A modified biodegradable magnesium alloy (AZ31, 96 wt% Mg, 3 wt% Al, and 1 wt% Zn) with polylacti... more A modified biodegradable magnesium alloy (AZ31, 96 wt% Mg, 3 wt% Al, and 1 wt% Zn) with polylactic acid (PLA) nanofibers was obtained by the electrospinning technique. The presence of PLA nanofibers was evidenced using Fourier transform infrared spectroscopy (FT-IR) and using an scanning electronic microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) module. The degradation behavior of an uncoated Mg alloy and a Mg alloy coated with PLA was evaluated through hydrogen evolution, pH, and electrochemical measurements in simulated body fluid. Contact angle measurements showed a shift from hydrophilic towards the hydrophobic character of the alloy after its coating with PLA nanofibers. Furthermore, the electrochemical measurement results show that the Mg based alloy coated with PLA inhibits hydrogen evolution, thus being less prone to degradation. The aim of this research is not only to reduce the corrosion rate of Mg alloy and to improve its properties with the h...
The current study presents research about electrodeposition in relation to electrospinning PCL wi... more The current study presents research about electrodeposition in relation to electrospinning PCL wires on a Zr substrate and loading the coating with vancomycin. The structural composition of the coatings was investigated via FT-IR analysis. The morphology evaluated using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, for the composition (SEM-EDS), evidenced the presence of the polymer wires, with and without drug vancomycin loading. The wettability of the coatings was evaluated from the hydrophobic–hydrophilic point of view, and the characterization was completed with mechanical and electrochemical tests. All the electrochemical tests performed in simulated body fluid highlighted that PCL represents a barrier against corrosion processes. The quantitative method to evaluate the loading efficiency shows that almost 80% of the total loaded vancomycin is released within 144 h; after the initial burst at 24 h, a steady release of vancomycin is observed ove...
The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L... more The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L, with fluoride, Zn and Cu as dopant ions, using an electrochemical procedure and also the attempt to select the best conditions for stainless steel. The surface was characterized using X-ray difraction, AFM and contact angle measurements. X-ray has evidenced crystaline phases, contact angle measurements has established the balance hydrophyl-hydrophob and AFM established roughness values. The inductively coupled spectrometry (ICP-MS) has quantified the amount of cooper and zinc ions released. In order to be used in biomedical applications hemolysis and antibacterial tests have been performed.
The aim of the present investigation is the electrochemical deposition of polypyrrole films from ... more The aim of the present investigation is the electrochemical deposition of polypyrrole films from choline chloride-based ionic liquids at various potential, period times and simultaneously an indomethacin embedding and release. The electrodeposition films were performed on CoCr commercial type Wirobond C (WBC) and, Heraenium CE (Hera) using as electroprocedures for deposition cyclic voltammetry and chronoamperometry. The morphology of obtained films was investigated using scanning electron microscopy (SEM). An FT-IR investigation of CoCr alloys before and after electrodeposition was able to identify the presence of polymer and drug. The research included an evaluation of the hydrophilic character of all studied samples and their electrochemical characterization in Tanni Zuchi artificial saliva. In the electrochemical study, the following methods have been used: open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization. Indomethacin release from t...
This paper is a review focused on the capability of graphene oxide (GO) coatings in preventing pe... more This paper is a review focused on the capability of graphene oxide (GO) coatings in preventing peri-implantitis. Firstly, the paper establishes GO’s place in the frame of carbonic materials and its role as a composite material in dentistry in the prevention of bacterial infections and in sustaining osseointegration. Secondly, the most relevant articles on GO as implant coatings and their associated shortcomings are presented and emphasizing is placed on the areas where more data is needed. The main chapters are devoted to the relationship between GO and biofilm formation on the implants and the surrounding periodontal tissue and we also attempt to evaluate GO’s efficacy in the case of peri-implantitis. Our findings strongly indicate that GO is a promising material for mitigating the problems mentioned, but some answers remain to be answered through rigorous research before declaring it a real success.
The present paper aims atincreasing the bioperformance of implantable Ti50Zr alloy using zwitteri... more The present paper aims atincreasing the bioperformance of implantable Ti50Zr alloy using zwitterionic cysteine drug coating. Aspects such as stability, biocompatibility, and antibacterial effects were investigated with the help of various methods such as infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM), electrochemical methods, contact angle determinations and cell response. The experimental data of zwitterionic cysteine coating indicate the existence of a hydration layer due to hydrophilic groups evidenced in FT-IR which is responsible for the decrease of contact angle and antibacterial capabilities. The electrochemical stability was evaluatedbased on Tafel plots and electrochemical impedance spectroscopy (EIS). The cell response to cysteine was determined with gingival fibroblasts measuring lactate dehydrogenase (LDH) activity, concentrations of nitric oxide (NO) and intracellular level of reactive oxygen species (ROS). All experimental results supported the inc...
Despite many discussions about Ti versus Zr, Ti remains the golden standard for dental implants. ... more Despite many discussions about Ti versus Zr, Ti remains the golden standard for dental implants. With the extended use of implants, their rejection in peri-implantitis due to material properties is going to be an important part of oral health problems. Extended use of implants leading to a statistical increase in implant rejection associated with peri-implantitis raises concerns in selecting better implant materials. In this context, starting in the last decade, investigation and use of TiZr alloys as alternatives for Ti in oral dentistry became increasingly more viable. Based on existing new results for Ti16Zr (Roxolid) implants and Ti50Zr alloy behaviour in oral environments, this paper presents the trends of research concerning the electrochemical stability, mechanical, and biological properties of this alloy with treated and untreated surfaces. The surface treatments were mostly performed by anodizing the alloy in various conditions as a non-sophisticated and cheap procedure, le...
Starting with a description of the meaning of sustainable coating nowadays, this review presents ... more Starting with a description of the meaning of sustainable coating nowadays, this review presents a selection of methods for sustainable coatings manufacture using raw materials, saving energy and costs. This selection creates an introduction for the coatings performances of intensively investigated coated alloys and their multifunctionality. There are many examples and EU recommendations to be discussed, and we especially chose to introduce sustainable coatings with both industrial and medical functions, such as bioinspired films and coatings on high-entropy alloys, biodegradable metallic alloys, etc. A special focus is on nanotechnology and nanomaterials in green procedures, enhancing coatings’ multifunctionality, introducing green corrosion inhibitors, smart additives, and coatings based on superhydrophobicity. The conclusions and future perspectives of sustainable and multifunctional coatings, as expressions of sustainable advanced materials, are based on important motivations of...
This review article was developed based on the scientometric analysis of the evaluated studies co... more This review article was developed based on the scientometric analysis of the evaluated studies conducted on titanium−zirconium (TixZr) alloys from 2000 to the present. The scientometric data obtained helped us to identify the most researched topics and these topics were further analyzed and discussed. An increasing number of researchers are considering TixZr alloys as opposed to the traditional ones because these alloys present improved mechanical properties and in some cases improved corrosion resistance and biocompatibility. Due to the natural layer of oxides formed on these alloys, multiple surface modification methods can be applied to solve some of the challenges faced in the field of implantable materials. A significant number of studies are now focusing on surface modifications at the nanometer scale or various coatings for improved corrosion resistance and biological interactions. Although not yet commercially available, a TiZr alloy with a nanostructured surface and embedde...
This paper compares two types of polylactic acid (PLA) coating on AZ31 alloy obtained by dip coat... more This paper compares two types of polylactic acid (PLA) coating on AZ31 alloy obtained by dip coating and electrospinning. Both types of coating were loaded with gentamicin sulphate (GS) and the drug-loading efficiency and release were assessed. A higher encapsulation and release efficiency of GS was seen for dip coating (73% and 49.53%, respectively) compared to nanofiber coating (65% and 12.37%, respectively). Furthermore, the antibacterial effect of the samples with and without GS was assessed using Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, showing that the samples with the drug encapsulated are more resistant to bacteria than the other samples. The electrochemical data reveal a higher stability in the SBF of the surface obtained by dipping than that obtained by electrospinning. The PLA coating shows a porosity of 46% for the sample obtained through dip coating and 32% for nanofibers, which is in accordance with the BET analysis results. ...
High-frequency ingredients, at time scales of 22 and ~80 years, present in observatory data and m... more High-frequency ingredients, at time scales of 22 and ~80 years, present in observatory data and main field models, are also components of the radial field evolution at core surface. In this paper we focus on the ~80-year variation in the gufm1 model. Time-longitude plots covering a time span of about 320 years, at various latitudes between 60N and 60S, show a clear westward movement of the ~80-year features from the 30S-30N latitude band. The travelling speed of the latter is derived empirically and by means of spectral analysis. Time-latitude plots for several longitude bands indicate also a northward component of the movement of some features.
High frequency secular variation components at 22 and ~80 years timescales were evidenced in the ... more High frequency secular variation components at 22 and ~80 years timescales were evidenced in the 100-150 years-long series of geomagnetic annual means from several geomagnetic observatories, after eliminating solar activity related variations (Schwabe and Hale cycles effects). They are superimposed on a so-called steady variation that carries the largest part of the field. The 22- and ~80-year variations, with amplitudes of 20-100 nT and, respectively, several hundred nT, are significant in terms of secular variation at regional and local scale and in terms of ingredients of geomagnetic jerks. In terms of the present analysis, the geomagnetic jerks are a result of the superposition of the 11-year external contribution on the 22- and the ~80-year variations; the external contribution is decisive in establishing the very short time scale characterizing jerks and, to some extent, also the amplitude and timing of the jerk. Main field geomagnetic models (IGRF-10th, CM4) are used to impro...
Additional file 2: Fig. S2. Animation of the geographical distribution of the core surface radial... more Additional file 2: Fig. S2. Animation of the geographical distribution of the core surface radial component of the sub-centennial constituent.
A modified biodegradable magnesium alloy (AZ31, 96 wt% Mg, 3 wt% Al, and 1 wt% Zn) with polylacti... more A modified biodegradable magnesium alloy (AZ31, 96 wt% Mg, 3 wt% Al, and 1 wt% Zn) with polylactic acid (PLA) nanofibers was obtained by the electrospinning technique. The presence of PLA nanofibers was evidenced using Fourier transform infrared spectroscopy (FT-IR) and using an scanning electronic microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) module. The degradation behavior of an uncoated Mg alloy and a Mg alloy coated with PLA was evaluated through hydrogen evolution, pH, and electrochemical measurements in simulated body fluid. Contact angle measurements showed a shift from hydrophilic towards the hydrophobic character of the alloy after its coating with PLA nanofibers. Furthermore, the electrochemical measurement results show that the Mg based alloy coated with PLA inhibits hydrogen evolution, thus being less prone to degradation. The aim of this research is not only to reduce the corrosion rate of Mg alloy and to improve its properties with the h...
The current study presents research about electrodeposition in relation to electrospinning PCL wi... more The current study presents research about electrodeposition in relation to electrospinning PCL wires on a Zr substrate and loading the coating with vancomycin. The structural composition of the coatings was investigated via FT-IR analysis. The morphology evaluated using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, for the composition (SEM-EDS), evidenced the presence of the polymer wires, with and without drug vancomycin loading. The wettability of the coatings was evaluated from the hydrophobic–hydrophilic point of view, and the characterization was completed with mechanical and electrochemical tests. All the electrochemical tests performed in simulated body fluid highlighted that PCL represents a barrier against corrosion processes. The quantitative method to evaluate the loading efficiency shows that almost 80% of the total loaded vancomycin is released within 144 h; after the initial burst at 24 h, a steady release of vancomycin is observed ove...
The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L... more The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L, with fluoride, Zn and Cu as dopant ions, using an electrochemical procedure and also the attempt to select the best conditions for stainless steel. The surface was characterized using X-ray difraction, AFM and contact angle measurements. X-ray has evidenced crystaline phases, contact angle measurements has established the balance hydrophyl-hydrophob and AFM established roughness values. The inductively coupled spectrometry (ICP-MS) has quantified the amount of cooper and zinc ions released. In order to be used in biomedical applications hemolysis and antibacterial tests have been performed.
The aim of the present investigation is the electrochemical deposition of polypyrrole films from ... more The aim of the present investigation is the electrochemical deposition of polypyrrole films from choline chloride-based ionic liquids at various potential, period times and simultaneously an indomethacin embedding and release. The electrodeposition films were performed on CoCr commercial type Wirobond C (WBC) and, Heraenium CE (Hera) using as electroprocedures for deposition cyclic voltammetry and chronoamperometry. The morphology of obtained films was investigated using scanning electron microscopy (SEM). An FT-IR investigation of CoCr alloys before and after electrodeposition was able to identify the presence of polymer and drug. The research included an evaluation of the hydrophilic character of all studied samples and their electrochemical characterization in Tanni Zuchi artificial saliva. In the electrochemical study, the following methods have been used: open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization. Indomethacin release from t...
This paper is a review focused on the capability of graphene oxide (GO) coatings in preventing pe... more This paper is a review focused on the capability of graphene oxide (GO) coatings in preventing peri-implantitis. Firstly, the paper establishes GO’s place in the frame of carbonic materials and its role as a composite material in dentistry in the prevention of bacterial infections and in sustaining osseointegration. Secondly, the most relevant articles on GO as implant coatings and their associated shortcomings are presented and emphasizing is placed on the areas where more data is needed. The main chapters are devoted to the relationship between GO and biofilm formation on the implants and the surrounding periodontal tissue and we also attempt to evaluate GO’s efficacy in the case of peri-implantitis. Our findings strongly indicate that GO is a promising material for mitigating the problems mentioned, but some answers remain to be answered through rigorous research before declaring it a real success.
The present paper aims atincreasing the bioperformance of implantable Ti50Zr alloy using zwitteri... more The present paper aims atincreasing the bioperformance of implantable Ti50Zr alloy using zwitterionic cysteine drug coating. Aspects such as stability, biocompatibility, and antibacterial effects were investigated with the help of various methods such as infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM), electrochemical methods, contact angle determinations and cell response. The experimental data of zwitterionic cysteine coating indicate the existence of a hydration layer due to hydrophilic groups evidenced in FT-IR which is responsible for the decrease of contact angle and antibacterial capabilities. The electrochemical stability was evaluatedbased on Tafel plots and electrochemical impedance spectroscopy (EIS). The cell response to cysteine was determined with gingival fibroblasts measuring lactate dehydrogenase (LDH) activity, concentrations of nitric oxide (NO) and intracellular level of reactive oxygen species (ROS). All experimental results supported the inc...
Despite many discussions about Ti versus Zr, Ti remains the golden standard for dental implants. ... more Despite many discussions about Ti versus Zr, Ti remains the golden standard for dental implants. With the extended use of implants, their rejection in peri-implantitis due to material properties is going to be an important part of oral health problems. Extended use of implants leading to a statistical increase in implant rejection associated with peri-implantitis raises concerns in selecting better implant materials. In this context, starting in the last decade, investigation and use of TiZr alloys as alternatives for Ti in oral dentistry became increasingly more viable. Based on existing new results for Ti16Zr (Roxolid) implants and Ti50Zr alloy behaviour in oral environments, this paper presents the trends of research concerning the electrochemical stability, mechanical, and biological properties of this alloy with treated and untreated surfaces. The surface treatments were mostly performed by anodizing the alloy in various conditions as a non-sophisticated and cheap procedure, le...
Starting with a description of the meaning of sustainable coating nowadays, this review presents ... more Starting with a description of the meaning of sustainable coating nowadays, this review presents a selection of methods for sustainable coatings manufacture using raw materials, saving energy and costs. This selection creates an introduction for the coatings performances of intensively investigated coated alloys and their multifunctionality. There are many examples and EU recommendations to be discussed, and we especially chose to introduce sustainable coatings with both industrial and medical functions, such as bioinspired films and coatings on high-entropy alloys, biodegradable metallic alloys, etc. A special focus is on nanotechnology and nanomaterials in green procedures, enhancing coatings’ multifunctionality, introducing green corrosion inhibitors, smart additives, and coatings based on superhydrophobicity. The conclusions and future perspectives of sustainable and multifunctional coatings, as expressions of sustainable advanced materials, are based on important motivations of...
This review article was developed based on the scientometric analysis of the evaluated studies co... more This review article was developed based on the scientometric analysis of the evaluated studies conducted on titanium−zirconium (TixZr) alloys from 2000 to the present. The scientometric data obtained helped us to identify the most researched topics and these topics were further analyzed and discussed. An increasing number of researchers are considering TixZr alloys as opposed to the traditional ones because these alloys present improved mechanical properties and in some cases improved corrosion resistance and biocompatibility. Due to the natural layer of oxides formed on these alloys, multiple surface modification methods can be applied to solve some of the challenges faced in the field of implantable materials. A significant number of studies are now focusing on surface modifications at the nanometer scale or various coatings for improved corrosion resistance and biological interactions. Although not yet commercially available, a TiZr alloy with a nanostructured surface and embedde...
This paper compares two types of polylactic acid (PLA) coating on AZ31 alloy obtained by dip coat... more This paper compares two types of polylactic acid (PLA) coating on AZ31 alloy obtained by dip coating and electrospinning. Both types of coating were loaded with gentamicin sulphate (GS) and the drug-loading efficiency and release were assessed. A higher encapsulation and release efficiency of GS was seen for dip coating (73% and 49.53%, respectively) compared to nanofiber coating (65% and 12.37%, respectively). Furthermore, the antibacterial effect of the samples with and without GS was assessed using Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, showing that the samples with the drug encapsulated are more resistant to bacteria than the other samples. The electrochemical data reveal a higher stability in the SBF of the surface obtained by dipping than that obtained by electrospinning. The PLA coating shows a porosity of 46% for the sample obtained through dip coating and 32% for nanofibers, which is in accordance with the BET analysis results. ...
High-frequency ingredients, at time scales of 22 and ~80 years, present in observatory data and m... more High-frequency ingredients, at time scales of 22 and ~80 years, present in observatory data and main field models, are also components of the radial field evolution at core surface. In this paper we focus on the ~80-year variation in the gufm1 model. Time-longitude plots covering a time span of about 320 years, at various latitudes between 60N and 60S, show a clear westward movement of the ~80-year features from the 30S-30N latitude band. The travelling speed of the latter is derived empirically and by means of spectral analysis. Time-latitude plots for several longitude bands indicate also a northward component of the movement of some features.
High frequency secular variation components at 22 and ~80 years timescales were evidenced in the ... more High frequency secular variation components at 22 and ~80 years timescales were evidenced in the 100-150 years-long series of geomagnetic annual means from several geomagnetic observatories, after eliminating solar activity related variations (Schwabe and Hale cycles effects). They are superimposed on a so-called steady variation that carries the largest part of the field. The 22- and ~80-year variations, with amplitudes of 20-100 nT and, respectively, several hundred nT, are significant in terms of secular variation at regional and local scale and in terms of ingredients of geomagnetic jerks. In terms of the present analysis, the geomagnetic jerks are a result of the superposition of the 11-year external contribution on the 22- and the ~80-year variations; the external contribution is decisive in establishing the very short time scale characterizing jerks and, to some extent, also the amplitude and timing of the jerk. Main field geomagnetic models (IGRF-10th, CM4) are used to impro...
Additional file 2: Fig. S2. Animation of the geographical distribution of the core surface radial... more Additional file 2: Fig. S2. Animation of the geographical distribution of the core surface radial component of the sub-centennial constituent.
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