the Ti-15Mo alloy surface to become slightly more hydrophilic; however, the formation of the PLGA layer loaded with drug increased the contact angle to 96.5° ± 2.2°, respectively. After 4 weeks of polymer layer degradation, the registered signals on the 1H NMR spectrum were identical to the signals registered for lactic acid (LAc), which confirms that the polymer layer was degraded within a short period of time. The concentration of drug released into the artificial saliva was investigated using high-performance liquid chromatography (HPLC) up to 12 h of coatings immersion. During the first hour of coating degradation in artificial saliva, and the concentration of the drug (13 μg/ml) was enough to inhibit bacterial growth of S. aureus and S. epidermidis. These results were confirmed by agar plate diffusion method and evaluation of the minimal inhibitory concentration (MIC). The cytocompatibility of the materials was determined using the osteoblast-like cells MG-63, and the viability and cell morphology (live/dead staining) were also evaluated. The results showed that amoxicillin influences the osteoblast-like MG-63 cells' behavior during cell culture, especially for the first few hours. The influence on the type of surface treatment on MG-63 cell behavior during 7 days of culture is discussed in this paper. To the best of our knowledge, this is the first time that a fast-degrading layer with amoxicillin has been deposited on previously anodized Ti surface. The formation of functional coating may find application as a cytocompatible coating to prevent bacterial adhesion on long-term implant surfaces. Graphical abstract Unlabelled Image Highlights • Formation of oxide-polymer layer loaded by amoxicillin on Ti alloy is discussed. • Amoxicillin released from coating inhibit grown of S. aureus and S. epidermidis. • Porous coating with drug was cytocompatible with osteoblast-like MG-63 cells. [ABSTRACT FROM AUTHOR]

During anodization, the properties of the oxide layer depend on the chemical composition of the titanium alloy and on the parameters applied during surface treatment. The properties of the anodized surfaces influence their further functionalization. In this paper, ceramic multilayer coatings were formed on the Ti-6Al-7Nb, Ti-13Nb-13Zr, and Ti-15Mo alloys. A silica layer with wollastonite particles was formed on all the previously anodized Ti alloy samples. Using scanning electron microscopy, Raman spectroscopy, and X-ray diffractometry, respectively, the surface morphology, chemical composition and phase composition of the hybrid ceramic layers were investigated. In addition, the adhesion and hardness of the coatings were determined. The contact angle of the coatings was between 90.0 ± 0.2° and 114.3 ± 5.9°, and the surface roughness was < 2 μm. The modified surfaces were immersed in solutions containing protein-like collagen type I or lactoferrin. The coated Ti-15Mo surface exhibited the highest influence on both types of protein concentration in phosphate-buffered saline solution. However, after 1 day of culture, the adsorbed lactoferrin on the entire surface enhanced the growth of osteoblast-like MG-63 cells. Significant differences in cell culture were observed after 7 days, where the number of cells was much higher on the modified surface with lactoferrin. Collagen type I did not significantly enhance the cell behaviour; moreover, a large number of dead cells were found on these samples. [ABSTRACT FROM AUTHOR]

Titanium (Ti) dental implants were anodized in calcium hypophosphite solution to obtain a porous, bioactive layer. The anodized implant surface was covered by a poly(sebacic anhydride) (PSBA) layer with amoxicillin. SEM analysis showed an irregular distribution of the antibiotic on the surface. However, confocal microscopy images revealed the formation of a uniform polymer layer. The thickness of the oxide and polymer layers was similar, between 6 and 9 μm. PSBA is an easy, hydrolysable polymer. After the polymer with amoxicillin was immersed in phosphate buffered solution (PBS) for 1 h, >53 % of hydrolysis products were detected by 1H NMR spectroscopy. After 9 days of polymer immersion, the hydrolysis product content was >67 %. Drug release was analyzed using high-performance liquid chromatography (HPLC). After 1 h of implant immersion in PBS an average of 6.0 μg/mL of amoxicillin was released. Importantly, the released concentration of amoxicillin was enough to inhibit S. aureus and S. epidermidis growth, minimal inhibitory concentration (inhibition zones between 27 mm and 30 mm) and decrease bacteria adhesion to the implant surface were achieved. This paper presents the cytocompatibility results of PSBA, amoxicillin, and extracts collected from the implants exposed to mouse fibroblast L929 and osteoblast-like MG-63 cells. PSBA concentrations up to 1 % did not significantly affect cell viability. Amoxicillin concentrations up to 150 μL/mL were cytocompatible with both cell lines. Cell viability was >70 % for both cell lines after 24 h of treatment with extracts from modified implants that were immersed in PBS for 72 h prior to viability experiments. This work presents a simple method to obtain a hybrid, bacteriostatic and biocompatible layer on long-term implant surfaces. These techniques may find application in the surface treatment of various Ti implants with a variety of shapes and sizes for veterinary applications. [Display omitted] • Surface of Ti implant was modified by anodization process and using the poli(sebacic anhydride layer) with amoxicillin. • The non-cytotoxic concentration of the polymer and amoxicillin was found. • The extracts collected from the implants with the hybrid layer were not cytotoxic. • The hybrid coatings successfully decreased number of the bacteria and enhanced the antibacterial properties of the implant. [ABSTRACT FROM AUTHOR]

The effect of the sulfate-reducing bacteria (SRB, Desulfovibrio desulfuricans ) on the surface properties and corrosion resistance of an electropolished NiTi alloy was assessed. NiTi samples were exposed to abiotic and biotic media (Postgate medium + artificial saliva) for different exposure periods (24, 168 and 720 h). Electrochemical impedance spectroscopy (EIS) measurements were carried out in physiological Ringer’s solution to assess the effect of biofilms on the electrochemical properties of the NiTi alloy. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to analyze the properties and chemical compositions of the surface that was modified with biofilm. Evident influence of SRB on the surface of the NiTi alloy was observed, and the most intense effect was observed after 168 h of bioexposure. Biofilm-covered NiTi alloy was characterized by reduced resistance ( R i ) and higher capacitance ( C i ) in the barrier region of the oxide. However, some restoration of the protective properties of the passive film was observed in samples that had been exposed to bacteria for 720 h. XPS studies showed that no significant changes from the surface chemistry of the abiotic NiTi samples were induced by biofilm formation. [ABSTRACT FROM AUTHOR]

Results on D. desulfuricans biofilm formation on austenitic-ferritic duplex (2205 DSS) and superaustenitic (904L) stainless steels are presented. Surface characterization including the structure, configuration and chemical composition of biofilms were carried out using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Electrochemical impedance spectroscopy (EIS) measurements were used to monitor the attachment activity of bacteria on the steels' surface and to determine the effect of bacteria on passivity. It was proved that investigated steels are rapidly colonized by bacteria. The presence of biofilm caused significant ennoblement of 904L steel surface, while retarded the attainment of high passive state of 2205 DSS. XPS analysis revealed significant sulphidation of the biofilm and its layered structure. Accumulation of sulphides and hydroxides was proved in the outermost layer, while the increasing contents of disulphides, organometallic and C N bonds were detected in the internal part of the biofilm. Irreversible bondings between steel matrix and biofilm had also been observed. [ABSTRACT FROM AUTHOR]

This work aims to quantify the effect of anodization voltage and electrolyte composition used during DC plasma electrolytic oxidation (PEO), operated as a 2-step process, on the surface properties of the resulting oxide coatings on tantalum. The first step consisted of galvanostatic anodization (150 mA cm −2 ) of the tantalum workpiece up to several limiting voltages (200, 300, 400 and 500 V). After attaining the limiting voltage, the process was switched to voltage control, which resulted in a gradual decrease of the anodic current density. The anodic treatment was realized in a 0.5 M Ca(H 2 PO 2 ) 2 solution, which was then modified by the addition of 1.15 M Ca(HCOO) 2 as well as 1.15 M and 1.5 M Mg(CH 3 COO) 2 . The increasing voltage of anodization led to the formation of thicker coatings, with larger pores and enriched with electrolytes species to a higher extent. The solutions containing HCOO − and CH 3 COO − ions caused the formation of coatings which were slightly hydrophobic (high contact angle). In the case of the samples anodized up to 500 V, scattered crystalline deposits were observed. Bioactive phases, such as hydroxyapatite, were detected in the treated oxide coatings by XRD and XPS. [ABSTRACT FROM AUTHOR]

Present work describes investigations of a two-step process consisting of galvanostatic anodising in a 1 M HSO solution at 100 mA cm up to the limiting voltages of 20, 60, 80, 100 and 120 V, directly after which potentiostatic regime was employed and the current was allowed to drop. The total treatment time (5 min) was held constant for all samples. The treatment was carried out to improve the corrosion resistance of zirconium in physiological conditions, which was determined by electrochemical evaluation in Ringer's solution. XPS studies revealed that after anodising sulphur was incorporated into the oxide film in the form of sulphated zirconia. The maximum content of sulphate in the oxide layer was observed after anodising at 80 V. Anodising at higher voltages resulted in formation of coatings with decreasing amount of sulphur. It was found that there is a strong correlation between the sulphur content in the oxide layers and the measured corrosion current density. On the other hand, the pitting corrosion resistance seemed to be unaffected by the presence of S and it was improving with the increasing limiting voltage of the treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three different Mg sources were used to form PEO layers on titanium. • Bioactive Ca, P, and Mg was successfully introduced into the Ti surface during PEO. • The Mg-incorporated PEO coatings exhibited a fungi- and bacteriostatic effect. • The fungi- and bacteriostatic effect depends of the chemical form of Mg. This paper reports the surface modification of titanium via a plasma electrolytic oxidation (PEO) process in baths based on 0.1 M Ca(H 2 PO 2) 2 with Mg-containing additives: insoluble MgO or MgHPO 4 or highly-soluble Mg(CH 3 COO) 2. The surface morphology and roughness were investigated using scanning electron microscopy (SEM), which showed that porous oxide layers were formed and the roughness increased. To determine the presence of bioactive Ca and P and bacteriostatic Mg, energy-dispersive X-ray spectroscopy (EDX) analysis was performed, as well as XPS analysis and Raman spectroscopy, which proved their successful incorporation into the oxide layer. All investigated oxide coatings were continuous and the thickest one was observed on Ti-PEO-MgP surface (5.2 µm–7.5 µm). The bacteriostatic and fungistatic properties of the investigated surfaces were determined via Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Candida albicans ATCC 2091 adhesion tests. The concentration of Mg and Ti released from the PEO-modified Ti surfaces after immersion up to 14 days in Ringer's solution was evaluated via ICP-OES technique. All studied Mg-containing PEO coatings exhibited bacteriostatic and fungistatic properties, which suggests the possible application of Mg-doped titanium PEO coatings as long-term implant materials dedicated to bone tissue. [ABSTRACT FROM AUTHOR]

The study investigated the effect of aging time on the protective properties of submicron thickness sol-gel coatings. Coatings were based on zirconia and silica modified with fluoroalkyl substituents that were deposited on P265GH steel and were aged for 3 years. The corrosion tests were carried out in sodium chloride solution and liquid caprolactam. The physicochemical properties of the obtained materials were determined using scanning electron microscopy (SEM), Raman spectrometry, and nuclear magnetic resonance (NMR). The roughness and wettability of the tested samples were also measured with a profilometer and tensiometer. The protective properties were determined by electrochemical and immersion tests. The coating containing ZrO 2 was more stable over time. In the case of the 'SiO 2 + F' fluorine-modified coating, polarization resistance increased by about 3 orders of magnitude compared to the uncoated P265GH steel. However, after 3 years, the protective nature of this type of coating had deteriorated, compared to its initial state. Moreover, it seems that the 'ZrO 2 ' coating better covered all valleys in the surface, forming a smoother surface, while the 'SiO 2 + F' coating better reproduced the surface topography, also depositing on the ridged surface and creating a thin continuous film. [Display omitted] • The stability of sol-gel structures were monitored over a three year period at room atmosphere. • Conductive and un-conductive environments were used to define the protection property of thin sol-gel films. • An organically modified silica coating was characterized by the best protection properties. • An organically modified silica coating better reproduced the surface topography. • A silica- zirconia coating system was the most stable after three years aging at room atmosphere. [ABSTRACT FROM AUTHOR]

Poly( d , l -lactide- co -glycolide) 50/50 layer was formed on the previously anodized Ti-15Mo alloy surface and evaluated in terms of morphology (SEM), electrochemical analysis and biocompatibility (cell adhesion and biofilm formation tests). The polymer uniformly covered the porous oxide layer and filled the pores. The molar ratio of the comonomers in the copolymer was chosen to obtain the material, with degradation time of 4 weeks. The degradation process of polymer-oxide coatings was evaluated using 1 H and 13 C NMR. The oxide and polymer-oxide layers were cytocompatible, and osteoblast-like MG-63 cells were well adhered to the modified surfaces. The hybrid gentamicin-PLGA loaded coatings formed on the titanium alloy surface exhibited antimicrobial activity against Staphylococcus aureus . The coatings improved the corrosion resistance of the substrate in Ringer solution. Formation of the hybrid polymer-oxide layer on the Ti-15Mo alloy surface is a promising approach to obtain ‘smart materials’. [ABSTRACT FROM AUTHOR]

Results on biofilm formation and microbiologically influenced corrosion induced by pure D. desulfuricans strain on 2205 duplex stainless steel (DSS) are presented. Biofilm development stimulated by DSM642 standard strain was evaluated with reference to their metabolic activity and to the surface characterization including the structure and configuration of the biofilm. Electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves) and X-ray photoelectron spectroscopy (XPS) were carried out to determine the effect of bacteria on the passivity and corrosion resistance of 2205 DSS. The electrochemical results showed that the DSS corrosion resistance was affected in the presence of DSM642 biofilm. This statement was based on the significant decrease in the charge transfer resistance ( R 1 ) obtained from EIS and the increase in the measured current densities obtained from potentiodynamic polarization curves. Although the breakdown potentials ( E b ) were still high, SEM observations revealed micropits as well as signs of crevice attack on the steel surface. Significant sulphidation of the passive film affected the nature of cathodic behaviour of steel and helped to impede micropit growth. XPS analysis revealed the layered structure of the biofilm. Accumulation of sulphides and hydroxides was proved in the outermost layer, while the increasing contents of disulphides, organometallic and C N bonds were detected along the biofilm thickness in the XPS analysis. [ABSTRACT FROM AUTHOR]

This paper presents research on modifying the surface of Ti-15Mo alloy using electropolishing and anodic passivation. The electropolishing process was carried out in solutions containing sulfuric acid, ethylene glycol, ammonium fluoride and oxalic acid. Whereas a voltage range from 20 to 100 V and a 1 M orthophosphoric acid solution were used during the anodic passivation. The influence of above mentioned processes parameters on the quality of the obtained oxide layer on Ti-15Mo alloy was investigated. The analysis of Ti-15Mo surface after modification was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), ellipsometry, and mechanical tests. Moreover, the corrosion resistance was investigated using a potentiostatic method in Ringer’s solution. It was found that electropolishing leads to an increase in the surface homogeneity and to the form of an oxide layer, which consisted of TiO 2 and MoO 3 . Whereas the oxide layers obtained during anodic passivation were characterized by different properties depending on the applied voltage. The anodic passivation at various voltages (20–100 V) increased the surface wettability (94.5°–87.6°) in comparison to the electropolished sample (97.5°). Moreover, the obtained oxide layer after anodization exhibited a high hardness. The electrolytic polishing and anodic passivation of Ti-15Mo also improved corrosion resistance of the alloy in contact with Ringer's solution. The sample anodized at 80 V presented the highest corrosion resistance by the smallest corrosion current density (1.4 nA cm −2 ) and the highest polarization resistance (37.4 MΩ cm 2 ). [ABSTRACT FROM AUTHOR]

Tricalcium phosphate was deposited on the surface of anodized titanium alloys (Ti-6Al-7Nb, Ti-13Nb-13Zr and Ti-15Mo) using the electrophoretic technique (EPD). The multilayer coatings were formed by a three-step experiment. The influences of voltage (step I), time (step II) and concentration of TCP in the suspensions (step III) on the ceramic particle deposition was investigated. The appropriate conditions were determined for each titanium alloy surface modification. The total thickness of the anodized titanium alloys increased, the surface roughness decreased and the wettability increased after TCP particle deposition. A TL-XRD investigation showed that the multilayer coatings were mainly amorphous. All the coatings adhered well to the substrate. The surface modifications increased the corrosion resistance in Ringer’s solution, particularly for the Ti-15Mo alloy. In addition, the multilayer coatings formed on this titanium alloy exhibited the best cytocompatibility with MG-63 osteoblast-like cells. [ABSTRACT FROM AUTHOR]

The investigations of plasma electrolytic oxidation (PEO) process of Nb in a 1.5 mol dm −3 Ca(H 2 PO 2 ) 2 and 0.5 mol dm −3 Mg(CH 3 COO) 2 solution at a constant anodic current density of 150 mA cm −2 up to several limiting voltages (200, 300, 400 and 500 V) were described. The resulting oxide layers were characterised in terms of their physicochemical properties and corrosion resistance (DC and AC techniques) in Ringer’s solution at 37.0 ± 0.5 °C. The growth of the oxide layers during the PEO treatment was monitored using a digital camera and the sparks formed on the surface of niobium were analysed. The effect of the anodisation voltage on the oxide layer thickness (from less than 1 μm up to 150 μm), incorporation of the electrolyte solution species (the relative content of Nb in the coatings dropped from 36.5 to 0.7 at%), adhesion strength (the L c2 increased from 6.31 ± 0.38 to 14.10 ± 0.47 N) and corrosion resistance (the R p changed from 10.4 ± 2.7 to 60.9 ± 13.7 MΩ cm 2 ) was described. Additionally, the phase and chemical compositions of the oxide layers were studied. [ABSTRACT FROM AUTHOR]

The Ti–13Nb–13Zr alloy can successfully be used as a bone implant because it contains elements that are not harmful to the human body. However, to increase its osseointegration and corrosion resistance, this alloy is subjected to surface modifications. In this work, Ti–13Nb–13Zr alloy was modified by plasma electrolytic oxidation (PEO) in a 0.1 M NH 4 H 2 PO 4 solution with the addition of Ca 3 (PO 4 ) 2 powder (25 g/dm 3 ) under voltages of 150, 300 and 400 V. The morphology, cross-section, chemical composition, surface roughness and corrosion resistance of the coatings formed on the substrate by the PEO process are presented in this work. An increase in the applied voltage caused an increase in the number of pores and an increase in the amounts of calcium and phosphorus incorporated in the oxide layer. Analysis showed that all samples were covered by titanium oxide, which was present in the form of anatase. The results demonstrated that the surface modification of the Ti–13Nb–13Zr alloy through the PEO process improves its corrosion resistance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Particle crystallinity specifically affected surface topography and bioactivity. • Amorphous particles led to the higher content of calcium phosphates in the surface. • Both particle types showed similar incorporation pattern for Ti and TAV substrates. • Particle crystallinity is a new potential instrument for adjustment of PEO coatings. One way to improve characteristics of oxide coatings prepared by plasma electrolytic oxidation (PEO) method in suspensions lies in variation of solid particle properties. In this study, the effect of particle crystallinity on different physicochemical properties and bioactivity of coatings prepared on Ti and Ti6Al4V substrates was studied, and repeatability of resulting characteristics was assessed depending on selected substrates. PEO was performed in direct current mode at a voltage of 350 V in electrolytes containing 0.1 M KH 2 PO 4 and 100 g.L-1 of stoichiometric crystalline hydroxyapatite or amorphous tricalcium phosphate particles with average size of ∼ 450 nm. Series of measured physical parameters included coating thickness, as well as surface wettability, roughness and topography. Surface and cross-sectional chemical composition was studied by Raman and EDX spectroscopy, while bioactivity was evaluated with simulated body fluid tests. Results showed specific influence of particle crystallinity on surface morphology and repeatable particle incorporation pattern depending on the substrate utilized. It was found that amorphous particles lead to the increased amount of incorporated calcium phosphate phases followed by improved coating bioactivity and possible explanation of this phenomenon was suggested. Variation of particle crystallinity was proposed as a new potential instrument for the adjustment of PEO coating properties. [ABSTRACT FROM AUTHOR]

• One-step method of composite catalytic powders preparation using electrodeposition process have been proposed. • Usage of different current density during electrodeposition resulted in different Ni:Cu ratio despite identical electrolytic bath composition – easy control of the final material properties. • Obtained composites show good catalytic activity towards methanol oxidation in alkaline media. • Presence of GO in NiCuGO composite material have significantly improved its catalytic activity. • Prepared catalytic powders show good stability in reaction conditions. In this paper, an easy one-pot synthesis of an NiCuGO composite catalyst through electrodeposition is outlined. Various characterization techniques, such as SEM and XRD, were used for the characterization of the prepared catalyst. The catalyst's electrochemical activity was examined using cyclic voltammetry and chronoamperometry in 1 M KOH and 2 M MeOH / 1 M KOH solutions. The use of high current densities, 15.6 and 20.8 A dm−2, allowed the preparation of powder coatings that after removal of the supporting material showed good electrocatalytic properties towards the methanol oxidation reaction (Ep a 671 mV, ip a 28.6 mA cm−2, 33.7 mA mg−1). For materials deposited with a higher current density, the presence of graphene oxide significantly increased their active surface (1.38 vs 1.04 mF cm−2). Such results suggest that electrodeposition can be a good alternative to "wet chemical" methods, such as hydrothermal process, that can require usage of toxic solvents, such as hydrazine for the preparation of catalysts for the direct methanol fuel cell (DMFC). [Display omitted] [ABSTRACT FROM AUTHOR]

• PEO in the borate bath brought more anti-corrosion effect than in the silicate bath. • The PEO oxide coatings were modified with the use of corrosion inhibitors (CIs). • The single-step method was the addition of 0.1 g L−1 of a CI to the Si or B bath. • The sequential method was the dipping of the coating in a CI solution and DC PEO. • Mullite, α - and γ -Al 2 O 3 were detected in the PEO oxide coatings. • Acrylic acid was the most effective CI in both single-step and sequential methods. The 6061 aluminum alloy was surface-treated by plasma electrolytic oxidation (PEO) in silicate- and borate-based electrolyte systems. The authors attempted to incorporate selected corrosion inhibitors (8-hydroxyquinoline, 2-mercaptobenzothiazole, poly(acrylic acid) with molecular weights of 1800 and 450,000 g mol−1, and acrylic acid) into the oxide coating to provide long-lasting protection of the substrate. These inhibitors were either added directly to the electrolyte for the treatment or loaded into the coatings through a sequential PEO procedure. Electrochemical corrosion tests showed that acrylic acid-modified coatings provided the best protection. In general, of the two methods, the sequential PEO gave more reproducible anti-corrosion effects. [Display omitted] [ABSTRACT FROM AUTHOR]

· Fine pore, bioactive oxide coatings with superior corrosion resistance were obtained on Zr-Ti-Nb alloy via PEO treatment. · EDTA combined with an organic source of calcium enables the incorporation of calcium into the oxide coating from stable and clear electrolytes. · EDTA-based electrolyte led to improvements in the overall productivity and reproducibility of the PEO processing of the Zr-Ti-Nb alloy. The present work concerns the surface modification of the Zr-Ti-Nb alloy by plasma electrolytic oxidation (PEO) to develop stable oxide coatings with enhanced functionality and bioactivity. The use of ethylenediaminetetraacetic acid (EDTA)-based electrolytes with an organic source of calcium provided repeatable conditions for the production of microporous PEO oxide coatings with a satisfactory level of incorporation of calcium, phosphorus, and amino groups. The PEO coatings were produced using the DC regime and the best current-voltage conditions for the oxidation were proposed. The morphology and chemical composition of the oxide coatings fabricated on the Zr-Ti-Nb alloy were investigated using scanning electron microscopy (SEM+EDS), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Uniform films with fine pore size and ZrO 2 as the predominant oxide phase were formed. The oxide films showed superior corrosion resistance compared to the untreated Zr-Ti-Nb alloy. The results of the experiments indicate that this new alloy modified with the proposed PEO treatment shows potential for biomedical applications. [ABSTRACT FROM AUTHOR]

A variety of N-(1-methoxyalkyl)amides react with benzotriazole in the presence of PPh3⋅HBF4 and organic bases (Hünig's base, DBU or DABCO) or solid-state-supported bases (SiO2-Pip or IRA-67) in CHCl3 to give N-[1-(benzotriazol-1-yl)alkyl]amides in good yields. The most convenient and efficient procedure for obtaining N-[1-(benzotriazol-1-yl)alkyl]amides consists, however, of the addition of benzotriazole sodium salt to a solution of crude 1-(N-acylamino)alkyltriphenylphosphonium salt, obtained in situ from N-(1-methoxyalkyl)amides and PPh3·HBF4. A combination of these reactions with the recently described electrochemical decarboxylative α-methoxylation of N-acyl-α-amino acids in the presence of SiO2-Pip enables an effective two-pot transformation of N-acyl-α-amino acids to N-[1-(benzotriazol-1-yl)alkyl]amides. [ABSTRACT FROM AUTHOR]

Abstract: Herein, an investigation of the anodic oxidation process of pure tantalum metal in a solution composed of potassium silicate (K2SiO3) and potassium hydroxide (KOH) under different voltage conditions is reported. The selected process voltages were 100, 200 and 400V. Anodic oxidation conducted below the dielectric potential of the metal oxide did not alter the surface morphology, whereas the process carried out at a voltage of 400V led to the development of a highly porous structure, which is typical of plasma electrolytic oxidation (PEO). A significant amount of electrolyte ions, especially Si species, was observed in the case of the PEO treatment of tantalum. Silicon was present in the forms of silica and silicate species, with silica being the dominant form. Anodisation under specific conditions was shown to markedly improve the corrosion performance of tantalum in Ringer's simulated body fluid. [Copyright &y& Elsevier]

[Display omitted] • Ti-15Mo alloy surface was treated via plasma electrolytic oxidation. • Insoluble Cu 3 (PO 4) 2 particles were used for the first time as PEO bath additives. • A successful incorporation of copper into oxide coatings was confirmed. • Bacteriostatic properties against S. aureus and E. coli were established. • Cytocompatibility was determined using MG-63 osteoblast-like cells tests. This report describes the plasma electrolytic oxidation (PEO) treatment of Ti-15Mo alloy surfaces in baths containing 0.1 M Ca(H 2 PO 2) 2 with different insoluble copper-based additives: CuO or Cu 3 (PO 4) 2. The aim of this work was to fabricate oxide coatings with bacteriostatic and cytocompatible properties. The surface morphology, roughness, and wettability (based on dynamic water contact angle measurements) of the oxide coatings were evaluated. Additionally, the presence of copper compounds and bioactive calcium and phosphorus in the investigated oxide coatings was confirmed using various spectroscopic and crystallographic techniques. The highest copper concentration (3.5 at.%) was detected in the oxide layer obtained using a PEO suspension bath comprising Cu 3 (PO 4) 2 and Ca 3 (PO 4) 2. The oxide coating generated from a PEO bath containing CuO had the lowest copper concentration (0.1 at.%). The bacteriostatic properties of the obtained Cu-doped oxide layers were established based on bacterial adhesion tests using Gram-positive Staphylococcus aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922). On the Cu-incorporated surfaces, the number of surface-adhered bacterial colonies was ~10–100 times lower than on the reference Ti-15Mo surface, and ~105 times lower than on tryptic soy broth medium. The materials' cytocompatibilities were confirmed through tests with MG-63 osteoblast-like cells. [ABSTRACT FROM AUTHOR]

• Black glasses are polymer derived ceramics based on silicon oxycarbide. • Preceramic precursors were obtained via the sol-gel method. • Coatings were deposited using the dip-coating technique. • Addition of cerium ions was intended to enhance corrosion resistance of coatings. • Limited amount of cerium improved properties of the material. Amorphous silicon oxycarbide (SiOC) based materials are customarily called black glasses. In this work, hermetic layers on the steel substrate based on amorphous SiOC were obtained. The material was modified with cerium ions. Based on the literature, Ce as the modifier is responsible for i.e. enhancement of the corrosion resistance of materials and their antibacterial properties. SiCeOC coatings were produced via ceramization of the polymeric precursors synthesized by the sol-gel method and deposited on the metallic substrates with the use of the dip-coating technique. Numerous structural and microstructural studies were applied for the examination. It was proven that cerium is present in the material in the form of the inclusions and the material might be described as the SiOC/CeO 2 composite. The surface properties such as roughness, wettability and surface free energy were also analyzed. Corrosion resistance tests were also conducted to establish the influence of the modification with cerium ions on the characteristics of the basal material. The results illustrated that a limited amount of the modifier enhanced corrosion resistance of black glasses without changes in their structure. However, the modification does not promote Ce ion release and the antibacterial tests showed the materials do not possess antibacterial properties. [ABSTRACT FROM AUTHOR]

• Anodic oxidation of Zn-Co alloy coatings was realized in an ethanol solution. • The obtained thin passive films had various interference colours. • The thickness of the thin films was nanometric in size. • The oxide and alkoxide forms were present in the passive layer. • The anodizing had a beneficial effect on improvement of the corrosion resistance. Passive layers were formed on electrolytic Zn-Co alloy coatings in an ethanolic solution with sodium hydroxide by anodic oxidation. The obtained thin films were characterized by their morphology (OM, SEM), chemical analysis (XPS), thickness and deep-profile chemical analysis (GDOES) and corrosion properties (NSS test, EIS). Because of the appearance of interference colours with all of the samples, they were also characterized by UV-Vis absorption spectroscopy. The colours varied and were related to the thicknesses of the obtained thin films, which ranged from 91 to 220 nm. The passive films grew linearly with the terminal voltage. Based on the XPS results, mixed (oxide-alkoxide) compositions were found to have a beneficial influence towards providing improved corrosion resistance. According to the conducted corrosion studies, the best protection was ensured when the coatings were anodized at terminal voltages between 30 and 50 V. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Triply periodic minimal surfaces (TPMS) are known for their advanced mechanical properties and are wrinkle-free with a smooth local topology. These surfaces provide suitable conditions for cell attachment and proliferation. In this study, the in vitro osteoinductive and antibacterial properties of scaffolds with different minimal pore diameters and architectures were investigated. For the first time, scaffolds with TPMS architecture were treated electrochemically by plasma electrolytic oxidation (PEO) with and without silver nanoparticles (AgNPs) to enhance the surface bioactivity. It was found that the scaffold architecture had a greater impact on the osteoblast cell activity than the pore size. Through control of the architecture type, the collagen production by osteoblast cells increased by 18.9% and by 43.0% in the case of additional surface PEO bioactivation. The manufactured scaffolds demonstrated an extremely low quasi-elastic modulus (comparable with trabecular and cortical bone), which was 5–10 times lower than that of bulk titanium (6.4–11.4 GPa vs 100–105 GPa). The AgNPs provided antibacterial properties against both gram-positive and gram-negative bacteria and had no significant impact on the osteoblast cell growth. Complex experimental results show the in vitro effectiveness of the PEO-modified TPMS architecture, which could positively impact the clinical applications of porous bioactive implants. Unlabelled Image • 3D printed titanium scaffolds • Electrochemical bioactivation of 3D scaffolds • Cell growth dependency of scaffolds architecture • Silver nanoparticles on porous titanium [ABSTRACT FROM AUTHOR]

Plasma Electrolytic Oxidation (PEO) is as a promising technique to modify metal surfaces by application of oxide ceramic coatings with appropriate physical, chemical and biological characteristics. Therefore, objective of this research was to find the simplest settings, yet able to produce relevant bioactive implant surfaces layers on Ti implants by means of PEO. We show that an electrolyte containing potassium dihydrogen phosphate as a source of P and either calcium hydroxide or calcium formate as a source of Ca in combination with a chelating agent, ethylenediamine tetraacetic acid (EDTA), is suitable for PEO to deliver coatings with desired properties. We determined surface morphology, roughness, wettability, chemical and phase composition of titanium after the PEO process. To investigate biocompatibility and bacterial properties of the PEO oxide coatings we used microbial and cell culture tests. The electrolyte based on Ca(OH) 2 and EDTA promotes active crystallization of apatites after PEO processing of the Ti implants. The PEO layers can increase electrochemical corrosion resistance. The PEO can be potentially used for development of bioactive surfaces with increased support of eukaryotic cells while inhibiting attachment and growth of bacteria without use of antibacterial agents. Unlabelled Image • Ceramic coatings on titanium dental implants were obtained via PEO with calcium and phosphate ions. • EDTA greatly enhanced efficiency of deposition of calcium and phosphorus into the PEO generated surface layers. • PEO surface layers induce crystallization of apatites upon exposure to body-like environment in simulated body fluids. • PEO coatings support attachment and proliferation of eukaryotic cells while inhibiting attachment and growth of bacteria. [ABSTRACT FROM AUTHOR]

This paper reports on the plasma electrolytic oxidation (PEO) of titanium alloy Ti-15Mo in baths containing zinc to obtain biomaterials with bacteriostatic and antibacterial properties. The Ti-15Mo surface was oxidised in a 0.1 M Ca(H 2 PO 2) 2 bath containing zinc compound particles: ZnO or Zn 3 (PO 4) 2. During the PEO process, the applied voltage was 300 V, and the current density was 150 mA∙cm−2. The surface morphology, roughness and wettability were determined. It has been noted that both roughness and wettability of Ti-15Mo alloy surface increased after PEO. EDX and XPS chemical composition analysis was carried out, and Raman spectroscopy was also performed indicating that Zn has been successfully incorporated into oxide layer. To investigate the antibacterial properties of the PEO oxide coatings, microbial tests were carried out. The bacterial adhesion test was performed using four different bacterial strains: reference Staphylococcus aureus (ATCC 25923), clinical Staphylococcus aureus (MRSA 1030), reference Staphylococcus epidermidis (ATCC 700296) and clinical Staphylococcus epidermidis (15560). Performed zinc-containing oxide coatings did not indicate the bacteria growth inducing effect. Additionally, the cytocompatibility of the formed oxide layers was characterised by MG-63 osteoblast-like live/dead tests. The surface bioactivity and cytocompatibility increased after the PEO process. The zinc was successfully incorporated into the titanium oxide layer. Based on the obtained results of the studies, it can be claimed that zinc-containing PEO layers can be an interesting course of bacteriostatic titanium biomaterials development. Unlabelled Image • The porous oxide layers containing zinc were formed on Ti-15Mo alloy surface. • PEO suspension baths consisting of Zn 3 (PO 4) 2 particles were used for the first time. • The zinc particles amount in PEO bath influences on surface morphology. • Microbial tests indicate bacteriostatic effect of zinc against Staphylococcus. • MG-63 osteoblast-like cells tests indicate good cytocompatibility of oxide layers. [ABSTRACT FROM AUTHOR]

This paper presents the surface treatment results of titanium, veterinary bone wedges. The functional coating is composed of a porous oxide layer (formed by a plasma electrolytic oxidation process) and a polymer poly(sebacic anhydride) (PSBA) layer loaded with amoxicillin (formed by dip coatings). The coatings were porous and composed of Ca (4.16%-6.54%) and P (7.64%-9.89% determined by scanning electron microscopy with EDX) in the upper part of the implant. The titanium bone wedges were hydrophilic (54° water contact angle) and rough (surface area (Sa):1.16 μm) The surface tension determined using diiodomethane was 68.6 ± 2.0° for the anodized implant and was similar for hybrid coatings: 60.7 ± 2.2°. 12.87 ± 0.91 µg/mL of amoxicillin was released from the implants during the first 30 min after immersion in the phosphate-buffered saline (PBS) solution. This concentration was enough to inhibit the Staphylococcus aureus ATCC 25923, and Staphylococcus epidermidis ATCC12228 growth. The obtained inhibition zones were between 27.3 ± 2.1 mm-30.7 ± 0.6 mm when implant extract after 1 h or 4 h immersion in PBS was collected. Various implant biocompatibility analyses were performed under in vivo conditions, including pyrogen test (3 rabbits), intracutaneous reactivity (3 rabbits, 5 places by side), acute systemic toxicity (20 house mice), and local lymph node assay (LLNA) (20 house mice). The extracts from implants were collected in polar and non-polar solutions, and the tests were conducted according to ISO 10993 standards. The results from the in vivo tests showed, that the implant's extracts are not toxic (mass body change below 5%), not sensitizing (SI < 1.6), and do not show the pyrogen effect (changes in the temperature 0.15ºC). The biocompatibility tests were performed in a certificated laboratory with a good laboratory practice certificate after all the necessary permissions., (© 2024. The Author(s).)

Titanium currently has a well-established position as the gold standard for manufacturing dental implants; however, it is not free of flaws. Mentions of possible soft-tissue discoloration, corrosion, and possible allergic reactions have led to the development of zirconia dental implants. Various techniques for the surface modification of titanium have been applied to increase titanium implants' ability to osseointegrate. Similarly, to achieve the best possible results, zirconia dental implants have also had their surface modified to promote proper healing and satisfactory long-term results. Despite zirconium oxide being a ceramic material, not simply a metal, there have been mentions of it being susceptible to corrosion too. In this article, we aim to review the literature available on zirconia implants, the available techniques for the surface modification of zirconia, and the effects of these techniques on zirconia's biological properties. Zirconia's biocompatibility and ability to osseointegrate appears unquestionably good. Despite some of its mechanical properties being, factually, inferior to those of titanium, the benefits seem to outweigh the drawbacks. Zirconia implants show very good success rates in clinical research. This is partially due to available methods of surface treatment, including nanotopography alterations, which allow for improved wettability, bone-to-implant contact, and osteointegration in general.

Photothermal therapy (PTT) is a method for eradicating tumor tissues through the use of photothermal materials and photosensitizing agents that absorb light energy from laser sources and convert it into heat, which selectively targets and destroys cancer cells while sparing healthy tissue. MXenes have been intensively investigated as photosensitizing agents for PTT. However, achieving the selectivity of MXenes to the tumor cells remains a challenge. Specific antibodies (Ab) against tumor antigens can achieve homing of the photosensitizing agents toward tumor cells, but their immobilization on MXene received little attention. Here, we offer a strategy for the selective ablation of melanoma cells using MXene-polydopamine-antiCEACAM1 Ab complexes. We coated Ti 3 C 2 T x MXene with polydopamine (PDA), a natural compound that attaches Ab to the MXene surface, followed by conjugation with an anti-CEACAM1 Ab. Our experiments confirm the biocompatibility of the Ti 3 C 2 T x -PDA and Ti 3 C 2 T x -PDA-antiCEACAM1 Ab complexes across various cell types. We also established a protocol for the selective ablation of CEACAM1-positive melanoma cells using near-infrared irradiation. The obtained complexes exhibit high selectivity and efficiency in targeting and eliminating CEACAM1-positive melanoma cells while sparing CEACAM1-negative cells. These results demonstrate the potential of MXene-PDA-Ab complexes for cancer therapy. They underline the critical role of targeted therapies in oncology, offering a promising avenue for the precise and safe treatment of melanoma and possibly other cancers characterized by specific biomarkers. Future research will aim to refine these complexes for clinical use, paving the way for new strategies for cancer treatment.

The newest technology allows the medical industry to manufacture innovative products such as milled titanium prosthodontic parts in an implant for a screw-retained suprastructure. In the literature, there are some articles on the clinical usage of subperiosteal implants, but none of these publications, either in PubMed or Google Scholar, thoroughly describe the workflow for the design and manufacture of individual implants for maxillofacial surgery with milled threads for a screw-retained prosthodontic bridge. The aim of the article is to present a step-by-step method of producing personalized implants, from the first steps of production to the implantation of the final product. The article includes information on patient qualification for surgery, computational preparation and skull printing, planning of Mai Implants ® , meshing, 3D printing and milling, cleaning, rinsing, anodizing, and laser marking, as well as the cleaning and sterilization process in a hospital or dental clinic. A detailed description of implant production allows for the analysis of each step and the development of technology. The production of implants is an expensive procedure, but considering all the advantages of the Mai Implants ® treatment and the disadvantages of alternatives, the product is worth the price.

This paper reports the results of our study on electrochemical polishing of titanium and a Ti-based alloy using non-aqueous electrolyte. It was shown that electropolishing ensured the removal of surface defects, thereby providing surface smoothing and decreasing surface roughness. The research was conducted using samples made of titanium and Ti 6 Al 4 V alloy, as well as implant system elements: implant analog, multiunit, and healing screw. Electropolishing was carried out under a constant voltage (10-15 V) with a specified current density. The electrolyte used contained methanol and sulfuric acid. The modified surface was subjected to a thorough analysis regarding its surface morphology, chemical composition, and physicochemical properties. Scanning electron microscope images and profilometer tests of roughness confirmed significantly smoother surfaces after electropolishing. The surface profile analysis of processed samples also yielded satisfactory results, showing less imperfections than before modification. The EDX spectra showed that electropolishing does not have significant influence on the chemical composition of the samples.

This research aimed to evaluate the effectiveness of new organic substances, including a novel ionic liquid based on polyhexamethylenebiguanidine, polyhexamethyleneguanidine, and safranin in the copper electrorefining process. Experiments were conducted on a small laboratory scale using industrial copper anodes. Single doses of new additives did not improve process indicators (current efficiency, average cell voltage, specific energy consumption) or the quality of copper cathode deposits. However, a combination of a new ionic liquid based on polyhexamethylenebiguanidine and thiourea resulted in a satisfactory current efficiency of 97%, an average cell voltage of 0.110 V, a low specific energy consumption index of approximately 100 kWh/t Cu , and smooth cathode surfaces. These results were superior to those obtained with industrial additives (bone glue and thiourea). The findings enhance our understanding of how these substances influence the electrorefining process and suggest the potential for more efficient and sustainable methods. Further research is recommended to validate these findings and explore their industrial applications.

Background: Presently, the management of patients with maxilla bone defects of the Cawood V or VI class is achieved using zygomatic or individual implants or through augmentation of the bone. For zygomatic implants, the ORIS criteria represent the most common factor in helping practitioners register success rates. The zygomatic anatomy-guided approach (ZAGA)and zygomatic orbital floor (ZOF) are factors that are crucial to examining the anatomy of a particular patient before the procedure. The aim of thisarticle is to find the statistical relationship between the abovementioned terms and other factors., Methods: A total of 81 patients underwent zygomatic implant procedures in different configurations. The ORIS, ZAGA, and ZOF parameters were compared with other factors such as type of surgery, sex, age, and the anatomy of the zygomatic bone., Results: Most patients in this article were classified as ZAGA Class 2. The relationships between type of surgery and ZAGA classification, and ZAGA and sinus/maxilla zygomatic implant localization were statistically significant., Conclusions: The ZAGA and ZOF scales are practical and valuable factors that should be taken into account before surgery, whereas to date, criteria better than the ORIS scale have not been described in terms of the success of zygomatic implants. The ZOF scale might omit perforation of the orbit because this parameter warns a practitioner to be aware of the anatomy of the orbit.

Dental implants have become a routine, affordable, and highly reliable technology to replace tooth loss. In this regard, titanium and its alloys are the metals of choice for the manufacture of dental implants because they are chemically inert and biocompatible. However, for special cohorts of patients, there is still a need for improvements, specifically to increase the ability of implants to integrate into the bone and gum tissues and to prevent bacterial infections that can subsequently lead to peri-implantitis and implant failures. Therefore, titanium implants require sophisticated approaches to improve their postoperative healing and long-term stability. Such treatments range from sandblasting to calcium phosphate coating, fluoride application, ultraviolet irradiation, and anodization to increase the bioactivity of the surface. Plasma electrolytic oxidation (PEO) has gained popularity as a method for modifying metal surfaces and delivering the desired mechanical and chemical properties. The outcome of PEO treatment depends on the electrochemical parameters and composition of the bath electrolyte. In this study, we investigated how complexing agents affect the PEO surfaces and found that nitrilotriacetic acid (NTA) can be used to develop efficient PEO protocols. The PEO surfaces generated with NTA in combination with sources of calcium and phosphorus were shown to increase the corrosion resistance of the titanium substrate. They also support cell proliferation and reduce bacterial colonization and, hence, lead to a reduction in failed implants and repeated surgeries. Moreover, NTA is an ecologically favorable chelating agent. These features are necessary for the biomedical industry to be able to contribute to the sustainability of the public healthcare system. Therefore, NTA is proposed to be used as a component of the PEO bath electrolyte to obtain bioactive surface layers with properties desired for next-generation dental implants.

New conductive materials for tissue engineering are needed for the development of regenerative strategies for nervous, muscular, and heart tissues. Polycaprolactone (PCL) is used to obtain biocompatible and biodegradable nanofiber scaffolds by electrospinning. MXenes, a large class of biocompatible 2D nanomaterials, can make polymer scaffolds conductive and hydrophilic. However, an understanding of how their physical properties affect potential biomedical applications is still lacking. We immobilized Ti 3 C 2 T x MXene in several layers on the electrospun PCL membranes and used positron annihilation analysis combined with other techniques to elucidate the defect structure and porosity of nanofiber scaffolds. The polymer base was characterized by the presence of nanopores. The MXene surface layers had abundant vacancies at temperatures of 305-355 K, and a voltage resonance at 8 × 10 4 Hz with the relaxation time of 6.5 × 10 6 s was found in the 20-355 K temperature interval. The appearance of a long-lived component of the positron lifetime was observed, which was dependent on the annealing temperature. The study of conductivity of the composite scaffolds in a wide temperature range, including its inductive and capacity components, showed the possibility of the use of MXene-coated PCL membranes as conductive biomaterials. The electronic structure of MXene and the defects formed in its layers were correlated with the biological properties of the scaffolds in vitro and in bacterial adhesion tests. Double and triple MXene coatings formed an appropriate environment for cell attachment and proliferation with mild antibacterial effects. A combination of structural, chemical, electrical, and biological properties of the PCL-MXene composite demonstrated its advantage over the existing conductive scaffolds for tissue engineering.

The characteristics such as microtopography, physical and chemical properties influence the behavior of an implant in a soft tissue. Anodization-as a potent method of titanium alloy surface modification-of the transgingival abutment or healing screw, has achieved some improvement. One of the possible surface treatment method is low-pressure radiofrequency oxygen plasma treatment. The aim of the study was to evaluate the chemical properties and cytocompatibility of the experimental surface. Titanium discs made of grade-23 titanium alloy (Ti-6Al-4V) anodized (A sample) with different voltage parameters (28, 67, 78, and 98 V) were included in the study. Half of the samples regarded as the "S" group were additionally treated with low-pressure radiofrequency oxygen plasma treatment. The surfaces were characterized using scanning electron microscopy, X-ray spectroscopy and Raman spectroscopy, and electrochemically investigated via a corrosion test. Furthermore, two cell lines were used, including the CHO-compatible reference line and a primary human fibroblast line for the MTT assay; direct (contact) cytotoxicity of the materials was tested with the cells, and the growth of fibroblasts on the surfaces of the different materials was tested. The morphology of the "S"-treated samples did not differ from the morphology of only-anodized samples. However, the oxygen concentration on the surface in that group slightly increased by about 1% as a result of post-trial treatment. The highest corrosion resistance was observed for both A-78 V and S-78 V samples. The cytotoxicity assay revealed no changes in cell morphology or vitality. The MTT test proved comparable culture viability among all groups; however, the "S" samples showed statistically significantly higher fibroblast proliferation and adhesion scores compared to the "A" samples. Through the in vitro study, the low-pressure radiofrequency oxygen plasma treatment of the anodized Ti-6Al-4V alloy presented itself as an auspicious option in the field of transgingival element surface modification of implants.

A new composite metal-insulator-metal (MIM) system consisting of exceptionally dense non-close-packed (NCP) arrays of gold or silver nanoparticles, porous anodic aluminum oxide (PAAO), and bulk aluminum substrate interacts strongly with visible light and may become a very useful component for optical applications. The proposed MIM structure can be synthesized using accessible lithography-free chemical and physical processes (anodization and capillary force assisted colloidal particle deposition) that are suitable for the low-cost production of specialized devices. Here, we present a systematic study to determine the essential MIM structure parameters (nanoparticle size and PAAO layer thickness) for localized surface plasmon resonance (LSPR) refractometric sensing. A performance comparison was done by recording the spectra of scattered light upon angled illumination in media with different refractive indices. A clear advantage for maximizing the signal to background ratio was observed in the case of 60 and 80 nm Au nanoparticles with a PAAO thickness in a narrow range between 300 and 375 nm. Sensitivity exceeding a 200 nm peak wavelength shift per refractive index unit was found for 60 nm Au nanoparticles on approximately 500-nm-thick PAAO. The experimental observations were supported by finite-difference time-domain (FDTD) simulations., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

In recent years, more and more emphasis has been placed on the development and functionalization of metallic substrates for medical applications to improve their properties and increase their applicability. Today, there are many different types of approaches and materials that are used for this purpose. Our idea was based on a combination of a chemically synthesized Ag-SiO 2 nanocomposite and the electrophoretic deposition approach on a NiTi-shape memory substrate. As a result, silver-silica coating was developed on a previously passivated alloy, which was then subjected to sintering at 700 °C for 2 h. The micrometer-sized coat-forming material was composed of large agglomerates consisting of silica and a thin film of submicron- and nano- spherical-shaped particles built of silver, carbon, and oxygen. Structurally, the coatings consisted of a combination of nanometer-sized silver-carbonate that was embedded in thin amorphous silica and siloxy network. The temperature impact had forced morphological and structural changes such as the consolidation of the coat-forming material, and the partial coalescence of the silver and silica particles. As a result, a new continuous complex ceramic coating was formed and was analyzed in more detail using the XPS, XRD, and Raman methods. According to the structural and chemical analyses, the deposited Ag-SiO 2 nanocomposite material's reorganization was due to its reaction with a passivated TiO 2 layer, which formed an atypical glass-like composite that consisted of SiO 2 -TiO 2 with silver particles that stabilized the network. Finally, the functionalization of the NiTi surface did not block the shape memory effect.

This paper describes a formation of hybrid coatings on a Ti-2Ta-3Zr-36Nb surface. This is accomplished by plasma electrolytic oxidation and a dip-coating technique with poly(adipic anhydride) ((C 6 H 8 O 3 )n) that is loaded with drugs: amoxicillin (C 16 H 19 N 3 O 5 S), cefazolin (C 14 H 14 N 8 O 4 S 3 ) or vancomycin (C 66 H 75 Cl 2 N 9 O 24 · xHCl). The characteristic microstructure of the polymer was evaluated using scanning electron microscopy and confocal microscopy. Depending on the surface treatment, the surface roughness varied (between 1.53 μm and 2.06 μm), and the wettability was change with the over of time. X-ray photoelectron spectroscopy analysis showed that the oxide layer did not affect the polymer layer or loaded drugs. However, the drugs lose their stability in a phosphate-buffered saline solution after 6.5 h of exposure, and its decrease was greater than 7% (HPLC analysis). The stability, drug release and concentration of the drug loaded into the material were precisely analyzed by high-performance liquid chromatography. The results correlated with the degradation of the polymer in which the addition of drugs caused the percent of degraded polymer to be between 35.5% and 49.4% after 1 h of material immersion, depending on the mass of the loaded drug and various biological responses that were obtained. However, all of the coatings were cytocompatible with MG-63 osteoblast-like cells. The drug concentrations released from the coatings were sufficient to inhibit adhesion of reference and clinical bacterial strains ( S. aureus ). The coatings with amoxicillin showed the best results in the bacterial inhibition zone, whereas coatings with cefazolin inhibited adhesion of the above bacteria on the surface., Competing Interests: Authors declare no conflict of interest., (© 2020 Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)

Oxide-polymer coatings were formed on the surface of the vanadium-free Ti-15Mo titanium alloy. The Ti alloy surface was modified by the plasma electrolytic oxidation process, and then, the polymer layer of a poly (D, l-lactide- co -glycolide) with doxycycline was formed. The polymer evenly covered the porous oxide layer and filled some of the pores. However, the microstructure of the polymer surface was completely different from that of the PEO layer. The surface morphology, roughness and microstructure of the polymer layer were examined by scanning electron microscopy (SEM) and a confocal microscope. The results confirmed the effectiveness of polymer and doxycycline deposition in their stable chemical forms. The drug analysis was performed by high-performance liquid chromatography. The 1 H NMR technique was used to monitor the course of hydrolytic degradation of PLGA. It was shown that the PLGA layer is hydrolysed within a few weeks, and the polyglycolidyl part of the copolymer is hydrolysed to glycolic acid as first and much faster than the polylactide one to lactic acid. This paper presents influence of different microstructures on the biological properties of modified titanium alloys. Cytocompatibility and bacterial adhesion tests were evaluated using osteoblast-like MG-63 cells and using the reference S. aureus and S. epidermidis strains. The results showed that the optimum concentration of doxycycline was found to inhibit the growth of the bacteria and that the layer is still cytocompatible., Competing Interests: None., (© 2020 Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)

Titanium and its aluminum and vanadium-free alloys have especially great potential for medical applications. Electrochemical surface modification improves their surface bioactivity and stimulates osseointegration process. In this work, the effect of plasma electrolytic oxidation of the β-type alloy Ti-15Mo surface on its bioactivity is presented. Bioactivity of the modified alloy was investigated by immersion in simulated body fluid (SBF). Biocompatibility of the modified alloys were tested using human bone marrow stromal cells (hBMSC) and wild intestinal strains (DV/A, DV/B, DV/I/1) of Desulfovibrio desulfuricans bacteria. The particles of apatite were formed on the anodized samples. Human BMSC cells adhered well on all the examined surfaces and expressed ALP, collagen, and produced mineralized matrix as determined after 10 and 21 days of culture. When the samples were inoculated with D. desulfuricans bacteria, only single bacteria were visible on selected samples. There were no obvious changes in surface morphology among samples. Colonization and bacterial biofilm formation was observed on as-ground sample. In conclusion, the surface modification improved the Ti-15Mo alloy bioactivity and biocompatibility and protected surface against colonization of the bacteria. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 903-913, 2016., (© 2015 Wiley Periodicals, Inc.)