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Fulltext Inhibitory Effect of Eco-Friendly Naturally Synthesized Silver Nanoparticles from the Leaf Extract of Medicinal Detarium microcarpum Plant on Pancreatic and Cervical Cancer Cells

Adebayo IA, Arsad H, Gagman HA, Ismail NZ, Samian MR

Asian Pac J Cancer Prev, 2020 May 01;21(5):1247-1252.
PMID: 32458629 DOI: 10.31557/APJCP.2020.21.5.1247

BACKGROUND: Recently, nanoparticle synthesis by eco-friendly methods has received tremendous attention due to the method advantages and also because of the application of the nanoparticles in cancer research. Therefore, in this study, we synthesized silver nanoparticles from Detarium microcarpum leaf phytochemicals and evaluated its inhibitory effect on pancreatic and cervical cancer cells.
MATERIALS AND METHODS: Silver nanoparticles (dAgNps) were synthesized by reacting phytochemicals of D. microcarpum leaves with silver nitrate for 12 hours. Cell viability assay was carried out to investigate the cytotoxic effect of dAgNps on HeLa and PANC-1 cells.
RESULTS: Scanning electron microscopy (SEM) and transmission electron microscopy(TEM) results revealed the average sizes of dAgNps are 81 nm and 84 nm respectively. The x-ray diffraction (XRD) pattern of dAgNps was similar to that of face centered cubic(fcc) structure of silver as reported by joint committee on powder diffraction standards (JCPDS) and fourier-transform infrared spectroscopy (FTIR) analysis showed that some phytochemicals of D. microcarpum such as polyphenols and flavonoids were likely involved in the reduction of Ag+ to form nanoparticles. Finally, cell viability assay revealed dAgNps inhibited PANC-1 and HeLa cell proliferations with IC50 values of 84 and 31.5 µg/ml respectively.
CONCLUSION: In conclusion, the synthesized nanoparticles from D. microcarpum leaves (dAgNps) have inhibitory effect on pancreatic and cervical cancer cells.

Matched MeSH terms: Metal Nanoparticles/administration & dosage*; Metal Nanoparticles/chemistry
Fulltext Biosynthesis of zinc oxide nanoparticles by cell-biomass and supernatant of Lactobacillus plantarum TA4 and its antibacterial and biocompatibility properties

Mohd Yusof H, Abdul Rahman N, Mohamad R, Zaidan UH, Samsudin AA

Sci Rep, 2020 Nov 17;10(1):19996.
PMID: 33204003 DOI: 10.1038/s41598-020-76402-w

This study aims to utilize the cell-biomass (CB) and supernatant (CFS) of zinc-tolerant Lactobacillus plantarum TA4 as a prospective nanofactory to synthesize ZnO NPs. The surface plasmon resonance for the biosynthesized ZnO NPs-CFS and ZnO NPs-CB was 349 nm and 351 nm, respectively, thereby confirming the formation of ZnO NPs. The FTIR analysis revealed the presence of proteins, carboxyl, and hydroxyl groups on the surfaces of both the biosynthesized ZnO NPs that act as reducing and stabilizing agents. The DLS analysis revealed that the poly-dispersity indexes was less than 0.4 for both ZnO NPs. In addition, the HR-TEM micrographs of the biosynthesized ZnO NPs revealed a flower-like pattern for ZnO NPs-CFS and an irregular shape for ZnO NPs-CB with particles size of 291.1 and 191.8 nm, respectively. In this study, the biosynthesized ZnO NPs exhibited antibacterial activity against pathogenic bacteria in a concentration-dependent manner and showed biocompatibility with the Vero cell line at specific concentrations. Overall, CFS and CB of L. plantarum TA4 can potentially be used as a nanofactory for the biological synthesis of ZnO NPs.

Matched MeSH terms: Metal Nanoparticles/administration & dosage*; Metal Nanoparticles/chemistry*
Fulltext Green synthesis of silver nanoparticles using Achillea biebersteinii flower extract and its anti-angiogenic properties in the rat aortic ring model

Baharara J, Namvar F, Ramezani T, Hosseini N, Mohamad R

Molecules, 2014 Apr 15;19(4):4624-34.
PMID: 24739926 DOI: 10.3390/molecules19044624

Silver nanoparticles display unique physical and biological properties which have attracted intensive research interest because of their important medical applications. In this study silver nanoparticles (Ab.Ag-NPs) were synthesized for biomedical applications using a completely green biosynthetic method using Achillea biebersteinii flowers extract. The structure and properties of Ab.Ag-NPs were investigated using UV-visible spectroscopic techniques, transmission electron microscopy (TEM), zeta potential and energy dispersive X-ray spectrometers (EDS). The UV-visible spectroscopic analysis showed the absorbance peak at 460 nm, which indicates the synthesis of silver nanoparticles. The average particle diameter as determined by TEM was found to be 12±2 nm. The zeta potential analysis indicated that Ab.Ag-NPs have good stability EDX analysis also exhibits presentation of silver element. As angiogenesis is an important phenomenon and as growth factors imbalance in this process causes the acceleration of several diseases including cancer, the anti-angiogenic properties of Ab.Ag-NPs were evaluated using the rat aortic ring model. The results showed that Ab.Ag-NPs (200 μg/mL) lead to a 50% reduction in the length and number of vessel-like structures. The synthesized silver nanoparticles from the Achillea biebersteinii flowers extract, which do not involve any harmful chemicals were well-dispersed and stabilized through this green method and showed potential therapeutic benefits against angiogenesis.

Matched MeSH terms: Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry*
Fulltext Green synthesis, characterisation and biological evaluation of plant-based silver nanoparticles using Quercus semecarpifolia Smith aqueous leaf extract

Khattak A, Ahmad B, Rauf A, Bawazeer S, Farooq U, Ali J, et al.

IET Nanobiotechnol, 2019 Feb;13(1):36-41.
PMID: 30964035 DOI: 10.1049/iet-nbt.2018.5063

The development of reliable and green methods for the fabrication of metallic nanoparticles (NPs) has many advantages in the field of nanotechnology. In this direction, the present work describes an eco-friendly and cost-effective protocol for the production of silver NPs (AgNPs) using an aqueous extract of Quercus semecarpifolia leaves. Different techniques were carried out for the characterisation of the synthesised AgNPs. The ultraviolet-visible spectroscopic analysis showed the highest absorbance peak at 430 nm. The particle size and structure were confirmed by scanning electron microscopy as well as transmission electron microscopy (TEM) analysis. From TEM imaging, it was revealed that the formed particles were spherical with an average size of 20-50 nm. The crystalline nature of the NPs was determined by X-ray powder diffraction patterns. Thermogravimetry and differential thermal analysis were also evaluated by a temperature increment from 100 to 1000°C. Bio-inspired synthesis of AgNPs was performed for their pharmacological evaluation in relation to the activities of the crude methanolic, n-hexane, chloroform, ethyl acetate, and aqueous extracts. Good cytotoxic activity was exhibited by the green-synthesised AgNPs (77%). Furthermore, the AgNPs were found to exhibit significant antioxidant activity at 300 μg/ml (82%). The AgNPs also exhibited good phytotoxic potential (75%).

Matched MeSH terms: Metal Nanoparticles/toxicity; Metal Nanoparticles/chemistry*
Fulltext Glucose oxidase complexed gold-graphene nanocomposite on a dielectric surface for glucose detection: a strategy for gestational diabetes mellitus

Ge Y, Lakshmipriya T, Gopinath SC, Anbu P, Chen Y, Hariri F, et al.

Int J Nanomedicine, 2019;14:7851-7860.
PMID: 31632005 DOI: 10.2147/IJN.S222238

BACKGROUND: Gestational diabetes mellitus is a commonly occurring metabolic disorder during pregnancy, affecting >4% of pregnant women. It is generally defined as the intolerance of glucose with the onset or initial diagnosis during pregnancy. This illness affects the placenta and poses a threat to the baby as it affects the supply of proper oxygen and nutrients.
PURPOSE: Due to the high percentage of affected pregnant women, it should be mandatory to evaluate glucose levels during pregnancy and there is a need for a continuous monitoring system.
METHODS: Herein, the investigators modified the interdigitated (di)electrodes (IDE) sensing surface to detect the glucose on covalently immobilized glucose oxidase (GOx) with the graphene. The characterization of graphene and gold nanoparticle (GNP) was performed by high-resolution microscopy.
RESULTS: Sensitivity was found to be 0.06 mg/mL and to enhance the detection, GOx was complexed with GNP. GNP-GOx was improved the sensitive detection twofold from 0.06 to 0.03 mg/mL, and it also displayed higher levels of current changes at all the concentrations of glucose that were tested. High-performance of the above IDE sensing system was attested by the specificity, reproducibility and higher sensitivity detections. Further, the linear regression analysis indicated the limit of detection to be between 0.02 and 0.03 mg/mL.
CONCLUSION: This study demonstrated the potential strategy with nanocomposite for diagnosing gestational diabetes mellitus.

Matched MeSH terms: Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry
Biosynthesis and structural characterization of Ag nanoparticles from white rot fungi

Chan YS, Mat Don M

Mater Sci Eng C Mater Biol Appl, 2013 Jan 1;33(1):282-8.
PMID: 25428073 DOI: 10.1016/j.msec.2012.08.041

Five species of white rot fungi were screened for their capability to synthesize Ag nanoparticles (AgNPs). Three modes of AgNP bioreduction were developed. Pycnoporus sanguineus is found as a potential candidate for the synthesis of AgNPs with a yield at 98.9%. The synthesized AgNPs were characterized using UV-vis spectroscopy, DLS, FTIR, TEM, and SEM. Results showed that AgNP absorption band was located at a peak of 420 nm. Both the SEM and TEM confirmed that the formation of AgNPs were mainly spherical with average diameters of 52.8-103.3 nm. The signals of silver atoms' presence in the mycelium were observed by SEM-EDS spectrum.

Matched MeSH terms: Metal Nanoparticles/toxicity; Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry*
Fulltext Optical absorption and photoluminescence studies of gold nanoparticles deposited on porous silicon

Amran TS, Hashim MR, Al-Obaidi NK, Yazid H, Adnan R

Nanoscale Res Lett, 2013 Jan 18;8(1):35.
PMID: 23331761 DOI: 10.1186/1556-276X-8-35

We present an investigation on a coupled system consists of gold nanoparticles and silicon nanocrystals. Gold nanoparticles (AuNPs) embedded into porous silicon (PSi) were prepared using the electrochemical deposition method. Scanning electron microscope images and energy-dispersive X-ray results indicated that the growth of AuNPs on PSi varies with current density. X-ray diffraction analysis showed the presence of cubic gold phases with crystallite sizes around 40 to 58 nm. Size dependence on the plasmon absorption was studied from nanoparticles with various sizes. Comparison with the reference sample, PSi without AuNP deposition, showed a significant blueshift with decreasing AuNP size which was explained in terms of optical coupling between PSi and AuNPs within the pores featuring localized plasmon resonances.

Matched MeSH terms: Metal Nanoparticles
Fulltext Biopolymers Regulate Silver Nanoparticle under Microwave Irradiation for Effective Antibacterial and Antibiofilm Activities

Velusamy P, Su CH, Venkat Kumar G, Adhikary S, Pandian K, Gopinath SC, et al.

PLoS One, 2016;11(6):e0157612.
PMID: 27304672 DOI: 10.1371/journal.pone.0157612

In the current study, facile synthesis of carboxymethyl cellulose (CMC) and sodium alginate capped silver nanoparticles (AgNPs) was examined using microwave radiation and aniline as a reducing agent. The biopolymer matrix embedded nanoparticles were synthesized under various experimental conditions using different concentrations of biopolymer (0.5, 1, 1.5, 2%), volumes of reducing agent (50, 100, 150 μL), and duration of heat treatment (30 s to 240 s). The synthesized nanoparticles were analyzed by scanning electron microscopy, UV-Vis spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy for identification of AgNPs synthesis, crystal nature, shape, size, and type of capping action. In addition, the significant antibacterial efficacy and antibiofilm activity of biopolymer capped AgNPs were demonstrated against different bacterial strains, Staphylococcus aureus MTCC 740 and Escherichia coli MTCC 9492. These results confirmed the potential for production of biopolymer capped AgNPs grown under microwave irradiation, which can be used for industrial and biomedical applications.

Matched MeSH terms: Metal Nanoparticles/radiation effects; Metal Nanoparticles/toxicity; Metal Nanoparticles/chemistry*
Fulltext Boosting Photovoltaic Performance of Dye-Sensitized Solar Cells Using Silver Nanoparticle-Decorated N,S-Co-Doped-TiO2 Photoanode

Lim SP, Pandikumar A, Lim HN, Ramaraj R, Huang NM

Sci Rep, 2015;5:11922.
PMID: 26146362 DOI: 10.1038/srep11922

A silver nanoparticle-decorated N,S-co-doped TiO2 nanocomposite was successfully prepared and used as an efficient photoanode in high-performance dye-sensitized solar cells (DSSCs) with N719 dye. The DSSCs assembled with the N,S-TiO2@Ag-modified photoanode demonstrated an enhanced solar-to-electrical energy conversion efficiency of 8.22%, which was better than that of a DSSC photoanode composed of unmodified TiO2 (2.57%) under full sunlight illumination (100 mWcm(-2), AM 1.5 G). This enhanced efficiency was mainly attributed to the reduced band gap energy, improved interfacial charge transfer, and retarded charge recombination process. The influence of the Ag content on the overall efficiency was also investigated, and the optimum Ag content with N,S-TiO2 was found to be 20 wt%. Because of the enhanced solar energy conversion efficiency of the N,S-TiO2@Ag nanocomposite, it should be considered as a potential photoanode for high-performance DSSCs.

Matched MeSH terms: Metal Nanoparticles
Fulltext Nanotoxic profiling of novel iron oxide nanoparticles functionalized with perchloric acid and SiPEG as a radiographic contrast medium

Mohamed MI, Mohammad MK, Abdul Razak HR, Abdul Razak K, Saad WM

Biomed Res Int, 2015;2015:183525.
PMID: 26075217 DOI: 10.1155/2015/183525

Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.

Matched MeSH terms: Metal Nanoparticles/toxicity*; Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry
Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium

Amin Yavari S, Chai YC, Böttger AJ, Wauthle R, Schrooten J, Weinans H, et al.

Mater Sci Eng C Mater Biol Appl, 2015 Jun;51:132-8.
PMID: 25842117 DOI: 10.1016/j.msec.2015.02.050

Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium.

Matched MeSH terms: Metal Nanoparticles/administration & dosage; Metal Nanoparticles/ultrastructure; Metal Nanoparticles/chemistry
One-pot green synthesis of highly reduced graphene oxide decorated with silver nanoparticles

Nur Suhaili Abd Aziz, Muhammad Khairullah Nor Azmi, Abdul Manaf Hashim

Sains Malaysiana, 2017;46:1083-1088.

A one-pot green sonochemical process assisted by ascorbic acid as the reducing agent to produce highly reduced graphene oxide (rGO) decorated with silver nanoparticles (AgNPs) is demonstrated. A complete removal of oxygen-containing group in the GO sheets was confirmed by no observation of the peak corresponds to C-O, C=O and -OH bond. The unexpected decrease of peak intensity corresponds to sp2 hybridized C=C group is explained by a so-called bond polarity effect. The peak observed at ~400 nm seems to show the presence of AgNPs and the red shifting of C=C peak to ~270 nm after the introduction of ascorbic acid indicates the formation of highly reduced GO. The increase of AgNPs size and the crumpled silk-like morphology after the introduction of ascorbic acid also indicate the aggressive reduction of both AgNPs and GO. The increase of ID/IG ratio after the introduction of ascorbic acid seems to indicate the increase of the number of small sp2 domains, the presence of unrepaired defects and the restoration of the sp2 network. This work provides the promising green sonochemical approach by utilizing non-toxic and environmental-friendly reducing agent to produce highly reduced GO decorated with AgNPs for various applications.

Matched MeSH terms: Metal Nanoparticles
Fulltext Application of Plasmonic Metal Nanoparticles in TiO2-SiO2 Composite as an Efficient Solar-Activated Photocatalyst: A Review Paper

Joseph CG, Taufiq-Yap YH, Musta B, Sarjadi MS, Elilarasi L

Front Chem, 2020;8:568063.
PMID: 33628762 DOI: 10.3389/fchem.2020.568063

Over the last decade, interest in the utilization of solar energy for photocatalysis treatment processes has taken centre-stage. Researchers had focused on doping TiO2 with SiO2 to obtain an efficient degradation rate of various types of target pollutants both under UV and visible-light irradiation. In order to further improve this degradation effect, some researchers resorted to incorporate plasmonic metal nanoparticles such as silver and gold into the combined TiO2-SiO2 to fully optimize the TiO2-SiO2's potential in the visible-light region. This article focuses on the challenges in utilizing TiO2 in the visible-light region, the contribution of SiO2 in enhancing photocatalytic activities of the TiO2-SiO2 photocatalyst, and the ability of plasmonic metal nanoparticles (Ag and Au) to edge the TiO2-SiO2 photocatalyst toward an efficient solar photocatalyst.

Matched MeSH terms: Metal Nanoparticles
Theory and experiment of optical absorption of platinum nanoparticles synthesized by gamma radiation

Gharibshahi E, Saion E, Johnston RL, Ashraf A

Appl Radiat Isot, 2019 May;147:204-210.
PMID: 30953937 DOI: 10.1016/j.apradiso.2019.02.015

Platinum nanoparticles were synthesized using the gamma radiolytic technique in an aqueous solution containing Platinum tetraammine chloride in presence of poly vinyl pyrrolidone, isopropanol, tetrahydrofuran and deionized water. The gamma irradiation was carried out in a60Co gamma source chamber and the particle size was found to decrease from 4.88 to 3.14 nm on increasing the gamma radiation dose from 80 to 120 kGy. UV-visible absorption spectra were measured and revealed two steady absorption maxima at 216 and 264 nm in the UV region, which was blue shifted (i.e. toward lower wavelength) with decreasing particle size. By taking the conduction electrons of an isolated particle that are not entirely free, but instead bound to their respective quantum levels, the optical absorption of platinum nanoparticles can be calculated via intra-band quantum excitation for particle sizes similar to those measured experimentally. We found that the calculated absorption maxima of electronic excitations matched the measured absorption maxima well. This finding suggests that the optical absorption of metal nanoparticles commonly applied in nanoscience and nanotechnology can be described accurately by the quantum excitation of conduction electrons.

Matched MeSH terms: Metal Nanoparticles
Fulltext Novel Carbon Quantum Dots/Silver Blended Polysulfone Membrane with Improved Properties and Enhanced Performance in Tartrazine Dye Removal

Gan JY, Chong WC, Sim LC, Koo CH, Pang YL, Mahmoudi E, et al.

Membranes (Basel), 2020 Aug 03;10(8).
PMID: 32756315 DOI: 10.3390/membranes10080175

This study produced a novel polysulfone (PSF) membrane for dye removal using lemon-derived carbon quantum dots-grafted silver nanoparticles (Ag/CQDs) as membrane nanofiller. The preparation of CQDs was completed by undergoing hydrothermal treatment to carbonize the pulp-free lemon juice into CQD solution. The CQD solution was then coupled with Ag nanoparticles to form Ag/CQDs nanohybrid. The synthesized powders were characterized in terms of morphologies, functional groups and surface charges. A set of membranes was fabricated with different loadings of Ag/CQDs powder using the nonsolvent-induced phase separation (NIPS) method. The modified membranes were studied in terms of morphology, elemental composition, hydrophilicity and pore size. In addition, pure water flux, rejection test and fouling analysis of the membranes were evaluated using tartrazine dye. From the results, 0.5 wt % of Ag/CQD was identified as the optimum loading to be incorporated with the pristine PSF membrane. The modified membrane exhibited an excellent pure water permeability and dye rejection with improvements of 169% and 92%, respectively. In addition, the composite membrane also experienced lower flux decline, higher reversible fouling and lower irreversible fouling. This study has proven that the addition of CQD additives into membrane greatly improves the polymeric membrane's properties and filtration performance.

Matched MeSH terms: Metal Nanoparticles
Synthetic nanoparticle-conjugated bisindoles and hydrazinyl arylthiazole as novel antiamoebic agents against brain-eating amoebae

Kanwal, Mungroo MR, Anwar A, Ali F, Khan S, Abdullah MA, et al.

Exp Parasitol, 2020 Nov;218:107979.
PMID: 32866583 DOI: 10.1016/j.exppara.2020.107979

Balamuthia mandrillaris and Naegleria fowleri are free-living amoebae that can cause life-threatening infections involving the central nervous system. The high mortality rates of these infections demonstrate an urgent need for novel treatment options against the amoebae. Considering that indole and thiazole compounds possess wide range of antiparasitic properties, novel bisindole and thiazole derivatives were synthesized and evaluated against the amoebae. The antiamoebic properties of four synthetic compounds i.e., two new bisindoles (2-Bromo-4-(di (1H-indol-3-yl)methyl)phenol (denoted as A1) and 2-Bromo-4-(di (1H-indol-3-yl)methyl)-6-methoxyphenol (A2)) and two known thiazole (4-(3-Nitrophenyl)-2-(2-(pyridin-3-ylmethylene)hydrazinyl)thiazole (A3) and 4-(Biphenyl-4-yl)-2-(2-(1-(pyridin-4-yl)ethylidene)hydrazinyl)thiazole (A4)) were evaluated against B. mandrillaris and N. fowleri. The ability of silver nanoparticle (AgNPs) conjugation to enrich antiamoebic activities of the compounds was also investigated. The synthetic heterocyclic compounds demonstrated up to 53% and 69% antiamoebic activities against B. mandrillaris and N. fowleri respectively, while resulting in up to 57% and 68% amoebistatic activities, respectively. Antiamoebic activities of the compounds were enhanced by up to 71% and 51% against B. mandrillaris and N. fowleri respectively, after conjugation with AgNPs. These compounds exhibited potential antiamoebic effects against B. mandrillaris and N. fowleri and conjugation of synthetic heterocyclic compounds with AgNPs enhanced their activity against the amoebae.

Matched MeSH terms: Metal Nanoparticles
Formation of high-density crystalline-shape gold nanoparticles on indium tin oxide surfaces: effects of alcohothermal seeding

Umar AA, Salleh MM, Majlis BY, Oyama M

J Nanosci Nanotechnol, 2011 Jun;11(6):4974-80.
PMID: 21770130

We found that the gold nanoparticles with high-density and crystalline-shape, such as nanocubes, nanobricks, pentahedral nanorods, etc., can be realized on the surface by using a seed-mediated growth method with a unique seeding process, namely alcohothermal. By using a conventional growth solution that contains HAuCl4, cetyltrimethylammonium bromide, NaOH and ascorbic acid, gold nanoparticles with crystalline-morphology (gold nanocrystals) of yield up to ca. 95%, can be prepared. An alcohothermal seeding was carried out by a thermal reduction of gold ions from an alcoholic solution of gold salt on the surface through an annealing process at a moderate temperature, namely 250 degrees C. It is believed that the unique initial characteristic (presumably the structures) of the gold nanoseeds particles as the result of peculiar nanoseeds formation process, prepared using this approach, instead of a simple thermal restructuring of the as prepared nanoseeds as confirmed by the results of annealing treatment on the nanoseed prepared using the normal and in-situ reduction seeding, was as the driving factor for the projected growth of crystalline-shape gold nanoparticles on the surface. The crystalline-shape gold nanoparticles modified-surface should find a potential application in catalysis, sensors and SERS.

Matched MeSH terms: Metal Nanoparticles
Fulltext Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer

Mok PL, Leow SN, Koh AE, Mohd Nizam HH, Ding SL, Luu C, et al.

Int J Mol Sci, 2017 Feb 08;18(2).
PMID: 28208719 DOI: 10.3390/ijms18020345

Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases.

Matched MeSH terms: Metal Nanoparticles
Fulltext Dose enhancement effects by different size of gold nanoparticles under irradiation of megavoltage photon beam

Wan Nordiana W Abd Rahman, Raizulnasuha Ab Rashid, Mahfuzah Muhammad, Khairunisak Abdul Razak, Norhayati Dollah, Moshi Geso

Jurnal Sains Nuklear Malaysia, 2018;30(2):23-29.
MyJurnal

Gold nanoparticles (AuNPs) have been extensively investigated as dose enhancement agent to increase the lethal dose to the tumours while minimizing dose to the normal tissue. Their intriguing properties and characteristics such as small size and shape provide favorable option in increasing radiotherapy therapeutic efficiency. In this study, the effects of AuNPs size on the dose enhancement effects irradiated under megavoltage photon beams were investigated. The study was conducted in-vitro on HeLa cells using AuNPs of 5 nm and 15 nm sizes. The cells samples were incubated with AuNPs and irradiated with photon beam of energy 6 MV and 10 MV at 100 cm SSD and 10 cm x 10 cm field size. Clonogenic assay were performed to observe the dose enhancement effects on cell survival. Dose enhancement factor (DEF) were extrapolated and evaluated from the cell survival curves. The results show that both sizes of AuNPs produce dose enhancement with the larger size AuNPs of 15 nm produce more dose enhancement compare to 5 nm AuNPs for 6 MV photon beam. Dose enhancements were observed for 10 MV photon beams but DEF for both sizes AuNPs shows no differences. In conclusion, larger size AuNPs produce higher dose enhancement compare to small size of AuNPs which conclude that nanoparticles size is important factor that need to be taken into account for AuNPs to be applied in radiotherapy.

Matched MeSH terms: Metal Nanoparticles
Initial stages of GaAs/au eutectic alloy formation for the growth of GaAs nanowires

Rosnita M, Yussof W, Zuhairi I, Zulkafli O, Samsudi S

Sains Malaysiana, 2012;41:1133-1138.

Annealing temperature plays an important role in the formation of an Au-Ga eutectic alloy. The effects of the annealing temperature on gold nanoparticles colloid and substrate surface were studied using AFM, FE-SEM and TEM. At 600oC, the layer of gold colloids particle formed an island in the state of molten eutectic alloy and absorbed evaporated metalorganics to formed nanowire (NW) underneath the alloy. Pit formed on the substrate surface due to the chemical reactions during the annealing process have an impact on the direction of growth of the NW. Without annealing, the NW formed vertically on the GaAs (100) surface. The growth direction depends on the original nucleation facets and surface energy when annealed. When annealed, the wire base is large and curved due to the migration of Ga atoms on the substrate surface towards the tip of the wire and the line tension between the substrate surface and gold particle.

Matched MeSH terms: Metal Nanoparticles

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