Bimetallic gold/silver alloy nanoparticles prepared in the presence of tryptophan

The stable colloidal solutions of monometallic and bimetallic gold and silver nanoparticles (NPs) have been obtained in the presence of amino acid tryptophan. For the synthesis of bimetallic composition the metals were used in a molar ratio of Ag:Au = 3:1, 1:1 and 1:3. The only one plasmon resonance band in absorption spectra was located between the bands inherent to the individual metals and it was characteristic for “alloy” type bimetallic AgAu NPs. The position of its maximum strongly depends on the Ag:Au molar ratio. The surface of all synthesized nanoparticles carries a negative charge due to the stabilizing shell consisted of amino acid. In the paper we usedUV/visible spectroscopy and dynamic light scattering method to analyze the effect of experimental procedure on the properties of obtained NPs.Стабільні колоїдні розчини наночастинок (НЧ) срібла та золота та їх біметалічні композити зі співвідношенням металів Ag:Au = 3:1, 1:1, 1:3 синтезовані у присутності амінокислоти триптофану. В спектрах поглинання присутня лише одна смуга поглинання плазмонного резонансу НЧ, характерна для біметальних наночастинок сплаву AgAu, розташована між смугами індивідуальних металів. Положення максимуму поглинання дуже залежить від мольного співвідношення Ag:Au. Поверхня всіх синтезованих наночастинок має негативний заряд за рахунок стабілізуючою оболонки амінокислоти. Проаналізовано вплив експериментальних методик на властивості одержаних НЧ за допомогою УФ / видимої спектроскопії і методу динамічного світлорозсіювання.Стабильные коллоидные растворы наночастиц (НЧ) серебра и золота, а так же их биметаллические композиты с соотношением металлов Ag:Au = 3:1, 1:1, 1:3 синтезированы в присутствии аминокислоты триптофана. В спектрах поглощения присутствует только одна полоса плазмонного резонанса НЧ, характерная для биметаллических наночастиц сплава AgAu, находящаяся между полосами НЧ отдельных металлов. Положение ее максимума сильно зависит от мольного соотношения Ag:Au. Поверхность всех синтезированных наночастиц имеет отрицательный заряд за счёт стабилизирующей оболочки аминокислоты. Проанализировано влияние экспериментальных методик на свойства полученных НЧ с помощью УФ/видимой спестроскопии и метода динамического светорассеивания

In vitro effect of hyperthermic Ag and Au Fe₃O₄ nanoparticles in cancer cells

PURPOSE: To investigate the anti-cancer efficacy of hyperthermic Ag and Au Fe3O4 core nanoparticles via cytotoxicity study (MTT assay) and the underlying molecular mechanism of action (changes in gene expression via quantitive real time PCR (qRT-PCR). METHODS: HEK293, HCT116, 4T1 and HUH7 human cell lines and 4T1 musculus mammary gland cell line were incubated with Fe3O4 core Ag(Au) shell nanoparticles (NPs) prior to a hyperthermia session. MTT assay was performed to estimate the cytotoxic effects of these NPs. RNA extraction and cDNA synthesis followed so as to quantify mRNA fold change of hsp-70, p53, bcl-2 and casp-3 via qRT-PCR. RESULTS: Fe3O4 core Au shell (concentrations of 400 and 600μg/mL) produced the greatest reduction of viability on HCT116 and 4T1 cells while Fe3O4 core Ag shell (200, 400 and 600μg/mL) reduce viability on HUH7 cells. Hsp-70, p53 and casp-3 were up-regulated while bcl-2 was downregulated in most cases. CONCLUSIONS: Fe3O4 core Ag (Au) shell induced apoptosis on cancer cells (HCT116 and HUH7) via the p53/bcl-2/casp-3 pathway. 4T1 cells also underwent apoptosis via a p53-independent pathway

Anticancer effect of Ag, Au, and Ag/Au bimetallic nanoparticles prepared in the presence of tryptophan

The use of metal nanoparticles (NPs) in cancer managment has gained great attention the last decade. However a lot of research is needed to be conducted regarding the targeting potential, the therapeutic effects, their stability in vitro and in vivo and their cytotoxicity effects in order to be successfully incorporated in the clinical management of cancer. Previous studies in our lab, suggested the bimetallic AgAu NPs stabilized with aminoacid tryptophan as effective in attenuating potential hepatotoxicity and nephrotoxicity of NPs during their in vivo application. In the present study, we aimed to study the fabrication of bimetallic “alloy” AgAu nanoparticles with the specific aim to define the optimal metal composition in bimetallic NPs with maximal antitumor effect. To this end we also measured the cytotoxicity of the bimetallic NPs in cancer cell lines. From the study, it is outlined that the ratio Ag:Au = 3:1 is suggested to be the optimal metal composition in bimetallic AgAu NPs with maximal antitumor effect for their use as “chemotherapeutic agents,” while the bimetallic AgAu NPs with metal ratio 1:3 seems to be the less toxic, suggesting this ratio to be the optimal for future in vivo assays, such as targeted localized therapy. Additionally, taking into consideration localized surface plasmon resonance absorption of bimetallic NPs, their use is also suggested for various methods that include irradiation and/or heating. Copyright © 2017 American Scientific Publishers All rights reserved

Influence of the mold inhibitor on productivity and functional activity of broiler chicken’s liver

During the experiment broiler chickens were the object of the research. The purpose of the study was to study the effect of different doses of the Oxy-Nile mold inhibitor in rations with an increased content of B1 aflatoxin on the utility-beneficial qualities and functional activity of the liver of broiler chickens. In the course of the experiment, it was established that to optimize utility indicators and functional activity of the liver in the feed of broiler chickens with a tolerant concentration of B1 aflatoxin , it is recommended to include the Oxy-Nile mold inhibitor in the amount of 600 g / t of feed

Ag/Au Bimetallic Nanoparticles Trigger Different Cell Death Pathways and Affect Damage Associated Molecular Pattern Release in Human Cell Lines

Apoptosis induction is a common therapeutic approach. However, many cancer cells are resistant to apoptotic death and alternative cell death pathways including pyroptosis and necroptosis need to be triggered. At the same time, danger signals that include HMGB1 and HSP70 can be secreted/released by damaged cancer cells that boost antitumor immunity. We studied the cytotoxic effects of AgAu NPs, Ag NPs and Au NPs with regard to the programmed cell death (apoptosis, necroptosis, pyroptosis) and the secretion/release of HSP70 and HMGB1. Cancer cell lines were incubated with 30, 40 and 50 µg/mL of AgAu NPs, Ag NPs and Au NPs. Cytotoxicity was estimated using the MTS assay, and mRNA fold change of CASP1, CASP3, BCL-2, ZPB1, HMGB1, HSP70, CXCL8, CSF1, CCL20, NLRP3, IL-1β and IL-18 was used to investigate the associated programmed cell death. Extracellular levels of HMGB1 and IL-1β were investigated using the ELISA technique. The nanoparticles showed a dose dependent toxicity. Pyroptosis was triggered for LNCaP and MDA-MB-231 cells, and necroptosis for MDA-MB-231 cells. HCT116 cells experience apoptotic death and show increased levels of extracellular HMGB1. Our results suggest that in a manner dependent of the cellular microenvironment, AgAu NPs trigger mixed programmed cell death in P53 deficient MDA-MB-231 cells, while they also trigger IL-1β release in MDA-MB-231 and LNCaP cells and release of HMGB1 in HCT116 cells. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Ag/Au bimetallic nanoparticles inhibit tumor growth and prevent metastasis in a mouse model

Purpose: To evaluate the antitumor efficacy of Ag3Au1Trp1:2NPs in a SCID mouse cancer model, with respect to their effect on tumor growth, on tumor’s metastatic potential and the underlying molecular mechanism. Subjects and Methods: Ag3Au1Trp1:2NPs were radiolabeled with Gallium-68 and the biodistribution was studied in Swiss mice without tumors and in SCID mice bearing tumors. SCID mice received intratumoral Ag3Au1Trp1:2NPs and tumor size was measured using calipers. Lung and liver tissues were extracted and studied microscopically for the detection of any metastatic sites. Changes in the Caspase-3 and TNF-related apoptosis-inducing ligand (TRAIL) were also investigated using real-time PCR and Western blot techniques, respectively. Results: In the 4T1 tumor-bearing SCID mice, Ag3Au1Trp1:2NPs showed quick passive accumulation at tumor sites at 30 mins post-injection. Mice that received the highest dose of NPs (5.6mg/mL) demonstrated a 1.9-fold lower tumor volume compared to that of the control group at 11 days post-injection, while mice that did not receive NPs showed metastatic sites in liver and lung. Extracted tumor tissue of treated mice revealed increased Casp-3 mRNA levels as well as elevated TRAIL protein levels. Conclusion: Based on our results, Ag3Au1Trp1:2NPs express anti-tumor and anti-metastatic effects in vivo. Ag3Au1Trp1:2NPs also reach tumor site via the enhancement and retention effect which results in the apoptotic death of cancerous cells selectively via the extrinsic TRAIL-dependent pathway. © 2020 Katifelis et al