scholarly journals Photoregulation of Gold Nanoparticles Stabilized in a Diacetylenic Nanocapsule

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Saowalak Somjid ◽  
Apiwat Chompoosor ◽  
Somdej Kanokmedhakul ◽  
Saowapak Teerasong
Keyword(s):  
Gold Nanoparticles ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Spherical Shape ◽  
Average Diameter ◽  
Drug Carriers ◽  
Hydrophobic Core ◽  
Triggered Release ◽  
Hydrophobic Molecule ◽  
Positively Charged Gold Nanoparticle

The results of releasing a drug in a burst are unpredictable and one of the inherent drawbacks of using nanocarriers. Here, photoresponsive cationic gold nanoparticles to stabilize diacetylenic nanocapsules enabling photoregulated release of payloads are reported. The fabrication of these nanocapsules relied on an electrostatic interaction of a negatively charged diacetylenic core and a positively charged gold nanoparticle shell. Gold nanoparticles with photoresponsive ligands on their surfaces act as both hydrophobic core stabilizers and gatekeepers of the nanocapsules, while their polydiacetylene cores serve as hydrophobic drug carriers that can be tuned using UV irradiation. The morphology of nanocapsules was analyzed using TEM and dynamic light scattering. The resultant nanocapsules had a spherical shape with an average diameter of 152.9 ± 6.7 nm. Upon UV irradiation, the nanocapsules lost their integrity and an encapsulated model compound was released through diffusion. The release of a hydrophobic molecule was irradiation time dependent and thereby controllable. This light-triggered release provides an alternative strategy for controlled drug delivery.

scholarly journals Light-Regulated Release of Entrapped Drugs from Photoresponsive Gold Nanoparticles

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Kaniknun Sreejivungsa ◽  
Nattawut Suchaichit ◽  
Panawan Moosophon ◽  
Apiwat Chompoosor
Keyword(s):  
Gold Nanoparticles ◽  
Uv Irradiation ◽  
Uv Light ◽  
Irradiation Time ◽  
Drug Carrier ◽  
Uv Spectrophotometry ◽  
Substantial Impact ◽  
Naturally Occurring ◽  
Dye Release ◽  
Model Drug

Release of a payload in a spatiotemporal fashion has a substantial impact on increasing therapeutic efficacy. In this work, a novel monolayer of gold nanoparticles (AuNPs) featuring light-responsive ligands was investigated as a potential drug carrier whose drug release can be triggered by UV light. Hydrophobic molecules were noncovalently entrapped in the compartments of its monolayers. Once irradiated with UV light, the dinitrobenzyl linker was cleaved, leading to release of the entrapped agent. AuNPs were characterized using UV spectrophotometry, TEM, and a zetasizer. A naturally occurring compound extracted fromGoniothalamus elegansAst was chosen as a hydrophobic model drug. Entrapment and release of dye were monitored using fluorimetry. The percent encapsulation of dye was of 13.53%. Entrapped dye can be released upon UV irradiation and can be regulated by changing irradiation time. Up to83.95±2.2% entrapped dye can be released after irradiation for 20 minutes. In the absence of UV light, dye release was only 19.75%. For comparison purposes, AuNPs having no dinitrobenzyl groups showed a minimal release of 12.23% and 11.69% with and without UV light, respectively. This demonstrated an alternative strategy to encapsulate drugs using a noncovalent approach followed by their controlled release upon UV irradiation.

scholarly journals Albumin/Ag Nanoparticles Synthesized by Using UV-Irradiation and Estimation of Their Antibacterial Activity

2020 ◽  
pp. 36-45
Author(s):  
Randa Fawzi Elsupikhe ◽  
Tahani Soliman Alfazani ◽  
Fawzia Muftah Al-Jazwia ◽  
Hitham. Abo-Eisa ◽  
Imperiyka Hammad ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Average Diameter ◽  
Bulk Sample ◽  
Inhibitory Effect ◽  
Optimum Conditions ◽  
Ag Nps ◽  
Albumin Nanoparticles ◽  
Uv Lamp

Nano-scale (less than 100 nm) materials have received wide attention because of their rare properties that differ significantly from a bulk sample of the same material. In this research, a physical irradiation method by using UV lamp was established for preparation nanoparticles colloids of silver nanoparticles (Ag-NPs) with an eco-friendly stabilizer (Albumin). The preparation process was carried out using silver nitrate (AgNO3) in aqueous albumin at room temperature. The effects of UV-irradiation time and the concentrations of Ag+ and albumin on the particle size have been investigated. Moreover, the antibacterial effect of the Ag/Albumin nanoparticles has been tested. The results showed that, the UV–irradiation can influence the Ag-NPs size, which the of Nps  decreases with the UV–irradiation increases. The morphological study demonstrated well-dispersed spherical Ag-NPs with an average diameter of about 29 nm at the optimum conditions. The antibacterial results exhibited a significant inhibitory effect for the Ag-NPs that synthesized in this work. The current fabrication method of the silver nanoparticles colloid could be extended to other metals such as Cu- Nps and may possibly find various additional applications.    

scholarly journals One-Step Synthesis of PEGylated Gold Nanoparticles with Tunable Surface Charge

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Rares Stiufiuc ◽  
Cristian Iacovita ◽  
Raul Nicoara ◽  
Gabriela Stiufiuc ◽  
Adrian Florea ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Surface Charge ◽  
Colloidal Stability ◽  
Spherical Shape ◽  
Average Diameter ◽  
Molecular Chain ◽  
Surface Charges ◽  
One Step

The present work reports a rapid, simple and efficient one-step synthesis and detailed characterisation of stable aqueous colloids of gold nanoparticles (AuNPs) coated with unmodified poly(ethylene)glycol (PEG) molecules of different molecular weights and surface charges. By mixing and heating aqueous solutions of PEG with variable molecular chain and gold(III) chloride hydrate (HAuCl4) in the presence of NaOH, we have successfully produced uniform colloidal 5 nm PEG coated AuNPs of spherical shape with tunable surface charge and an average diameter of 30 nm within a few minutes. It has been found out that PEGylated AuNPs provide optical enhancement of the characteristic vibrational bands of PEG molecules attached to the gold surface when they are excited with both visible (532 nm) and NIR (785 nm) laser lines. The surface enhanced Raman scattering (SERS) signal does not depend on the length of the PEG molecular chain enveloping the AuNPs, and the stability of the colloid is not affected by the addition of concentrated salt solution (0.1 M NaCl), thus suggesting their potential use forin vitroandin vivoapplications. Moreover, by gradually changing the chain length of the biopolymer, we were able to control nanoparticles’ surface charge from −28 to −2 mV, without any modification of the Raman enhancement properties and of the colloidal stability.

scholarly journals BIOSYNTHESIS OF GOLD NANOPARTICLES BY BIOSORPTION USING NEOSARTORYA UDAGAWAE: CHARACTERIZATION AND INVITRO EVALUATION

2016 ◽  
Vol 8 (11) ◽  
pp. 108 ◽  
Author(s):  
V. Jhansi Lakshmi ◽  
K. P. Kannan
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Uv Spectroscopy ◽  
Spherical Shape ◽  
Average Diameter ◽  
Chloroauric Acid ◽  
Human Beings ◽  
Tem Analysis ◽  
The Stability

Objective: The present study was aimed to investigate gold nanoparticles synthesized by fungal isolate Neosartorya udagawae and determination of their stability in biofluids to probe their aptness in drug delivery applications.Methods: In this procedure, gold nanoparticles were prepared by biosynthesis using seven days old culture of Neosartorya udagawae and aqueous chloroauric acid. After the complete reaction, the fungal biomass was subjected to UV-Vis, XRD, FT-IR Spectrum analysis, TEM, Zeta potential, SEM and EDX analysis.Results: Intra/extracellular synthesis of gold nanoparticles was confirmed by a sharp peak at 526 nm in UV spectroscopy. SEM, TEM analysis demonstrates the spherical shape of AuNPs with an average diameter of 50 nm and XRD confirm the crystalline gold nanoparticles. FTIR analysis reveals the presence of the protein shell around the gold nanoparticles. The zeta potential value of AuNPs was-36mV which confirmed the stability of nanoparticles dispersion. Gold nanoparticles have shown high stability in biofluids of Bovine Serum Albumin and Phosphate Buffer Saline at pH-5, pH-7and pH-9 which mimic the human colonic biological environment.Conclusion: The fungal synthesis of AuNPs has been experimentally demonstrated and their stability in BSA, 10% NaCl and PBS at pH-7. This might be a promising option for drug delivery applications in carcinogenic colon disorders in human beings. 

Optimization of Gold Nanoparticles Synthesis using Design of Experiments Technique

2017 ◽  
Vol 68 (7) ◽  
pp. 1518-1423
Author(s):  
Adina Turcu Stiolica ◽  
Mariana Popescu ◽  
Maria Viorica Bubulica ◽  
Carmen Nicoleta Oancea ◽  
Claudiu Nicolicescu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Design Of Experiments ◽  
Process Model ◽  
Sodium Citrate ◽  
Drug Carriers ◽  
Chloroauric Acid ◽  
Gold Colloids ◽  
Citrate Concentration ◽  
Vis Spectroscopy

Gold nanoparticles are considered the newest drug carriers for different diseases. Therefore it is appropriate continuous optimization of their preparation. In this study, gold colloids with an average size of 1 - 26 nm were obtained by the reduction of tetrachloroauric acid with trisodium citrate. The nanomaterials were characterized by UV-Vis spectroscopy and dynamic light scattering technique. In addition, zeta potential was measured for samples synthesized in order to determine the stability of the colloids. A Two-level Full Factorial design was chosen to determine the optimum set of process parameters (chloroauric acid concentration and sodium citrate concentration) and their effect on various gold nanoparticles characteristics (size and zeta potential). These effects were quantified using Design of Experiments (DoE) with 5 runs and 1 centerpoint. The selected objective and process model in this investigation are screening and interaction. Findings from this research show that to obtain particles larger than 35 nm, it is recommended to increase sodium citrate concentration, at low chloroauric acid values. These conditions will help to achieve smaller zeta potential, too.

scholarly journals X-ray Fluorescence Uptake Measurement of Functionalized Gold Nanoparticles in Tumor Cell Microsamples

2021 ◽  
Vol 22 (7) ◽  
pp. 3691
Author(s):  
Oliver Schmutzler ◽  
Sebastian Graf ◽  
Nils Behm ◽  
Wael Y. Mansour ◽  
Florian Blumendorf ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Irradiation Time ◽  
High Sensitivity ◽  
Nanoparticle Uptake ◽  
X Ray ◽  
Functionalized Gold Nanoparticles ◽  
Uptake Measurement ◽  
Prostate Tumor Cells ◽  
Non Destructive

Quantitative cellular in vitro nanoparticle uptake measurements are possible with a large number of different techniques, however, all have their respective restrictions. Here, we demonstrate the application of synchrotron-based X-ray fluorescence imaging (XFI) on prostate tumor cells, which have internalized differently functionalized gold nanoparticles. Total nanoparticle uptake on the order of a few hundred picograms could be conveniently observed with microsamples consisting of only a few hundreds of cells. A comparison with mass spectroscopy quantification is provided, experimental results are both supported and sensitivity limits of this XFI approach extrapolated by Monte-Carlo simulations, yielding a minimum detectable nanoparticle mass of just 5 pg. This study demonstrates the high sensitivity level of XFI, allowing non-destructive uptake measurements with very small microsamples within just seconds of irradiation time.

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

scholarly journals Green Synthesis and Characterization of Pullulan Mediated Silver Nanoparticles through Ultraviolet Irradiation

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2382 ◽  
Author(s):  
Muhammad Jamshed Khan ◽  
Suriya Kumari ◽  
Kamyar Shameli ◽  
Jinap Selamat ◽  
Awis Qurni Sazili
Keyword(s):  
Silver Nanoparticles ◽  
Uv Irradiation ◽  
Irradiation Time ◽  
Edible Films ◽  
Crystallographic Structure ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Vis Spectroscopy ◽  
Face Centered ◽  
Average Lattice

Nanoparticles (NPs) are, frequently, being utilized in multi-dimensional enterprises. Silver nanoparticles (AgNPs) have attracted researchers in the last decade due to their exceptional efficacy at very low volume and stability at higher temperatures. Due to certain limitations of the chemical method of synthesis, AgNPs can be obtained by physical methods including sun rays, microwaves and ultraviolet (UV) radiation. In the current study, the synthesis of pullulan mediated silver nanoparticles (P-AgNPs) was achieved through ultraviolet (UV) irradiation, with a wavelength of 365 nm, for 96 h. P-AgNPs were formed after 24 h of UV-irradiation time and expressed spectra maxima as 415 nm, after 96 h, in UV-vis spectroscopy. The crystallographic structure was “face centered cubic (fcc)” as confirmed by powder X-ray diffraction (PXRD). Furthermore, high resolution transmission electron microscopy (HRTEM) proved that P-AgNPs were covered with a thin layer of pullulan, with a mean crystalline size of 6.02 ± 2.37. The average lattice fringe spacing of nanoparticles was confirmed as 0.235 nm with quasi-spherical characteristics, by selected area electron diffraction (SAED) analysis. These green synthesized P-AgNPs can be utilized efficiently, as an active food and meat preservative, when incorporated into the edible films.

scholarly journals Designer nanoparticles: incorporating size, shape and triggered release into nanoscale drug carriers

2010 ◽  
Vol 7 (4) ◽  
pp. 479-495 ◽  
Author(s):  
Mary Caldorera-Moore ◽  
Nathalie Guimard ◽  
Li Shi ◽  
Krishnendu Roy
Keyword(s):  
Drug Carriers ◽  
Triggered Release

Effect of Gold Nanoparticles Size on Detection of Methylphosphonic Acid Hydrolysis Product of Nerve Agent

2021 ◽  
Vol 25 (7) ◽  
pp. 1-7
Author(s):  
Fellyzra Elvya Pojol ◽  
Buong Woei Chieng ◽  
Keat Khim Ong ◽  
Rashid Jahwarhar Izuan Abd ◽  
Mohd Junaedy Osman ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Inverse Method ◽  
Direct Method ◽  
Hydrolysis Product ◽  
Spherical Shape ◽  
Methylphosphonic Acid ◽  
Visible Spectroscopy ◽  
Transmission Electron ◽  
Citrate Reduction ◽  
Chloride Trihydrate

Citrate reduction of gold (III) chloride trihydrate (HAuCl4) is commonly used method to synthesise citrate-capped gold nanoparticles (cit-AuNPs). In this study, the sequence of reagents addition was modified (“inverse” method) to synthesise smaller size of cit-AuNPs than the standard Turkevich method (“direct” method). Ultraviolet-visible spectroscopy (UV-vis) and field emission transmission electron microscopy (FETEM) confirmed the formation of cit-AuNPs. The cit-AuNPs synthesized using “inverse” method are smaller in size (14.0 ± 3.03 nm) with uniform spherical shape compared to “direct” method (23.5 ± 7.52 nm). Smaller particles size of cit-AuNPs provide higher efficiency and sensitivity for detection of methylphosphonic acid (MPA) via colorimetric incorporated with image processing with a linear range from 2.5 to 12.5 mM and a low detection limit of 6.28 mM at shorter detection period (24 to 30 s).

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