Gold Nanoparticles For Enhancement Research Articles

Harnessing Synthetic Strategies for Enhanced Gold Nanoparticle Functionality in Cancer Treatment

Harnessing Synthetic Strategies for Enhanced Gold Nanoparticle Functionality in Cancer Treatment

Numerical investigation of plasmon-enhanced emission from a nanofiber coupled single photon emitter

This study explores the enhancement of emission from a single photon emitter in a quantum communication network by coupling the source with an optical nanofiber and leveraging gold nanoparticles for Purcell enhancement. Large Purcell enhancements of more than 50 times were recently reported experimentally, but the understanding of important issues, including the maximum Purcell factor and limits to quantum efficiency due to ohmic losses, is still lacking. Our findings reveal that the reported experimental results are reasonable, and confirm that such composite devices provide a promising route for high-efficiency single photon sources coupled to an optical fiber-based quantum communication network.

Conjugation of Hypericin to Gold Nanoparticles for Enhancement of Photodynamic Therapy in MCF-7 Breast Cancer Cells.

Breast cancer, among the different types of cancer, is one of the most diagnosed cancers and the leading cause of mortalities amongst women. Factors, including genetic and epigenetic alterations in tumors, make it resistant to therapies, which results in treatment failures and/or recurrence. Furthermore, the existing therapies have many unfavorable side effects leading to poor prognosis and reduced therapeutic outcomes. Photodynamic therapy (PDT) is one of the most effective cancer therapies with increased selectivity and specificity toward cancer cells. As a result, the use of gold nanoparticles (AuNP) further improves the effectiveness of PDT by increasing the drug loading capacity into the cells. In this study, hypericin (Hyp) photosensitizer (PS) was adsorbed on gold nanoparticles (AuNPs) by sonication to achieve physical adsorption of the PS to AuNP. The resulting compound was characterized by FTIR, Zeta potential, UV-Vis spectroscopy, and TEM. The compound was used for the PDT treatment of MCF-7 human breast cancer in vitro. Cellular responses at 12 h post-PDT at 10 J/cm2 were observed. Cellular morphology, LDH membrane integrity, ATP luminescence assay, and Annexin V/PI staining were performed. The results demonstrated typical cell death morphological features while the biochemical responses indicated increased LDH and decreased ATP levels. In conclusion, this study presents an insight into the application of advanced PDT in breast cancer cells by inducing cancer cell death in vitro via apoptosis.

Extracellular Vesicle (EV) Dot Blotting for Multiplexed EV Protein Detection in Complex Biofluids.

Extracellular vesicles (EVs) are nanoscale vesicles secreted from cells, carrying biomolecular cargos similar to their cells of origin. Measuring the protein content of EVs in biofluids can offer a crucial insight into human health and disease. For example, detecting tumor-derived EVs' protein markers can aid in early diagnosis of cancer, which is life-saving. In order to use these EV proteins for diagnosis, sensitive and multiplexed methods are required. The current methods for EV protein detection typically require large sample consumption due to challenges with sensitivity and often need an EV isolation step for complex biofluid samples such as blood plasma. In this work, we have developed a simple and sensitive method for multiplexed detection of protein markers on EV membrane surfaces, which we call "EV dot blotting", inspired by conventional dot blotting techniques. After optimization of multiple factors such as antibody concentration, blocking reagent, type of 3D membranes, and use of gold nanoparticles for signal enhancement, cancer-cell-derived EVs were spiked in pooled normal human plasma for conducting a multiplexed assay in a microarray format. Without the need of isolating EVs from blood plasma, a limit of detection of 3.1 × 105 EVs/mL or 1863 EVs/sample was achieved for CD9 protein, 4.7 × 104 EVs/mL or 281 EVs/sample for CD24, and 9.0 × 104 EVs/mL or 538 EVs/sample for EpCAM, up to 4 orders of magnitude lower than those of conventional ELISA. This platform offers sensitive, multiplexed, simple, and low-cost EV protein detection directly from complex biofluids with minimal sample consumption, providing a useful tool for multiplexed EV protein quantification for a variety of applications.

Enhanced Gold Nanoparticle aggregation with cancer cell DNA for improved radiation therapy and immune response in cancer treatment

In the United States, cancer is the second leading cause of death after heart disease and hundreds of thousands of people pass away each year due to this deadly disease. Many treatments for cancer are nonselective and do not provide long‐lasting immunity in case of recurrence. Gold nanoparticles can provide a more targeted radiation therapy and better effectiveness through heat generation and formation of reactive oxygen species via hydrolysis reaction which can cause DNA damage in the tumor. Unfortunately, gold particles have low photothermal transduction efficiency and must be aggregated to improve performance. To achieve this, positively charged gold nanoparticles were aggregated with MDA MB 231 cancer cell DNA to increase gold nanoparticle aggregation, to elicit higher photothermal efficiency, and to stimulate an immune response. In vitro analysis demonstrated DNA size and concentration dependent gold nanoparticle aggregation, which varied little in the pH range of 5.5 to 8.6. Furthermore, these aggregates elicited an immune response via delivery of DNA for direct transfection of antigen presenting cells. Tumor necrosis factor alpha released from mouse RAW macrophages increased in the presence of the cancer cell DNA aggregated gold particles. This work suggests that the promise of combination therapy using cancer cell DNA not only can improve photothermal therapy of gold nanoparticles, but also can elicit an immune response in cancer treatment.

Nanostructured Gold Thin Film Electrode Derived from Surfactant-Free Gold Nanoparticles for Enhancement in Electrocatalysis

Nanostructured Gold Thin Film Electrode Derived from Surfactant-Free Gold Nanoparticles for Enhancement in Electrocatalysis

Zwitterionic Polymer Coatings Enhance Gold Nanoparticle Stability and Uptake in Various Biological Environments.

Zwitterionic polymers are a class of materials that have demonstrated utility as non-fouling surfaces for medical devices and drug delivery vehicles. Here, we develop a synthesis protocol to produce zwitterionic polymers as coatings for gold nanoparticles and evaluate nanoparticle stability and biological function after exposure to various biological fluids. Thiol-functionalized polymethacryloyloxyethyl phosphorylcholine polymers (pMPC) were synthesized in nontoxic solvents via photoinitiated free radical polymerization with a radical addition-fragmentation chain transfer (RAFT) agent and coated onto gold nanoparticles. pMPC-coated nanoparticles exhibited reduced particle aggregation, improved suspension stability, and decreased protein adsorption upon exposure to serum and lung lavage fluid (BALF). Cell uptake in A549 cells was greater for pMPC-coated particles than uncoated particles after exposure to serum and BALF, with no observed cell toxicity, but pMPC-coated particles experienced higher levels of cell uptake after serum exposure than BALF exposure, suggesting that differences in the composition of the fluids result in differing impacts on particle fate. These zwitterionic polymers may serve as useful nanoparticle coatings to enhance particle stability and uptake in various biological environments.

Theoretical evaluation of enhanced gold nanoparticle delivery to PC3 tumors due to increased hydraulic conductivity or recovered lymphatic function after mild whole body hyperthermia.

The objective of this study is to investigate the effect of hyperthermia-induced improvement of hydraulic conductivity and lymphatic function on both tumoral IFP reduction and nanoparticle delivery to PC3 tumors. We developed a theoretical model for nanoparticle transport in a tumor incorporating Starling's law, Darcy's law, transient convection, and diffusion of chemical species in porous media, and nanoparticle accumulation in tumors. Results have shown that both mechanisms were effective to decrease the IFP at the tumor center from 1600 Pa in the control without heating to 800 Pa in tumors with whole body heating. IFP reductions not only elevate the nanoparticle concentration in the tumor, but also result in a more uniform nanoparticle concentration in the tumor than that in the control without heating. Due to the IFP reductions at the tumor center and/or local blood perfusion increases, the final amount of accumulated nanoparticles in the tumor increased by more than 35-95% when compared to the control without heating. We conclude that increases in the hydraulic conductivity and recovery of lymphatic functions are possible mechanisms that lead to IFP reductions and enhancement in nanoparticle deposition in PC3 tumors observed in our in vivo experimental studies.

A pH-Responsive System Based on Fluorescence Enhanced Gold Nanoparticles for Renal Targeting Drug Delivery and Fibrosis Therapy.

BackgroundStimuli-responsive gold nano-assemblies have attracted attention as drug delivery systems in the biomedical field. However, there are challenges achieving targeted delivery and controllable drug release for specific diseases.Materials and MethodsIn this study, a glutathione (GSH)-modified fluorescent gold nanoparticle termed AuLA-GSH was prepared and a Co2+-induced self-assembly drug delivery platform termed AuLA-GSH-Co was constructed. Both the pH-responsive character and drug loading behavior of AuLA-GSH-Co were studied in vitro. Kidney-targeting capability was investigated in vitro and in vivo. Finally, the anti-fibrosis efficiency of AuLA-GSH-Co in a mouse model of unilateral ureteral obstruction (UUO) was explored.ResultsAuLA-GSH-Co was sensitive to pH changes and released Co2+ in acidic conditions, allowing it to have controllable drug release abilities. AuLA-GSH-Co was found to improve cellular uptake of Co2+ ions compared to CoCl2 in vitro. AuLA-GSH exhibited specific renal targeting and prolonged renal retention time with low non-specific accumulation in vivo. Moreover, the anti-fibrosis efficiency of AuLA-GSH-Co was higher compared to CoCl2 in a mouse model of unilateral ureteral obstruction (UUO).ConclusionAuLA-GSH-Co could greatly enhance drug delivery efficiency with renal targeting capability and obviously relieve renal fibrosis, providing a promising strategy for renal fibrosis therapy.

Engineering nanotubular titania with gold nanoparticles for antibiofilm enhancement and soft tissue healing promotion

The success rate of titanium dental implants were challenged from peri-implant infections. However, pure titanium surfaces possess no antibacterial properties and are bio-inert for soft tissue healing delay. In the present study, the anodized titania nanotubes (TiO2-NTs) on Ti substrate were fabricated following by Au nanoparticle (AuNPs) deposition. The AuNPs incorporation into hierarchical TiO2-NTs would not only exhibit photocatalytic activity by visible-light irradiation, but also generate more quantum yield of reactive oxygen species, due to the prevention of electron-hole recombination and the surface plasmon resonance of Au, thus resulting in an enhanced antibacterial effect against multispecies biofilm. Antibacterial efficacy of AuNPs/TiO2-NTs was positively corelated with Au nanoparticle amount in TiO2-NTs samples. Besides, AuNPs decoration would also exert favorable functions on cell attachment, proliferation and migration of fibroblast. Experiments in animal model also indicated a superior soft tissue healing promotion for AuNPs/TiO2-NTs. Therefore, this designed AuNPs/TiO2-NTs is beneficial and applicable to dental implant surfaces to inhibit pathogens, promote soft tissue healing and combat periodontitis.

Nanostructured Hematite Decorated with Gold Nanoparticles for Functionalization and Biocompatibility

Iron oxides have attracted the attention of researchers due to their abundance, low cost, low toxicity, and versatility of applications. According to the composition and crystalline structure, iron oxides may have characteristics of semiconductors and magnetic materials, such as hematite (α‐Fe2O3) and magnetite (Fe3O4), respectively. The property of biocompatibility of hematite is essential to be applied in the construction of micro‐/nanorobots (MNRs). Herein, the decoration of hierarchically structured core/shell Fe3O4/Fe2O3 microtubes and foils with gold nanoparticles (AuNPs) for functionalization and enhancement of biocompatibility that favor the use in MNR fabrication is presented. In this case, the synthesis of AuNPs takes advantage of the capacity of hematite to reduce Au3+ photochemically under excitation by a sunlight simulator. The yield of AuNPs covering the microtube surface is dependent on the gold salt concentration used for the synthesis. The AuNP‐decorated hematite surfaces of the microtube and foil are functionalized with thiol poly(ethylene glycol) fluorescein, exhibiting increase in conductivity favored by irradiation with visible light. AuNPs also favor cell adherence and proliferation with the maintenance of mitochondrial transmembrane potential. Therefore, the hematite surface of the microtubes decorated with AuNPs is a promising material for the application in micro‐/nanorobots and bioelectronics.

Equivalence of silver and gold nanoparticles for dose enhancement in nanoparticle-aided brachytherapy

The goal of radiotherapy is to deliver a clinical dose to the tumor while sparing the surrounding healthy tissues. The problem associated with radiotherapy is the lack of selectivity between the tumor and the healthy tissue. The methodology for depositing a higher dose selectively in the tumor region by making tumor radio-sensitive with the infusion of nanoparticles (NPs) is being evolved. Several materials have been explored for NP-aided radiotherapy. Gold and silver NPs have been studied in more detail. However, silver is relatively less expensive and the use of silver NP-aided radiotherapy may be an economical choice. The dose enhancement factor (DEF) for gold and silver with mono-energetic photons having energy from 20 keV to 500 keV were computed using a theoretical method to confirm the suitability of the silver as a substitute for gold NPs. The optimal energy to achieve the similar dose enhancement with silver and gold is found to be 50–70 keV. The 170Tm brachytherapy source was identified as the source with optimum energy to achieve the same level of dose enhancement using both NPs. The DEF in the prostate region was calculated using the Monte Carlo method for 170Tm source. The DEFs of 1.94 ± 0.01 and 1.92 ± 0.01 were recorded at a fixed concentration of 7 mg of gold and silver NPs inside per gram of tumor respectively. The use of silver NPs instead of gold NPs is a cost effective option for the treatment of prostate cancer with 170Tm brachytherapy source.

Portable Smartphone-based Colorimetric Analyzer with Enhanced Gold Nanoparticles for On-site Tests of Seafood Safety.

Saxitoxin (STX) is one of the paralytic shellfish poisons (PSP) that endanger people's health. It is necessary to develop methods for the on-site rapid detection for STX in order to prevent safety accidents. An enzyme-linked immunosorbent assay (ELISA) is timesaving and effective, but it is not suitable for large-scale in-field tests due to the expensiveness of commercial ELISA kits and the bulkiness of a microtiter plate reader (MTPR). In this study, a portable smartphone-based colorimetric analyzer (SBCA) with a cost-effictive enhanced gold nanoparticle-based ELISA (EGNB-ELISA) was proposed for STX detection. In a bicinchoninic acid (BCA) protein assay (R2 = 0.9939) and a glucose assay (R2 = 0.9937), SBCA was shown to be in good agreement with MTPR. EGNB-ELISA had a 12.5-fold lower detection limit (0.4 ng/mL) and a lower detection range (1 - 50 ng/mL, Y = 0.4037X + 0.3564, R2 = 0.9797) than the classical ELISA. The recovery rate ranged over 89.1 - 112.2%. The whole detection system, combining both homemade SBCA and ENGB-ELISA, is expected to satisfy the needs of on-site STX sample tests to guarantee seafood safety.

Regulation of gold nanoparticles for the rare earth luminescence enhancement based on nanoporous silica glass

A silica composite system with rare earth ions and gold nanoparticles was fabricated based on nanoporous silica glass. The formation and optical properties of the systems were controlled by the nanoparticles doping concentration and heat treatment. The luminescence intensity dependence on the HAuCl4 doping concentration and heat-treated temperature were investigated. At the optimized concentration of HAuCl4 and heat-treated temperature, the maximal luminescence intensity can be enhanced up to 14.33-fold for Yb2+ and 10.52-fold for Eu2+. It is indicated that the rare earth ions luminescence can be regulated by interactions distance between different types of RE ions and metal NPs as well as the state of nanopores.

PR357: Human β‐defensin 3 combined gold nanoparticles for enhancement of osteogenic differentiation of human periodontal ligament cells in inflammatory microenvironments

PR357: Human β‐defensin 3 combined gold nanoparticles for enhancement of osteogenic differentiation of human periodontal ligament cells in inflammatory microenvironments

Double-enhanced lateral flow immunoassay for potato virus X based on a combination of magnetic and gold nanoparticles

This study presents the joint use of magnetic nanoparticles (MNPs) and gold nanoparticles (GNPs) for double enhancement in a lateral flow immunoassay (LFIA). The study realizes two types of enhancement: (1) increasing the concentration of analytes in the samples using conjugates of MNPs with specific antibodies and (2) increasing the visibility of the label through MNP aggregation caused by GNPs. The proposed strategy was implemented using a LFIA for potato virus X (PVX), a significant potato pathogen. MNPs conjugated with biotinylated antibodies specific to PVX and GNPs conjugated with streptavidin were synthesized and characterized. The LFIAs with and without the proposed enhancements were compared. The double-enhanced LFIA achieved the highest sensitivity, equal to 0.25 ng mL−1 and 32 times more sensitivity than the non-enhanced LFIA (detection limit: 8 ng mL−1). LFIAs using one of the types of amplification (magnetic concentration without GNPs-causing aggregation or MNP aggregation without the concentration stage) showed intermediate levels of sensitivity. The double-enhanced LFIA was successfully used for PVX detection in potato leaves. The results for PVX detection in the infected plants were similar for the double-enhanced LFIA developed and the conventional LFIA based on the GNP conjugates; however, the new system provided significant coloring enhancement. This study confirmed that a simple combination of MNPs and GNPs has great potential for high-sensitivity detection and could possibly be adopted for LFIAs of other compounds.

Simple synthesis of uniformly small gold nanoparticles for sensitivity enhancement in colorimetric detection of Pb2+ by improving nanoparticle reactivity and stability

Sensitivity of lead detection (upto 0.1 nM) is greatly improved by enhancing the reactivity and stability of small gold nanoparticles.

Human β-defensin 3-combined gold nanoparticles for enhancement of osteogenic differentiation of human periodontal ligament cells in inflammatory microenvironments.

ObjectiveIt is a great challenge to absorb and conduct biophysicochemical interactions at the nano-bio interface. Peptides are emerging as versatile materials whose function can be programmed to perform specific tasks. Peptides combined nanoparticles might be utilized as a new approach of treatment. Human β-defensin 3 (hBD3), possesses both antimicrobial and proregeneration properties. Gold nanoparticles (AuNPs) have shown promising applications in the field of tissue engineering. However, the coordinating effects of AuNPs and hBD3 on human periodontal ligament cells (hPDLCs) remain unknown. In this study, we systematically investigated whether AuNPs and hBD3 would be able to coordinate and enhance the osteogenic differentiation of hPDLCs in inflammatory microenvironments, and the underlying mechanisms was explored.MethodshPDLCs were stimulated with E. coli-LPS, hBD3 and AuNPs. Alkaline phosphatase (ALP) and alizarin red S staining were used to observe the effects of hBD3 and AuNPs on the osteogenic differentiation of hPDLCs. Real-time PCR and western blot were performed to evaluate the osteogenic differentiation and Wnt/β-catenin signaling pathway related gene and protein expression.ResultsIn the inflammatory microenvironments stimulated by E. coli-LPS, we found that AuNPs and hBD3 increased the proliferation of hPDLCs slightly. In addition, hBD3-combined AuNPs could significantly enhance ALP activities and mineral deposition in vitro. Meanwhile, we observed that the osteogenic differentiation-related gene and protein expressions of ALP, collagenase-I (COL-1) and runt-related transcription factor 2 (Runx-2) were remarkably upregulated in the presence of hBD3 and AuNPs. Moreover, hBD3-combined AuNPs strongly activated the Wnt/β-catenin signaling pathway and upregulated the gene and protein expression of β-catenin and cyclin D1. Furthermore, hBD3-combined AuNPs induced osteogenesis, which could be reversed by the Wnt/β-catenin signaling pathway inhibitor (ICG-001).ConclusionThe present study demonstrated that hBD3 combined AuNPs could significantly promote the osteogenic differentiation of hPDLCs in inflammatory microenvironments via activating the Wnt/β-catenin signaling pathway.

Microwave Accelerated Green Synthesis of Gold Nanoparticles Using Gum Arabic and their Physico-Chemical Properties Assessments

Abstract Microwave enhanced gold nanoparticles (Au NPs) were synthesized using gum Arabic as both reducing and stabilizing agents. Response surface methodology was applied to study effects of the Au NPs synthesized parameters, namely, microwave exposure time (90–180 s) and the amount of AgNO3 solution (1–10 mL) on the mean particle size, mixture solution color and concentration of the synthesized Au NPs. The colloidal solution containing well-dispersed and spherical fabricated Au NPs with mean particle size (22 nm) and maximum concentration (159 ppm) and color (1.12 absorbance unit, a.u.), were obtained at the optimal synthesis conditions, using 8.17 mL of HAuCl4 (1 mM) and 2 mL of gum Arabic solution (4% w/v) during microwave exposure time of 180 s. The physico-chemical properties of the synthesized Au NPs at obtained optimum synthesis conditions were characterized by Fourier transform-infrared spectroscopy, UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction, transmission electron microscopy and field emission scanning electron microscopy.

Towards breast cancer rotational radiotherapy with synchrotron radiation

PurposeWe performed the first investigations, via measurements and Monte Carlo simulations on phantoms, of the feasibility of a new technique for synchrotron radiation rotational radiotherapy for breast cancer (SR3T). MethodsA Monte Carlo (MC) code based on Geant4 toolkit was developed in order to simulate the irradiation with the SR3T technique and to evaluate the skin sparing effect in terms of centre-to-periphery dose ratio at different energies in the range 60–175keV. Preliminary measurements were performed at the Australian Synchrotron facility. Radial dose profiles in a 14-cm diameter polyethylene phantom were measured with a 100-mm pencil ionization chamber for different beam sizes and compared with the results of MC simulations. Finally, the dose painting feasibility was demonstrated with measurements with EBT3 radiochromic films in a phantom and collimating the SR beam at 1.5cm in the horizontal direction. ResultsMC simulations showed that the SR3T technique assures a tumour-to-skin absorbed dose ratio from about 7:1 (at 60keV photon energy) to about 10:1 (at 175keV), sufficient for skin sparing during radiotherapy. The comparison between the results of MC simulations and measurements showed an agreement within 5%. Two off-centre foci were irradiated shifting the rotation centre in the horizontal direction. ConclusionsThe SR3T technique permits to obtain different dose distributions in the target with multiple rotations and can be guided via synchrotron radiation breast computed tomography imaging, in propagation based phase-contrast conditions. Use of contrast agents like iodinated solutions or gold nanoparticles for dose enhancement (DE-SR3T) is foreseen and will be investigated in future work.