Use Of Gold Nanoparticles Research Articles

Application of Gold Nanoparticles for High-Sensitivity Fluorescence Polarization Aptamer Assay for Ochratoxin A

The use of gold nanoparticles (GNPs) as carriers for the decrease in the detection limit of a fluorescence polarization (FP) aptamer assay is proposed. The common FP assay is based on the use of polarized exciting light and changes in the polarization of emitted light by the fluorophore–analyte conjugate before and after its binding with a receptor of the target analyte. Aptamers’ application as receptors in such an assay is limited due to their low molecular weight and, consequently, insufficient influence on polarization of emitted light. This limitation can be overcome by the inclusion of aptamers in larger intermolecular complexes. In the present work, the advantages of GNPs as unified, stable, and simply modified carriers for aptamers are demonstrated. The FP aptamer assay is realized with the use of GNPs with average diameter of 8.7 nm and ochratoxin A (OTA) as the target analyte. Finally, the assay is tested for OTA control in spiked white wine. The reached limit of detection is 2.3 µg/kg, which is 25-fold lower as compared to native aptamer. The time of the assay is 15 min. The universality of the proposed approach makes it possible to use aptamers for FP assays of various low-molecular-weight substances.

Construction of Efficient Bio-Electrochemical Devices; An Improved Electricity Production from Cyanobacterium (Leptolyngbia sp.) Based on π-Conjugated Conducting Polymers/Gold Nanoparticles Composite Interfaces

In this study, the electrochemical communication of Lyptolyngbia sp. (CYN82) were accomplished using two different DtP type conducting polymers 4-(4H-Dithieno[3,2-b:2’,3’-d]pyrrole-4-yl)aniline, P(DtP-Py-NH2) and 5-(4H-dithieno [3,2-b:2’,3’-d]pyrol-4-yl) naphtalene-1-amine, P(DtP-Nptyl-NH2) via electropolymerization. After that, p-aminothiophenol and 2-mercaptoethane functionalized AuNPs were cross-linked to DtP polymers modified GE as a result of electropolymerization. Bioelectrodes were obtained by attaching of Leptolyngbia sp. onto the conducting polymer/AuNP modified GEs and stabilized on the electrode surface by using a dialysis membrane. These electrode structures were generated enhanced photocurrent due to high wiring capacity and high electron transfer ability. Electrons are formed as a result of oxidation in CYN82 by photosynthesis in water under visible light is easily transferred to the GE by DtP/AuNP structure (Figure 1). Photocurrent experiments were proved the transfer of electrons were achieved and the effect of P(DtP-Py-NH2) and P(DtP-Nptyl-NH2) polymers reveal that the photocurrent obtained from the electrode using polymer is almost eight-fold greater than the electrode without using polymer. This result indicates that the polymer is highly effective in electron transfer. Another important point in obtaining the enhanced photocurrent is the use of gold nanoparticles in the electrode structure. Results clearly show that the photocurrent measured from the electrodes with AuNP is higher than the other electrodes (without AuNP). Conductivity of AuNP and oligoaniline bridges serves a very suitable surface for fast electron transfer from CYN82 to the gold electrode. A 25 nA cm-2 photocurrent was observed by GE/Leptolyngbia sp.. After the electrode modifications, a significant improvement in the photocurrent up to 630 nA cm-2 was achieved. Bioelectrodes P(DtP-Py-NH2)/AuNP/CYN82 and P(DtP-Nptyl-NH2)/AuNP/CYN82 were tested with diuron, clorpyrifos and atrazine which are the important pesticides as by the decrease in photocurrent which is resulted from inhibition of photosynthesis by pesticides [1].

Multiwavelength Q-switched pulse operation with gold nanoparticles as saturable absorber

A multiwavelength Q-switched pulse operation obtained directly using a Tm-doped fiber laser and employing gold nanoparticles (GNPs) as a saturable absorber (SA material) is reported. The GNPs SA exhibits a modulation depth of 5.4% and a nonsaturable loss of 21.3%. Due to the saturable absorption and the high nonlinearity, dual-wavelength and triple-wavelength Q-switched pulse operations are obtained at pump power levels of 200 and 500 mW. To the best of our knowledge, this is the first ever reported use of GNPs as SA in multiwavelength Q-switched lasing generation.

Gold Nanoparticle-Based Colorimetric Strategies for Chemical and Biological Sensing Applications.

Gold nanoparticles are popularly used in biological and chemical sensors and their applications owing to their fascinating chemical, optical, and catalytic properties. Particularly, the use of gold nanoparticles is widespread in colorimetric assays because of their simple, cost-effective fabrication, and ease of use. More importantly, the gold nanoparticle sensor response is a visual change in color, which allows easy interpretation of results. Therefore, many studies of gold nanoparticle-based colorimetric methods have been reported, and some review articles published over the past years. Most reviews focus exclusively on a single gold nanoparticle-based colorimetric technique for one analyte of interest. In this review, we focus on the current developments in different colorimetric assay designs for the sensing of various chemical and biological samples. We summarize and classify the sensing strategies and mechanism analyses of gold nanoparticle-based detection. Additionally, typical examples of recently developed gold nanoparticle-based colorimetric methods and their applications in the detection of various analytes are presented and discussed comprehensively.

Gold as a Possible Alternative to Platinum-Based Chemotherapy for Colon Cancer Treatment

Due to the increasing incidence and high mortality associated with colorectal cancer (CRC), novel therapeutic strategies are urgently needed. Classic chemotherapy against CRC is based on oxaliplatin and other cisplatin analogues; however, platinum-based therapy lacks selectivity to cancer cells and leads to deleterious side effects. In addition, tumor resistance to oxaliplatin is related to chemotherapy failure. Gold(I) derivatives are a promising alternative to platinum complexes, since instead of interacting with DNA, they target proteins overexpressed on tumor cells, thus leading to less side effects than, but a comparable antitumor effect to, platinum derivatives. Moreover, given the huge potential of gold nanoparticles, the role of gold in CRC chemotherapy is not limited to gold(I) complexes. Gold nanoparticles have been found to be able to overcome multidrug resistance along with reduced side effects due to a more efficient uptake of classic drugs. Moreover, the use of gold nanoparticles has enhanced the effect of traditional therapies such as radiotherapy, photothermal therapy, or photodynamic therapy, and has displayed a potential role in diagnosis as a consequence of their optic properties. Herein, we have reviewed the most recent advances in the use of gold(I) derivatives and gold nanoparticles in CRC therapy.

Targeted laser therapy synergistically enhances efficacy of antibiotics against multi-drug resistant Staphylococcus aureus and Pseudomonas aeruginosa biofilms

The growing prevalence of biofilm-associated multi-drug resistant (MDR) bacteria necessitates the innovation of non-traditional approaches to improve the effectiveness of mainstay antibiotics. Here, we evaluated the use of gold nanoparticle (GNP)-targeted pulsed laser therapy to enhance antibiotic efficacy against in vitro methicillin-resistant Staphylococcus aureus (MRSA) and MDR Pseudomonas aeruginosa biofilms. Treatment with antibody-conjugated GNPs followed by nanosecond-pulsed laser irradiation at 532 nm (~1.0 J/cm2) dispersed 96–99% of the biofilms relative to controls. GNP-targeted laser therapy combined with gentamicin or amikacin caused a synergistic 4- and 5-log reduction in the viability of MRSA and P. aeruginosa biofilms, respectively, whereas GNP-targeted laser therapy or antibiotics alone decreased biofilm viability by only ~1 log. Notably, GNP-targeted laser therapy was able to increase the antibiotic susceptibility of the biofilms to the level of drug sensitivity observed in planktonic MRSA and P. aeruginosa cultures, further indicating effective biofilm dispersal via this novel approach.

Gold Nanoparticles Disrupt Tumor Microenvironment - Endothelial Cell Cross Talk To Inhibit Angiogenic Phenotypes in Vitro.

It is currently recognized that perpetual cross talk among key players in tumor microenvironment such as cancer cells (CCs), cancer associated fibroblasts (CAFs), and endothelial cells (ECs) plays a critical role in tumor progression, metastasis, and therapy resistance. Disruption of the cross talk may be useful to improve the outcome of therapeutics for which limited options are available. In the current study we investigate the use of gold nanoparticles (AuNPs) as a therapeutic tool to disrupt the multicellular cross talk within the TME cells with an emphasis on inhibiting angiogenesis. We demonstrate here that AuNPs disrupt signal transduction from TME cells (CCs, CAFs, and ECs) to ECs and inhibit angiogenic phenotypes in vitro. We show that conditioned media (CM) from ovarian CCs, CAFs, or ECs themselves induce tube formation and migration of ECs in vitro. Migration of ECs is also induced when ECs are cocultured with CCs, CAFs, or ECs. In contrast, CM from the cells treated with AuNPs or cocultured cells pretreated with AuNPs demonstrate diminished effects on ECs tube formation and migration. Mechanistically, AuNPs deplete ∼95% VEGF165 from VEGF single-protein solution and remove up to ∼45% of VEGF165 from CM, which is reflected on reduced activation of VEGF-Receptor 2 (VEGFR2) as compared to control CM. These results demonstrate that AuNPs inhibit angiogenesis via blockade of VEGF-VEGFR2 signaling from TME cells to endothelial cells.

Green synthesised‐gold nanoparticles in photothermal therapy of breast cancer

In this work, the use of gold nanoparticles (AuNPs), synthesised using Curcuma mangga (CM) extract in photothermal killing of breast cancer (MCF-7) cells is demonstrated. CM-AuNPs showed higher photothermal heating efficiency compared to citrate-AuNPs upon irradiation with a 532 nm laser. In addition, treatment of MCF-7 cells with CM-AuNPs coupled with laser irradiation for 120 s was found to significantly reduce (72%) the cell viability compared to about 13%, obtained with citrate-AuNPs. Results from flow cytometry showed that the CM-AuNP-dependent photothermal-induced MCF-7 cells death was triggered mainly by apoptosis mechanism. All these results suggested the potential use of CM-AuNPs as therapeutic agents in cancer therapy.

A fluorometric and colorimetric method for determination of trypsin by exploiting the gold nanocluster-induced aggregation of hemoglobin-coated gold nanoparticles.

A dual-signal assay is described for the determination of trypsin based on the use of gold nanoparticles (AuNPs) that aggregate in the presence of gold nanoclusters (AuNCs) due to electrostatic interaction. This is accompanied by a color change from red to blue. However, if hemoglobin (Hb) is present in the solution, it will attach to the surface of AuNPs, thus preventing aggregation. The Hb-coated AuNPs quench the fluorescence of AuNCs. Trypsin can hydrolyze Hb and destroy the protective coating of Hb on the AuNPs. As a result, AuNP aggregation will occur after the addition of AuNCs, and the blue fluorescence of the AuNCs with 365nm excitation and 455nm maximum emission peak is recovered. Thus, trypsin can be determined by measurement of fluorescence emission intensity. Additionally, trypsin can be determined by the maximum absorption peak wavelength between 530nm and 610nm. Fluorescence increases linearly in the 10-2500ng⋅mL-1 concentration range, and absorbance in the 20-2000ng·mL-1 concentration range. The limits of detection are 4.6ng·mL-1 (fluorometry) and 8.4ng·mL-1 (colorimetry), respectively. The assay is sensitive and selective, and can be applied to the determination of trypsin in serum. Graphical abstract Schematic presentation of a fluorometric and colorimetric method for determination of trypsin. The presence of hemoglobin (Hb) protects AuNPs from agglomeration after adding AuNCs and the fluorescence of AuNCs is quenched. With trypsin present, trypsin destroys the coating of AuNPs by Hb. AuNPs aggregate again and the fluorescence recovers after the addition of AuNCs.

Intracisternal delivery of PEG-coated gold nanoparticles results in high brain penetrance and long-lasting stability

BackgroundThe increasing use of gold nanoparticles (AuNPs) in the field of neuroscience instilled hope for their rapid translation to the clinical practice. AuNPs can be engineered to carry therapeutics or diagnostics in the diseased brain, possibly providing greater cell specificity and low toxicity. Although there is a general enthusiasm for these tools, we are in early stages of their development. Overall, their brain penetrance, stability and cell specificity are critical issues that must be addressed to drive AuNPs to the clinic.ResultsWe studied the kinetic, distribution and stability of PEG-coated AuNPs in mice receiving a single injection into the cisterna magna of the 4th ventricle. AuNPs were conjugated with the fluorescent tag Cy5.5 (Cy5.5-AuNPs) to track their in vivo distribution. Fluorescence levels from such particles were detected in mice for weeks. In situ analysis of brains by immunofluorescence and electron microscopy revealed that Cy5.5-AuNPs penetrated the brain parenchyma, spreading in the CNS parenchyma beneath the 4th ventricle. Cy5.5-AuNPs were preferentially found in neurons, although a subset of resting microglia also entrapped these particles.ConclusionsOur results suggest that the ICM route for delivering gold particles allows the targeting of neurons. This approach might be pursued to carry therapeutics or diagnostics inside a diseased brain with a surgical procedure that is largely used in gene therapy approaches. Furthermore, this approach could be used for radiotherapy, enhancing the agent’s efficacy to kill brain cancer cells.

Gold Nanoparticle-Integrated Scaffolds for Tissue Engineering and Regenerative Medicine.

The development of scaffolding materials that recapitulate the cellular microenvironment and provide cells with physicochemical cues is crucial for successfully engineering functional tissues that can aid in repairing damaged organs. The use of gold nanoparticles for tissue engineering and regenerative medicine has raised great interest in recent years. In this mini review, we describe the shape-dependent properties of gold nanoparticles, and their versatile use in creating tunable nanocomposite scaffolds with improved mechanical and electrical properties for tissue engineering. We further describe using gold nanoparticle-integrated scaffolds to achieve improved stem cells proliferation and differentiation. Finally, we discuss the main challenges and prospects for clinical translation of gold nanoparticles-hybrid scaffolds.

Development of a New Local Therapeutic Approach for BOS: Efficacy of Imatinib Loaded -antiCD44 Coated Gold Nanoparticles In Vitro and In Vivo

Purpose The use of gold nanoparticles (GNPs) as local targeted drug delivery system are a promising issue for several orphan diseases. Bronchiolitis obliterans syndrome (BOS) represents about 70% of cases of chronic lung allograft dysfunction limiting long term survival after lung transplant, and occurs also as chronic pulmonary involvement in the context of GVHD. To now treatment strategies in BOS are scarce and poorly effective. In the present work, we investigated the effect of GNP decorated with the half chain of monoclonal antibody against CD44 (GNP-HC), surface receptor overexpressed by primary BOS derived mesenchymal cells (MCs) that cause the partial or total occlusion of alveolar tract. We loaded GNP-HC with imatinib (GNP-HCim), an cAbl inhibitor used in the management of chronic GVHD. Methods In vitro experiments were performed on MCs derived from BOS patients evaluating cell cytotoxicity after incubation with GNP-HC, GNP-HCim and Imatinib alone. We further performed a mouse heterotopic trachea transplantation model modified by the subcutaneous placement of Alzet Model 2004 miniosmotic pumps used to deliver into the trachea different solutions at a constant rate for 28 days. This was performed in order to assess the efficacy of the local intratracheal administration of our nanovectors. Results Thanks to MTT and apoptosis assay we observed that GNP-HCim decrease MCs viability more than GNP-HC and Imatinib alone, due to an induction of apoptosis (50 ± 0.5 % for GNP-HCim in contrast to GNP-HC 40 ± 0.35 % and Imatinib alone 30 ± 1.2 %). Moreover, animal model data confirmed the in vitro results: GNP-HCim significantly reduced the percentage of tracheal obliterative area (12.99 ± 2.5%) respect to GNP-HC (46.79± 5.7%) and vehicle treated mice (30.92 ± 5.8%). Conclusion We conclude that this approach by newly developed nano-based strategies for BOS treatment and especially targeted imatinib gold nanoparticles are promising candidates for further development.

Toxicity of gold nanoparticles in a commercial dietary supplement drink on connective tissue fibroblast cells

Due to an increased use of gold nanoparticles (AuNPs) in various consumer products we aimed to investigate the cytotoxic impact of AuNPs found in a commercial dietary supplement drink (SD-AuNPs). The cytotoxic impact of SD-AuNPs was determined in mouse connective tissue fibroblasts (L929). The cells were treated with different concentrations of SD-AuNPs (0.2, 0.5, 10, 20, 30, 40, and 50 µg/mL). The results indicated that the toxicological effect of SD-AuNPs on L929 cells occurred in a dose-dependent manner. Significant reduction of cell viability was found in L929 cells treated with 10, 20, 30, 40, and 50 µg/mL SD-AuNPs for 24 h. L929 cells treated with 40 and 50 µg/mL SD-AuNPs produced significant intracellular reactive oxygen species and TNF-α. High levels of intracellular uptake of these compounds were also observed in L929 cells treated with 50 µg/mL SD-AuNPs.

Enhanced Secretion of Functional Insulin with DNA-Functionalized Gold Nanoparticles in Cells.

We have previously shown the use of gold nanoparticles (AuNPs) functionalized with DNA (AuNP-DNA) to increase insulin mRNA translation in a cell-free system. In this study, we translate the concept into a whole cell system to demonstrate functionality despite the additional complexity of intracellular delivery and mRNA translation inside living cells. We selected an insulin-secreting pancreatic islet cell line, RIN-5F, as our model and designed a DNA oligomer (insDNA) that is complementary to the 3'-untranslated region of insulin mRNA for conjugation to AuNPs (AuNP-insDNA). AuNP-insDNA was stable in the extracellular environment of RIN-5F cells for up to 24 h, without eliciting any cell toxicity. Upon cellular entry, AuNP-insDNA was able to sustain enhanced insulin secretion from 6 to 12 h post-incubation, peaking at 10 h with an enhancement factor of 1.69-fold. This enhancement was not observed when insDNA was removed or replaced with poly thymine or poly adenine DNAs. The enhanced insulin secreted was 100% functional and capable of binding to its insulin receptor. The outcome of this study demonstrated the feasibility of AuNP-DNA to enhance the synthesis of proteins in whole cells and could serve as a new direction of invoking a patient's own beta cells to increase insulin secretion for treatment of diabetes.

Detection of cancer antigens (CA-125) using gold nano particles on interdigitated electrode-based microfluidic biosensor

Integrating microfluidics with biosensors is of great research interest with the increasing trend of lab-on-the chip and point-of-care devices. Though there have been numerous studies performed relating microfluidics to the biosensing mechanisms, the study of the sensitivity variation due to microfluidic flow is very much limited. In this paper, the sensitivity of interdigitated electrodes was evaluated at the static drop condition and the microfluidic flow condition. In addition, this study demonstrates the use of gold nanoparticles to enhance the sensor signal response and provides experimental results of the capacitance difference during cancer antigen-125 (CA-125) antigen–antibody conjugation at multiple concentrations of CA-125 antigens. The experimental results also provide evidence of disease-specific detection of CA-125 antigen at multiple concentrations with the increase in capacitive signal response proportional to the concentration of the CA-125 antigens. The capacitive signal response of antigen–antibody conjugation on interdigitate electrodes has been enhanced by approximately 2.8 times (from 260.80 to 736.33 pF at 20 kHz frequency) in static drop condition and approximately 2.5 times (from 205.85 to 518.48 pF at 20 kHz frequency) in microfluidic flow condition with gold nanoparticle-coating. The capacitive signal response is observed to decrease at microfluidic flow condition at both plain interdigitated electrodes (from 260.80 to 205.85 pF at 20 kHz frequency) and gold nano particle coated interdigitated electrodes (from 736.33 to 518.48 pF at 20 kHz frequency), due to the strong shear effect compared to static drop condition. However, the microfluidic channel in the biosensor has the potential to increase the signal to noise ratio due to plasma separation from the whole blood and lead to the increase concentration of the biomarkers in the blood volume for sensing.

Enhanced optical properties of YAG:Ce yellow phosphor by modification with gold nanoparticles

In this paper methods of synthesis and characterization of cerium doped yttrium aluminum garnet (YAG:Ce) and the improvement of properties by in situ modification using gold nanoparticles are presented. YAG:Ce phosphor was obtained by cations co-precipitation followed by thermal treatment at 1000 °C, while for the development of the Au-YAG:Ce nanocomposites, the Turkevich method was used. The quality of the phosphor particles and composite has been structurally, morphologically and optically studied. It has been emphasized the obtaining of high purity phosphor and maintenance of the YAG:Ce garnet structure after modifying the phosphor surface with gold nanoparticles. Also, the use of gold nanoparticles has led to improvements in optical and morphological properties as a result of lowering the agglomeration trend. Improvement of optical properties makes possible the use of Au-YAG:Ce composite thus developing low energy light sources and with high performance.

Use of gold nanoparticles in MAGIC-f gels to 18 MeV photon enhancement

Objective(s): Normoxic MAGIC-f polymer gels are established dosimeters used for three dimensional dose quantifications in radiotherapy. Nanoparticles with high atomic number such as gold are novel radiosensitizers used to enhance doses delivered to tumors. The aim of this study was to investigate the effect of gold nanoparticles (GNPs) in enhancing percentage depth doses (PDDs) within the MAGIC-f gel exposed to linear accelerator (linac) high energy photon beams. Materials and Methods: The MAGIC-f gel was fabricated based on its standard composition with some modifications. The PDDs in tubes containing the gel were calculated by using a common Monte Carlo code (Geant4) followed by experimental verifications. Then, GNPs with an average diameter of 15 nm and a concentration of 0.1 mM were embedded in the gel, poured into falcon tubes and irradiated with 18 MeV beams of an Elekta linac. Finally, similar experimental and Monte Carlo (MC) calculations were made to determine the effect of using GNPs on some dosimetric parameters of interest.Results: The results of experimental measurements and simulated MC calculations showed a dose enhancement factor (DEF) of 1.12±0.08 and 1.13±0.04, respectively due to the use of GNPs when exposed to 18 MeV linac energies.Conclusion: The results indicated that the fabricated MAGIC-f gel could be recommended as a suitable tool for three dimensional dosimetric investigations at high energy radiotherapy procedures wherein GNPs are used.

Gold Nanoparticles and their Applications in Cancer Treatment

Background: Cancer nanotechnology has become a prime field of investigations for the scientists nowadays. There are several nanocarrier systems used for effective cancer therapeutics and gold nanoparticles (GNPs/AuNPs) have become promising vehicles for the delivery of anticancer drugs into their targets. Gold nanoparticles (GNPs/AuNPs) have been explored for tumor targeting, tumor imaging, and photothermal therapy of cancer due to their unique physicohemical and optical characteristics. Methods: We searched about recent research progress made in the field of gold nanoparticulate systems for effective elimination of cancer. Our main focus was on the use of gold nanoparticles (spherical), gold nanorods, and gold nanostars for improved cancer therapy. Results: Gold nanoparticles are suited well for cancer therapeutics due to their higher biocompatibility and lesser toxicity. They can be utilized actively or passively both for the targeting of tumor cells. Conclusion: Recently, gold nanoparticulates have been investigated preclinically for the treatment of cancer. Their clinical practice is still a challenge and it is necessary to carry out clinical practice of gold nanoparticles to make them available in the market. Future advancement in the field of gold nanoparticles will likely produce better results in cancer therapeutics. Keywords: Biocompatibility, clinical, gold nanoparticles, nanotechnology, photothermal, cancer treatment.

Shikimoyl-ligand decorated gold nanoparticles for use in ex vivo engineered dendritic cell based DNA vaccination.

Since mannose receptors (MRs) are expressed on the surfaces of dendritic cells (DCs), the most professional antigen presenting cells in our body, DNA vaccine carriers containing either covalently grafted mannosyl- or mannose-mimicking shikimoyl-ligands are being increasingly used in ex vivo DC-transfection based DNA vaccination. To this end, we have recently demonstrated that ex vivo immunization of mice with liposomes of shikimoylated cationic amphiphiles containing a 6-amino hexanoic acid spacer group in the head-group region in complexation with melanoma antigen (MART1) encoded DNA vaccine (pCMV-MART1) induces long lasting anti-melanoma immune responses (C. Voshavar, et al., J. Med. Chem., 2017, 60, 1605-1610). This finding prompted us to examine, in the present investigation, the efficacies of gold nanoparticles conjugated to the mannose-mimicking shikimoyl ligand (SL) via a 6-amino hexane thiol spacer (AuNPs-SL) for use in ex vivo DC-transfection based genetic immunization. Herein, we report on the design, synthesis, physico-chemical characterization and bioactivities of AuNPs-SL. Dynamic light scattering and transmission electron microscopy studies revealed the hydrodynamic diameters of theAuNPs-SL nanoconjugates to be within the range of 23-44 nm and their surface potentials within the range of 9-28 mV. MTT-assay showed the non-cytotoxic nature of AuNPs-SL and the findings in the electrophoretic gel retardation assays revealed strong DNA binding properties of the AuNPs-SL. Importantly, subcutaneous immunization of C57BL/6J mice with DCs ex vivo transfected with an electrostatic complex of AuNPs-SL & melanoma antigen (MART1) encoded DNA vaccine (p-CMV-MART1) induced a long lasting (100 days) anti-tumor immune response in immunized mice upon subsequent challenge with a lethal dose of melanoma. Notably, mice immunized with either autologous mbmDCs ex vivo pre-transfected with nanoplexes of shikimoylated AuNPs-SL & an irrelevant pCMV-SPORT-β-gal plasmid (without having encoded melanoma antigen) or untransfected DCs showed no lasting protection against subsequent tumor challenge. The presently described shikimoyl-decorated gold nanoparticles (AuNPs-SL) are expected to find future use in ex vivo DC-transfection based genetic immunization against cancer and other infectious diseases.

Pemetrexed-loaded nanoparticles targeted to malignant pleural mesothelioma cells: an in vitro study.

PurposeMalignant pleural mesothelioma (MPM) is an aggressive tumor characterized by poor prognosis. Its incidence is steadily increasing due to widespread asbestos exposure. There is still no effective therapy for MPM. Pemetrexed (Pe) is one of the few chemotherapeutic agents approved for advanced-stage disease, although the objective response to the drug is limited. The use of gold nanoparticles (GNPs) as a drug delivery system promises several advantages, including specific targeting of malignant cells, with increased intracellular drug accumulation and reduced systemic toxicity, and, in the case of MPM, direct treatment administration into the pleural space. This study aims at exploring CD146 as a potential MPM cell-specific target for engineered Pe-loaded GNPs and to assess their effectiveness in inhibiting MPM cell line growth.MethodsMPM cell lines and primary cultures obtained by pleural effusions from MPM patients were assayed for CD146 expression by flow cytometry. Internalization by MPM cell lines of fluorescent dye-marked GNPs decorated with a monoclonal anti CD146 coated GNPs (GNP-HC) was proven by confocal microscopy. The effects of anti CD146 coated GNPs loaded with Pe (GNP-HCPe) on MPM cell lines were evaluated by cell cycle (flow cytometry), viability (MTT test), clonogenic capacity (soft agar assay), ROS production (electric paramagnetic resonance), motility (wound healing assay), and apoptosis (flow cytometry).ResultsGNP-HC were selectively uptaken by MPM cells within 1 hour. MPM cell lines were blocked in the S cell cycle phase in the presence of GNP-HCPe. Both cell viability and motility were significantly affected by nanoparticle treatment compared to Pe. Apoptotic rate and ROS production were significantly higher in the presence of nanoparticles. Clonogenic capacity was completely inhibited following nanoparticle internalization.ConclusionGNP-HCPe treatment displays in vitro antineoplastic action and is more effective than Pe alone in inhibiting MPM cell line malignant phenotype. The innovative use of specifically targeted GNPs opens the perspective of local intrapleural administration to avoid normal cell toxicity and enhance chemotherapy efficacy.