The bioaccumulation and toxicity induced by gold nanoparticles in rats in vivo can be detected by ultraviolet-visible (UV-visible) spectroscopy

2012 ◽  
Vol 11 (39) ◽  
Author(s):  
Mohamed Anwar K. Abdelhalim
Keyword(s):  
Gold Nanoparticles ◽  
Visible Spectroscopy ◽  
Uv Visible

Biosynthesis of Gold Nanoparticles with Serratia marcescens Bacteria

2015 ◽  
Vol 1132 ◽  
pp. 19-35
Author(s):  
S.O. Dozie-Nwachukwu ◽  
J.D. Obayemi ◽  
Y. Danyo ◽  
G. Etuk-Udo ◽  
N. Anuku ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Serratia Marcescens ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Color Changes ◽  
Transmission Electron ◽  
Helium Ion ◽  
Ph Conditions ◽  
Uv Visible ◽  
Ion Microscopy

This paper presents the biosynthesis of gold nanoparticles from the bacteria, Serratia marcescens.The intra-and extra-cellular synthesis of gold nanoparticles is shown to occur over a range of pH and incubation times in cell-free exracts and biomass ofserratia marcescensthat were reacted with 2.5mM Tetrachloroauric acid (HAuCl4). The formation of gold nanoparticles was identified initially via color changes from yellow auro-chloride to shades of red or purple in gold nanoparticle solutions. UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray spectroscopy (EDS), Helium Ion Microscopy (HIM) and Dynamic Light Scattering (DLS) were also used to characterize gold nanoparticles produced within a range of pH conditions. The results show clearly that the production of gold nanoparticles from cell-free extracts require shorter times than the production of gold nanoparticles from the biomass.

scholarly journals FTIR and UV‒vis study of chemically engineered biomaterial surfaces for protein immobilization

2002 ◽  
Vol 16 (3-4) ◽  
pp. 351-360 ◽  
Author(s):  
Herman Mansur ◽  
Rodrigo Oréfice ◽  
Marivalda Pereira ◽  
Zélia Lobato ◽  
Wander Vasconcelos ◽  
...  
Keyword(s):  
Colorimetric Assay ◽  
Protein Immobilization ◽  
Research Field ◽  
Male Rats ◽  
Visible Spectroscopy ◽  
Functional Abnormality ◽  
Specific Chemical ◽  
Uv Visible

The biomaterials research field has broadened in the last 3 decades, including replacement of diseased or damaged parts, assist in healing, correct and improve functional abnormality, drug delivery systems, immunological kits and biosensors. Proteins play crucial role in almost every biological system. They are involved in enzymatic catalysis, transport and storage, coordinated motion, mechanical support, immune protection, control of growth and cell differentiation among many others. The immobilization of proteins onto surface functionalized substrates has been one of the most promising areas in bioengineering field. It is important to note that the term immobilization can refer either to a temporary or to a permanent localization of the biomolecule on or within a support. Proteins have very particular chain configurations and conformations that promote high levels of specificity during chemical interactions. In the present work, we aimed to study the phenomenon of protein immobilization onto biomaterial with chemically engineered surface. We have tailored the surface of the porous gels of SiO2with 5 different silane surface modifying agents: tetraethoxysilane (TEOS), 3‒mercaptopropyltrimethoxysilane (MPTMS) and 3‒aminopropyltriethoxysilane (APTES), 3‒glycidoxypropyltrimethoxysilane (GPTMS) and 3‒isocyanatopropyltriethoxysilane (ICPES). Fourier Transform Infrared Spectroscopy (FTIR) was used to characterize the presence of all specific chemical groups in the materials. The surface functionalized gels were then immersed in porcine insulin (PI) solutions for protein immobilization. The incorporation of protein within the gels was also monitored by FTIR spectroscopy. The kinetics of protein adsorption and desorption from the gel matrixin vitrotests were monitored by UV‒visible spectroscopy. We could not observe any evidence of denaturation of insulin after its desorption from gel matrices using UV‒visible spectroscopy technique.In vivotests with adult male rats were used to verify the immobilized insulin bioactivity after implantation of different biomaterial with functionalized surfaces. Plasma glucose levels were obtained by using the Glucose GOD‒ANA Colorimetric Assay. All surface modified materials have presented acute hypoglycemic peak response associated with the insulin bioactivity.

Synthesis and Characterization of Gold Nanoparticles Synthesized in Gel and Paper by Electrolysis

2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gold Nanoparticles ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Visible Spectroscopy ◽  
Gold Leaf ◽  
Uv Visible ◽  
Scanning Electron

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.

scholarly journals Synthesis, Characterization and Bioactivity Profiling of Gold Nanoparticles of Trachyspermum Ammi Crude Extract

2021 ◽  
Author(s):  
Saud Bawazeer ◽  
Abdur Rauf ◽  
Humaira Naz ◽  
Syed Uzair Ali Shah ◽  
Dania Saad Waggas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Nanoparticles ◽  
Bacillus Subtilis ◽  
Crude Extract ◽  
Broad Band ◽  
Soluble Starch ◽  
Klebsiella Pneumonia ◽  
Trachyspermum Ammi ◽  
Uv Visible

Trachyspermum ammi seeds were selected for photochemical study. The crude T. ammi methanol and aqueous extracts showed the presence of alkaloids, saponins, steroids, terpenoids, coumarins, betacyanins, flavonoids and soluble starch. The synthesis of gold nanoparticles (AuNPs) using T. ammi extract was characterized using UV-visible, and FT-IR spectroscopy. The appearance of sharp peak at 520 nm in the UV visible spectra, and the appearance of broad band nanoparticles spectra at 563.21 cm-1, 516.92 cm-1 and 462.92 cm-1 as well as the disappearance of the carboxyl OH bond and carbon-carbon triple bond supported the formation of AuNPs. The crude T. ammi methanol and AuNPs were investigated for antioxidant potential using DPPH· free radical assay, which shows that crude extract has significant antioxidant effect. The synthesized AuNPs was also evaluated for antibacterial activities against staphylococcus aureus, Klebsiella pneumonia and Bacillus subtilis. The crude extract showed activity against Bacillus subtilis, while AuNPs showed activity against staphylococcus aureus. The in vivo sedative effect and analgesic effect were enhanced in AuNPs treated animals in 5 times less dose (i.e., 5, and 10 mg/kg) than that of crude extract. It was concluded that T. ammi extract include capping and reducing agents, which make it capable to be developed as stable AuNPs. The biological action of AuNPs is either enhanced (sedative and analgesic) or changed (antibacterial activity), when compared with that of plant extract.

scholarly journals Cj1386, an Atypical Hemin-Binding Protein, Mediates Hemin Trafficking to KatA in Campylobacter jejuni

2014 ◽  
Vol 197 (5) ◽  
pp. 1002-1011 ◽  
Author(s):  
Annika Flint ◽  
Alain Stintzi
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Biochemical Properties ◽  
Wild Type ◽  
Visible Spectroscopy ◽  
Content Type ◽  
Increased Sensitivity ◽  
Uv Visible

Catalase enzymes detoxify H2O2by the dismutation of H2O2into O2and H2O through the use of hemin cofactors. While the structure and biochemical properties of catalase enzymes have been well characterized over many decades of research, it remained unclear how catalases acquire hemin. We have previously reported that Cj1386 is essential for ensuring proper hemin content inCampylobacter jejunicatalase (KatA) (A. Flint, Y. Q. Sun, and A. Stintzi, J Bacteriol194:334–345, 2012). In this report, an in-depth molecular characterization of Cj1386 was performed to elucidate the mechanistic details of this association. Coimmunoprecipitation assays revealed that KatA-Cj1386 transiently interactin vivo, and UV-visible spectroscopy demonstrated that purified Cj1386 protein binds hemin. Furthermore, hemin titration experiments determined that hemin binds to Cj1386 in a 1:1 ratio with hexacoordinate hemin binding. Mutagenesis of potential hemin-coordinating residues in Cj1386 showed that tyrosine 57 was essential for hemin coordination when Cj1386 was overexpressed inEscherichia coli. The importance of tyrosine 57 in hemin traffickingin vivowas confirmed by introducing thecj1386Y57Aallele into aC. jejuniΔcj1386mutant background. Thecj1386Y57Amutation resulted in increased sensitivity toward H2O2relative to the wild type, suggesting that KatA was not functional in this strain. In support of this finding, KatA immunoprecipitated from the Δcj1386+cj1386Y57Amutant had significantly reduced hemin content compared to that of thecj1386WTbackground. Overall, these findings indicate that Cj1386 is involved in directly trafficking hemin to KatA and that tyrosine 57 plays a key role in this function.

FORMATION OF GOLD NANOPARTICLES IN ZEOLITES

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2321-2326 ◽  
Author(s):  
A. PESTRYAKOV ◽  
I. TUZOVSKAYA ◽  
E. SMOLENTSEVA ◽  
N. BOGDANCHIKOVA ◽  
F. C. JENTOFT ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Sample Preparation ◽  
Ftir Spectroscopy ◽  
Diffuse Reflectance ◽  
External Surface ◽  
Molar Ratio ◽  
Visible Spectroscopy ◽  
Redox Treatment ◽  
Charged Clusters ◽  
Uv Visible

The formation of gold nanoparticles in mordenites has been studied by the methods of FTIR spectroscopy of adsorbed CO and diffuse reflectance UV-visible spectroscopy. Different states of ionic and metallic gold were detected in the zeolite cavities and on the external surface of the zeolite – Au + and Au 3+ ions, charged clusters Au n δ+, and neutral nanoparticles Au m . The relative amount of these states depends on the method of sample preparation, type of redox treatment and the SiO 2/ Al 2 O 3 molar ratio.

scholarly journals Cisplatin bioconjugated enzymatic GNPs amplify the effect of cisplatin with acquiescence

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sana Iram ◽  
Manaal Zahera ◽  
Iram Wahid ◽  
Abu Baker ◽  
Mohammad Raish ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Gold Nanoparticles ◽  
Cell Lines ◽  
Tertiary Structure ◽  
Cancer Cell Line ◽  
Lung Cancer Cell Line ◽  
Osteosarcoma Cell ◽  
Visible Spectroscopy ◽  
Shape Distribution ◽  
Uv Visible

Abstract Enzymatic gold nanoparticles (B-GNPs) have been synthesized using a natural anticancer agent bromelain (a cysteine protease) and these nanoparticles were used to bioconjugate Cisplatin (highly effective against osteosarcoma and lung cancer). Cisplatin bioconjugated bromelain encapsulated gold nanoparticles (B-C-GNPs) were found profoundly potent against same cancers at much lower concentration with minimum side effects due to the synergistic effect of bromelain. The B-C-GNPs have been observed to inhibit the proliferation of osteosarcoma cell lines Saos-2 and MG-63 with IC50 estimation of 4.51 µg/ml and 3.21 µg/ml, respectively, and against small lung cancer cell line A-549 with IC50 2.5 µg/ml which is lower than IC50 of cisplatin against same cell lines. The B-GNPs/B-C-GNPs were characterized by TEM, UV-Visible spectroscopy, Zeta potential and DLS to confirm the production, purity, crystalline nature, stability of nanoemulsion, size and shape distribution. The change in 2D and 3D conformation of bromelain after encapsulation was studied by Circular Dichroism and Fluorometry, respectively. It was found that after encapsulation, a 19.4% loss in secondary structure was observed, but tertiary structure was not altered significantly and this loss improved the anticancer activity. The confirmation of bioconjugation of cisplatin with B-GNPs was done by UV-Visible spectroscopy, TEM, FTIR, 2D 1H NMR DOSY and ICP-MS. Further, it was found that almost ~4 cisplatin molecules bound with each B-GNPs nanoparticle.

scholarly journals The cbiS Gene of the Archaeon Methanopyrus kandleri AV19 Encodes a Bifunctional Enzyme with Adenosylcobinamide Amidohydrolase and α-Ribazole-Phosphate Phosphatase Activities

2006 ◽  
Vol 188 (12) ◽  
pp. 4227-4235 ◽  
Author(s):  
Jesse D. Woodson ◽  
Jorge C. Escalante-Semerena
Keyword(s):  
High Performance ◽  
Biochemical Characterization ◽  
The Other ◽  
Bifunctional Enzyme ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Cobyric Acid ◽  
Methanopyrus Kandleri

ABSTRACT Here we report the initial biochemical characterization of the bifunctional α-ribazole-P (α-RP) phosphatase, adenosylcobinamide (AdoCbi) amidohydrolase CbiS enzyme from the hyperthermophilic methanogenic archaeon Methanopyrus kandleri AV19. The cbiS gene encodes a 39-kDa protein with two distinct segments, one of which is homologous to the AdoCbi amidohydrolase (CbiZ, EC 3.5.1.90) enzyme and the other of which is homologous to the recently discovered archaeal α-RP phosphatase (CobZ, EC 3.1.3.73) enzyme. CbiS function restored AdoCbi salvaging and α-RP phosphatase activity in strains of the bacterium Salmonella enterica where either step was blocked. The two halves of the cbiS genes retained their function in vivo when they were cloned separately. The CbiS enzyme was overproduced in Escherichia coli and was isolated to >95% homogeneity. High-performance liquid chromatography, UV-visible spectroscopy, and mass spectroscopy established α-ribazole and cobyric acid as the products of the phosphatase and amidohydrolase reactions, respectively. Reasons why the CbiZ and CobZ enzymes are fused in some archaea are discussed.

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