Fe3O4 and Fe3O4core Aushell-based Hyperthermia Reduces Expression of Proliferation Markers Ki-67, TOP2A and TPX2 in a Human Breast Cancer Cell Line.

BACKGROUND/AIM: Hyperthermia represents an adjuvant local anticancer strategy which relies on the increase of temperature beyond the physiological level. In this study, we investigated the anticancer potential of Fe3O4 and Fe3O4core Aushell nanoparticles as hyperthermic agents in terms of cytotoxicity and studied the expression of cellular markers of proliferation (changes in mRNA levels via real-time polymerase chain reaction). MATERIALS AND METHODS: The human breast cancer cell line SK-BR-1 was incubated with either Fe3O4 or Fe3O4core Aushell nanoparticles stabilized with tryptophan, prior to hyperthermia treatment. The normal HEK293 cell line was used as a control. Toxicity was determined using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay to estimate possible toxic effects of the tested nanoparticles. After RNA extraction and cDNA synthesis, mRNA expression of three indicators of proliferation, namely marker of proliferation Ki-67, DNA topoisomerase II alpha (TOP2A) and TPX2 microtubule nucleation factor (TPX2), was investigated. RESULTS: At each concentration tested, Fe3O4core Aushell nanoparticles showed greater toxicity compared to Fe3O4, while SK-BR-3 cells were more susceptible to their cytotoxic effects compared to the HEK293 cell line. The expression of Ki-67, TOP2A and TPX2 was reduced in SK-BR-3 cells by both Fe3O4 or Fe3O4core Aushell nanoparticles compared to untreated cells, while the only observed change in HEK293 cells was the up-regulation of TOP2A. CONCLUSION: Both Fe3O4core Aushell and Fe3O4 NPs exhibit increased cytotoxicity to the cancer cell line tested (SK-BR-3) compared to HEK293 cells. The down-regulation in SK-BR-3 cells of the three proliferative markers studied, Ki-67, TOP2A and TPX2, after incubation with NPs suggests that cells that survived thermal destruction were not actively proliferating.

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-1ß and IL-18 was used to investigate the associated programmed cell death. Extracellular levels of HMGB1 and IL-1ß 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-1ß release in MDA-MB-231 and LNCaP cells and release of HMGB1 in HCT116 cells.

Antiviral Effect of Nonfunctionalized Gold Nanoparticles against Herpes Simplex Virus Type-1 (HSV-1) and Possible Contribution of Near-Field Interaction Mechanism.

The antiviral activity of nonfunctionalized gold nanoparticles (AuNPs) against herpes simplex virus type-1 (HSV-1) in vitro was revealed in this study. We found that AuNPs are capable of reducing the cytopathic effect (CPE) of HSV-1 in Vero cells in a dose- and time-dependent manner when used in pretreatment mode. The demonstrated antiviral activity was within the nontoxic concentration range of AuNPs. Interestingly, we noted that nanoparticles with smaller sizes reduced the CPE of HSV-1 more effectively than larger ones. The observed phenomenon can be tentatively explained by the near-field action of nanoparticles at the virus envelope. These results show that AuNPs can be considered as potential candidates for the treatment of HSV-1 infections.

Multifunctional Magneto-Plasmonic Fe3O4/Au Nanocomposites: Approaching Magnetophoretically-Enhanced Photothermal Therapy.

Magneto-plasmonic nanocomposites can possess properties inherent to both individual components (iron oxide and gold nanoparticles) and are reported to demonstrate high potential in targeted drug delivery and therapy. Herein, we report on Fe3O4/Au magneto-plasmonic nanocomposites (MPNC) synthesized with the use of amino acid tryptophan via chemical and photochemical reduction of Au ions in the presence of nanosized magnetite. The magnetic field (MF) induced aggregation was accompanied by an increase in the absorption in the near-infrared (NIR) spectral region, which was demonstrated to provide an enhanced photothermal (PT) effect under NIR laser irradiation (at 808 nm). A possibility for therapeutic application of the MPNC was illustrated using cancer cells in vitro. Cultured HeLa cells were treated by MPNC in the presence of MF and without it, following laser irradiation and imaging using confocal laser scanning microscopy. After scanning laser irradiation of the MPNC/MF treated cells, a formation and rise of photothermally-induced microbubbles on the cell surfaces was observed, leading to a damage of the cell membrane and cell destruction. We conclude that the synthesized magneto-plasmonic Fe3O4/Au nanosystems exhibit magnetic field-induced reversible aggregation accompanied by an increase in NIR absorption, allowing for an opportunity to magnetophoretically control and locally enhance a NIR light-induced thermal effect, which holds high promise for the application in photothermal therapy.

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.

Ag/Au bimetallic nanoparticles induce apoptosis in human cancer cell lines via P53, CASPASE-3 and BAX/BCL-2 pathways.

Au/Ag bimetallic nanoparticles (BNPs) exhibit a wide range of excellent electronic, chemical, biological, mechanical and thermal properties due to synergistic effects. However, critical questions regarding stability, biocompatibility and their cytotoxic effects remain to be answered. In this study, Ag/Au BNPs have been synthesized as "alloy" via a chemical reduction method using double molar excess of tryptophan [ν(M):ν(Trp) = 1:2]. We then estimated their toxicity in HCT116, 4T1, HUH7 and HEK293 cell lines in monocellular and spheroid cultures. Ag/Au nanoparticles with metal ratio 3:1, had the maximal antitumor effect in cancer cell lines, while the toxicity was found significantly decreased in non-cancerous cell lines. Our results were also compared to previous data regarding Ag/Au using single molar excess of tryptophan [ν(M):ν(Trp) = 1:1], suggesting that tryptophan has a protective effect on HEK293 and not in cancer cells. Aiming to investigate the molecular mechanism behind nanopartricles cytotoxicity, we studied the expression of cell cycle and apoptosis related genes on HCT116, 4T1, and HUH7 monocellular culture. Hence, we showed that bimetallic cytotoxicity is mediated via the caspase and the p53/Bax/Bcl-2 apoptotic pathway. In conclusion, our study suggests tryptophan ratio along with metal ratio used in Ag/Au BNPs as a successful way to control the toxicity in cancer cells towards non-cancerous cells, underlying the potency of bimetallic nanoparticles as selective anti-tumor agents.

Antitumor Activity of Alloy and Core-Shell-Type Bimetallic AgAu Nanoparticles.

Nanoparticles (NPs) of noble metals, namely gold and silver, remain promising anticancer agents capable of enhancing current surgery- and chemotherapeutic-based approaches in cancer treatment. Bimetallic AgAu composition can be used as a more effective agent due to the synergetic effect. Among the physicochemical parameters affecting gold and silver nanoparticle biological activity, a primary concern relates to their size, shape, composition, charge, etc. However, the impact of metal components/composition as well as metal topological distribution within NPs is incompletely characterized and remains to be further elucidated and clarified. In the present work, we tested a series of colloidal solutions of AgAu NPs of alloy and core-shell type for an antitumor activity depending on metal molar ratios (Ag:Au = 1:1; 1:3; 3:1) and topological distribution of gold and silver within NPs (AucoreAgshell; AgcoreAushell). The efficacy at which an administration of the gold and silver NPs inhibits mouse Lewis lung carcinoma (LLC) growth in vivo was compared. The data suggest that in vivo antitumor activity of the studied NPs strongly depends on gold and silver interaction arising from their ordered topological distribution. NPs with Ag core covered by Au shell were the most effective among the NPs tested towards LLC tumor growth and metastasizing inhibition. Our data show that among the NPs tested in this study, AgcoreAushell NPs may serve as a suitable anticancerous prototype.

Effects of Photochromic Furan-Based Diarylethenes on Gold Nanoparticles Aggregation.

The photochromic properties of furan-based diarylethenes and their interaction with citrate-capped gold nanoparticles were investigated by ultraviolet/visible absorption spectroscopy and transmission electron microscopy. We identified the optimal concentration of diarylethenes in water-ethanol mixture required for stability of colloidal systems. Nanoparticles coupled with diarylethene derivatives exhibit a new surface plasmon resonance band coming from their aggregation. We analyzed the effects of functional side-chain groups on aggregation process. These results can be considered as a basis for further designing of novel hybrid nanomaterials and optoelectronic elements.

The pH-Dependent Stucture and Properties of Au and Ag Nanoparticles Produced by Tryptophan Reduction.

In the work, an attempt was made to combine different experimental conditions to obtain stable gold and silver nanoparticles in the presence of amino acid tryptophan. The pH-dependent properties of gold and silver nanoparticles were studied. UV/visible spectroscopy and laser desorption/ionization mass spectrometry data confirm kynurenine pathway for tryptophan conversion in such systems.

Tryptophan-Assisted Synthesis Reduces Bimetallic Gold/Silver Nanoparticle Cytotoxicity and Improves Biological Activity.

Aiming to reduce the potential in vivo hepato-and nephrotoxicity of Ag/Au bimetallic nanoparticles (NPs) stabilized by sodium dodecyl sulphate (SDS), an approach involving a simultaneous reduction of silver nitrate and tetrachlorauratic acid using tryptophan (Trp) as a reducing/stabilizing agent was applied during NP synthesis. The obtained Ag/Au/Trp NPs (5-15 nm sized) were able to form stable aggregates with an average size of 370-450 nm and were potentially less toxic than Ag/Au/SDS in relation to a mouse model system based on clinical biochemical parameters and oxidative damage product estimation. Ag/Au/Trp NPs were shown to exhibit anticancer activity in relation to a Lewis lung carcinoma model. The data generated from the present study support the fact that the use of tryptophan in NP synthesis is effective in attenuating the potential hepatotoxicity and nephrotoxicity of NPs during their in vivo application.