scholarly journals Formation of Tribofilm in the Friction of Fluorinated Diamond-Like Carbon (FDLC) Film against Ti6Al4V in Bovine Serum Albumin (BSA) Solution

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 903
Author(s):  
Tengfei Zhang ◽  
Zhaoying Xu ◽  
Yongyao Su ◽  
Jinbiao Wang ◽  
Lu Li ◽  
...  

A route to reducing the wear of the metal counterpart in the friction of meatal against diamond-like carbon (DLC) is to form a lubricating tribofilm on the metal counterface. However, in liquid lubricating conditions, the formation of tribofilm can be influenced by both the lubricating medium and the counterpart material. Here we report the effect of lubricating biomolecule and doping fluorine element on the formation of tribofilm in fluorinated DLC (FDLC)-Ti6Al4V friction system. A group of ball-on-disc frictional experiments with different sliding speeds and normal loads were performed in phosphate buffer solution (PBS) and bovine serum albumin (BSA) solution. The results showed the formation of tribofilm was inhibited by the absorption of biomolecules on the frictional surface, thus improving the friction coefficient and wear of Ti6Al4V counterpart. Doping fluorine into DLC film also can restrain the formation of tribofilm on Ti6Al4V counterface. As a result, tribofilm is difficult to form when Ti6Al4V counterface slides against FDLC in BSA solution. Fluorinated DLC film should be considered carefully for the anti-wear use in body fluid containing biomolecules because it might cause severe wear of the counterpart material.

2011 ◽  
Vol 284-286 ◽  
pp. 1764-1769 ◽  
Author(s):  
Vitalijs Lakevics ◽  
Janis Locs ◽  
Dagnija Loca ◽  
Valentina Stepanova ◽  
Liga Berzina-Cimdina ◽  
...  

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed.


Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 61 ◽  
Author(s):  
Choshun Yoneyama ◽  
Shoufan Cao ◽  
Anna Igual Munoz ◽  
Stefano Mischler

Tribocorrosion, as the interaction between mechanical wear and electrochemical corrosion, has been found to be the main problem causing the failure and limiting the lifetime of metal-on-metal artificial hip joints. Better understanding of the tribocorrosion mechanisms of CoCrMo alloys is needed in order to reduce the degradation of this alloy, especially in the presence of proteins as one of the organic components present in synovial fluid. In this study, tribocorrosion tests of a low carbon CoCrMo alloy in phosphate buffer solution (PBS) with and without bovine serum albumin (BSA) in two different concentrations at different applied potentials (passive and cathodic) were carried out. The results show that the effect of proteins on wear and friction was concentration and potential dependent. In the cathodic domain (absence of very thin passive film), wear was very low in all solutions and the friction was significantly reduced by the addition of BSA to PBS even at low BSA concentrations. However, in the passive domain, the friction and wear were found not to be affected when the BSA concentration was 0.5 g/L, while they were reduced when increasing the BSA concentration to 36 g/L. The tribocorrosion results were rationalized through an existing tribocorrosion model and the effect of BSA on wear and friction was explained by the consideration of physical factors such as changes in viscosity and double layer structure, because in the present results no tribofilm formation was observed.


Chemosensors ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 31
Author(s):  
Rodrigo da Costa Duarte ◽  
Fabiano da Silveira Santos ◽  
Bruno Bercini de Araújo ◽  
Rodrigo Cercena ◽  
Daniela Brondani ◽  
...  

In this study, we synthesized a spiropyran containing an electron-withdrawing carboxyl group in good yield by condensation of an aromatic aldehyde with enamine indole. The spiropyran absorbed at the ultraviolet region with a maximum at approximately 300 nm, demonstrating slight solvatochromism (~3 nm). A fluorescent emission around 360 nm was observed with a higher solvatochromic effect (~12 nm), indicating higher electronic delocalization in the excited state. The photoreversibility of the open and closed forms of spiropyran excited at 300 nm and 365 nm was not observed, indicating that the absence of the nitro group plays a fundamental role in this equilibrium. Theoretical calculations were also applied for better understanding the photophysics of these compounds. Electrochemical characterization revealed the values of the HOMO and LUMO energy levels at −1.89 eV (electron affinity) and −5.61 eV (ionization potential), respectively. Thermogravimetric analysis showed excellent thermal stability of the spiropyran, with 5% weight loss at approximately 250 °C. Finally, the photophysical features were used to explore the interaction of spiropyran with bovine serum albumin in a phosphate buffer solution, where a significant suppression mechanism was observed.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 90 ◽  
Author(s):  
Paula Ossowicz ◽  
Proletina Kardaleva ◽  
Maya Guncheva ◽  
Joanna Klebeko ◽  
Ewelina Świątek ◽  
...  

The development of ionic liquids based on active pharmaceutical ingredients (API-ILs) is a possible solution to some of the problems of solid and/or hydrophobic drugs such as low solubility and bioavailability, polymorphism and an alternative route of administration could be suggested as compared to the classical drug. Here, we report for the first time the synthesis and detailed characterization of a series of ILs containing a cation amino acid esters and anion ketoprofen (KETO-ILs). The affinity and the binding mode of the KETO-ILs to bovine serum albumin (BSA) were assessed using fluorescence spectroscopy. All compounds bind in a distance not longer than 6.14 nm to the BSA fluorophores. The estimated binding constants (KA) are in order of 105 L mol−1, which is indicative of strong drug or IL-BSA interactions. With respect to the ketoprofen-BSA system, a stronger affinity of the ILs containing l-LeuOEt, l-ValOBu, and l-ValOEt cation towards BSA is clearly seen. Fourier transformed infrared spectroscopy experiments have shown that all studied compounds induced a rearrangement of the protein molecule upon binding, which is consistent with the suggested static mechanism of BSA fluorescence quenching and formation of complexes between BSA and the drugs. All tested compounds were safe for macrophages.


Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3395 ◽  
Author(s):  
Iulia Matei ◽  
Cristina Maria Buta ◽  
Ioana Maria Turcu ◽  
Daniela Culita ◽  
Cornel Munteanu ◽  
...  

The formation and growth of gold nanoparticles (AuNPs) were investigated in pH 7 buffer solution of bovine serum albumin (BSA) at room temperature. The processes were monitored by UV-Vis, circular dichroism, Raman and electron paramagnetic resonance (EPR) spectroscopies. TEM microscopy and dynamic light scattering (DLS) measurements were used to evidence changes in particle size during nanoparticle formation and growth. The formation of AuNPs at pH 7 in the absence of BSA was not observed, which proves that the albumin is involved in the first step of Au(III) reduction. Changes in the EPR spectral features of two spin probes, CAT16 and DIS3, with affinity for BSA and AuNPs, respectively, allowed us to monitor the particle growth and to demonstrate the protective role of BSA for AuNPs. The size of AuNPs formed in BSA solution increases slowly with time, resulting in nanoparticles of different morphologies, as revealed by TEM. Raman spectra of BSA indicate the interaction of albumin with AuNPs through sulfur-containing amino acid residues. This study shows that albumins act as both reducing agents and protective corona of AuNPs.


2014 ◽  
Vol 16 (3) ◽  
pp. 97-105 ◽  
Author(s):  
Mesut Karahan ◽  
Zeynep Mustafaeva ◽  
Cemal Özeroğlu

Abstract The binary and ternary complex formations of poly(methyl vinyl ether-co-maleic anhydride) (PMVEMA) with copper ions and with bovine serum albumin (BSA) in the presence of copper ions in phosphate buffer solution at pH = 7 were examined by the techniques of UV-visible, fluorescence, dynamic light scattering, atomic force microscopy measurements. In the formation of binary complexes of PMVEMA-Cu(II), the addition of copper ions to the solution of PMVEMA in phosphate buffer solution at pH = 7 forms homogeneous solutions when the molar ratio of Cu(II)/MVEMA is 0.5. Then the formations of ternary complexes of PMVEMA-Cu(II)-BSA were examined. Study analysis revealed that the toxicities of polymer-metal and polymer-metal-protein mixture solutions depend on the nature and ratio of components in mixtures.


2021 ◽  
Author(s):  
Tahmineh Atloo ◽  
Ramin Mohammadkhani ◽  
Ali Mohammadi ◽  
Kasra Arbabi Zaboli ◽  
Saeed Kaboli ◽  
...  

Abstract In this work, first, copper oxide nanoparticles (CUO NPs) were synthesized by physical methods and then coated with the bovine serum albumin (BSA) via biologically meditated minerals to form CUO@BSA NPs. Finally, curcumin (CUR) as an anticancer drug were immobilized on the surface of CUO@BSA NPS. The properties of CUO@BSA-CUR NPS were investigated by FTIR, UV-Vis, TEM, and AFM spectroscopes. It was found that the synthesized CUO@BSA-CUR nanoparticles were spherical with a particle size of 20 to 30 nm and have a sustained release of CUR at 37°C in buffer solution. Also, the result of release in biological environment showed that maximum drug release rate for this nanocarrier in pH 7.4 was measured 75% after 48 hours. The cytotoxicity of CUO@BSA-CUR on MDA-MB-231 cell line was studied. The results showed that CUO@BSA-CUR nanoparticles have significant cytotoxic activity on this cell line, while the results of MTT assay indicated the CUO@BSA NPs have no toxicity effect on the cancer cells.


2007 ◽  
Vol 361-363 ◽  
pp. 71-74 ◽  
Author(s):  
Giichiro Kawachi ◽  
T. Watanabe ◽  
K. Kikukta ◽  
Chikara Ohtsuki

Micrometer-sized hydroxyapatite (HA) with rod-shape was prepared to investigate protein adsorption onto its crystal face, through hydrothermal processing. Adsorption of Bovine serum albumin (BSA) and Lysozyme from chicken egg white (LSZ) on rod-shaped HA crystals with approximately 50 μm in length and 1 μm thickness was examined in phosphate buffer solution. The amount of adsorbed BSA was decreased with increasing phosphate concentration in the examined solution. Adsorption of LSZ was increased with increasing phosphate concentration in the buffer solution up to 50 mmol/L (mM), while it was remarkably decreased when the phosphate concentration reached approximately 100 mM. These phenomena lead to understanding of chromatographic characters of HA for separation of acidic and basic proteins.


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