Evaluation of core-shell Fe3O4@Au nanoparticles as radioenhancer in A549 cell lung cancer model.

In radiotherapy, metallic nanoparticles are of high interest in the fight against cancer for their radiosensitizing effects. This study aimed to evaluate the ability of core-shell Fe3O4@Au nanoparticles to potentiate the irradiation effects on redox-, pro-inflammatory markers, and cell death of A549 human pulmonary cancer cells. The hybrid Fe3O4@Au nanoparticles were synthesized using green chemistry principles by the sonochemistry method. Their characterization by transmission electron microscopy demonstrated an average size of 8 nm and a homogeneous distribution of gold. The decreased hydrodynamic size of these hybrid nanoparticles compared to magnetite (Fe3O4) nanoparticles showed that gold coating significantly reduced the aggregation of Fe3O4 particles. The internalization and accumulation of the Fe3O4@Au nanoparticles within the cells were demonstrated by Prussian Blue staining. The reactive oxygen species (ROS) levels measured by the fluorescent probe DCFH-DA were up-regulated, as well as mRNA expression of SOD, catalase, GPx antioxidant enzymes, redox-dependent transcription factor Nrf2, and ROS-producing enzymes (Nox2 and Nox4), quantified by RT-qPCR. Furthermore, irradiation coupled with Fe3O4@Au nanoparticles increased the expression of canonical pro-inflammatory cytokines and chemokines (TNF-α, IL-1ß, IL-6, CXCL8, and CCL5) assessed by RT-qPCR and ELISA. Hybrid nanoparticles did not potentiate the increased DNA damage detected by immunofluorescence following the irradiation. Nevertheless, Fe3O4@Au caused cellular damage, leading to apoptosis through activation of caspase 3/7, secondary necrosis quantified by LDH release, and cell growth arrest evaluated by clonogenic-like assay. This study demonstrated the potential of Fe3O4@Au nanoparticles to potentiate the radiosensitivity of cancerous cells.

Impact of Green Gold Nanoparticle Coating on Internalization, Trafficking, and Efficiency for Photothermal Therapy of Skin Cancer.

Skin cancer is a global health issue and mainly composed of melanoma and nonmelanoma cancers. For the first clinical proof of concept on humans, we decided to study good prognosis skin cancers, i.e., carcinoma basal cell. In UE, the first-line treatment remains surgical resection, healing most of the tumors, but presents aesthetic disadvantages with a high reoccurrence rate on exposed areas. Moreover, the therapeutic indications could extend to melanoma and metastasis, which is a different medical strategy that could combine this treatment. Indeed, patients with late-stage melanoma are in a therapeutic impasse, despite recent targeted and immunological therapies. Photothermal therapy using gold nanoparticles is the subject of many investigations due to their strong potential to treat cancers by physical, thermal destruction. We developed gold nanoparticles synthesized by green chemistry (gGNPs), using endemic plant extract from Reunion Island, which have previously showed their efficiency at a preclinical stage. Here, we demonstrate that these gGNPs are less cytotoxic than gold nanoparticles synthesized by Turkevich's method. Furthermore, our work describes the optimization of gGNP coating and stabilization, also taking into consideration the gGNP path in cells (endocytosis, intracellular trafficking, and exocytosis), their specificity toward cancerous cells, their cytotoxicity, and their in vivo efficiency. Finally, based on the metabolic switch of cancerous cells overexpressing Glut transporters in skin cancers, we demonstrated that glucose-stabilized gGNP (gGNP@G) enables a quick internalization, fourfold higher in cancerous cells in contrast to healthy cells with no side cytotoxicity, which is particularly relevant to target and treat cancer.

Polyphenol Characterization of the Aqueous Extract from Hubertia ambavilla L. (Asteraceae) by HPLC-DAD-ESI-MSn and Assessment of Its Antioxidant Activity.

In this work, phytochemical components, and the antioxidant properties of an aqueous extract obtained from a medicinal plant Hubertia ambavilla, endemic to Reunion Island, were investigated. A total of 37 compounds were detected and identified by high-performance liquid chromatography (UHPLC) using a photodiode-array detector (DAD) coupled with electrospray ionization/mass spectrometry (ESI/MSn ). From calibration curves, the quantity of secondary metabolites in the aqueous extract was calculated. The mean amounts of phenols, flavonoids, and condensed tannins found were 158.38±1.20 mg GAE/g DE, 60.41±1.65 mg AE/g DE and 23.77±1.36 mg CE/g DE, respectively. The in vitro antioxidant properties of the Hubertia ambavilla plant were measured using three methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging and ferric reducing antioxidant power. The results showed that crude aqueous extract of H. ambavilla had effective radical scavenging and reducing power in comparison with standard antioxidant compounds. In conclusion, the crude extract herein presented offers a natural alternative biosource of antioxidants with potential applications in food and health industries.

Dataset concerning plasmonic thermal destruction of murine melanoma by gold nanoparticles obtained by green chemistry.

The data presented in this article are related to the research paper "Proof of concept of plasmonic thermal destruction of surface cancers by gold nanoparticles obtained by green chemistry" (Ben Hadadda et al, 2019). In this article, we examined plasmonic thermal destruction of murine melanoma using gold nanoparticles obtained by green chemistry. The presented data were obtained by measuring tumor volume and mice weight in different groups of mice murine melanoma B16F10 treated or not with the nanoparticles and coupled to laser irradiation. These data were compared to the clinical reference treatment: anti-PD1 monoclonal antibody. The data were analyzed in order to be able to compare the antitumor effect of our treatment (photothermal plasmonic therapy using gold nanoparticles) and the reference treatment.

Assessment of antioxidant and dermoprotective activities of gold nanoparticles as safe cosmetic ingredient.

Hubertia ambavilla, an endemic plant originating from Reunion Island in the Indian Ocean, is traditionally used as an anti-inflammatory and in healing, both for internal and external use. Polyphenolic compounds from aqueous phase extractions can reduce metal salts into nanoparticles and stabilize them in one step. Although gold nanoparticles are well described in the literature as anti-ageing ingredients, the nanoparticles presented herein are novel and are synthesized using a green process. We demonstrate their efficiency as dermoprotective, free radical scavenger and antioxidant cosmetic ingredients. Comparison with common nanoparticles obtained by the Turkevich method clearly emphasizes the necessity to carefully screen the products used for nanoparticle coatings, as they play a major role in the biological properties of the product. Hubertia ambavilla mediated gold nanoparticles are non-toxic to human dermal fibroblasts, possess free radical scavenging potential, and protect against damage to fibroblast and dermal cells caused by ultraviolet A radiation.

Proof of concept of plasmonic thermal destruction of surface cancers by gold nanoparticles obtained by green chemistry.

A greener approach for the design of surface plasmon resonant gold nanoparticles has been obtained with a hydrosoluble fraction of an endemic asteraceae medicinal plant. This medicinal plant is originated from Indian Ocean and demonstrates its bioreducing activity in the design of stable green nanomedicine in aqueous media. This article describes the preclinical assessment of the efficacy of these novel nanocandidates on murine model by intratumoral and intravenous injections. It definitely demonstrates two key points in the treatment of cancer: 1) optimization of the tumor microenvironment targeting by specific ligands for a limited damage on healthy tissue, 2) the need to screen the specific irradiation dose (time, power) taking into account the type of tumor.

Optical imaging of disseminated leukemia models in mice with near-infrared probe conjugated to a monoclonal antibody.

BACKGROUND: The assessment of anticancer agents to treat leukemia needs to have animal models closer to the human pathology such as implantation in immunodeficient mice of leukemic cells from patient samples. A sensitive and early detection of tumor cells in these orthotopic models is a prerequisite for monitoring engraftment of leukemic cells and their dissemination in mice. Therefore, we developed a fluorescent antibody based strategy to detect leukemic foci in mice bearing patient-derived leukemic cells using fluorescence reflectance imaging (FRI) to determine when to start treatments with novel antitumor agents. METHODS: Two mAbs against the CD44 human myeloid marker or the CD45 human leukocyte marker were labeled with Alexa Fluor 750 and administered to leukemia-bearing mice after having verified the immunoreactivity in vitro. Bioluminescent leukemic cells (HL60-Luc) were used to compare the colocalization of the fluorescent mAb with these cells. The impact of the labeled antibodies on disease progression was further determined. Finally, the fluorescent hCD45 mAb was tested in mice engrafted with human leukemic cells. RESULTS: The probe labeling did not modify the immunoreactivity of the mAbs. There was a satisfactory correlation between bioluminescence imaging (BLI) and FRI and low doses of mAb were sufficient to detect leukemic foci. However, anti-hCD44 mAb had a strong impact on the tumor proliferation contrary to anti-hCD45 mAb. The use of anti-hCD45 mAb allowed the detection of leukemic patient cells engrafted onto NOD/SCID mice. CONCLUSIONS: A mAb labeled with a near infrared fluorochrome is useful to detect leukemic foci in disseminated models provided that its potential impact on tumor proliferation has been thoroughly documented.

Monitoring of tumour progression using bioluminescence imaging and computed tomography scanning in a nude mouse orthotopic model of human small cell lung cancer.

Human small cell lung carcinoma (SCLC) is the most aggressive type of lung cancer but no clinically relevant animal model has been developed to date. Such a model would be valuable to study the molecular aspects of tumour progression and to test the effectiveness of new treatment agents. We generated a reproducible and reliable nude mouse orthotopic model of human SCLC with NCI-H209 tumour cells genetically modified to express firefly luciferase. Cells were analysed for long-term stability of bioluminescence and a clone was passaged twice subcutaneously to enhance tumorigenicity. Cells resuspended in Matrigel and/or EDTA RPMI medium containing a (99m)Tc-labelled tin colloid used as tracer were implanted intrabronchially with a catheter inserted into the trachea and positioned in the main bronchus using X-ray-guided imaging. Deposition of cells into the lung was then assessed by scintigraphy. The growth of the primary tumour was sensitively and non-invasively followed by bioluminescence imaging that allowed real-time monitoring of tumour progression in the same animals over a 2-12-week period. Additional 3D bioluminescence imaging and computed tomography scanning were used to document tumour location and measurements that were confirmed by histological analyses. In conclusion, this original nude mouse orthotopic model resembles various stages of human small cell lung cancer, and therefore could be used to evaluate new treatment strategies.

Use of an image restoration process to improve spatial resolution in bioluminescence imaging.

To improve spatial resolution in in vivo bioluminescence imaging, a photon scattering correction, image restoration method was tested. The chosen algorithm was tested on in vivo bioluminescent images acquired on three representative tumor models: subcutaneous, pulmonary, and disseminated peritoneal. Tumor size was chosen as a quantitative criterion, such that the tumor reference measurements (determined photographically or by computed tomography) were compared to those derived from bioluminescent images, before and after restoration. This technique allowed a significant reduction to be achieved in the relative error between reference measurements and dimensions derived from bioluminescent images. In addition, improved delineation of the tumor foci was achieved. The restoration method allows spatial resolution in bioluminescence imaging to be improved, with interesting perspectives in terms of staging and quantitation in experimental oncology.

99mTc-HYNIC-spermine for imaging polyamine transport system-positive tumours: preclinical evaluation.

PURPOSE: F14512 exploiting the polyamine transport system (PTS) for tumour cell delivery has been described as a potent antitumour agent. The optimal use of this compound will require a probe to identify tumour cells expressing a highly active PTS that might be more sensitive to the treatment. The aim of this study was to design and characterize a scintigraphic probe to evaluate its uptake in cancer cells expressing the PTS. METHODS: Three polyamines coupled to a hydrazinonicotinamide (HYNIC) moiety were synthesized and labelled with 99mTc. Their radiochemical purity was determined by HPLC. The plasma stability of the 99mTc-HYNIC-spermine probe and its capacity to accumulate into PTS-active cells were also evaluated. In vitro internalization was tested using murine melanoma B16/F10 cells and human lung carcinoma A549 cells. Biodistribution was determined in healthy mice and tumour uptake was studied in B16/F10 tumour-bearing mice. A HL-60-Luc human leukaemia model was used to confront single photon emission computed tomography (SPECT) images obtained with the 99mTc-labelled probe with those obtained by bioluminescence. RESULTS: The 99mTc-HYNIC-spermine probe was selected for its capacity to accumulate into PTS-active cells and its stability in plasma. In vitro studies demonstrated that the probe was internalized in the cells via the PTS. In vivo measurements indicated a tumour to muscle scintigraphic ratio of 7.9±2.8. The combined bioluminescence and scintigraphic analyses with the leukaemia model demonstrated that the spermine conjugate accumulates into the tumour cells. CONCLUSION: The 99mTc-HYNIC-spermine scintigraphic probe is potentially useful to characterize the PTS activity of tumours. Additional work is needed to determine if this novel conjugate may be useful to analyse the PTS status of patients with solid tumours.

Preclinical activity of F14512, designed to target tumors expressing an active polyamine transport system.

We have exploited the polyamine transport system (PTS) to deliver selectively a spermine-drug conjugate, F14512 to cancer cells. This study was aimed to define F14512 anticancer efficacy against tumor models and to investigate whether fluorophor-labeled polyamine probes could be used to identify tumors expressing a highly active PTS and that might be sensitive to F14512 treatments. Eighteen tumor models were used to assess F14512 antitumor activity. Cellular uptake of spermine-based fluorescent probes was measured by flow cytometry in cells sampled from tumor xenografts by needle biopsy. The accumulation of the fluorescent probe within B16 tumors in vivo was assessed using infrared fluorescence imaging. This study has provided evidence of a major antitumor activity for F14512. Significant responses were obtained in 67% of the tumor models evaluated, with a high level of activity recorded in 33% of the responsive models. Complete tumor regressions were observed after i.v., i.p. or oral administrations of F14512 and its antitumor activity was demonstrated over a range of 2-5 dose levels, providing evidence of its good tolerance. The level of cellular fluorescence emitted by the fluorescent probes was higher in cells sampled from tumors sensitive to F14512 treatments than from F14512-refractory tumors. We suggest that these probes could be used to identify tumors expressing a highly active PTS and guide the selection of patients that might be treated with F14512. These results emphasize the preclinical interest of this novel molecule and support its further clinical development.

Quantitation in bioluminescence imaging by correction of tissue absorption for experimental oncology.

PURPOSE: We have developed a method of quantitation for correcting tissue absorption in in vivo bioluminescence imaging (BLI). PROCEDURES: Variations of luciferin emission spectrum were determined and were related to photon absorption to determine a correction curve. This was validated by combining BLI with tomoscintigraphy and tomodensitometry, which were applied to a lymphoma model. RESULTS: Tissue absorption affects luciferin emission spectrum, mainly for wavelengths less than 620 nm. So, we have selected two filters bordering 620 nm to quantify spectral modifications. A significant correlation was obtained between the spectral analysis and the percentage of transmitted light through tissues (R(2) = 0.97). On a disseminated tumour model, we have shown that such a methodology is of great interest to compare bioluminescent signals and to get more accurate quantitative data about tumour proliferation. CONCLUSIONS: Spectral analysis allows improved quantitation of BLI and could be of value to perform pharmacological studies and to follow tumour progression in models with tumours evolving in different locations.

Tumor burden influences exposure and response to rituximab: pharmacokinetic-pharmacodynamic modeling using a syngeneic bioluminescent murine model expressing human CD20.

Clinical studies have shown a large interindividual variability in rituximab exposure and its significant influence on clinical response in patients receiving similar doses of antibody. The aim of this study was to evaluate the influence of tumor burden on dose-concentration-response relationships of rituximab. Murine lymphoma cells (EL4, 8 x 10(3)), transduced with human CD20 cDNA and transfected with luciferase plasmid (EL4-huCD20-Luc), were intravenously injected into C57BL/6J mice. Tumor burden detection, dissemination, and progression were evaluated quantitatively by in vivo bioluminescence imaging. Different doses of rituximab (6, 12, 20, or 40 mg/kg) were infused 13 days after lymphoma cell inoculation, and rituximab serum concentrations were measured by enzyme-linked immunosorbent assay. Without rituximab, all mice developed disseminated lymphoma and died within 30 days, whereas a significant dose-response relationship was observed in mice receiving rituximab. The 20-mg/kg dose was adequate to study interindividual variability in response because 23% of mice were cured, 59% had partial response, and 18% had disease progression. Rituximab concentrations were inversely correlated with tumor burden; mice with low tumor burden had high rituximab concentrations. Furthermore, rituximab exposure influenced response and survival. Finally, using a pharmacokinetic-pharmacodynamic model, we demonstrated that tumor burden significantly influenced rituximab efficacy.