Search

Researchers are keenly interested in developing metal-based nanoparticles using plant sources as they are eco-friendly, less expensive and simpler. Zinc oxide nanoparticles, symbolized as D-ZnONPs and M-ZnONPs were synthesized in this study utilizing the leaves of D. indica and M. micrantha, respectively, and studied their impact on the growth inhibition of various bacterial strains and on the photocatalysis. By displaying the distinctive surface plasmon resonance (SPR) band at 373 nm in UV-Vis and bands at 450-480 cm -1 corresponding to Zn-O stretching FTIR spectroscopy imparted the formation of ZnONPs which was further supported by X-ray diffraction analysis by showing the polycrystalline nature and a hexagonal wurtzite structure. The spherical form and average particle size of 30 nm of the produced ZnONPs, as confirmed by electron microscopy, are also confirmed to be crystalline. Under natural sunlight, both ZnONPs demonstrate excellent degradation efficacy about 96-99 % within 100 min towards methylene blue (MB). Furthermore, it is noteworthy that both the synthesized ZnONPs exhibited 55-60 % efficacy with respect to antibiotics in inhibiting the growth of various pathogenic bacterial strains. Overall, ZnONPs can be produced on a large-scale using plant sources and employed them in environmental remediation and cosmetic industries as prominent components., (© 2024 The Authors. ChemistryOpen published by Wiley-VCH GmbH.)

Nanoparticles (NPs) are utilized in various applications, posing potential risks to human health, tissues, cells, and macromolecules. This study aimed to investigate the ultrastructural alterations in hepatocytes and renal tubular cells induced by metallic and metal oxide NPs. Adult healthy male Wistar albino rats ( Rattus norvegicus ) were divided into 6 ( n = 7) control and 6 treated groups ( n = 7). The rats in the treated groups exposed daily to silver NPs, gold NPs, zinc oxide NPs, silicon dioxide NPs, copper oxide NPs, and ferric oxide NPs for 35 days. The members of the control group for each corresponding NPs received the respective vehicle. Liver and kidney tissue blocks from all rats were processed for Transmission Electron Microscopy (TEM) examinations. The hepatocytes and renal tubular cells of all NPs-treated rats demonstrated mitochondrial ultrastructural alterations mainly cristolysis, swelling, membrane disruption, lucent matrices, matrices lysis, and electron-dense deposits. However, other organelles demonstrated injury but to a lesser extent in the form of shrunken nuclei, nuclear membrane indentation, endoplasmic reticulum fragmentation, cellular membranes enfolding, brush border microvilli disruption, lysosomal hyperplasia, ribosomes dropping, and peroxisome formation. One may conclude from the findings that the hepatocytes and the renal tubular cells mitochondria are the main targets for nanoparticles toxicity ending in mitochondrial disruption and cell injury. Further studies taking into account the relation of mitochondrial ultrastructural damage with a weakened antioxidant defense system induced by chronic exposure to nanomaterials are needed., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Copper oxide nanomaterials (CuO NPs) have been widely utilized in many fields, including antibacterial materials, anti-tumor, osteoporosis treatments, imaging, drug delivery, cosmetics, lubricants for metallic coating, the food industry, and electronics. Little is known about the potential risk to human health and ecosystems. The present work was conducted to investigate the ultrastructural changes induced by 20 ± 5 nm CuO NPs in hepatic tissues. Adult healthy male Wister albino rats were exposed to 36 intraperitoneal (ip) injections of 25 nm CuO NPs (2 mg/kg bw). Liver biopsies from all rats under study were processed for transmission electron microscopy (TEM) processing and examination for hepatic ultrastructural alterations. The hepatic tissue of rats exposed to repeated administrations of CuO NPs exhibited the following ultrastructural alterations: extensive mitochondrial damage in the form of swelling, crystolysis and matrix lysis, formation of phagocytized bodies and myelin multilayer figures, lysosomal hyperplasia, cytoplasmic degeneration and vacuolation, fat globules precipitation, chromatin clumping, and nuclear envelope irregularity. The findings indicated that CuO NPs interact with the hepatic tissue components and could induce alterations in the hepatocytes with the mitochondria as the main target organelles of copper nanomaterials. More work is recommended for better understanding the pathogenesis of CuO NPs., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The encapsulation of plant extract in nanomatrices has limitations due to its adhesion to walls, size control, high cost and long durations that results in low yield. Macroscale and microscale level techniques for development of micro/nanoparticles may impact the encapsulation of plant extract. This study aimed to evaluate the relative efficiency of microscale and macroscale techniques for encapsulation of plant extract, which is not compared yet. Keeping this in view, encapsulation of Calotropis gigantea leaves extract (CaG) was attained in silver-conjugated poliglusam nanomatrices (POL/Ag) to induce apoptosis in invasive ductal carcinoma (IDC) cells. The ethanolic CaG extract was prepared using percolation method and characterized by chemical tests for its active phytochemical compounds. The droplet-based microfluidic system was utilized as microscale encapsulation technique for CaG in nanomatrices at two different aqueous to oil flow rate ratios 1.0:1.5, and 1.0:3.0. Moreover, conventional batch system was utilized as macroscale encapsulation technique consisted of hot plate magnetic stirrer. The prepared nanomatrices were analysed for antioxidant activity using DPPH test and for cytotoxicity analysis using MCF-7 cells. The characteristic peaks of UV-Vis, FTIR and XRD spectrum confirmed the synthesis of CaG(POL/Ag) by both the encapsulation methods. However, microfluidic system was found to be more expedient because of attaining small and uniform sized silver nanoparticles (92 ± 19 nm) at high flow rate and achieving high encapsulation efficiency (80.25%) as compared to the conventional batch method (52.5%). CaG(POL/Ag) nanomatrices found to have significant antioxidant activity (p = 0.0014) against DPPH radical scavenging activity. The CaG(POL/Ag) of the smallest sized formulated by the microfluidic system has also shown the highest cytotoxicity (90%) as compared to batch method (70%) at 80 µg/mL. Our results indicate that the microscale technique using microfluidic system is a more efficient method to formulate size-controlled CaG(POL/Ag) nanomatrices and achieve high encapsulation of plant extract. Additionally, CaG(Pol/Ag) was found to be an efficient new combination for inducing potent (p < 0.0001) apoptosis in IDC cells. Therefore, CaG(Pol/Ag) can be further tested as an anti-cancer agent for in-vivo experiments., (© 2023. Springer Nature Limited.)

Silver nanoparticles (AgNPs) have been generally used due to their strong antibacterial, antiviral and antifungal and antimicrobial properties. However, their toxicity is a subject of sustained debate, thus requiring further studies. Hence, this study examines the adverse effects of the sub-dermal administered dose of AgNPs (200 nm) on the liver, kidney and heart of male Wistar rats. Thirty male rats were randomly distributed into six groups of five animals per group. Group A and D served as the control and received distilled water for 14 and 28 days respectively. Groups B and C were sub-dermally exposed to AgNPs at 10 and 50 mg/kg daily for 14 days while E and F were sub-dermally exposed to AgNPs at 10 and 50 mg/kg daily for 28 days. The liver, kidney and heart of the animals were collected, processed and used for biochemical and histological analysis. Our results revealed that the subdermal administration of AgNPs induced significant increased (p < 0.05) activities of aspartate aminotransferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), urea, creatinine, and malondialdehyde (MDA) while decreasing the levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and total thiol groups in the rat tissues. Our findings suggest that the subdermal administration of AgNPs induced oxidative stress and impaired the hepatic, renal and cardiac functions of male Wistar rats., (© 2023. The Author(s).)

Copper oxide nanomaterials are used in many biomedical, agricultural, environmental, and industrial sectors with potential risk to human health and the environment. The present study was conducted to determine the renal ultrastructural damage caused by 25 nm CuO nanoparticles in renal tissues. Adult healthy male Wister Albino rats ( Rattus norvegicus ) were administered 35 intraperitoneal injections of CuO nanoparticles (2 mg/kg). Ultrastructural changes were evaluated using transmission electron microscopy techniques. The renal tissues of rats with subchronic exposure to CuO nanoparticles demonstrated glomerular alterations that included hypertrophic endothelial cells, dilated capillaries and occlusions, podocyte hypertrophy, pedicle disorganization, mesangial cell hyperplasia, and crystalloid precipitation. Moreover, the treated renal cells exhibited mitochondrial swelling and crystolysis, cytoplasmic vacoulization, lysosomal hypertrophy, apoptotic activity, endoplasmic reticulum dilatation, nuclear deformity, chromatin dissolution, and basement membrane thickening. In addition, disruption and disorganization of the renal cells microvilli together with cystolic inclusions were also detected. It was concluded from the present findings that CuO nanoparticles could interact with the components of the renal tissues in ways that could cause ultrastructural injury, suggesting renal tissue pathophysiology. Additional studies are suggested for a better understanding the nanotoxicity of CuO nanomaterials.

Organophosphates (OPs) are neurotoxic agents also used as pesticides that can permanently block the active site of the acetylcholinesterase (AChE). A robust and sensitive detection system of OPs utilising the enzyme mimic potential of the cysteamine capped gold nanoparticles (C-AuNPs) was developed. The detection assay was performed by stepwise addition of AChE, parathion ethyl (PE)-a candidate OP, acetylcholine chloride (ACh), C-AuNPs, and 3, 3', 5, 5'-tetramethylbenzidine (TMB) in the buffer solution. The whole sensing protocol completes in 30-40 min, including both incubations. The Transmission Electron Microscopy (TEM) results indicated that the NPs are spherical and have an average size of 13.24 nm. The monomers of C-AuNPs exhibited intense catalytic activity (nanozyme) for the oxidization of TMB, revealed by the production of instant blue colour and confirmed by a sharp peak at 652 nm. The proposed biosensor's detection limit and linear ranges were 5.8 ng·mL -1 and 11.6-92.8 ng·mL -1 , respectively, for PE. The results strongly advocate that the suggested facile colorimetric biosensor may provide an excellent platform for on-site monitoring of OPs.

In this study, the rGO-PEI-AgNPs sensor was designed as a new effective platform to sensitive monitoring of deltamethrin in human plasma samples. For this purpose, reduced graphene oxide (rGO)-supported polyethylenimine (PEI) was used as a suitable substrate for dispersion of silver nanoparticles (AgNPs) as amplification and catalytic element. Therefore, a novel interface (rGO-PEI-AgNPs) was prepared by the fully electrochemical method on the surface of glassy carbon electrodes. The engineered nano-sensor showed a wide dynamic range of 10 nM to 1 mM and low limit of quantification (LLOQ) as 10 nM in human plasma sample, which revealed excellent analytical performance for the recognition of deltamethrin with high sensitivity and reproducibility through differential pulse voltammetry and square wave voltammetry techniques. The results confirm that rGO-PEI-AgNPs as a novel biocompatible interface can provide appropriate, reliable, affordable, rapid, and user-friendly diagnostic tools in the detection of deltamethrin in human real samples., (© 2021 John Wiley & Sons Ltd.)

In the present work, silver nanoparticles were prepared by using the extract of Camellia Sinensis. The extract contains phytochemicals which are mainly polyphenols acting as the natural reducing and stabilizing agents leading to the formation of uniformly dispersed and stabilized silver nanoparticles. The synthesis of silver nanoparticles was significantly influenced by the impact of the pH, as well as temperature conditions. It was found that at pH 5 and 25 °C, nanoparticles of different morphologies (spherical, polygonal, capsule) and sizes were formed. However, with the increase in temperature from 25 °C to 65 °C but at the same pH, these particles started attaining the spherical shape of different sizes owing to an increase in the reduction rate. Furthermore, for the reaction of the mixture at 65 °C, an increase in pH from 5 to 11 led to an increase in the monodispersity of spherically shaped nanoparticles, attributed to the hydroxide ions facilitated reduction. The prepared nanoparticles were investigated for their antibacterial activity using Nathan's Agar Well-Diffusion method. It was found that AgNPs prepared at pH 9 and 65 °C demonstrated strong antibacterial activity against gram-negative Escherichia coli in contrast to gram-positive Staphylococcus aureus. In reference to the cytotoxic potency, the prepared AgNPs showed clear cytotoxicity for HeLa cells and showcased a close relationship between activity and concentration as evidenced by the decrease in the percentage (100 to 30%) of metabolically active cells up to 25 µM-75 µM concentration of silver nanoparticles.

Published studies indicate that virtually any kind of botanical material can be exploited to make biocompatible, safe, and cost-effective silver nanoparticles. This hypothesis is supported by the fact that plants possess active bio-ingredients that function as powerful reducing and coating agents for Ag+. In this respect, a phytomediation method provides favourable monodisperse, crystalline, and spherical particles that can be easily purified by ultra-centrifugation. However, the characteristics of the particles depend on the reaction conditions. Optimal reaction conditions observed in different experiments were 70-95 °C and pH 5.5-8.0. Green silver nanoparticles (AgNPs) have remarkable physical, chemical, optical, and biological properties. Research findings revealed the versatility of silver particles, ranging from exploitation in topical antimicrobial ointments to in vivo prosthetic/organ implants. Advances in research on biogenic silver nanoparticles have led to the development of sophisticated optical and electronic materials with improved efficiency in a compact configuration. So far, eco-toxicity of these nanoparticles is a big challenge, and no reliable method to improve the toxicity has been reported. Therefore, there is a need for reliable models to evaluate the effect of these nanoparticles on living organisms., (© 2021 The Authors. IET Nanobiotechnology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.)

Titanium dioxide nanoparticles (TiO 2 NPs) have novel application and are used in many household application, nanomedicine, agriculture, industries and pharmaceutical products. These applications may be accompanied with potential risk in human health and the ecosystems. The current study was carried out to find out the acute damage that might be induced by TiO 2 NPs in the heart and testis. Three groups of Wistar albino rats (Rattus norvegicus) were subjected to a single dose TiO 2 NPs (126, 252, 378 mg/kg bw). Cardiac and testicular biopsies from each animal under study were handled for histological and histochemical examination. Rats exposed to TiO 2 NPs demonstrated the following cardiac alterations: myofibres wavy appearance, myofibre disarray, partial cross striation, cardiomyocytes hydropic degeneration together with vacuolation and nuclear alterations. Moreover, acute exposure to TiO 2 NPs induced the following testicular alterations: spermatocytes degeneration, spermatids sloughing and interstitial edema. The presented cardiac and testicular alterations were dose dependent. From the findings of the present study, it might be concluded that TiO 2 nanomaterials are capable of inducing acute cardiac and testicular damage that is dose dependent and could adversely affect the function of the vital organs., (© 2020 The Authors. IET Nanobiotechnology published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology.)

Metallic nanoparticles (NPs) are widely used in medical preparations. The present study aims to find out the influence of widely used five metallic NPs on the expression of major hepatic drug-metabolizing enzyme (DME) genes. Six groups of BALB/C mice, 7 mice each, were exposed to: Gold NPs, silver NPs, copper oxide NPs, silicon dioxide NPs and zinc oxide NPs, for 21 days. Liver biopsies from all mice were subjected to mouse cyp3a11, cyp2c29, ugt2b1 and interleukin-6 (il6) gene expression quantification using real-time polymerase chain reaction, in addition to inflammatory cell infiltration examination. All tested NPs caused a sharp and significant (ANOVA, p value <0.05) downregulation in the expression of DME genes, with the highest influence was observed in mice exposed to copper oxide NPs. Additionally, all NPs induced hepatic inflammation and upregulated the expression of il6 gene, which were inversely correlated with the expression of DMEs. It is concluded that all tested NPs downregulated the expression of DME genes, with the highest influence exhibited by copper oxide NPs, in correlation with inflammation and il6 gene induction in the liver. Further studies are needed to find out the effect of anti-inflammatory compounds against the alterations induced by metallic NPs exposure on hepatic DMEs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A facile, green synthesis of selenium doped zinc oxide nano-antibiotic (Se-ZnO-NAB) using the Curcuma longa extract is reported to combat the increased emergence of methicillin-resistant Staphylococcus aureus (MRSA). The developed Se-ZnO-NAB were characterized for their physicochemical parameters and extensively evaluated for their toxicological potential in an animal model. The prepared Se-ZnO-NABs were characterized via Fourier transformed infrared spectroscopy to get functional insight into their surface chemistry, scanning electron microscopy revealing the polyhedral morphology with a size range of 36 ± 16 nm, having -28.9 ± 6.42 mV zeta potential, and inductively coupled plasma optical emission spectrometry confirming the amount of Se and Zn to be 14.43 and 71.70 mg L-1 respectively. Moreover, the antibacterial activity against MRSA showed significantly low minimum inhibitory concentration at 6.2 μg mL-1 when compared against antibiotics. Also, total protein content and reactive oxygen species production in MRSA, under the stressed environment of Se-ZnO-NAB, significantly (p < 0.05) decreased compared to the negative control. Moreover, the results of acute oral toxicity in rats showed moderate variations in blood biochemistry and histopathology of vital organs. The teratogenicity and fetal evaluations also revealed some signs of toxicity along with changes in biochemical parameters. The overall outcomes suggest that Se-ZnO-NAB can be of significant importance for combating multi-drug resistance but must be used with extreme caution, particularly in pregnancy, as moderate toxicity was observed at a toxic dose of 2000 mg kg-1.

Silver nanoparticles (Ag NPs) are widely used in nanomedicine, pharmaceutical products, industry and other consumer products owing to their unique physiochemical properties with probable potential risk to human health and the ecosystems. The aim of this work was to investigate the in-life morphological effects, biochemical, histological and histochemical alterations that might be induced by variable sizes of Ag NPs in hepatic, renal and testicular tissues with the hypothesis that variable sizes of nano-Ag could induce variable effects in the vital organs. Five groups of adult healthy male mice (BALB/C) were exposed to 35 intraperitoneal injections of Ag NPs (1 mg/kg bw) using five different particle sizes (10, 20, 40, 60 and 100 nm). All mice were subjected to in-life morphometric, biochemical, histological and histochemical analysis. The findings demonstrated that Ag NPs could induce alterations in the average body weight gain, food consumption, water intake and organ indices. In addition, these NPs significantly altered hepatic and renal biomarkers. Moreover, Ag NPs produced ground glass hepatocyte cytoplasm, with mitotic activity, nuclear alterations, degeneration, glycogen depletion and inflammatory cells infiltration in the liver. The kidneys of treated mice exhibited proximal renal tubules degeneration, distal renal tubules regeneration, glomerular shrinkage, Bowman's capsule thickening and interstitial inflammation. The testicular tissues demonstrated spermatocyte sloughing and spermatid giant cell formation. The findings together indicated that Ag NPs could interact with the anatomical structures of the liver, kidney and testis in ways that could induce injury. In addition, the results indicated that smaller Ag NPs posed a greater potential risk than the larger ones, which might be associated with their behaviour, dissolution rate, bioavailability and their probable variable toxicokinetics.

The potential pharmaceutical application of nanoparticles has led to the toxicity within the male reproductive system. In the present study, the effects of silver nanoparticles (Ag-NPs) on hematological parameters, free radical generation, antioxidant system, sperm parameters, and organ histo-morphometry in male rats were investigated. Ag-NPs were produced by the reduction of silver ions, while the formation of which was monitored by UV-visible spectrophotometry. Zeta potential, transmission, and scanning electron microscopies were applied for the characterization of AgNPs. A total of 30 rats were divided into 6 groups and were sub-dermally exposed to Ag-NPs at the dosage of 0 (control), 10, and 50 mg/kg bodyweight (bw) doses for either 7 or 28 days. Ag-NP administration altered hematological indices and caused dose-dependent decreases in sperm motility, velocity, kinematic parameters, concentrations of luteinizing hormone, follicle-stimulating hormone, and testosterone. In the epididymis and testis, the concentrations of malondialdehyde and peroxide increases while superoxide dismutase, catalase, reduced glutathione, and total thiol group decreases. These findings suggest that Ag-NP triggered hormonal imbalance and induce oxidative stress in testis and epididymis; which negatively affect sperm parameters of male rats.

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%).

In a couple of decades, nanotechnology has become a trending technology owing to its integrated science collection that incorporates variety of fields such as chemistry, physics, medicine, catalytic processes, food processing industries, electronics and energy sectors. One of the emerging fields of nanotechnology that has gained momentous admiration is nano-biotechnology. Nano-biotechnology is an integrated combination of biology with nanotechnology that encompasses the tailoring, and synthesis of small particles that are less than 100nm in size and subsequent exploitation of these particles for their biological applications. Though the variety of physical techniques and chemical procedures are known for the nanoparticles synthesis, biological approach is considered to be the preferred one. Environmental hazards and concerns associated with the physical and chemical approaches of nanoparticles synthesis has added impetus and zenith to the biological approach involving the use of plants and microorganisms. The current review article is focused on the synthesis of plant-derived (phytochemical) gold nanoparticles alongside their scope in biomedical applications., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

OBJECTIVE: To investigate the histomorphometric alterations induced in testicular tissues by variable sizes of silver nanoparticles (SNPs). STUDY DESIGN: Male mice (BALB/C) were treated with SNPs (1 mg/kg) using 5 different sizes (10, 20, 40, 60, and 100 nm) for 35 days. Testicular biopsies from all mice under study were examined histomorphologically. RESULTS: SNPs sized 10 and 20 nm had provoked morphometric changes in the testes of the subjected mice together with the following histological alterations: seminiferous tubules, degeneration, spermatocyte cytoplasmic vacuolation, spermatocyte sloughing, and spermatid giant cell formation. Larger SNPs (40, 60, and 100 nm) induced little or no testicular histomorphometric alterations. CONCLUSION: The findings of the present work may indicate that subchronic exposure to SNPs could have a deleterious impact on the testicular tissues and spermatogenic process that could affect fertility and reproduction, with smaller SNPs being more toxic than larger ones.

Peristaltic transport of copper-water nanofluid in an inclined channel is reported in the presence of mixed convection. Both velocity and thermal slip conditions are considered. Mathematical modelling has been carried out using the long wavelength and low Reynolds number approximations. Resulting coupled system of equations is solved numerically. Quantities of interest are analyzed through graphs. Numerical values of heat transfer rate at the wall for different parameters are obtained and examined. Results showed that addition of copper nanoparticles reduces the pressure gradient, axial velocity at the center of channel, trapping and temperature. Velocity slip parameter has a decreasing effect on the velocity near the center of channel. Temperature of nanofluid increases with increase in the Grashoff number and channel inclination angle. It is further concluded that the heat transfer rate at the wall increases considerably in the presence of copper nanoparticles.

Nanoparticles of copper(I) oxide (cuprous oxide; Cu2O) were able to be synthesized from nano-restricted copper acetate (Cu(OAc)2) in micropores of single-wall carbon nanotubes (SWNTs) by visible-light photoreduction. The specific structure of confined Cu(OAc)2 in the micropore is indispensable for the reduction process to Cu2O by the irradiation, because, in general, aqueous solution of Cu(OAc)2 can be reduced under UV-light irradiated conditions. The present results strongly suggest that the micropore of SWNTs whose pore width is in the micropore-size range can play as nanoreactor space for the synthesis of Cu2O through the nano-restricted precursor whose reactivity is different from that in the bulk phase., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We report herein an unprecedented one-step green synthesis of gold nanoparticles (G-AuNps), using naturally occurring Korean red ginseng root (Panax ginseng C.A. Meyer) without any special reducing/capping agents. The AuNps generated through this ginseng-mediated process did not aggregate suggesting that the phytochemicals present in them serve as excellent coatings on the nanoparticles and thus, provide robust shielding from aggregations. The ginseng-generated AuNps exhibit remarkable in vitro stability in various buffers including: cysteine, histidine, saline, sodium chloride and a host of pH ranges. Furthermore, the phytochemical coatings on the G-AuNps rendered them nontoxic as demonstrated through detailed cytotoxicity assays using WST-8 counting kit, performed on normal cervical cells lines. The present study opens up a new possibility of conveniently synthesizing AuNps using natural products which will be useful in optoelectronic and biomedical applications., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Gold colloidal nanoparticles were prepared by the liquid laser ablation of a gold metal plate in water and also by the citrate reduction of HAuCl(4).4H2O. The gold colloidal nanoparticles with the plasmonic band strongly absorb light, which is converted to the photothermal energy. This photothermal energy gives a cytotoxic effect on epithelial carcinoma cells. Interestingly, we found that the size and shape of the nanoparticles are changed by light during the photothermal process in vitro. The cervical carcinoma cell line (HeLa cell) was incubated with the colloidal gold nanoparticles and then exposed to continuous visible light at 400-600 nm with UV- and heat-cutoff filters. The distinct cell-killing effect was observed by this procedure. In the absence of the gold colloidal nanoparticles, only a small amount of cells were photothermally destroyed.