In Vitro Apatite Formation on Polymer Substrates Irradiated by the Simultaneous Use of Oxygen Cluster and Monomer Ion Beams

2007 ◽  
Vol 1020 ◽  
Author(s):  
Masakazu Kawashita ◽  
Rei Araki ◽  
Gikan H Takaoka
Keyword(s):  
Functional Groups ◽  
Silicone Rubber ◽  
Silicon Oxide ◽  
Ion Beams ◽  
Phosphate Solution ◽  
Apatite Formation ◽  
Oh Groups ◽  
Oxygen Cluster ◽  
Simultaneous Use

AbstractPolyethylene (PE) and silicone rubber substrates were irradiated at an acceleration voltage of 7kV and a dose of 1×1015 ions/cm2 by the simultaneous use of oxygen cluster and monomer ion beams, and then soaked in CaCl2 solution. Apatite-forming ability of the substrates was examined using a metastable calcium phosphate solution that had 1.5 times the ion concentrations of a normal simulated body fluid (1.5SBF). After the irradiation, the hydrophilic functional groups such as COOH and silicon oxide cluster (SiOx) were formed at the PE and silicone rubber surfaces, respectively. The hydrophilicity of the substrates was remarkably improved by the irradiation. The irradiated PE and silicone rubber substrates formed apatite in 1.5SBF, whereas unirradiated ones did not form it. These results suggest that the functional groups such as COOH groups and Si-OH groups induced apatite nucleation in 1.5SBF.

Surface Structure and Apatite-Forming Ability of Silicone Rubber Substrates Irradiated by Cluster Ion Beams

2007 ◽  
Vol 361-363 ◽  
pp. 551-554
Author(s):  
Kawashita Masakazu ◽  
Rei Araki ◽  
Gikan H. Takaoka
Keyword(s):  
Silicone Rubber ◽  
Silicon Oxide ◽  
Ion Beams ◽  
Phosphate Solution ◽  
Ion Concentrations ◽  
Rubber Surface ◽  
Cluster Ion Beams ◽  
Cluster Ion ◽  
Acceleration Voltage ◽  
Cacl2 Solution

Silicone rubber substrates were irradiated at an acceleration voltage of 7 kV and a dose of 1×1015 ions/cm2 by the simultaneous use of oxygen cluster and monomer ion beams, and then soaked in CaCl2 solution. Apatite-forming ability of the substrates was examined using a metastable calcium phosphate solution that had 1.5 times the ion concentrations of a normal simulated body fluid (1.5SBF). After the irradiation, the silicon oxide clusters (SiOx) were formed at the silicone rubber surface. The hydrophilicity of the substrates was remarkably improved by the irradiation. The irradiated silicone rubber substrates formed apatite in 1.5SBF, whereas unirradiated ones did not form it. These results suggest that the functional groups such as Si–OH and/or COOH groups induced apatite nucleation in 1.5SBF.

Biomimetic Bone-Like Apatite Coating on Anodised Titanium in Simulated Body Fluid under UV Irradiation

2017 ◽  
Vol 888 ◽  
pp. 251-255 ◽  
Author(s):  
T.C. Lee ◽  
Pramod Koshy ◽  
Hasan Zuhudi Abdullah ◽  
M.I. Idris
Keyword(s):  
Uv Irradiation ◽  
Uv Light ◽  
Light Treatment ◽  
Disodium Salt ◽  
Apatite Formation ◽  
Oh Groups ◽  
Uva Irradiation ◽  
Apatite Coating ◽  
Titanium Foils

Low temperature deposition techniques of bioceramics coatings are now being researched and developed to avoid deficiencies inherent in high temperature techniques. Biomimetic coatings is a solution-based method conducted at ambient temperature to deposit bioactive coatings on the surface. The current study aims to investigate the effect of ultraviolet (UV) irradiation on the coating of bone-like apatite on the anodised surface. High purity titanium foils were anodised with an applied voltage of 350 V, current density of 70 mA.cm-2 in mixture of 0.04 M β-glycerophosphate disodium salt pentahydrate (β-GP) and 0.4 M calcium acetate (CA) for 10 min. After anodic oxidation, UV light treatment was conducted in pH-adjusted distilled water for 12 hours with ultraviolet light A (UVA) irradiation. Subsequently, the UV-treated anodised titanium foils were soaked in SBF for 7 days with/without UVA irradiation. After SBF immersion for 7 days, anodised titanium with combination of UV light treatment and UV irradiation during in vitro testing was fully covered by highly crystalline bone-like apatite at maximal thickness of 2.8 μm. This occurred mainly due to the formation of large amounts of Ti-OH groups which act as nucleation sites for bone-like apatite. This study also revealed that UV irradiation during in vitro testing is superior in promoting growth of bone-like apatite compared to UV light treatment. The suggested mechanism for bone-like apatite formation on anodised titanium under different UV irradiation conditions is illustrated in this article. The findings of this study indicated that biomimetic bone-like apatite coating with assistance of UV irradiation is an effective method in accelerating the formation of bone-like apatite.

scholarly journals Chemical Modification of Silicone Rubber by Oxygen Cluster and Monomer Ion Beams

2010 ◽  
Vol 35 (4) ◽  
pp. 781-784 ◽  
Author(s):  
Hiromichi Ryuto ◽  
Rei Araki ◽  
Takashi Yakushiji ◽  
Gikan H. Takaoka
Keyword(s):  
Chemical Modification ◽  
Silicone Rubber ◽  
Ion Beams ◽  
Oxygen Cluster

Effect of UV Wavelength on Apatite Formation of Anodised Titanium

2015 ◽  
Vol 1125 ◽  
pp. 465-469
Author(s):  
Te Chuan Lee ◽  
Hasan Zuhudi Abdullah ◽  
Maizlinda Izwana Idris
Keyword(s):  
Uv Light ◽  
Chemical Properties ◽  
Light Treatment ◽  
Disodium Salt ◽  
Light Illumination ◽  
Apatite Formation ◽  
Oh Groups ◽  
Novel Method ◽  
Titanium Foils

A novel method to accelerate the apatite formation on the anodised titanium is proposed in this article. The processing was composed of two steps which were UV light treatment after anodic oxidation, and UV light illumination during soaking in simulated body fluid (SBF). This study aims to investigate the effect of different UV wavelengths during SBF on the apatite formation of anodised titanium. The titanium foils were anodised in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). Subsequently, the anodised titanium foils were pre-treated with UV light. In vitro was conducted by illuminating with different wavelengths of UV light (254nm and 365nm) in SBF. Field emission scanning electron microscopy (FESEM) and X-ray diffractometer (XRD) were used to characterise the surface morphology and crystallinity of anodised titanium. The results showed that donut-shaped pores with anatase/rutile phases were formed on the surface of anodised titanium. Apart from that, the UV light treatment did change the chemical properties of anodised titanium by producing more •OH groups. After UV light illumination in SBF for 1 week, the anodised titanium foils were fully covered by bone-like apatite.

Apatite-Forming Ability of Polymer Substrates Irradiated by Oxygen Cluster Ion Beams

2007 ◽  
Vol 330-332 ◽  
pp. 111-114 ◽  
Author(s):  
Kawashita Masakazu ◽  
Satomi Itoh ◽  
Kazunori Miyamoto ◽  
Rei Araki ◽  
Gikan H. Takaoka
Keyword(s):  
Substrate Surface ◽  
Ion Beams ◽  
Human Blood Plasma ◽  
Polymer Substrates ◽  
Ion Concentrations ◽  
Cluster Ion Beams ◽  
Cluster Ion ◽  
Oxygen Cluster ◽  
Simultaneous Use ◽  
Acceleration Voltage

Polyethylene (PE) substrates were irradiated at a dose of 1×1015 ions·cm−2 by the simultaneous use of oxygen (O2) cluster and monomer ion beams. The acceleration voltage for the ion beams was 7 kV. Unirradiated and irradiated PE substrates were soaked in simulated body fluid with ion concentrations 1.5 times of those of human blood plasma (1.5SBF) for 7 days. The irradiated PE substrate formed apatite on its surface, whereas unirradiated one did not form it. This is attributed to the formation of functional groups effective for apatite nucleation, such as COOH groups, on the substrate surface by the simultaneous use of O2 cluster and monomer ion beams. In addition, the apatite-forming ability of the irradiated substrate was improved by the subsequent CaCl2 treatment. This suggests that Ca2+ ions present on the substrate surface accelerated the apatite deposition. We can conclude that apatite-forming ability can be induced on surface of polyethylene by the simultaneous use of O2 cluster and monomer ion beams.

scholarly journals In silico study the interaction of heterocyclic bases with peptide moieties of proteins in the "fragment-to-fragment" approach

2021 ◽  
Vol 16 (1) ◽  
pp. 34-43
Author(s):  
Yevheniia Velihina ◽  
Nataliya Obernikhina ◽  
Stepan Pilyo ◽  
Maryna Kachaeva ◽  
Oleksiy Kachkovsky
Keyword(s):  
Amino Acids ◽  
Hydrogen Bonding ◽  
Binding Energy ◽  
Functional Groups ◽  
In Silico ◽  
Peptide Bond ◽  
Oh Groups ◽  
Free Peptide ◽  
Heterocyclic Bases

The binding affinity of model peptide moieties (Pept) and heterocyclic bases involving 1,3-oxazoles that are condensed with pyridine and pyrimidine as pharmacophores (Pharm) was investigated in silico and analyzed within the «fragment-to-fragment» approach. The anellation of the heterocyclic rings increasing their acceptor properties is accompanied by gaining stability of the [Pharm-Pept] complexes formed by the π,π-stacking interaction. It was found that elongation of the polypeptide chain led to a twofold increase of the stabilization energy of the [Pharm-Pept] complexes. The stability of the hydrogen bonding ([HB]) [Pharm-BioM] complexes formed by means of the interaction between the dicoordinated nitrogen atom of the heterocycle and the functional groups of peptide amino acids (-OH, -NH2, -SH) was evaluated. It was demonstrated that [HB]-complexes that were formed by hydrogen bonds formation with amino acid that contained OH groups had the largest stabilization effect. The anellation with pyridine and pyrimidine rings led to stability increase of the complexes formed by the hydrogen bonding mechanism. The binding energy of [HB]-complexes for compounds 2b and 3 with a «free» peptide bond of the extended part of the protein is lower compared to amino acids with OH-functional groups. On the contrary, the binding energy of compound 4 with peptides was 2 kcal/mol higher. Compound 4 demonstrated the most pronounced biological activity in vitro studies.

Proteolipid and Calculus Matrix Calcification In Vitro

1977 ◽  
Vol 56 (2) ◽  
pp. 140-142 ◽  
Author(s):  
J. Ennever ◽  
J.J. Vogel ◽  
L.J. Riggan ◽  
S.B. Paoloski
Keyword(s):  
Calcium Phosphate ◽  
Column Chromatography ◽  
Phosphate Solution ◽  
Apatite Formation ◽  
Single Protein

The initiator of calculus matrix calcification, in vitro, was isolated. Crude phospholipid, known to contain the factor, was separated into five fractions by column chromatography. A single protein-containing fraction induced apatite formation during incubation in a metastable calcium phosphate solution. The nucleating fraction was identified as a proteolipid.

Surface Modification of Titanium Implant and In Vitro Biocompatibility Evaluation

2005 ◽  
Vol 288-289 ◽  
pp. 315-318 ◽  
Author(s):  
Quan Zeng ◽  
Zhi Qing Chen ◽  
Quan Li Li ◽  
Gang Li ◽  
Brian W. Darvell
Keyword(s):  
Functional Groups ◽  
Chemical Treatment ◽  
Water Immersion ◽  
Titanium Implant ◽  
Hot Water ◽  
Porous Network ◽  
Subsequent Aging ◽  
Oh Groups ◽  
Anatase Titania

The improvement of the amount of OH functional groups and bioactivity of titanium metal was attempted by chemical treatment and subsequent hot water treatments. The surface morphology, chemical composition and crystal structure were used to characterize the Ti surfaces and their biocompatibility was evaluated by culturing with osteoblasts. Porous network bioactive anatase were prepared by immersion in the 5 M NaOH at 80ı for 24 h, followed by soaking in the water at 80ı for 48 h. The treatment with H2O2/HCl solution at 80ı for 30 min followed by hot water aging also produced an anatase titania gel layer. Percentage of surface OH groups was determined by XPS analysis. After chemical treatment and subsequent aging in hot water, the amount of surface OH groups increased. The modified Ti surface promoted the proliferation and the ALP activities of osteoblasts. These results indicate that the NaOH or H2O2/HCl treatment and subsequent hot water immersion improve the biocompatibility of Ti samples. On the other hand, a high OH group concentration is very important as functional groups for the apatite nucleation or biochemical modification via an organometallic interface of immobilizing biomolecules.

scholarly journals Predicting Sooting Propensity of Oxygenated Fuels Using Artificial Neural Networks

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1070
Author(s):  
Abdul Gani Abdul Jameel
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Functional Groups ◽  
Average Error ◽  
Ann Model ◽  
Oh Groups ◽  
Unseen Data ◽  
Learning Capabilities ◽  
Artificial Neural ◽  
Oxygenated Fuels

The self-learning capabilities of artificial neural networks (ANNs) from large datasets have led to their deployment in the prediction of various physical and chemical phenomena. In the present work, an ANN model was developed to predict the yield sooting index (YSI) of oxygenated fuels using the functional group approach. A total of 265 pure compounds comprising six chemical classes, namely paraffins (n and iso), olefins, naphthenes, aromatics, alcohols, and ethers, were dis-assembled into eight constituent functional groups, namely paraffinic CH3 groups, paraffinic CH2 groups, paraffinic CH groups, olefinic –CH=CH2 groups, naphthenic CH-CH2 groups, aromatic C-CH groups, alcoholic OH groups, and ether O groups. These functional groups, in addition to molecular weight and branching index, were used as inputs to develop the ANN model. A neural network with two hidden layers was used to train the model using the Levenberg–Marquardt (ML) training algorithm. The developed model was tested with 15% of the random unseen data points. A regression coefficient (R2) of 0.99 was obtained when the experimental values were compared with the predicted YSI values from the test set. An average error of 3.4% was obtained, which is less than the experimental uncertainty associated with most reported YSI measurements. The developed model can be used for YSI prediction of hydrocarbon fuels containing alcohol and ether-based oxygenates as additives with a high degree of accuracy.

Sign in / Sign up

Export Citation Format

Share Document