Enhanced type I photoreaction of indocyanine green via electrostatic-force-driven aggregation

Nanoscale ◽  
2020 ◽  
Vol 12 (17) ◽  
pp. 9517-9523 ◽  
Author(s):  
Huizhen Fan ◽  
Yu Fan ◽  
Wenna Du ◽  
Rui Cai ◽  
Xinshuang Gao ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Indocyanine Green ◽  
Electrostatic Force ◽  
Type I ◽  
Positively Charged

ICG forms aggregates in positively charged mesoporous silica, which show an enhanced type I photoreaction pathway.

Sorption Mechanism of Carbon-14 by Hardened Cement Paste

1995 ◽  
Vol 412 ◽  
Author(s):  
K. Noshita ◽  
T. Nishi ◽  
M. Matsuda ◽  
T. Izumida
Keyword(s):  
Electrostatic Force ◽  
Cementitious Materials ◽  
Hardened Cement ◽  
Sorption Mechanism ◽  
Carbon 14 ◽  
Adsorption Sites ◽  
Radioactive Waste Repositories ◽  
Waste Repositories ◽  
Positively Charged

AbstractCarbon-14 sorption by cementitious materials should be enhanced to ensure the long term safety of radioactive waste repositories. The sorption mechanism of inorganic C- 14 (CO32- was investigated using batch sorption experiments and zeta potential measurements. The results suggested that C-14 was adsorbed onto the cement surface by an electrostatic force, due to the reaction between SiO2 and CaO contained in the cementitious composition. That is, SiO2 was originally negatively charged (SiO-) in cement, but became positively charged through the interaction of Ca2+. These positive sites on the SiO2 surface adsorbed inorganic C-14. Ordinary Portland cement (OPC) did not contain enough SiO2 compared with its CaO content to produce sufficient numbers of C-14 adsorption sites. The C-14 distribution coefficient (Kd) was increased from 2,000 to 7,000 mL/g by adding SiO2 to OPC.

scholarly journals Membrane Topogenesis of a Type I Signal-Anchor Protein, Mouse Synaptotagmin Ii, on the Endoplasmic Reticulum

2000 ◽  
Vol 150 (4) ◽  
pp. 719-730 ◽  
Author(s):  
Yuichiro Kida ◽  
Masao Sakaguchi ◽  
Mitsunori Fukuda ◽  
Katsuhiko Mikoshiba ◽  
Katsuyoshi Mihara
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Membrane ◽  
Type I ◽  
Hydrophobic Region ◽  
Anchor Protein ◽  
Nascent Polypeptide ◽  
Charged Residues ◽  
Er Targeting ◽  
Signal Anchor ◽  
Positively Charged

Synaptotagmin II is a type I signal-anchor protein, in which the NH2-terminal domain of 60 residues (N-domain) is located within the lumenal space of the membrane and the following hydrophobic region (H-region) shows transmembrane topology. We explored the early steps of cotranslational integration of this molecule on the endoplasmic reticulum membrane and demonstrated the following: (a) The translocation of the N-domain occurs immediately after the H-region and the successive positively charged residues emerge from the ribosome. (b) Positively charged residues that follow the H-region are essential for maintaining the correct topology. (c) It is possible to dissect the lengths of the nascent polypeptide chains which are required for ER targeting of the ribosome and for translocation of the N-domain, thereby demonstrating that different nascent polypeptide chain lengths are required for membrane targeting and N-domain translocation. (d) The H-region is sufficiently long for membrane integration. (e) Proline residues preceding H-region are critical for N-domain translocation, but not for ER targeting. The proline can be replaced with amino acid with low helical propensity.

scholarly journals Mesoporous silica-coated gold nanorods with embedded indocyanine green for dual mode X-ray CT and NIR fluorescence imaging

2011 ◽  
Vol 19 (18) ◽  
pp. 17030 ◽  
Author(s):  
Teng Luo ◽  
Peng Huang ◽  
Guo Gao ◽  
Guangxia Shen ◽  
Shen Fu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Indocyanine Green ◽  
Fluorescence Imaging ◽  
Gold Nanorods ◽  
Dual Mode ◽  
X Ray ◽  
Nir Fluorescence

scholarly journals Development of Multifunctional Cosmetic Cream Using Bioactive Materials from Streptomyces sp. T65 with Synthesized Mesoporous Silica Particles SBA-15

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 278
Author(s):  
Ram Hari Dahal ◽  
Tuan Manh Nguyen ◽  
Dong Seop Shim ◽  
Joon Young Kim ◽  
Jangyul Lee ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Cell Lines ◽  
Radical Scavenging ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Type I ◽  
Mushroom Tyrosinase ◽  
Dpph Radical ◽  
Crude Product ◽  
Dpph Radical Scavenging

Various cosmetics having a single function are increasingly being used, but cosmetics having multifunctional activities remain limited. We aimed to develop a multifunctional cosmetic cream having antioxidant, anti-tyrosinase, anti-aging and antimicrobial activities. Antimicrobial activities were performed by disc-diffusion method. Cell toxicity and cell proliferations were evaluated in a 96-well plate with different cell lines such as HaCaT, RAW264.7, CCD-986Sk, B16F1, and B16F10. Mushroom tyrosinase inhibition, elastase inhibition, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were evaluated and IC50 was calculated. Mesoporous silica particle was synthesized using Pluronic P123 and tetraethyl ortho-silicate (TEOS). Facial pictures were captured by VISIA-CR (Facial Imaging System for Clinical Research). Roughness of image was analysed by PRIMOS software and brightness of image was analyzed by Chromameter CR-400. The crude product of strain T65 inhibited the different human pathogenic bacteria such as Bacillus subtilis, Escherichia coli, Propionibacterium acnes, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. The IC50 of T65 crude product for mushroom tyrosinase, elastase, and DPPH radical scavenging activities were 58.73, 14.68, and 6.31 µg/mL, respectively. T65 crude product proliferated collagen type I in CCD-986Sk cell up to 145.91% ± 9.11% (mean ± SD; mean of 24, 48, and 72 h) at 250 pg/mL. Synthesized mesoporous particles (SBA-15) confirmed the sustainable performance by control-release for three days. Formulated functional cosmetic cream containing T65 embedded SBA-15, significantly decreased the skin roughness by 4.670% and increased the skin brightness by 0.472% after application of 4 weeks. T65 crude product inhibited both Gram-positive and Gram-negative pathogens. Synthesized mesoporous particle, SBA-15, confirmed the physiologically active substance was released in sustainable release condition. T65 crude product showed impeccable antimicrobial, antioxidant, anti-aging, and whitening activities with non-cytotoxic effects to different cell lines related to the human skin.

scholarly journals Utilization of Sodium Hexametaphosphate for Separating Scheelite from Calcite and Fluorite Using an Anionic–Nonionic Collector

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 705 ◽  
Author(s):  
Jianhua Kang ◽  
Yuehua Hu ◽  
Wei Sun ◽  
Zhiyong Gao ◽  
Runqing Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Negative Charge ◽  
Electrostatic Force ◽  
Sodium Hexametaphosphate ◽  
Infrared Spectrometry ◽  
Low Grade ◽  
X Ray ◽  
Charged Surfaces ◽  
Selective Reagent ◽  
Positively Charged

This study presents a highly selective reagent system that utilizes sodium hexametaphosphate (SHMP) to improve the separation of scheelite from calcite and fluorite using an anionic–nonionic collector. The recoveries of calcite and fluorite decreased to 20% as the SHMP dose exceeded 6 × 10−6 mol/L, whereas that of scheelite remained at 85%. The interaction mechanisms of minerals with SHMP were investigated through equilibrium speciation, Zeta potential, Fourier transform infrared spectrometry, and X-ray photoelectron spectroscopy analyses. SHMP exists as hydrogen phosphate anion in the aqueous solution with a pH of 7–12. Moreover, it may be adsorbed intensively on the positively charged surfaces of calcite and fluorite via electrostatic force or chelation with calcium ion to impede further adsorption of the assembled collector. By comparison, the adsorption of SHMP is feeble on the scheelite surface because of its negative charge. The roughing grade of low-grade scheelite ore is substantially improved from 0.74% to 1.65% compared with that in the contrast test in the absence of SHMP.

scholarly journals Functionalization of Hollow Mesoporous Silica Nanoparticles for Improved 5-FU Loading

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaodong She ◽  
Lijue Chen ◽  
Chengpeng Li ◽  
Canzhong He ◽  
Li He ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Electrostatic Force ◽  
Mesoporous Silica Nanoparticles ◽  
Drug Loading ◽  
Hollow Structure ◽  
Loading Capacity ◽  
Amine Functionalized ◽  
Alkaline Conditions ◽  
Hollow Mesoporous Silica

Hollow mesoporous silica nanoparticles were successfully fabricated and functionalized with appropriate silanes. After modifications, amine, carboxyl, cyano, and methyl groups were grafted onto the nanoparticles and all functionalized hollow mesoporous silica nanoparticles maintained a spherical and hollow structure with a mean diameter of ~120 nm and a shell thickness of ~10 nm. The loading capacity of the hollow mesoporous silica nanoaprticles to the anticancer drug, 5-fluorouracil, can be controlled via precise functionalization. The presence of amine groups on the surface of nanoparticles resulted in the highest loading capacity of 28.89%, due to the amine functionalized nanoparticles having a similar hydrophilicity but reverse charge to the drug. In addition, the change in pH leads to the variation of the intensity of electrostatic force between nanoparticles and the drug, which finally affects the loading capacity of amine functionalized hollow mesoporous silica nanoparticles to some extent. Higher drug loading was observed at pH of 7.4 and 8.5 as 5-fluorouracil becomes more deprotonated in alkaline conditions. The improved drug loading capacity by amine functionalized hollow mesoporous silica nanoparticles has demonstrated that they can become potential intracellular 5-fluorouracil delivery vehicles for cancers.

Electric Field-Assisted Assembly of Type-I Collagen for Applications in Biomedical Micro-Systems

2005 ◽  
Author(s):  
Tiffany E. Miller ◽  
Eniko T. Enikov
Keyword(s):  
Electric Field ◽  
Type I Collagen ◽  
Negative Electrode ◽  
Positive Electrode ◽  
Type I ◽  
Solution Ph ◽  
Force Microscopy ◽  
Atomic Force ◽  
Micro Systems ◽  
Positively Charged

In the field of nanotechnology and applied engineering, an area that has received a great deal of attention is that of nanoassembly. The objective of this study was to demonstrate nanoassembly of type-I collagen on specified surfaces in response to an electric field. Two, otherwise identical, collagen solutions were prepared and adjusted to pHs of 5.5 and 8. The isoelectric fosusing point of collagen occurs at pH=6.7 which implies that the suspended collagen fibers in the aforementioned solutions possessed a net positive or negative charge, respectively. In each collagen solution, one volt was applied through a set of submerged electrodes for one minute. Atomic force microscopy was used to detect if and where assembly had occurred on the electrodes. The positively charged fibrils (pH=5.5) assembled on the negative electrode, but not on the positive electrode. The negatively charged fibrils (pH=8) assembled only on the positive electrode, but not on the negative electrode. In both cases, assembly occurred on the electrode of opposite charge of the suspended collagen fibrils, which was anticipated. The assembly of the positively charged fibrils (pH=5.5) on the cathode produced larger fibers than the fibers that were produced by the negatively charged fibrils (pH=8) on the anode. This indicated the more favorable environment for nanoassembly was the positively charged fibril solution (pH=5.5).

Positively Charged Nanogold Combined with Expanded Mesoporous Silica-Based Immunoassay for the Detection of Avermectin

2020 ◽  
Vol 13 (5) ◽  
pp. 1129-1137
Author(s):  
Chunguo Zhang ◽  
Yingying Zhong ◽  
Qiyi He ◽  
Ding Shen ◽  
Miaobo Ye ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Positively Charged
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