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Sample records for nanoparticles exhibits cell

  1. Green Synthesized Silver Nanoparticles Exhibit Reduced Toxicity to Mammalian Cells and Retain Antimicrobial Activity

    EPA Science Inventory

    The interest in silver nanoparticles (AgNPs) and silver nanomaterial stems from their antimicrobial properties. AgNPs are being added to clothing, paint, refrigerators, washing machines and a variety of other commercially available items. Recent in vitro and in vivo studies, howe...

  2. Ferromagnetism exhibited by nanoparticles of noble metals.

    PubMed

    Maitra, Urmimala; Das, Barun; Kumar, Nitesh; Sundaresan, Athinarayanan; Rao, C N R

    2011-08-22

    Gold nanoparticles with average diameters in the range 2.5-15 nm, prepared at the organic/aqueous interface by using tetrakis(hydroxymethyl)phosphonium chloride (THPC) as reducing agent, exhibit ferromagnetism whereby the saturation magnetization M(S) increases with decreasing diameter and varies linearly with the fraction of surface atoms. The value of M(S) is higher when the particles are present as a film instead of as a sol. Capping with strongly interacting ligands such as alkane thiols results in a higher M(S) value, which varies with the strength of the metal-sulfur bond. Ferromagnetism is also found in Pt and Ag nanoparticles prepared as sols, and the M(S) values vary as Pt>Au>Ag. A careful study of the temperature variation of the magnetization of Au nanoparticles, along with certain other observations, suggests that small bare nanoparticles of noble metals could indeed possess ferromagnetism, albeit weak, which is accentuated in the presence of capping agents, specially alkane thiols which form strong metal-sulfur bonds.

  3. Encapsulated paclitaxel nanoparticles exhibit enhanced anti-tumor efficacy in A549 non-small lung cancer cells.

    PubMed

    Huang, Guojin; Zang, Bao; Wang, Xiaowei; Liu, Gang; Zhao, Jianqiang

    2015-12-01

    In the present study, paclitaxel (PTX) were encapsulated with polyethylene glycol (PEG)-polylactide (PLA)/D-α tocopheryl polyethylene glycol 1000 succinate (TPGS) (PEG-PLA/TPGS) and the enhanced anti-tumor activity of this PTX mixed micelles (PTX-MM) was evaluated in lung cancer cells. The PTX-MM prepared by a solvent evaporation method was demonstrated to have high drug-loading efficiency (23.2%), high encapsulation efficiency (76.4%), and small size (59 nm). In vitro release assay showed the slow release behavior of PTX-MM, suggesting the good stability of the PTX-MM essential for long circulation time. In vitro kinetics assay demonstrated that PTX-MM could promote absorption and increase relative bioavailability. The anti-cancer efficiency of PTX-MM was also examined by both in vitro and in vivo studies. PTX-MM exhibits obvious cytotoxicity against lung cancer cells with much lower IC50 value when compared with commercial formulated PTX or PTX + TPGS. The xenograft tumor model studies on nude mice indicated that PTX-MM inhibits tumor growth more effectively than other formulations. It was also found that most of mixed micelles were integral in tumor site to exhibit anti-cancer activity. Our results suggested that the use of PTX-MM as an anti-cancer drug may be an effective approach to treat lung cancer. PMID:26525950

  4. Electroactive Polymer Nanoparticles Exhibiting Photothermal Properties.

    PubMed

    Cantu, Travis; Rodier, Bradley; Iszard, Zachary; Kilian, Alissa; Pattani, Varun; Walsh, Kyle; Weber, Katharina; Tunnell, James; Betancourt, Tania; Irvin, Jennifer

    2016-01-01

    A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step process that finishes with Negishi coupling. Negishi coupling is a cross-coupling process in which a chemical precursor is first lithiated, followed by transmetallation with ZnCl2. The resultant organozinc compound can be coupled to a dibrominated aromatic precursor to give the conjugated monomer. Polymer films can be prepared via electropolymerization of the monomer and characterized using cyclic voltammetry and ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. Nanoparticles (NPs) are prepared via emulsion polymerization of the monomer using a two-surfactant system to yield an aqueous dispersion of the polymer NPs. The NPs are characterized using dynamic light scattering, electron microscopy, and UV-Vis-NIR-spectroscopy. Cytocompatibility of NPs is investigated using the cell viability assay. Finally, the NP suspensions are irradiated with a NIR laser to determine their effectiveness as potential materials for photothermal therapy (PTT). PMID:26780244

  5. Liposomal nanoparticles encapsulating iloprost exhibit enhanced vasodilation in pulmonary arteries

    PubMed Central

    Jain, Pritesh P; Leber, Regina; Nagaraj, Chandran; Leitinger, Gerd; Lehofer, Bernhard; Olschewski, Horst; Olschewski, Andrea; Prassl, Ruth; Marsh, Leigh M

    2014-01-01

    Prostacyclin analogues are standard therapeutic options for vasoconstrictive diseases, including pulmonary hypertension and Raynaud’s phenomenon. Although effective, these treatment strategies are expensive and have several side effects. To improve drug efficiency, we tested liposomal nanoparticles as carrier systems. In this study, we synthesized liposomal nanoparticles tailored for the prostacyclin analogue iloprost and evaluated their pharmacologic efficacy on mouse intrapulmonary arteries, using a wire myograph. The use of cationic lipids, stearylamine, or 1,2-di-(9Z-octadecenoyl)-3-trimethylammonium-propane (DOTAP) in liposomes promoted iloprost encapsulation to at least 50%. The addition of cholesterol modestly reduced iloprost encapsulation. The liposomal nanoparticle formulations were tested for toxicity and pharmacologic efficacy in vivo and ex vivo, respectively. The liposomes did not affect the viability of human pulmonary artery smooth muscle cells. Compared with an equivalent concentration of free iloprost, four out of the six polymer-coated liposomal formulations exhibited significantly enhanced vasodilation of mouse pulmonary arteries. Iloprost that was encapsulated in liposomes containing the polymer polyethylene glycol exhibited concentration-dependent relaxation of arteries. Strikingly, half the concentration of iloprost in liposomes elicited similar pharmacologic efficacy as nonencapsulated iloprost. Cationic liposomes can encapsulate iloprost with high efficacy and can serve as potential iloprost carriers to improve its therapeutic efficacy. PMID:25045260

  6. Mammalian cells exhibit a range of sensitivities to silver nanoparticles that are partially explicable by variations in antioxidant defense and metallothionein expression

    PubMed Central

    Zhang, Haiyuan; Wang, Xiang; Wang, Meiying; Li, Linjiang; Chang, Chong Hyun; Ji, Zhaoxia; Xia, Tian; Nel, Andre E.

    2015-01-01

    While it is well known that there are interspecies differences in Ag sensitivity, we have also observed differences in the cytotoxic responses of mammalian cells to silver nanoparticles (Ag NPs). In order to explore these response outcomes, six cell lines, including epithelial cells (Caco-2, NHBE, RLE-6TN and BEAS-2B) and macrophages (RAW 264.7 and THP-1) of human and rodent origin were exposed to 20 nm citrate- and PVP-coated AgNPs with Au cores as well as 20 nm citrate-coated particles without cores. A MTS assay showed that while Caco-2 and NHBE cells were resistant to particles over a 0.1- 50 μg/mL dose range, RAW 264.7, THP-1, RLE-6TN and BEAS-2B cells were more susceptible. While there were small differences in dissolution rates, there were no major differences in the cytotoxic potential of the different particles. However, we did observe differences in anti-oxidant defense and metallothionein expression among different cell types, which can partially explain differential AgNP sensitivity. So it is important to consider these differences in understanding the potential heterogeneous effects of nano Ag on mammalian biological systems. PMID:25930061

  7. Lipid-Coated Cisplatin Nanoparticles Induce Neighboring Effect and Exhibit Enhanced Anticancer Efficacy

    PubMed Central

    Guo, Shutao; Wang, Yuhua; Miao, Lei; Xu, Zhenghong; Lin, C. Michael; Zhang, Yuan; Huang, Leaf

    2014-01-01

    Encapsulation of cisplatin (CDDP) into nanoparticles (NPs) with high drug loading and encapsulation efficiency has been difficult due to the poor solubility of CDDP. However, this barrier has been overcome with a reverse microemulsion method appropriating CDDP’s poor solubility to our advantage promoting the synthesis of a pure cisplatin nanoparticle with a high drug loading capacity (approximately 80.8wt%). Actively targeted CDDP NPs exhibited significant accumulation in human A375M melanoma tumor cells in vivo. In addition, CDDP NPs achieved potent anti-tumor efficacy through the neighboring effect at a dose of 1 mg/kg when injected weekly via IV without inducing nephrotoxicity. The neighboring effect regards an observation made in vivo when the tumor cells that took up CDDP NPs released active drug following apoptosis. Via diffusion, surrounding cells that were previously unaffected showed intake of the released drug and their apoptosis soon followed. This observation was also made in vitro when A375M melanoma tumor cells incubated with CDDP NPs exhibited release of active drug and induced apoptosis on untreated neighboring cells. However, the neighboring effect was unique to rapidly proliferating tumor cells. Liver functional parameters and H&E staining of liver tissue in vivo failed to detect any difference between CDDP NP treated and control groups in terms of tissue health. By simultaneously promoting an increase in cytotoxicity and a lesser degree of side effects over free CDDP, CDDP NPs show great therapeutic potential with lower doses of drug while enhancing anti-cancer effectiveness. PMID:24083505

  8. Interaction of nanoparticles with cells.

    PubMed

    Mailänder, Volker; Landfester, Katharina

    2009-09-14

    Nanoparticles and their interaction with human cells have been a focus of many groups during the past decade. We discuss and review here the progress in the field of understanding and harnessing the interactions of polymeric nanoparticles synthesized by the miniemulsion process with different cell types. Nanotechnology and the hereby produced nanomaterials have promised to make use of specific properties of supramolecular assemblies and nanomaterials so that hitherto inaccessible effects can be exploited for new applications. Examples are superparamagnetism or the high surface area helpful for catalysis and adsorption. In biology and medicine, superparamagnetic iron oxide nanoparticles have been used for cell selection and as magnetic resonance imaging (MRI) contrast agents. Furthermore, uptake of nanoparticles into a wide variety of cells is an effect that seems to be specific for materials in the range of 50-200 nm. Surface modifications (positively or negatively charged side groups of the polymers, amino acids, or peptides/proteins) enhance this uptake. Knowledge about factors influencing cellular uptake, like size, surface properties, cell type, and endocytotic pathways, enables optimization of labeling and selection of cells and nanoparticles for applications in vitro and in vivo. For in vivo applications, we will focus on how nanoparticles can cross the blood-brain barrier. PMID:19637907

  9. Novel, silver-ion-releasing nanofibrous scaffolds exhibit excellent antibacterial efficacy without the use of silver nanoparticles.

    PubMed

    Mohiti-Asli, Mahsa; Pourdeyhimi, Behnam; Loboa, Elizabeth G

    2014-05-01

    Nanofibers, with their morphological similarities to the extracellular matrix of skin, hold great potential for skin tissue engineering. Over the last decade, silver nanoparticles have been extensively investigated in wound-healing applications for their ability to provide antimicrobial benefits to nanofibrous scaffolds. However, the use of silver nanoparticles has raised concerns as these particles can penetrate into the stratum corneum of skin, or even diffuse into the cellular plasma membrane. We present and evaluate a new silver ion release polymeric coating that we have found can be applied to biocompatible, biodegradable poly(l-lactic acid) nanofibrous scaffolds. Using this compound, custom antimicrobial silver-ion-releasing nanofibers were created. The presence of a uniform, continuous silver coating on the nanofibrous scaffolds was verified by XPS analysis. The antimicrobial efficacy of the antimicrobial scaffolds against Staphylococcus aureus and Escherichia coli bacteria was determined via industry-standard AATCC protocols. Cytotoxicity analyses of the antimicrobial scaffolds toward human epidermal keratinocytes and human dermal fibroblasts were performed via quantitative analyses of cell viability and proliferation. Our results indicated that the custom antimicrobial scaffolds exhibited excellent antimicrobial properties while also maintaining human skin cell viability and proliferation for silver ion concentrations below 62.5μgml(-1) within the coating solution. This is the first study to show that silver ions can be effectively delivered with nanofibrous scaffolds without the use of silver nanoparticles.

  10. Surface modification of monodisperse magnetite nanoparticles for improved intracellular uptake to breast cancer cells.

    PubMed

    Zhang, Yong; Zhang, Jing

    2005-03-15

    Nanoparticles have been widely used for a variety of biomedical applications and there is a growing need for highly specific and efficient uptake of the nanoparticles into target cells. Poly(ethylene glycol) (PEG), folic acid (FA), and their conjugate PEG-FA were attached to magnetite nanoparticles to compare their effects on the improvement of intracellular uptake of the nanoparticles to human breast cancer cells, BT-20. AFM and TEM results indicated that the nanoparticles after surface modification were monodisperse, with coatings on individual nanoparticles. The cell culture experiments showed that the PEG-FA coated nanoparticles were internalized into BT-20 cancer cells and exhibited higher efficiency of intracellular uptake than only PEG- or FA-coated nanoparticles. The surface modification protocols can also be used to modify the surfaces of other nanoparticles for targeting intracellular delivery.

  11. DNA damage in cells exhibiting radiation-induced genomic instability

    DOE PAGESBeta

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesismore » that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.« less

  12. DNA damage in cells exhibiting radiation-induced genomic instability

    SciTech Connect

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesis that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.

  13. Green synthesis of silver nanoparticles using Delphinium denudatum root extract exhibits antibacterial and mosquito larvicidal activities

    NASA Astrophysics Data System (ADS)

    Suresh, Gopal; Gunasekar, Poosali Hariharan; Kokila, Dhanasegaran; Prabhu, Durai; Dinesh, Devadoss; Ravichandran, Nagaiya; Ramesh, Balasubramanian; Koodalingam, Arunagirinathan; Vijaiyan Siva, Ganesan

    2014-06-01

    Green synthesis of silver nanoparticles (AgNPs) using aqueous root extract of Delphinium denudatum (Dd) by reduction of Ag+ ions from silver nitrate solution has been investigated. The synthesized DdAgNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FTIR). The prepared DdAgNPs showed maximum absorbance at 416 nm and particles were polydispersed in nature, spherical in shape and the size of the particle obtained was ⩽85 nm. The DdAgNPs exhibited antibacterial activity against Staphylococcus aureus ATCC 6538, Bacillus cereus NCIM 2106, Escherichia coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027. The DdAgNPs showed potent larvicidal activity against second instar larvae of dengue vector Aedes aegypti with a LC50 value of 9.6 ppm.

  14. Fabricating solar cells with silicon nanoparticles

    DOEpatents

    Loscutoff, Paul; Molesa, Steve; Kim, Taeseok

    2014-09-02

    A laser contact process is employed to form contact holes to emitters of a solar cell. Doped silicon nanoparticles are formed over a substrate of the solar cell. The surface of individual or clusters of silicon nanoparticles is coated with a nanoparticle passivation film. Contact holes to emitters of the solar cell are formed by impinging a laser beam on the passivated silicon nanoparticles. For example, the laser contact process may be a laser ablation process. In that case, the emitters may be formed by diffusing dopants from the silicon nanoparticles prior to forming the contact holes to the emitters. As another example, the laser contact process may be a laser melting process whereby portions of the silicon nanoparticles are melted to form the emitters and contact holes to the emitters.

  15. Ion mediated targeting of cells with nanoparticles

    NASA Astrophysics Data System (ADS)

    Maheshwari, Vivek; Fu, Jinlong

    2010-03-01

    In eukaryotic cells, Ca^2+ ions are necessary for intracellular signaling, in activity of mitochondria and a variety of other cellular process that have been linked to cell apoptosis, proteins synthesis and cell-cycle regulation. Here we show that Ca^2+ ions, serving as the bio-compatible interface can be used to target Saccharomyces cerevisiae (SaC, baker's yeast), a model eukaryotic cell, with Au nanoparticles (10 nm). The Ca^2+ ions bind to the carboxylic acid groups in the citrate functionalized Au nanoparticles. This transforms the nanoparticles into micron long 1-D branched chain assemblies due to inter-particle dipole-dipole interaction and inter-particle bonding due to the divalent nature of the Ca^2+ ion. A similar transformation is observed with the use of divalent ions Mg^2+, Cd^2+ and Fe^2+. The 1-D assembly aids the interfacing of ion-nanoparticles on the cell by providing multiple contact points. Further monovalent ions such as Na^+ are also effective for the targeting of the cell with nanoparticles. However Na-Au nanoparticles are limited in their deposition as they exist in solution as single particles. The cells remain alive after the deposition process and their vitality is unaffected by the interfacing with ion-nanoparticles.

  16. Simulation of transport and extravasation of nanoparticles in tumors which exhibit enhanced permeability and retention effect.

    PubMed

    Podduturi, Vishwa Priya; Magaña, Isidro B; O'Neal, D Patrick; Derosa, Pedro A

    2013-10-01

    Determining the factors that influence the delivery of sub-micron particles to tumors and understanding the relative importance of each of these factors is fundamental to the optimization of the particle delivery process. In this paper, a model that combines random walk with the pressure driven movement of nanoparticles in a tumor vasculature is presented. Nanoparticle movement in a cylindrical tube with dimensions similar to the tumor's blood capillary with a single pore is simulated. Nanoparticle velocities are calculated as a pressure driven flow over imposed to Brownian motion. The number and percentage of nanoparticles leaving the blood vessel through a single pore is obtained as a function of pore size, nanoparticle size and concentration, interstitial pressure, and blood pressure. The model presented here is able to determine the importance of these controllable parameters and thus it can be used to understand the process and predict the best conditions for nanoparticle-based treatment. The results indicate that the nanoparticle delivery gradually increases with pore size and decreases with nanoparticle size for tumors with high interstitial fluid pressure (in this work we found this behavior for head and neck carcinoma and for metastatic melanoma with interstitial pressures of 18mmHg and 19mmHg, respectively). For tumors with lower interstitial fluid pressure (rectal carcinoma with 15.3mmHg) however, delivery is observed to have little sensitivity to particle size for almost the entire nanoparticle size range. Though an increase in nanoparticle concentration increases the number of nanoparticles being delivered, the efficiency of the delivery (percentage of nanoparticles delivered) is found to remain closely unaffected.

  17. Gold Nanoparticle Quantitation by Whole Cell Tomography.

    PubMed

    Sanders, Aric W; Jeerage, Kavita M; Schwartz, Cindi L; Curtin, Alexandra E; Chiaramonti, Ann N

    2015-12-22

    Many proposed biomedical applications for engineered gold nanoparticles require their incorporation by mammalian cells in specific numbers and locations. Here, the number of gold nanoparticles inside of individual mammalian stem cells was characterized using fast focused ion beam-scanning electron microscopy based tomography. Enhanced optical microscopy was used to provide a multiscale map of the in vitro sample, which allows cells of interest to be identified within their local environment. Cells were then serially sectioned using a gallium ion beam and imaged using a scanning electron beam. To confirm the accuracy of single cross sections, nanoparticles in similar cross sections were imaged using transmission electron microscopy and scanning helium ion microscopy. Complete tomographic series were then used to count the nanoparticles inside of each cell and measure their spatial distribution. We investigated the influence of slice thickness on counting single particles and clusters as well as nanoparticle packing within clusters. For 60 nm citrate stabilized particles, the nanoparticle cluster packing volume is 2.15 ± 0.20 times the volume of the bare gold nanoparticles.

  18. Cytotoxicity of monodispersed chitosan nanoparticles against the Caco-2 cells

    SciTech Connect

    Loh, Jing Wen; Saunders, Martin; Lim, Lee-Yong

    2012-08-01

    Published toxicology data on chitosan nanoparticles (NP) often lack direct correlation to the in situ size and surface characteristics of the nanoparticles, and the repeated NP assaults as experienced in chronic use. The aim of this paper was to breach these gaps. Chitosan nanoparticles synthesized by spinning disc processing were characterised for size and zeta potential in HBSS and EMEM at pHs 6.0 and 7.4. Cytotoxicity against the Caco-2 cells was evaluated by measuring the changes in intracellular mitochondrial dehydrogenase activity, TEER and sodium fluorescein transport data and cell morphology. Cellular uptake of NP was observed under the confocal microscope. Contrary to established norms, the collective data suggest that the in vitro cytotoxicity of NP against the Caco-2 cells was less influenced by positive surface charges than by the particle size. Particle size was in turn determined by the pH of the medium in which the NP was dispersed, with the mean size ranging from 25 to 333 nm. At exposure concentration of 0.1%, NP of 25 ± 7 nm (zeta potential 5.3 ± 2.8 mV) was internalised by the Caco-2 cells, and the particles were observed to inflict extensive damage to the intracellular organelles. Concurrently, the transport of materials along the paracellular pathway was significantly facilitated. The Caco-2 cells were, however, capable of recovering from such assaults 5 days following NP removal, although a repeat NP exposure was observed to produce similar effects to the 1st exposure, with the cells exhibiting comparable resiliency to the 2nd assault. -- Highlights: ► Chitosan nanoparticles reduced mitochondrial dehydrogenase activity. ► Cellular uptake of chitosan nanoparticles was observed. ► Chitosan nanoparticles inflicted extensive damage to the cell morphology. ► The transport of materials along the paracellular pathway was facilitated.

  19. Interactions of Model Cell Membranes with Nanoparticles

    NASA Astrophysics Data System (ADS)

    D'Angelo, S. M.; Camesano, T. A.; Nagarajan, R.

    2011-12-01

    The same properties that give nanoparticles their enhanced function, such as high surface area, small size, and better conductivity, can also alter the cytotoxicity of nanomaterials. Ultimately, many of these nanomaterials will be released into the environment, and can cause cytotoxic effects to environmental bacteria, aquatic organisms, and humans. Previous results from our laboratory suggest that nanoparticles can have a detrimental effect on cells, depending on nanoparticle size. It is our goal to characterize the properties of nanomaterials that can result in membrane destabilization. We tested the effects of nanoparticle size and chemical functionalization on nanoparticle-membrane interactions. Gold nanoparticles at 2, 5,10, and 80 nm were investigated, with a concentration of 1.1x1010 particles/mL. Model cell membranes were constructed of of L-α-phosphatidylcholine (egg PC), which has negatively charged lipid headgroups. A quartz crystal microbalance with dissipation (QCM-D) was used to measure frequency changes at different overtones, which were related to mass changes corresponding to nanoparticle interaction with the model membrane. In QCM-D, a lipid bilayer is constructed on a silicon dioxide crystal. The crystals, oscillate at different harmonic frequencies depending upon changes in mass or energy dissipation. When mass is added to the crystal surface, such as through addition of a lipid vesicle solution, the frequency change decreases. By monitoring the frequency and dissipation, we could verify that a supported lipid bilayer (SLB) formed on the silica surface. After formation of the SLB, the nanoparticles can be added to the system, and the changes in frequency and dissipation are monitored in order to build a mechanistic understanding of nanoparticle-cell membrane interactions. For all of the smaller nanoparticles (2, 5, and 10 nm), nanoparticle addition caused a loss of mass from the lipid bilayer, which appears to be due to the formation of holes

  20. Electronic and surface properties of PbS nanoparticles exhibiting efficient multiple exciton generation.

    PubMed

    Hardman, Samantha J O; Graham, Darren M; Stubbs, Stuart K; Spencer, Ben F; Seddon, Elaine A; Fung, Ho-Ting; Gardonio, Sandra; Sirotti, Fausto; Silly, Mathieu G; Akhtar, Javeed; O'Brien, Paul; Binks, David J; Flavell, Wendy R

    2011-12-01

    Ultrafast transient absorption measurements have been used to study multiple exciton generation in solutions of PbS nanoparticles vigorously stirred to avoid the effects of photocharging. The threshold and slope efficiency of multiple exciton generation are found to be 2.5 ± 0.2 ×E(g) and 0.34 ± 0.08, respectively. Photoemission measurements as a function of nanoparticle size and ageing show that the position of the valence band maximum is pinned by surface effects, and that a thick layer of surface oxide is rapidly formed at the nanoparticle surfaces on exposure to air. PMID:21993370

  1. Modeling of interactions between nanoparticles and cell membranes

    NASA Astrophysics Data System (ADS)

    Ban, Young-Min

    containing the nanoparticles exhibit localized perturbation around the nanoparticle. The nanoparticles are not likely to affect membrane protein function by the weak perturbation of the internal stress in the membrane. Due to the short-ranged interactions between the nanoparticles, the nanoparticles would not form aggregates inside membranes. The effect of lipid peroxidation on cell membrane deformation is assessed. The peroxidized lipids introduce a perturbation to the internal structure of the membrane leading to higher amplitude of the membrane fluctuations. Higher concentration of the peroxidized lipids induces more significant perturbation. Cumulative effects of lipid peroxidation caused by nanoparticles are examined for the first time. The considered amphiphilic particle appears to reduce the perturbation of the membrane structure at its equilibrium position inside the peroxidized membrane. This suggests a possibility of antioxidant effect of the nanoparticle.

  2. Nanoparticle adhesion in proton exchange membrane fuel cell electrodes

    NASA Astrophysics Data System (ADS)

    He, Qianping; Joy, David C.; Keffer, David J.

    2013-11-01

    Carbon supported platinum (Pt/C) catalyst remains among the most preferable catalyst materials for Proton Exchange Membrane (PEM) fuel cells. However, platinum (Pt) particles suffer from poor durability and encounter electrochemical surface area (ESA) loss under operation with the accompany of Pt nanoparticle coarsening. Several proposed mechanisms have involved the Pt detachment from its carbonate support as an initial step for the deactivation of Pt nanoparticles. In this study, we investigated the detachment mechanism from the nano-adhesion point of view. Classic molecular dynamics simulations are performed on systems contain Pt nanoparticles of different sizes and shapes. A thin Nafion film (1 nm) at different hydration levels is also included in the system to study the environmental effect on nanoparticle adhesion. We found that the adhesion force strengthens as the Pt size goes up. Pt nanoparticles of tetrahedral shape exhibit relatively stronger connection with the carbon substrate due to its unique ‘anchor-like’ structure. Adhesion is enhanced with the introduction of a Nafion. The humidity level in the Nafion film has a rather complicated effect on the strength of nanoparticle adhesion. The binding energies and maximum adhesive forces are reported for all systems studied.

  3. Stem cell tracking with optically active nanoparticles

    PubMed Central

    Gao, Yu; Cui, Yan; Chan, Jerry KY; Xu, Chenjie

    2013-01-01

    Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell tracking with modern imaging modalities offers insight into the underlying biological process of the stem-cell-based therapies, with the goal to reveal cell survival, migration, homing, engraftment, differentiation, and functions. Adaptability, sensitivity, resolution, and non-invasiveness have contributed to the longstanding use of optical imaging for stem cell tracking and analysis. To identify transplanted stem cells from the host tissue, optically active probes are usually used to label stem cells before the administration. In comparison to the traditional fluorescent probes like fluorescent proteins and dyes, nanoparticle-based probes are advantageous in terms of the photo-stabilities and minimal changes to the cell phenotype. The main focus here is to overview the recent development of optically active nanoparticles for stem cells tracking. The related optical imaging modalities include fluorescence imaging, photoacoustic imaging, Raman and surface enhanced Raman spectroscopy imaging. PMID:23638335

  4. Regenerated hair cells exhibit a transient resistance to aminoglycoside toxicity.

    PubMed

    Hashino, E; Salvi, R J

    1996-05-13

    Recent studies have demonstrated that sensory hair cells in the avian inner ear are reproduced by cell proliferation in response to the death of the original hair cell population. The regenerated hair cells appear to construct functional synaptic contacts, thereby transmitting acoustic signals to the peripheral nervous system. One of the most extraordinary, but overlooked characteristics of these regenerated hair cells, is their ability to survive in a highly ototoxic environment. Here, we report that hair cells regenerated after kanamycin induced hair cell loss can survive for a substantially longer time period than their predecessors during prolonged exposure to aminoglycoside antibiotics. The prolonged survival, however, belongs solely to the immature status of regenerated hair cells. Once the regenerated hair cells reach morphological maturation, they become vulnerable to aminoglycoside toxicity. Immunohistochemical evaluation of kanamycin suggested that kanamycin may be taken up into hair cells via a receptor-mediated endocytosis at their apical surfaces. By contrast, kanamycin was rarely incorporated into the cytoplasm of the regenerated hair cells. These results suggest that the process of a receptor-mediated transmembrane transport at the apical surface of hair cells is developmentally regulated, and that the lack of some of the assembly involved in the transmembrane transport could be responsible for the inhibition of aminoglycoside uptake, leading immature hair cells to be aminoglycoside resistant. PMID:8782910

  5. Lunar soil simulant and synthesized nanoparticles of magnetite exhibit diverse neurotoxic potential

    NASA Astrophysics Data System (ADS)

    Borisova, Tatiana; Krisanova, Natalia; Sivko, Roman; Nazarova, Anastasiya; Borysov, Arseniy

    Lunar soli simulant can be deleterious to human physiology and the components of lunar soil may be internalized by lung epithelium and may overcome the blood-brain barrier. Nanoparticles of ferric oxide are one of the components of Lunar soil simulants. Neurotoxic potential of lunar soil simulant and synthesized nanoparticles of magnetite was analyzed. The size of particles, their effects on membrane potential, acidification of synaptic vesicles, uptake and ambient level of glutamate, which is the major excitatory neurotransmitter in the CNS, were studied in isolated rat brain nerve terminals (synaptosomes) using photon correlation spectroscopy, spectrofluorimetry, radiolabeled assay, respectively. No significant effect of Lunar soil simulant and synthesized nanoparticles of magnetite on acidification of synaptic vesicles were found in synaptosomes. Also, nanoparticles did not influence the potential of the plasma membrane of synaptosomes. Unspecific binding of L-[14C]glutamate to synaptosomes was not altered by nanoparticles of magnetite, whereas in the presence of Lunar soil simulant this parameter was changed. Thus, it was suggested that Lunar soil simulant might disturb glutamate homeostasis in the mammalian CNS.

  6. Tracking stem cells using magnetic nanoparticles

    PubMed Central

    Cromer Berman, Stacey M.; Walczak, Piotr; Bulte, Jeff W.M.

    2011-01-01

    Stem cell therapies offer great promise for many diseases, especially those without current effective treatments. It is believed that noninvasive imaging techniques, which offer the ability to track the status of cells after transplantation, will expedite progress in this field and help to achieve maximized therapeutic effect. Today’s biomedical imaging technology allows for real-time, noninvasive monitoring of grafted stem cells including their biodistribution, migration, survival, and differentiation, with magnetic resonance imaging (MRI) of nanoparticle-labeled cells being one of the most commonly used techniques. Among the advantages of MR cell tracking are its high spatial resolution, no exposure to ionizing radiation, and clinical applicability. In order to track cells by MRI, the cells need to be labeled with magnetic nanoparticles, for which many types exist. There are several cellular labeling techniques available, including simple incubation, use of transfection agents, magnetoelectroporation, and magnetosonoporation. In this overview article, we will review the use of different magnetic nanoparticles and discuss how these particles can be used to track the distribution of transplanted cells in different organ systems. Caveats and limitations inherent to the tracking of nanoparticle-labeled stem cells are also discussed. PMID:21472999

  7. Organically Modified Silica Nanoparticles Interaction with Macrophage Cells: Assessment of Cell Viability on the Basis of Physicochemical Properties.

    PubMed

    Kumar, Dhiraj; Mutreja, Isha; Keshvan, Prashant C; Bhat, Madhusudan; Dinda, Amit K; Mitra, Susmita

    2015-11-01

    Silica nanoparticles have drawn a lot of attention for nanomedicine application, and this is attributed to their biocompatibility and ease of surface functionalization. However, successful utilization of these inorganic systems for biomedical application depends on their physicochemical properties. This study, therefore, discusses in vitro toxicity of organically modified silica nanoparticles on the basis of size, shape, and surface properties of silica nanoparticles. Spherical- and oval-shaped nanoparticles having hydroxyl and amine groups were synthesized in Tween 80 micelles using different organosilanes. Nanoparticles of similar size and morphology were considered for comparative assessment. "As-prepared" nanoparticles were characterized in terms of size, shape, and surface properties using ZetaSizer, transmission electron microscopy, and Fourier transform infrared to establish the above parameters. In vitro analysis in terms of nanoparticle-based toxicity was performed on J-774 (macrophage) cell line using propidium iodide-4',6-diamidino-2-phenylindol and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Fluorescent dye-entrapped nanoparticles were used to visualize the uptake of the nanoparticles by macrophage cells. Results from cell studies suggested low levels of toxicity for different nanoparticle formulations studied, therefore are suitable for nanocarrier application for poorly soluble molecules. On the contrary, the nanoparticles of similar size and shape, having amine groups and low net negative charge, do not exhibit any in vitro cytotoxicity.

  8. Staphylococcal Enterotoxin O Exhibits Cell Cycle Modulating Activity

    PubMed Central

    Hodille, Elisabeth; Alekseeva, Ludmila; Berkova, Nadia; Serrier, Asma; Badiou, Cedric; Gilquin, Benoit; Brun, Virginie; Vandenesch, François; Terman, David S.; Lina, Gerard

    2016-01-01

    Maintenance of an intact epithelial barrier constitutes a pivotal defense mechanism against infections. Staphylococcus aureus is a versatile pathogen that produces multiple factors including exotoxins that promote tissue alterations. The aim of the present study is to investigate the cytopathic effect of staphylococcal exotoxins SEA, SEG, SEI, SElM, SElN and SElO on the cell cycle of various human cell lines. Among all tested exotoxins only SEIO inhibited the proliferation of a broad panel of human tumor cell lines in vitro. Evaluation of a LDH release and a DNA fragmentation of host cells exposed to SEIO revealed that the toxin does not induce necrosis or apoptosis. Analysis of the DNA content of tumor cells synchronized by serum starvation after exposure to SEIO showed G0/G1 cell cycle delay. The cell cycle modulating feature of SEIO was confirmed by the flow cytometry analysis of synchronized cells exposed to supernatants of isogenic S. aureus strains wherein only supernatant of the SElO producing strain induced G0/G1 phase delay. The results of yeast-two-hybrid analysis indicated that SEIO’s potential partner is cullin-3, involved in the transition from G1 to S phase. In conclusion, we provide evidence that SEIO inhibits cell proliferation without inducing cell death, by delaying host cell entry into the G0/G1 phase of the cell cycle. We speculate that this unique cell cycle modulating feature allows SEIO producing bacteria to gain advantage by arresting the cell cycle of target cells as part of a broader invasive strategy. PMID:27148168

  9. Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating.

    PubMed

    Rosman, Christina; Pierrat, Sebastien; Tarantola, Marco; Schneider, David; Sunnick, Eva; Janshoff, Andreas; Sönnichsen, Carsten

    2014-01-01

    In this work, we study epithelial cell growth on substrates decorated with gold nanorods that are functionalized either with a positively charged cytotoxic surfactant or with a biocompatible polymer exhibiting one of two different end groups, resulting in a neutral or negative surface charge of the particle. Upon observation of cell growth for three days by live cell imaging using optical dark field microscopy, it was found that all particles supported cell adhesion while no directed cell migration and no significant particle internalization occurred. Concerning cell adhesion and spreading as compared to cell growth on bare substrates after 3 days of incubation, a reduction by 45% and 95%, respectively, for the surfactant particle coating was observed, whereas the amino-terminated polymer induced a reduction by 30% and 40%, respectively, which is absent for the carboxy-terminated polymer. Furthermore, interface-sensitive impedance spectroscopy (electric cell-substrate impedance sensing, ECIS) was employed in order to investigate the micromotility of cells added to substrates decorated with various amounts of surfactant-coated particles. A surface density of 65 particles/µm(2) (which corresponds to 0.5% of surface coverage with nanoparticles) diminishes micromotion by 25% as compared to bare substrates after 35 hours of incubation. We conclude that the surface coating of the gold nanorods, which were applied to the basolateral side of the cells, has a recognizable influence on the growth behavior and thus the coating should be carefully selected for biomedical applications of nanoparticles. PMID:25671143

  10. Variation in the uptake of nanoparticles by monolayer cultured cells using high resolution MeV ion beam imaging

    NASA Astrophysics Data System (ADS)

    Tao, Ye; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-Belle; Bettiol, Andrew A.; Watt, Frank

    2015-04-01

    Gold nanoparticle uptake by cells is being increasingly studied because of its potential in biomedical applications. In this work, we show how scanning transmission ion microscopy can be employed to visualize and quantify 50 nm gold nanoparticles taken up by individual cells. Preliminary studies have indicated that the cellular content of gold nanoparticles exhibits a wide variation (up to a factor of 10) among individual cells. This cell-to-cell variation can affect the efficiency of utilizing gold nanoparticles for therapeutic or diagnostic purposes.

  11. TPGS-Stabilized Curcumin Nanoparticles Exhibit Superior Effect on Carrageenan-Induced Inflammation in Wistar Rat.

    PubMed

    Rachmawati, Heni; Safitri, Dewi; Pradana, Aditya Trias; Adnyana, I Ketut

    2016-01-01

    Curcumin, a hydrophobic polyphenol compound derived from the rhizome of the Curcuma genus, has a wide spectrum of biological and pharmacological applications. Previously, curcumin nanoparticles with different stabilizers had been produced successfully in order to enhance solubility and per oral absorption. In the present study, we tested the anti-inflammatory effect of d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS)-stabilized curcumin nanoparticles in vivo. Lambda-carrageenan (λ-carrageenan) was used to induce inflammation in rats; it was given by an intraplantar route and intrapelurally through surgery in the pleurisy test. In the λ-carrageenan-induced edema model, TPGS-stabilized curcumin nanoparticles were given orally one hour before induction and at 0.5, 4.5, and 8.5 h after induction with two different doses (1.8 and 0.9 mg/kg body weight (BW)). Sodium diclofenac with a dose of 4.5 mg/kg BW was used as a standard drug. A physical mixture of curcumin-TPGS was also used as a comparison with a higher dose of 60 mg/kg BW. The anti-inflammatory effect was assessed on the edema in the carrageenan-induced paw edema model and by the volume of exudate as well as the number of leukocytes reduced in the pleurisy test. TPGS-stabilized curcumin nanoparticles with lower doses showed better anti-inflammatory effects, indicating the greater absorption capability through the gastrointestinal tract. PMID:27537907

  12. TPGS-Stabilized Curcumin Nanoparticles Exhibit Superior Effect on Carrageenan-Induced Inflammation in Wistar Rat

    PubMed Central

    Rachmawati, Heni; Safitri, Dewi; Pradana, Aditya Trias; Adnyana, I Ketut

    2016-01-01

    Curcumin, a hydrophobic polyphenol compound derived from the rhizome of the Curcuma genus, has a wide spectrum of biological and pharmacological applications. Previously, curcumin nanoparticles with different stabilizers had been produced successfully in order to enhance solubility and per oral absorption. In the present study, we tested the anti-inflammatory effect of d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS)-stabilized curcumin nanoparticles in vivo. Lambda-carrageenan (λ-carrageenan) was used to induce inflammation in rats; it was given by an intraplantar route and intrapelurally through surgery in the pleurisy test. In the λ-carrageenan-induced edema model, TPGS-stabilized curcumin nanoparticles were given orally one hour before induction and at 0.5, 4.5, and 8.5 h after induction with two different doses (1.8 and 0.9 mg/kg body weight (BW)). Sodium diclofenac with a dose of 4.5 mg/kg BW was used as a standard drug. A physical mixture of curcumin-TPGS was also used as a comparison with a higher dose of 60 mg/kg BW. The anti-inflammatory effect was assessed on the edema in the carrageenan-induced paw edema model and by the volume of exudate as well as the number of leukocytes reduced in the pleurisy test. TPGS-stabilized curcumin nanoparticles with lower doses showed better anti-inflammatory effects, indicating the greater absorption capability through the gastrointestinal tract. PMID:27537907

  13. Imaging nanoparticles in cells by nanomechanical holography

    NASA Astrophysics Data System (ADS)

    Tetard, Laurene; Passian, Ali; Venmar, Katherine T.; Lynch, Rachel M.; Voy, Brynn H.; Shekhawat, Gajendra; Dravid, Vinayak P.; Thundat, Thomas

    2008-08-01

    Nanomaterials have potential medical applications, for example in the area of drug delivery, and their possible adverse effects and cytotoxicity are curently receiving attention. Inhalation of nanoparticles is of great concern, because nanoparticles can be easily aerosolized. Imaging techniques that can visualize local populations of nanoparticles at nanometre resolution within the structures of cells are therefore important. Here we show that cells obtained from mice exposed to single-walled carbon nanohorns can be probed using a scanning probe microscopy technique called scanning near field ultrasonic holography. The nanohorns were observed inside the cells, and this was further confirmed using micro Raman spectroscopy. Scanning near field ultrasonic holography is a useful technique for probing the interactions of engineered nanomaterials in biological systems, which will greatly benefit areas in drug delivery and nanotoxicology.

  14. Mammalian cell growth on gold nanoparticle-decorated substrates is influenced by the nanoparticle coating

    PubMed Central

    Rosman, Christina; Pierrat, Sebastien; Tarantola, Marco; Schneider, David; Sunnick, Eva; Janshoff, Andreas

    2014-01-01

    Summary In this work, we study epithelial cell growth on substrates decorated with gold nanorods that are functionalized either with a positively charged cytotoxic surfactant or with a biocompatible polymer exhibiting one of two different end groups, resulting in a neutral or negative surface charge of the particle. Upon observation of cell growth for three days by live cell imaging using optical dark field microscopy, it was found that all particles supported cell adhesion while no directed cell migration and no significant particle internalization occurred. Concerning cell adhesion and spreading as compared to cell growth on bare substrates after 3 days of incubation, a reduction by 45% and 95%, respectively, for the surfactant particle coating was observed, whereas the amino-terminated polymer induced a reduction by 30% and 40%, respectively, which is absent for the carboxy-terminated polymer. Furthermore, interface-sensitive impedance spectroscopy (electric cell–substrate impedance sensing, ECIS) was employed in order to investigate the micromotility of cells added to substrates decorated with various amounts of surfactant-coated particles. A surface density of 65 particles/µm2 (which corresponds to 0.5% of surface coverage with nanoparticles) diminishes micromotion by 25% as compared to bare substrates after 35 hours of incubation. We conclude that the surface coating of the gold nanorods, which were applied to the basolateral side of the cells, has a recognizable influence on the growth behavior and thus the coating should be carefully selected for biomedical applications of nanoparticles. PMID:25671143

  15. Inhibition of rhotekin exhibits antitumor effects in lung cancer cells

    PubMed Central

    ZHANG, WEIZHEN; LIANG, ZHENYU; LI, JING

    2016-01-01

    Lung cancer is the leading cause for cancer-related death, however, the pathogenesis mechanism is poorly understood. Although the rhotekin (RTKN) gene has been reported to encode an effector for the Rho protein that has critical roles in regulating cell growth, the role of RTKN in lung cancer has not been investigated. In clinical lung cancer patient tumor samples, we identified that the RTKN gene expression level was significantly higher in tumor tissues compared to that of the adjacent normal tissues. To investigate the molecular mechanisms of RTKN in lung cancer, we established RTKN stable knock-down A549 and SPC-A-1 lung adenocarcinoma cell lines using lentiviral transfection of RTKN shRNA and evaluated the antitumor effects. The results showed that RTKN knock-down inhibited lung adenocarcinoma cell viability, induced S phase arrest and increased cell apoptosis. In addition, RTKN knock-down inhibited lung cancer cell invasion and adhesion. Further analysis showed that the S phase promoting factors cyclindependent kinase (CDK)1 and CDK2 levels were decreased in RTKN knock-down cells, and that the DNA replication initiation complex proteins Minichromosome maintenance protein complex (MCM)2 and MCM6 were decreased as well in RTKN knock-down cells. These results indicated that the RTKN protein was associated with lung cancer in clinic samples and exerted anticancer activity in lung adenocarcinoma cells through inhibiting cell cycle progression and the DNA replication machinery. These findings suggest that RTKN inhibition may be a novel therapeutic strategy for lung adenocarcinoma. PMID:26935528

  16. Modified Bleomycin Disaccharides Exhibiting Improved Tumor Cell Targeting

    PubMed Central

    2015-01-01

    The bleomycins (BLMs) are a family of antitumor antibiotics used clinically for anticancer chemotherapy. Their antitumor selectivity derives at least in part from their ability to target tumor cells, a property that resides in the carbohydrate moiety of the antitumor agent. In earlier studies, we have demonstrated that the tumor cell selectivity resides in the mannose carbamoyl moiety of the BLM saccharide and that both the BLM disaccharide and monosaccharide containing the carbamoyl moiety were capable of the delivery/uptake of a conjugated cyanine dye into cultured cancer cell lines. Presently, the nature of the participation of the carbamoyl moiety has been explored further to provide compounds of utility for defining the nature of the mechanism of tumor cell recognition and uptake by BLM saccharides and in the hope that more efficient compounds could be identified. A library of seven disaccharide–Cy5** dye conjugates was prepared that are structural analogues of the BLM disaccharide. These differed from the natural BLM disaccharide in the position, orientation, and substitution of the carbamoyl group. Studies of these compounds in four matched sets of tumor and normal cell lines revealed a few that were both tumor cell selective and internalized 2–4-fold more efficiently than the natural BLM disaccharide. PMID:25272367

  17. Application of fluorescence labeled liposome nanoparticles in the cell imaging

    NASA Astrophysics Data System (ADS)

    Hu, Jianbing; Li, Huimin; He, Xiaoxiao; Gong, Ping; Wang, Kemin; Zhang, Shouchun

    2007-05-01

    Fluorescence labeled liposome nanoparticles were prepared by dispersion of film method. The size of nanoparticles was around 50 nm. DPPE-FITC synthesized in our lab was used to label the liposome nanoparticles. Anti-cytokeratins 19 antibody was connected to the surface of the fluorescence liposome nanoparticles. After incubation with MGC cells and COS-7 cells for 30 min, MGC cells were selectively recognized by anti-cytokeratins 19 antibody modified liposome nanoparticles and well imaged under laser confocal microscope. This fluorescence labeled liposome nanoparticles is expected to have good applications in cell recognition and tumor diagnosis.

  18. A universal nanoparticle cell secretion capture assay.

    PubMed

    Fitzgerald, Wendy; Grivel, Jean-Charles

    2013-02-01

    Secreted proteins play an important role in intercellular interactions, especially between cells of the immune system. Currently, there is no universal assay that allows a simple noninvasive identification and isolation of cells based on their secretion of various products. We have developed such a method. Our method is based on the targeting, to the cell surface, of heterofunctional nanoparticles coupled to a cell surface-specific antibody and to a secreted protein-specific antibody, which captures the secreted protein on the surface of the producing cell. Importantly, this method does not compromise cellviability and is compatible with further culture and expansion of the secreting cells.

  19. Biological cell manipulation by magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Gertz, Frederick; Khitun, Alexander

    2016-02-01

    We report a manipulation of biological cells (erythrocytes) by magnetite (Fe3O4) nanoparticles in the presence of a magnetic field. The experiment was accomplished on the top of a micro-electromagnet consisting of two magnetic field generating contours. An electric current flowing through the contour(s) produces a non-uniform magnetic field, which is about 1.4 mT/μm in strength at 100 mA current in the vicinity of the current-carrying wire. In responses to the magnetic field, magnetic nanoparticles move towards the systems energy minima. In turn, magnetic nanoparticles drag biological cells in the same direction. We present experimental data showing cell manipulation through the control of electric current. This technique allows us to capture and move cells located in the vicinity (10-20 microns) of the current-carrying wires. One of the most interesting results shows a periodic motion of erythrocytes between the two conducting contours, whose frequency is controlled by an electric circuit. The obtained results demonstrate the feasibility of non-destructive cell manipulation by magnetic nanoparticles with micrometer-scale precision.

  20. Air stable organic-inorganic nanoparticles hybrid solar cells

    DOEpatents

    Qian, Lei; Yang, Jihua; Xue, Jiangeng; Holloway, Paul H.

    2015-09-29

    A solar cell includes a low work function cathode, an active layer of an organic-inorganic nanoparticle composite, a ZnO nanoparticle layer situated between and physically contacting the cathode and active layers; and a transparent high work function anode that is a bilayer electrode. The inclusion of the ZnO nanoparticle layer results in a solar cell displaying a conversion efficiency increase and reduces the device degradation rate. Embodiments of the invention are directed to novel ZnO nanoparticles that are advantageous for use as the ZnO nanoparticle layers of the novel solar cells and a method to prepare the ZnO nanoparticles.

  1. Radiosensitization of paclitaxel, etanidazole and paclitaxel+etanidazole nanoparticles on hypoxic human tumor cells in vitro.

    PubMed

    Jin, Cheng; Bai, Ling; Wu, Hong; Tian, Furong; Guo, Guozhen

    2007-09-01

    Paclitaxel and etanidazole are hypoxic radiosensitizers that exhibit cytotoxic action at different mechanisms. The poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel, etanidazole and paclitaxel+etanidazole were prepared by o/w and w/o/w emulsification-solvent evaporation method. The morphology of the nanoparticles was investigated by scanning electron microscope (SEM). The drug encapsulation efficiency (EE) and release profile in vitro were measured by high-performance liquid chromatography (HPLC). The cellular uptake of nanoparticles for the human breast carcinoma cells (MCF-7) and the human carcinoma cervicis cells (HeLa) was evaluated by transmission electronic microscopy and fluorescence microscopy. Cell viability was determined by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical shape with size between 80 and 150 nm. The EE was higher for paclitaxel and lower for etanidazole. The drug release was controlled over time. The cellular uptake of nanoparticles was observed. Co-culture of the two tumor cell lines with drug-loaded nanoparticles demonstrated that released drug effectively sensitized hypoxic tumor cells to radiation. The radiosensitization of paclitaxel+etanidazole nanoparticles was more significant than that of single drug-loaded nanoparticles. PMID:17509678

  2. Nanoparticle Solar Cell Final Technical Report

    SciTech Connect

    Breeze, Alison, J; Sahoo, Yudhisthira; Reddy, Damoder; Sholin, Veronica; Carter, Sue

    2008-06-17

    The purpose of this work was to demonstrate all-inorganic nanoparticle-based solar cells with photovoltaic performance extending into the near-IR region of the solar spectrum as a pathway towards improving power conversion efficiencies. The field of all-inorganic nanoparticle-based solar cells is very new, with only one literature publication in the prior to our project. Very little is understood regarding how these devices function. Inorganic solar cells with IR performance have previously been fabricated using traditional methods such as physical vapor deposition and sputtering, and solution-processed devices utilizing IR-absorbing organic polymers have been investigated. The solution-based deposition of nanoparticles offers the potential of a low-cost manufacturing process combined with the ability to tune the chemical synthesis and material properties to control the device properties. This work, in collaboration with the Sue Carter research group at the University of California, Santa Cruz, has greatly expanded the knowledge base in this field, exploring multiple material systems and several key areas of device physics including temperature, bandgap and electrode device behavior dependence, material morphological behavior, and the role of buffer layers. One publication has been accepted to Solar Energy Materials and Solar Cells pending minor revision and another two papers are being written now. While device performance in the near-IR did not reach the level anticipated at the beginning of this grant, we did observe one of the highest near-IR efficiencies for a nanoparticle-based solar cell device to date. We also identified several key parameters of importance for improving both near-IR performance and nanoparticle solar cells in general, and demonstrated multiple pathways which showed promise for future commercialization with further research.

  3. Nanoparticle scattering for multijunction solar cells

    NASA Astrophysics Data System (ADS)

    Mellor, A.; Hylton, N. P.; Höhn, O.; Wellens, C.; Hauser, H.; Thomas, T.; Al-Saleh, Y.; Tucher, N.; Oliva, E.; Bläsi, B.; Ekins-Daukes, N. J.; Maier, S. A.

    2016-04-01

    We investigate the integration of Al nanoparticle arrays into the anti-reflection coatings (ARCs) of commercial triple-junction GaInP/ In0.01GaAs /Ge space solar cells, and study their effect on the radiation-hardness. It is postulated that the presence of nanoparticle arrays can improve the radiation-hardness of space solar cells by scattering incident photons obliquely into the device, causing charger carriers to be photogenerated closer to the junction, and hence improving the carrier collection efficiency in the irradiation-damaged subcells. The Al nanoparticle arrays were successfully embedded in the ARCs, over large areas, using nanoimprint lithography: a replication technique with the potential for high throughput and low cost. Irradiation testing showed that the presence of the nanoparticles did not improve the radiation-hardness of the solar cells, so the investigated structure has proven not to be ideal in this context. Nonetheless, this paper reports on the details and results of the nanofabrication to inform about future integration of alternative light-scattering structures into multi-junction solar cells or other optoelectronic devices.

  4. Functionalized magnetic-fluorescent hybrid nanoparticles for cell labelling.

    PubMed

    Lou, Lei; Yu, Ke; Zhang, Zhengli; Li, Bo; Zhu, Jianzhong; Wang, Yiting; Huang, Rong; Zhu, Ziqiang

    2011-05-01

    A facile method of synthesizing 60 nm magnetic-fluorescent core-shell bifunctional nanocomposites with the ability to label cells is presented. Hydrophobic trioctylphosphine oxide (TOPO)-capped CdSe@ZnS quantum dots (QDs) were assembled on polyethyleneimine (PEI)-coated Fe(3)O(4) nanoparticles (MNP). Polyethyleneimine was utilized for the realization of multifunction, including attaching 4 nm TOPO capped CdSe@ZnS quantum dots onto magnetite particles, altering the surface properties of quantum dots from hydrophobic to hydrophilic as well as preventing the formation of large aggregates. Results show that these water-soluble hybrid nanocomposites exhibit good colloidal stability and retain good magnetic and fluorescent properties. Because TOPO-capped QDs are assembled instead of their water-soluble equivalents, the nanocomposites are still highly luminescent with no shift in the PL peak position and present long-term fluorescence stability. Moreover, TAT peptide (GRKKRRQRRRPQ) functionalized hybrid nanoparticles were also studied due to their combined magnetic enrichment and optical detection for cell separation and rapid cell labelling. A cell viability assay revealed good biocompatibility of these hybrid nanoparticles. The potential application of the new magnetic-fluorescent nanocomposites in biological and medicine is demonstrated. PMID:21503355

  5. Targeted silver nanoparticles for ratiometric cell phenotyping

    NASA Astrophysics Data System (ADS)

    Willmore, Anne-Mari A.; Simón-Gracia, Lorena; Toome, Kadri; Paiste, Päärn; Kotamraju, Venkata Ramana; Mölder, Tarmo; Sugahara, Kazuki N.; Ruoslahti, Erkki; Braun, Gary B.; Teesalu, Tambet

    2016-04-01

    Affinity targeting is used to deliver nanoparticles to cells and tissues. For efficient targeting, it is critical to consider the expression and accessibility of the relevant receptors in the target cells. Here, we describe isotopically barcoded silver nanoparticles (AgNPs) as a tool for auditing affinity ligand receptors in cells. Tumor penetrating peptide RPARPAR (receptor: NRP-1) and tumor homing peptide GKRK (receptor: p32) were used as affinity ligands on the AgNPs. The binding and uptake of the peptide-functionalized AgNPs by cultured PPC-1 prostate cancer and M21 melanoma cells was dependent on the cell surface expression of the cognate peptide receptors. Barcoded peptide-functionalized AgNPs were synthesized from silver and palladium isotopes. The cells were incubated with a cocktail of the barcoded nanoparticles [RPARPAR (R), GKRK (K), and control], and cellular binding and internalization of each type of nanoparticle was assessed by inductively coupled plasma mass spectrometry. The results of isotopic analysis were in agreement with data obtained using optical methods. Using ratiometric measurements, we were able to classify the PPC-1 cell line as mainly NRP-1-positive, with 75 +/- 5% R-AgNP uptake, and the M21 cell line as only p32-positive, with 89 +/- 9% K-AgNP uptake. The isotopically barcoded multiplexed AgNPs are useful as an in vitro ratiometric phenotyping tool and have potential uses in functional evaluation of the expression of accessible homing peptide receptors in vivo.Affinity targeting is used to deliver nanoparticles to cells and tissues. For efficient targeting, it is critical to consider the expression and accessibility of the relevant receptors in the target cells. Here, we describe isotopically barcoded silver nanoparticles (AgNPs) as a tool for auditing affinity ligand receptors in cells. Tumor penetrating peptide RPARPAR (receptor: NRP-1) and tumor homing peptide GKRK (receptor: p32) were used as affinity ligands on the AgNPs. The

  6. ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells.

    PubMed

    Meidanchi, Alireza; Akhavan, Omid; Khoei, Samideh; Shokri, Ali A; Hajikarimi, Zahra; Khansari, Nakisa

    2015-01-01

    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~1 min for 2 mg mL(-1) of the nanoparticles in ethanol) by applying an external magnetic field (~1T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high radioresistant cells) under gamma irradiation of (60)Co source. The nanoparticles exhibited no significant effects on the cancer cells up to the high concentration of 100 μg mL(-1), in the absence of gamma irradiation. The gamma irradiation alone (2Gy dose) also showed no significant effects on the cells. However, gamma irradiation in the presence of 100 μg mL(-1) ZnFe2O4 nanoparticles resulted in ~53% inactivation of the cells (~17 times higher than the inactivation that occurred under gamma irradiation alone) after 24h. The higher cell inactivation was assigned to interaction of gamma radiation with nanoparticles (photoelectric effect), resulting in a high level electron release in the media of the radioresistant cells. Our results indicated that ZnFe2O4 nanoparticles not only can be applied in increasing the efficiency of radiotherapy, but also can be easily separated from the cell environment by using an external magnetic field after the radiotherapy.

  7. ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells.

    PubMed

    Meidanchi, Alireza; Akhavan, Omid; Khoei, Samideh; Shokri, Ali A; Hajikarimi, Zahra; Khansari, Nakisa

    2015-01-01

    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~1 min for 2 mg mL(-1) of the nanoparticles in ethanol) by applying an external magnetic field (~1T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high radioresistant cells) under gamma irradiation of (60)Co source. The nanoparticles exhibited no significant effects on the cancer cells up to the high concentration of 100 μg mL(-1), in the absence of gamma irradiation. The gamma irradiation alone (2Gy dose) also showed no significant effects on the cells. However, gamma irradiation in the presence of 100 μg mL(-1) ZnFe2O4 nanoparticles resulted in ~53% inactivation of the cells (~17 times higher than the inactivation that occurred under gamma irradiation alone) after 24h. The higher cell inactivation was assigned to interaction of gamma radiation with nanoparticles (photoelectric effect), resulting in a high level electron release in the media of the radioresistant cells. Our results indicated that ZnFe2O4 nanoparticles not only can be applied in increasing the efficiency of radiotherapy, but also can be easily separated from the cell environment by using an external magnetic field after the radiotherapy. PMID:25492003

  8. Controlled self-assembly of multiferroic core-shell nanoparticles exhibiting strong magneto-electric effects

    SciTech Connect

    Sreenivasulu, Gollapudi; Hamilton, Sean L.; Lehto, Piper R.; Srinivasan, Gopalan; Popov, Maksym; Chavez, Ferman A.

    2014-02-03

    Ferromagnetic-ferroelectric composites show strain mediated coupling between the magnetic and electric sub-systems due to magnetostriction and piezoelectric effects associated with the ferroic phases. We have synthesized core-shell multiferroic nano-composites by functionalizing 10–100 nm barium titanate and nickel ferrite nanoparticles with complementary coupling groups and allowing them to self-assemble in the presence of a catalyst. The core-shell structure was confirmed by electron microscopy and magnetic force microscopy. Evidence for strong strain mediated magneto-electric coupling was obtained by static magnetic field induced variations in the permittivity over 16–18 GHz and polarization and by electric field induced by low-frequency ac magnetic fields.

  9. Hybrid silver nanoparticle/conjugated polyelectrolyte nanocomposites exhibiting controllable metal-enhanced fluorescence

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyu; He, Fang; Zhu, Xi; Tang, Fu; Li, Lidong

    2014-03-01

    Metal-enhanced fluorescence of conjugated polyelectrolytes (CPs) is realized using a simple, green hybrid Ag nanocomposite film. Ag nanoparticles (Ag NPs) are pre-prepared by sodium citrate reduction and incorporated into agarose by mixing to form an Ag-containing agarose film (Ag@agarose). Through variation of the amount of Ag NPs in the Ag@agarose film as well as the thickness of the interlayer between CPs and the Ag@agarose film prepared of layer-by-layer assembly of chitosan and sodium alginate, a maximum 8.5-fold increase in the fluorescence of CPs is obtained. After introducing tyrosinase, this system also can be used to detect phenolic compounds with high sensitivity and good visualization under ultraviolet light.

  10. Hybrid silver nanoparticle/conjugated polyelectrolyte nanocomposites exhibiting controllable metal-enhanced fluorescence

    PubMed Central

    Wang, Xiaoyu; He, Fang; Zhu, Xi; Tang, Fu; Li, Lidong

    2014-01-01

    Metal-enhanced fluorescence of conjugated polyelectrolytes (CPs) is realized using a simple, green hybrid Ag nanocomposite film. Ag nanoparticles (Ag NPs) are pre-prepared by sodium citrate reduction and incorporated into agarose by mixing to form an Ag-containing agarose film (Ag@agarose). Through variation of the amount of Ag NPs in the Ag@agarose film as well as the thickness of the interlayer between CPs and the Ag@agarose film prepared of layer-by-layer assembly of chitosan and sodium alginate, a maximum 8.5-fold increase in the fluorescence of CPs is obtained. After introducing tyrosinase, this system also can be used to detect phenolic compounds with high sensitivity and good visualization under ultraviolet light. PMID:24638208

  11. Nanoparticle-based monitoring of cell therapy

    PubMed Central

    Xu, Chenjie; Mu, Luye; Roes, Isaac; Miranda-Nieves, David; Nahrendorf, Matthias; Ankrum, James A; Zhao, Weian; Karp, Jeffrey M

    2012-01-01

    Exogenous cell therapy aims to replace/repair diseased or dysfunctional cells and promises to revolutionize medicine by restoring tissue and organ function. To develop effective cell therapy, the location, distribution and long-term persistence of transplanted cells must be evaluated. Nanoparticle (NP) based imaging technologies have the potential to track transplanted cells non-invasively. Here we summarize the most recent advances in NP-based cell tracking with emphasis on (1) the design criteria for cell tracking NPs, (2) protocols for cell labeling, (3) a comparison of available imaging modalities and their corresponding contrast agents, (4) a summary of preclinical studies on NP-based cell tracking and finally (5) perspectives and future directions. PMID:22101191

  12. Analysis of the cytotoxicity of carbon-based nanoparticles, diamond and graphite, in human glioblastoma and hepatoma cell lines.

    PubMed

    Zakrzewska, Karolina Ewa; Samluk, Anna; Wierzbicki, Mateusz; Jaworski, Sławomir; Kutwin, Marta; Sawosz, Ewa; Chwalibog, André; Pijanowska, Dorota Genowefa; Pluta, Krzysztof Dariusz

    2015-01-01

    Nanoparticles have attracted a great deal of attention as carriers for drug delivery to cancer cells. However, reports on their potential cytotoxicity raise questions of their safety and this matter needs attentive consideration. In this paper, for the first time, the cytotoxic effects of two carbon based nanoparticles, diamond and graphite, on glioblastoma and hepatoma cells were compared. First, we confirmed previous results that diamond nanoparticles are practically nontoxic. Second, graphite nanoparticles exhibited a negative impact on glioblastoma, but not on hepatoma cells. The studied carbon nanoparticles could be a potentially useful tool for therapeutics delivery to the brain tissue with minimal side effects on the hepatocytes. Furthermore, we showed the influence of the nanoparticles on the stable, fluorescently labeled tumor cell lines and concluded that the labeled cells are suitable for drug cytotoxicity tests.

  13. Analysis of the cytotoxicity of carbon-based nanoparticles, diamond and graphite, in human glioblastoma and hepatoma cell lines.

    PubMed

    Zakrzewska, Karolina Ewa; Samluk, Anna; Wierzbicki, Mateusz; Jaworski, Sławomir; Kutwin, Marta; Sawosz, Ewa; Chwalibog, André; Pijanowska, Dorota Genowefa; Pluta, Krzysztof Dariusz

    2015-01-01

    Nanoparticles have attracted a great deal of attention as carriers for drug delivery to cancer cells. However, reports on their potential cytotoxicity raise questions of their safety and this matter needs attentive consideration. In this paper, for the first time, the cytotoxic effects of two carbon based nanoparticles, diamond and graphite, on glioblastoma and hepatoma cells were compared. First, we confirmed previous results that diamond nanoparticles are practically nontoxic. Second, graphite nanoparticles exhibited a negative impact on glioblastoma, but not on hepatoma cells. The studied carbon nanoparticles could be a potentially useful tool for therapeutics delivery to the brain tissue with minimal side effects on the hepatocytes. Furthermore, we showed the influence of the nanoparticles on the stable, fluorescently labeled tumor cell lines and concluded that the labeled cells are suitable for drug cytotoxicity tests. PMID:25816103

  14. Improvement of the separation of tumour cells from peripheral blood cells using magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Schwalbe, M.; Pachmann, K.; Höffken, K.; Clement, J. H.

    2006-09-01

    Circulating tumour cells are a key challenge in tumour therapy. Numerous approaches are on the way to achieving the elimination of these potential sources of metastasis formation. Antibody-directed magnetic cell sorting is supposed to enrich tumour cells with high selectivity, but low efficiency. The short term application of carboxymethyl dextran (CMD) coated magnetit/maghemit nanoparticles allows the discrimination of tumour cells from leukocytes. In the present work we show that the interaction of CMD nanoparticles is cell-type specific and time dependent. The breast cancer cell line MCF-7 and the CML cell line K-562 are characterized by a rapid and high interaction rate, whereas leukocytes exhibit a decelerated behaviour. The addition of carboxymethyl dextran or glucose stimulated the magnetic labelling of leukocytes. The variation of the degree of substitution of dextran with carboxymethyl groups did not affect the labelling profile of leukocytes and MCF-7 cells. In order to verify the in vitro results, whole blood samples from 13 cancer patients were analysed ex vivo. Incubation of the purified leukocyte fraction with CMD nanoparticles in the presence of low amounts of plasma reduced the overall cell content in the positive fraction. In contrast, the absolute number of residual tumour cells in the positive fraction was 90% of the initial amount.

  15. Novel self-micellizing anticancer lipid nanoparticles induce cell death of colorectal cancer cells.

    PubMed

    Sundaramoorthy, Pasupathi; Baskaran, Rengarajan; Mishra, Siddhartha Kumar; Jeong, Keun-Yeong; Oh, Seung Hyun; Kyu Yoo, Bong; Kim, Hwan Mook

    2015-11-01

    In the present study, we developed a novel drug-like self-micellizing anticancer lipid (SMAL), and investigated its anticancer activity and effects on cell death pathways in human colorectal cancer (CRC) cell lines. Three self-assembled nanoparticles were prepared, namely, SMAL102 (lauramide derivative), SMAL104 (palmitamide derivative), and SMAL108 (stearamide derivative) by a thin-film hydration technique, and were characterized for physicochemical and biological parameters. SMAL102 were nanosized (160.23 ± 8.11 nm) with uniform spherical shape, while SMAL104 and SMAL108 did not form spherical shape but formed large size nanoparticles and irregular in shape. Importantly, SMAL102 showed a cytotoxic effect towards CRC cell lines (HCT116 and HT-29), and less toxicity to a normal colon fibroblast cell line (CCD-18Co). Conversely, SMAL104 and SMAL108 did not have an anti-proliferative effect on CRC cell lines. SMAL102 nanoparticles were actively taken up by CRC cell lines, localized in the cell membrane, and exhibited remarkable cytotoxicity in a concentration-dependent manner. The normal colon cell line showed significantly less cellular uptake and non-cytotoxicity as compared with the CRC cell lines. SMAL102 nanoparticles induced caspase-3, caspase-9, and PARP cleavage in HT-29 cells, indicating the induction of apoptosis; whereas LC3B was activated in HCT116 cells, indicating autophagy-induced cell death. Collectively, these results demonstrate that SMAL102 induced cell death via activation of apoptosis and autophagy in CRC cell lines. The present study could be a pioneer for further preclinical and clinical development of such compounds. PMID:26342325

  16. DNA-assembled nanoparticle rings exhibit electric and magnetic resonances at visible frequencies.

    PubMed

    Roller, Eva-Maria; Khorashad, Larousse Khosravi; Fedoruk, Michael; Schreiber, Robert; Govorov, Alexander O; Liedl, Tim

    2015-02-11

    Metallic nanostructures can be used to manipulate light on the subwavelength scale to create tailored optical material properties. Next to electric responses, artificial optical magnetism is of particular interest but difficult to achieve at visible wavelengths. DNA-self-assembly has proved to serve as a viable method to template plasmonic materials with nanometer precision and to produce large quantities of metallic objects with high yields. We present here the fabrication of self-assembled ring-shaped plasmonic metamolecules that are composed of four to eight single metal nanoparticles with full stoichiometric and geometric control. Scattering spectra of single rings as well as absorption spectra of solutions containing the metamolecules are used to examine the unique plasmonic features, which are compared to computational simulations. We demonstrate that the electric and magnetic plasmon resonance modes strongly correlate with the exact shape of the structures. In particular, our computations reveal the magnetic plasmons only for particle rings of broken symmetries, which is consistent with our experimental data. We stress the feasibility of DNA self-assembly as a method to create bulk plasmonic materials and metamolecules that may be applied as building blocks in plasmonic devices.

  17. Silver polyvinyl pyrrolidone nanoparticles exhibit a capsular polysaccharide influenced bactericidal effect against Streptococcus pneumoniae

    PubMed Central

    Bibbs, Ronda K.; Harris, Rhonda D.; Peoples, Veolanda A.; Barnett, Cleon; Singh, Shree R.; Dennis, Vida A.; Coats, Mamie T.

    2014-01-01

    Streptococcus pneumoniae remains a leading cause of morbidity and mortality worldwide. The highly adaptive nature of S. pneumoniae exemplifies the need for next generation antimicrobials designed to avoid high level resistance. Metal based nanomaterials fit this criterion. Our study examined the antimicrobial activity of gold nanospheres, silver coated polyvinyl pyrrolidone (AgPVP), and titanium dioxide (TiO2) against various serotypes of S. pneumoniae. Twenty nanometer spherical AgPVP demonstrated the highest level of killing among the tested materials. AgPVP (0.6 mg/mL) was able to kill pneumococcal serotypes 2, 3, 4, and 19F within 4 h of exposure. Detailed analysis of cultures during exposure to AgPVP showed that both the metal ions and the solid nanoparticles participate in the killing of the pneumococcus. The bactericidal effect of AgPVP was lessened in the absence of the pneumococcal capsular polysaccharide. Capsule negative strains, JD908 and RX1, were only susceptible to AgPVP at concentrations at least 33% higher than their respective capsule expressing counterparts. These findings suggest that mechanisms of killing used by nanomaterials are not serotype dependent and that the capsular polysaccharide participates in the inhibition. In the near future these mechanisms will be examined as targets for novel antimicrobials. PMID:25520713

  18. DNA-Assembled Nanoparticle Rings Exhibit Electric and Magnetic Resonances at Visible Frequencies

    PubMed Central

    2015-01-01

    Metallic nanostructures can be used to manipulate light on the subwavelength scale to create tailored optical material properties. Next to electric responses, artificial optical magnetism is of particular interest but difficult to achieve at visible wavelengths. DNA-self-assembly has proved to serve as a viable method to template plasmonic materials with nanometer precision and to produce large quantities of metallic objects with high yields. We present here the fabrication of self-assembled ring-shaped plasmonic metamolecules that are composed of four to eight single metal nanoparticles with full stoichiometric and geometric control. Scattering spectra of single rings as well as absorption spectra of solutions containing the metamolecules are used to examine the unique plasmonic features, which are compared to computational simulations. We demonstrate that the electric and magnetic plasmon resonance modes strongly correlate with the exact shape of the structures. In particular, our computations reveal the magnetic plasmons only for particle rings of broken symmetries, which is consistent with our experimental data. We stress the feasibility of DNA self-assembly as a method to create bulk plasmonic materials and metamolecules that may be applied as building blocks in plasmonic devices. PMID:25611357

  19. Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells

    PubMed Central

    Strobel, Claudia; Förster, Martin

    2014-01-01

    Summary Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the metabolic impact of differently sized CeO2 (8 nm; 35 nm) and SiO2 nanoparticles (117 nm; 315 nm) on immortalized human microvascular (HMEC-1) and primary macrovascular endothelial cells (HUVEC), with particular focus on the CeO2 nanoparticles. The characterization of the CeO2 nanoparticles in cell culture media with varying serum content indicated a steric stabilization of nanoparticles due to interaction with proteins. After cellular uptake, the CeO2 nanoparticles were localized around the nucleus in a ring-shaped manner. The nanoparticles revealed concentration and time, but no size-dependent effects on the cellular adenosine triphosphate levels. HUVEC reacted more sensitively to CeO2 nanoparticle exposure than HMEC-1. This effect was also observed in relation to cytokine release after nanoparticle treatment. The CeO2 nanoparticles exhibited a specific impact on the release of diverse proteins. Namely, a slight trend towards pro-inflammatory effects, a slight pro-thrombotic impact, and an increase of reactive oxygen species after nanoparticle exposure were observed with increasing incubation time. For SiO2 nanoparticles, concentration- and time-dependent effects on the metabolic activity as well as pro-inflammatory reactions were detectable. In general, the effects of the investigated nanoparticles on endothelial cells were rather insignificant, since the alterations on the metabolic cell activity became visible at a nanoparticle concentration that is by far higher than those expected to occur in the in vivo situation (CeO2 nanoparticles: 100 µg/mL; SiO2

  20. Biocompatibility of cerium dioxide and silicon dioxide nanoparticles with endothelial cells.

    PubMed

    Strobel, Claudia; Förster, Martin; Hilger, Ingrid

    2014-01-01

    Cerium dioxide (CeO2) and silicon dioxide (SiO2) nanoparticles are of widespread use in modern life. This means that human beings are markedly exposed to them in their everyday life. Once passing biological barriers, these nanoparticles are expected to interact with endothelial cells, leading to systemic alterations with distinct influences on human health. In the present study we observed the metabolic impact of differently sized CeO2 (8 nm; 35 nm) and SiO2 nanoparticles (117 nm; 315 nm) on immortalized human microvascular (HMEC-1) and primary macrovascular endothelial cells (HUVEC), with particular focus on the CeO2 nanoparticles. The characterization of the CeO2 nanoparticles in cell culture media with varying serum content indicated a steric stabilization of nanoparticles due to interaction with proteins. After cellular uptake, the CeO2 nanoparticles were localized around the nucleus in a ring-shaped manner. The nanoparticles revealed concentration and time, but no size-dependent effects on the cellular adenosine triphosphate levels. HUVEC reacted more sensitively to CeO2 nanoparticle exposure than HMEC-1. This effect was also observed in relation to cytokine release after nanoparticle treatment. The CeO2 nanoparticles exhibited a specific impact on the release of diverse proteins. Namely, a slight trend towards pro-inflammatory effects, a slight pro-thrombotic impact, and an increase of reactive oxygen species after nanoparticle exposure were observed with increasing incubation time. For SiO2 nanoparticles, concentration- and time-dependent effects on the metabolic activity as well as pro-inflammatory reactions were detectable. In general, the effects of the investigated nanoparticles on endothelial cells were rather insignificant, since the alterations on the metabolic cell activity became visible at a nanoparticle concentration that is by far higher than those expected to occur in the in vivo situation (CeO2 nanoparticles: 100 µg/mL; SiO2 nanoparticles: 10

  1. Synergistic Targeting of Cell Membrane, Cytoplasm and Nucleus of Cancer Cells using Rod-Shaped Nanoparticles

    PubMed Central

    Barua, Sutapa; Mitragotri, Samir

    2014-01-01

    Design of carriers for effective delivery and targeting of drugs to cellular and sub-cellular compartments is an unmet need in medicine. Here, we report pure drug nanoparticles comprising camptothecin (CPT), trastuzumab (TTZ) and doxorubicin (DOX) to enable cell-specific interactions, subcellular accumulation and growth inhibition of breast cancer cells. CPT is formulated in the form of nanorods which are coated with TTZ. DOX is encapsulated in the TTZ corona around the CPT nanoparticle. Our results show that TTZ/DOX-coated CPT nanorods exhibit cell-specific internalization in BT-474 breast cancer cells, after which TTZ is recycled to the plasma membrane leaving CPT nanorods in the perinuclear region and delivering DOX into the nucleus of the cells. The effects of CPT-TTZ-DOX nanoparticles on growth inhibition are synergistic (combination index = 0.17±0.03) showing 10-10,000 fold lower inhibitory concentrations (IC50) compared to those of individual drugs. The design of antibody-targeted pure drug nanoparticles offers a promising design strategy to facilitate intracellular delivery and therapeutic efficiency of anticancer drugs. PMID:24053162

  2. Synergistic targeting of cell membrane, cytoplasm, and nucleus of cancer cells using rod-shaped nanoparticles.

    PubMed

    Barua, Sutapa; Mitragotri, Samir

    2013-11-26

    Design of carriers for effective delivery and targeting of drugs to cellular and subcellular compartments is an unmet need in medicine. Here, we report pure drug nanoparticles comprising camptothecin (CPT), trastuzumab (TTZ), and doxorubicin (DOX) to enable cell-specific interactions, subcellular accumulation, and growth inhibition of breast cancer cells. CPT is formulated in the form of nanorods which are coated with TTZ. DOX is encapsulated in the TTZ corona around the CPT nanoparticle. Our results show that TTZ/DOX-coated CPT nanorods exhibit cell-specific internalization in BT-474 breast cancer cells, after which TTZ is recycled to the plasma membrane, leaving CPT nanorods in the perinuclear region and delivering DOX into the nucleus of the cells. The effects of CPT-TTZ-DOX nanoparticles on growth inhibition are synergistic (combination index = 0.17 ± 0.03) showing 10-10 000-fold lower inhibitory concentrations (IC50) compared to those of individual drugs. The design of antibody-targeted pure drug nanoparticles offers a promising design strategy to facilitate intracellular delivery and therapeutic efficiency of anticancer drugs.

  3. Cell-Mediated Delivery of Nanoparticles: Taking Advantage of Circulatory Cells to Target Nanoparticles

    PubMed Central

    Anselmo, Aaron C.; Mitragotri, Samir

    2014-01-01

    Cellular hitchhiking leverages the use of circulatory cells to enhance the biological outcome of nanoparticle drug delivery systems, which often suffer from poor circulation time and limited targeting. Cellular hitchhiking utilizes the natural abilities of circulatory cells to: (i) navigate the vasculature while avoiding immune system clearance, (ii) remain relatively inert until needed and (iii) perform specific functions, including nutrient delivery to tissues, clearance of pathogens, and immune system surveillance. A variety of synthetic nanoparticles attempt to mimic these functional attributes of circulatory cells for drug delivery purposes. By combining the advantages of circulatory cells and synthetic nanoparticles, many advanced drug delivery systems have been developed that adopt the concept of cellular hitchhiking. Here, we review the development and specific applications of cellular hitchhiking-based drug delivery systems. PMID:24747161

  4. Inhibition of tumor-cell invasion with chlorotoxin-bound superparamagnetic nanoparticles.

    PubMed

    Veiseh, Omid; Gunn, Jonathan W; Kievit, Forrest M; Sun, Conroy; Fang, Chen; Lee, Jerry S H; Zhang, Miqin

    2009-02-01

    Nanoparticles have been investigated as drug delivery vehicles, contrast agents, and multifunctional devices for patient care. Current nanoparticle-based therapeutic strategies for cancer treatment are mainly based on delivery of chemotherapeutic agents to induce apoptosis or DNA/siRNA to regulate oncogene expression. Here, a nanoparticle system that demonstrates an alternative approach to the treatment of cancers through the inhibition of cell invasion, while serving as a magnetic resonance and optical imaging contrast agent, is presented. The nanoparticle comprises an iron oxide nanoparticle core conjugated with an amine-functionalized poly(ethylene glycol) silane and a small peptide, chlorotoxin (CTX), which enables the tumor cell-specific binding of the nanoparticle. It is shown that the nanoparticle exhibits substantially enhanced cellular uptake and an invasion inhibition rate of approximately 98% compared to unbound CTX ( approximately 45%). Significantly, the investigation from flow cytometry analysis, transmission electron microscopy, and fluorescent imaging reveals that the CTX-enabled nanoparticles deactivated the membrane-bound matrix metalloproteinase 2 (MMP-2) and induced increased internalization of lipid rafts that contain surface-expressed MMP-2 and volume-regulating ion channels through receptor-mediated endocytosis, leading to enhanced prohibitory effects. Since upregulation and activity of MMP-2 have been observed in tumors of neuroectodermal origin, and in cancers of the breast, colon, skin, lung, prostate, ovaries, and a host of others, this nanoparticle system can be potentially used for non-invasive diagnosis and treatment of a variety of cancer types.

  5. Cell membrane-camouflaged nanoparticles for drug delivery.

    PubMed

    Luk, Brian T; Zhang, Liangfang

    2015-12-28

    Nanoparticles can preferentially accumulate at sites of action and hold great promise to improve the therapeutic index of many drugs. While conventional methods of nanocarrier-mediated drug delivery have focused on primarily synthetic approaches, engineering strategies that combine synthetic nanoparticles with natural biomaterials have recently gained much attention. In particular, cell membrane-camouflaged nanoparticles are a new class of biomimetic nanoparticles that combine the unique functionalities of cellular membranes and engineering versatility of synthetic nanomaterials for effective delivery of therapeutic agents. Herein, we report on the recent progress on cell membrane-coated nanoparticles for drug delivery. In particular, we highlight three areas: (i) prolonging systemic circulation via cell membrane coating, (ii) cell-specific targeting via cell membrane coating, and (iii) applications of cell membrane coating for drug delivery. The cell membrane-camouflaged nanoparticle platform has emerged as a novel delivery strategy with the potential to improve the therapeutic efficacy for the treatment of a variety of diseases.

  6. Interaction of dermatologically relevant nanoparticles with skin cells and skin

    PubMed Central

    Rancan, Fiorenza; Ahlberg, Sebastian; Nazemi, Berouz; Choe, Chun Sik; Darvin, Maxim E; Hadam, Sabrina; Blume-Peytavi, Ulrike; Loza, Kateryna; Diendorf, Jörg; Epple, Matthias; Graf, Christina; Rühl, Eckart; Meinke, Martina C; Lademann, Jürgen

    2014-01-01

    Summary The investigation of nanoparticle interactions with tissues is complex. High levels of standardization, ideally testing of different material types in the same biological model, and combinations of sensitive imaging and detection methods are required. Here, we present our studies on nanoparticle interactions with skin, skin cells, and biological media. Silica, titanium dioxide and silver particles were chosen as representative examples for different types of skin exposure to nanomaterials, e.g., unintended environmental exposure (silica) versus intended exposure through application of sunscreen (titanium dioxide) or antiseptics (silver). Because each particle type exhibits specific physicochemical properties, we were able to apply different combinations of methods to examine skin penetration and cellular uptake, including optical microscopy, electron microscopy, X-ray microscopy on cells and tissue sections, flow cytometry of isolated skin cells as well as Raman microscopy on whole tissue blocks. In order to assess the biological relevance of such findings, cell viability and free radical production were monitored on cells and in whole tissue samples. The combination of technologies and the joint discussion of results enabled us to look at nanoparticle–skin interactions and the biological relevance of our findings from different angles. PMID:25551064

  7. Nanoparticle energy transfer on the cell surface.

    PubMed

    Bene, László; Szentesi, Gergely; Mátyus, László; Gáspár, Rezso; Damjanovich, Sándor

    2005-01-01

    Membrane topology of receptors plays an important role in shaping transmembrane signalling of cells. Among the methods used for characterizing receptor clusters, fluorescence resonance energy transfer between a donor and acceptor fluorophore plays a unique role based on its capability of detecting molecular level (2-10 nm) proximities of receptors in physiological conditions. Recent development of biotechnology has made possible the usage of colloidal gold particles in a large size range for specific labelling of cells for the purposes of electron microscopy. However, by combining metal and fluorophore labelling of cells, the versatility of metal-fluorophore interactions opens the way for new applications by detecting the presence of the metal particles by the methods of fluorescence spectroscopy. An outstanding feature of the metal nanoparticle-fluorophore interaction is that the metal particle can enhance spontaneous emission of the fluorophore in a distance-dependent fashion, in an interaction range essentially determined by the size of the nanoparticle. In our work enhanced fluorescence of rhodamine and cyanine dyes was observed in the vicinity of immunogold nanoparticles on the surface of JY cells in a flow cytometer. The dyes and the immunogold were targetted to the cell surface receptors MHCI, MHCII, transferrin receptor and CD45 by monoclonal antibodies. The fluorescence enhancement was sensitive to the wavelength of the exciting light, the size and amount of surface bound gold beads, as well as the fluorophore-nanoparticle distance. The intensity of 90 degrees scattering of the incident light beam was enhanced by the immunogold in a concentration and size-dependent fashion. The 90 degrees light scattering varied with the wavelength of the incident light in a manner characteristic to gold nanoparticles of the applied sizes. A reduction in photobleaching time constant of the cyanine dye was observed in the vicinity of gold particles in a digital imaging

  8. Synthesis of folate- pegylated polyester nanoparticles encapsulating ixabepilone for targeting folate receptor overexpressing breast cancer cells.

    PubMed

    Siafaka, P; Betsiou, M; Tsolou, A; Angelou, E; Agianian, B; Koffa, M; Chaitidou, S; Karavas, E; Avgoustakis, K; Bikiaris, D

    2015-12-01

    The aim of this study was the preparation of novel polyester nanoparticles based on folic acid (FA)-functionalized poly(ethylene glycol)-poly(propylene succinate) (PEG-PPSu) copolymer and loaded with the new anticancer drug ixabepilone (IXA). These nanoparticles may serve as a more selective (targeted) treatment of breast cancer tumors overexpressing the folate receptor. The synthesized materials were characterized by (1)H-NMR, FTIR, XRD and DSC. The nanoparticles were prepared by a double emulsification and solvent evaporation method and characterized with regard to their morphology by scanning electron microscopy, drug loading with HPLC-UV and size by dynamic light scattering. An average size of 195 nm and satisfactory drug loading efficiency (3.5%) were observed. XRD data indicated that IXA was incorporated into nanoparticles in amorphous form. The nanoparticles exhibited sustained drug release properties in vitro. Based on in vitro cytotoxicity studies, the blank FA-PEG-PPSu nanoparticles were found to be non-toxic to the cells. Fluorescent nanoparticles were prepared by conjugating Rhodanine B to PEG-PPSu, and live cell, fluorescence, confocal microscopy was applied in order to demonstrate the ability of FA-PEG-PPSu nanoparticles to enter into human breast cancer cells expressing the folate receptor.

  9. [Gd@C82(OH)22]n nanoparticles inhibit the migration and adhesion of glioblastoma cells

    PubMed Central

    WANG, JING; GU, FENG; DING, TING; LIU, XIAOLI; XING, GENGMEI; ZHAO, YULIANG; ZHANG, NING; MA, YONGJIE

    2010-01-01

    In our previous study, [Gd@C82(OH)22]n, a fullerene-based nanoparticle, exhibited potent anti-tumor effects in mouse tumor-bearing models without detectable toxicity. The mechanism involved in the anti-tumor effect exerted by [Gd@C82(OH)22]n remains to be elucidated. This study found that glioblastoma cells treated with [Gd@C82(OH)22]n nanoparticles showed a significant impairment in migration and adhesion by cell chemotaxis, scratch and adhesion assays in vitro. Furthermore, our data showed that the key proteins, CD40 and ICAM-1, were involved in the inhibition of adhesion in the [Gd@C82(OH)22]n nanoparticle-treated glioblastoma cells. Thus, our study suggests that the [Gd@C82(OH)22]n nanoparticle is a new potential anti-tumor effector and a therapeutic component for malignant glioblastoma infiltration. PMID:22966378

  10. The responses of immune cells to iron oxide nanoparticles.

    PubMed

    Xu, Yaolin; Sherwood, Jennifer A; Lackey, Kimberly H; Qin, Ying; Bao, Yuping

    2016-04-01

    Immune cells play an important role in recognizing and removing foreign objects, such as nanoparticles. Among various parameters, surface coatings of nanoparticles are the first contact with biological system, which critically affect nanoparticle interactions. Here, surface coating effects on nanoparticle cellular uptake, toxicity and ability to trigger immune response were evaluated on a human monocyte cell line using iron oxide nanoparticles. The cells were treated with nanoparticles of three types of coatings (negatively charged polyacrylic acid, positively charged polyethylenimine and neutral polyethylene glycol). The cells were treated at various nanoparticle concentrations (5, 10, 20, 30, 50 μg ml(-1) or 2, 4, 8, 12, 20 μg cm(-2)) with 6 h incubation or treated at a nanoparticle concentration of 50 μg ml(-1) (20 μg cm(-2)) at different incubation times (6, 12, 24, 48 or 72 h). Cell viability over 80% was observed for all nanoparticle treatment experiments, regardless of surface coatings, nanoparticle concentrations and incubation times. The much lower cell viability for cells treated with free ligands (e.g. ~10% for polyethylenimine) suggested that the surface coatings were tightly attached to the nanoparticle surfaces. The immune responses of cells to nanoparticles were evaluated by quantifying the expression of toll-like receptor 2 and tumor necrosis factor-α. The expression of tumor necrosis factor-α and toll-like receptor 2 were not significant in any case of the surface coatings, nanoparticle concentrations and incubation times. These results provide useful information to select nanoparticle surface coatings for biological and biomedical applications. PMID:26817529

  11. Plasmonic silver nanoparticles loaded titania nanotube arrays exhibiting enhanced photoelectrochemical and photocatalytic activities

    NASA Astrophysics Data System (ADS)

    Nishanthi, S. T.; Iyyapushpam, S.; Sundarakannan, B.; Subramanian, E.; Pathinettam Padiyan, D.

    2015-01-01

    A combination of electrochemical anodization and photochemical reduction is employed to fabricate highly ordered silver loaded titania nanotubes (Ag/TNT) arrays. The Ag/TNT samples show an extended optical absorbance from UV to visible region owing to the surface plasmon resonance effect of Ag. The photoluminescence intensity of Ag/TNT is significantly lower than that of pure titania revealing a decrease in charge carrier recombination. The photoelectrochemical properties of the prepared samples are studied using linear sweep and transient photocurrent measurements. Compared with pure TNT, the Ag loaded samples show a higher photoelectrochemical activity. The results demonstrate an efficient separation of photogenerated electron-hole pairs and the consequent increase in lifetime of charge carriers by Ag/TNT. The photocatalytic results of methyl orange dye degradation show that the Ag/TNT-3-05 sample exhibits the maximum degradation efficiency of 98.85% with kinetic rate constant of 0.0236(5) min-1 for 180 min light illumination.

  12. Gold Nanoparticles Enhanced Electroporation for Mammalian Cell Transfection

    PubMed Central

    Zu, Yingbo; Huang, Shuyan; Liao, Wei-Ching; Lu, Yang; Wang, Shengnian

    2015-01-01

    Electroporation figured prominently as an effective nonviral gene delivery approach for its balance on the transfection efficiency and cell viability, no restrictions of probe or cell type, and operation simplicity. The commercial electroporation systems have been widely adopted in the past two decades while still carry drawbacks associated with the high applied electric voltage, unsatisfied delivery efficiency, and/or low cell viability. By adding highly conductive gold nanoparticles (AuNPs) in electroporation solution, we demonstrated enhanced electroporation performance (i.e. better DNA delivery efficiency and higher cell viability) on mammalian cells from two different aspects: the free, naked AuNPs reduce the resistance of the electroporation solution so that the local pulse strength on cells was enhanced; targeting AuNPs (e.g., Tf-AuNPs) were brought to the cell membrane to work as virtual microelectrodes to porate cells with limited area from many different sites. The enhancement was confirmed with leukemia cells in both a commercial batch electroporation system and a home-made flow-through system using pWizGFP plasmid DNA probes. Such enhancement depends on the size, concentration, and the mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increased 2-3 folds at minimum sacrifice of cell viability. This new delivery concept, the combination of nanoparticles and electroporation technologies, may stimulate various in vitro and in vivo biomedical applications which rely on the efficient delivery of nucleic acids, anticancer drugs, or other therapeutic materials. PMID:24749393

  13. Gold nanoparticles enhanced electroporation for mammalian cell transfection.

    PubMed

    Zu, Yingbo; Huang, Shuyan; Liao, Wei-Ching; Lu, Yang; Wang, Shengnian

    2014-06-01

    Electroporation figured prominently as an effective nonviral gene delivery approach for its balance on the transfection efficiency and cell viability, no restrictions of probe or cell type, and operation simplicity. The commercial electroporation systems have been widely adopted in the past two decades while still carry drawbacks associated with the high applied electric voltage, unsatisfied delivery efficiency, and/or low cell viability. By adding highly conductive gold nanoparticles (AuNPs) in electroporation solution, we demonstrated enhanced electroporation performance (i.e., better DNA delivery efficiency and higher cell viability) on mammalian cells from two different aspects: the free, naked AuNPs reduce the resistance of the electroporation solution so that the local pulse strength on cells was enhanced; targeting AuNPs (e.g., Tf-AuNPs) were brought to the cell membrane to work as virtual microelectrodes to porate cells with limited area from many different sites. The enhancement was confirmed with leukemia cells in both a commercial batch electroporation system and a home-made flow-through system using pWizGFP plasmid DNA probes. Such enhancement depends on the size, concentration, and the mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increased 2-3 folds at minimum sacrifice of cell viability. This new delivery concept, the combination of nanoparticles and electroporation technologies, may stimulate various in vitro and in vivo biomedical applications which rely on the efficient delivery of nucleic acids, anticancer drugs, or other therapeutic materials.

  14. Fullerene nanoparticles exhibit greater retention in freshwater sediment than in model porous media.

    PubMed

    Zhang, Wei; Isaacson, Carl W; Rattanaudompol, U-sa; Powell, Tremaine B; Bouchard, Dermont

    2012-06-01

    Increasing production and use of fullerene-based nanomaterials underscore the need to determine their mobility in environmental transport pathways and potential ecological exposures. This study investigated the transport of two fullerenes (i.e., aqu/C(60) and water-soluble C(60) pyrrolidine tris-acid [C(60) PTA]) in columns packed with model porous media (Iota quartz and Ottawa sand) and a sediment from Call's creek under saturated and unsaturated steady-state flows. The fullerenes had the least retention in Iota quartz, and the greatest retention in the sediment at near neutral pH, correlating with the degree of grain surface chemical heterogeneity (e.g., amorphous Al hydroxides concentration increasing in the order of Iota quartzexhibited a strong dependency on solution pH that could be explained partly by the pH-dependent surface charge of fullerenes and grain surface, and partly by increased hydrophobicity of C(60) PTA when solution pH approaches its isoelectric point (IEP). Finally, fullerene retention was enhanced in unsaturated media, implying that fullerenes may be more attenuated in the vadose zone than in groundwater. PMID:22445188

  15. Circulating tumor cells exhibit stem cell characteristics in an orthotopic mouse model of colorectal cancer

    PubMed Central

    Niemietz, Thomas; Betzler, Alexander M.; Nanduri, Lahiri K.; Bork, Ulrich; Kahlert, Christoph; Thepkaysone, May-Linn; Swiersy, Anka; Büchler, Markus W.; Reissfelder, Christoph; Weitz, Jürgen; Rahbari, Nuh N.

    2016-01-01

    The prognosis of colorectal cancer (CRC) is closely linked to the occurrence of distant metastases, which putatively develop from circulating tumor cells (CTCs) shed into circulation by the tumor. As far more CTCs are shed than eventually metastases develop, only a small subfraction of CTCs harbor full tumorigenic potential. The aim of this study was to further characterize CRC-derived CTCs to eventually identify the clinically relevant subfraction of CTCs. We established an orthotopic mouse model of CRC which reliably develops metastases and CTCs. We were able to culture the resulting CTCs in vitro, and demonstrated their tumor-forming capacity when re-injected into mice. The CTCs were then subjected to qPCR expression profiling, revealing downregulation of epithelial and proliferation markers. Genes associated with cell-cell adhesion (claudin-7, CD166) were significantly downregulated, indicating a more metastatic phenotype of CTCs compared to bulk tumor cells derived from hepatic metastases. The stem cell markers DLG7 and BMI1 were significantly upregulated in CTC, indicating a stem cell-like phenotype and increased capacity of tumor formation and self-renewal. In concert with their in vitro and in vivo tumorigenicity, these findings indicate stem cell properties of mouse-derived CTCs. In conclusion, we developed an orthotopic mouse model of CRC recapitulating the process of CRC dissemination. CTCs derived from this model exhibit stem-cell like characteristics and are able to form colonies in vitro and tumors in vivo. Our results provide new insight into the biology of CRC-derived CTCs and may provide new therapeutic targets in the metastatic cascade of CRC. PMID:27029058

  16. Single-Chromophore-Based Photoswitchable Nanoparticles Enable Dual-Alternating-Color Fluorescence for Unambiguous Live Cell Imaging

    PubMed Central

    Tian, Zhiyuan; Wu, Wuwei; Wan, Wei; Li, Alexander D. Q.

    2009-01-01

    We have developed a class of spiropyran dyes and their fluorescence colors can be reversibly photoswitched from red color to green, blue, or nearly dark, thus alternating between two colors. Such individual dyes emit either one color or the other, but not both simultaneously. These photoswitchable dyes-enabled nanoparticles, however, emit either one pure color or a combination of both colors because the nanoparticle fluorescence originates from multiple dyes therein. As a result, the nanoparticle shines >30 times brighter than the state-of-the-art organic dyes such as fluorescein. Interestingly, these copolymer nanoparticles exhibit tunable non-specific interactions with live cells and nanoparticles containing properly balanced butyl acrylate and acrylamide monomers render essentially very little non-specific binding to live cells. Decorated with HMGA1 protein, these optically switchable dual-color nanoparticles undergo endocytosis and unambiguously identify themselves from fluorescence interference including autofluorescence, thus enabling a new tool for live cell imaging. PMID:19275146

  17. Nanoparticles and clinically applicable cell tracking

    PubMed Central

    Guenoun, Jamal; van Tiel, Sandra T; Krestin, Gabriel P

    2015-01-01

    In vivo cell tracking has emerged as a much sought after tool for design and monitoring of cell-based treatment strategies. Various techniques are available for pre-clinical animal studies, from which much has been learned and still can be learned. However, there is also a need for clinically translatable techniques. Central to in vivo cell imaging is labelling of cells with agents that can give rise to signals in vivo, that can be detected and measured non-invasively. The current imaging technology of choice for clinical translation is MRI in combination with labelling of cells with magnetic agents. The main challenge encountered during the cell labelling procedure is to efficiently incorporate the label into the cell, such that the labelled cells can be imaged at high sensitivity for prolonged periods of time, without the labelling process affecting the functionality of the cells. In this respect, nanoparticles offer attractive features since their structure and chemical properties can be modified to facilitate cellular incorporation and because they can carry a high payload of the relevant label into cells. While these technologies have already been applied in clinical trials and have increased the understanding of cell-based therapy mechanism, many challenges are still faced. PMID:26248872

  18. Dynamics of receptor-mediated nanoparticle internalization into endothelial cells.

    PubMed

    Gonzalez-Rodriguez, David; Barakat, Abdul I

    2015-01-01

    Nanoparticles offer a promising medical tool for targeted drug delivery, for example to treat inflamed endothelial cells during the development of atherosclerosis. To inform the design of such therapeutic strategies, we develop a computational model of nanoparticle internalization into endothelial cells, where internalization is driven by receptor-ligand binding and limited by the deformation of the cell membrane and cytoplasm. We specifically consider the case of nanoparticles targeted against ICAM-1 receptors, of relevance for treating atherosclerosis. The model computes the kinetics of the internalization process, the dynamics of binding, and the distribution of stresses exerted between the nanoparticle and the cell membrane. The model predicts the existence of an optimal nanoparticle size for fastest internalization, consistent with experimental observations, as well as the role of bond characteristics, local cell mechanical properties, and external forces in the nanoparticle internalization process.

  19. Detection of squamous carcinoma cells using gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Dai, Wei-Yun; Lee, Sze-tsen; Hsu, Yih-Chih

    2015-03-01

    The goal of this study is to use gold nanoparticle as a diagnostic agent to detect human squamous carcinoma cells. Gold nanoparticles were synthesized and the gold nanoparticle size was 34.3 ± 6.2 nm. Based on the over-expression of epidermal growth factor receptor (EGFR) biomarkers in squamous carcinoma cells, we hypothesized that EGFR could be a feasible biomarker with a target moiety for detection. We further modified polyclonal antibodies of EGFR on the surface of gold nanoparticles. We found selected squamous carcinoma cells can be selectively detected using EGFR antibody-modified gold nanoparticles via receptor-mediated endocytosis. Cell death was also examined to determine the survival status of squamous carcinoma cells with respect to gold nanoparticle treatment and EGFR polyclonal antibody modification.

  20. Bio-synthesis of gold nanoparticles by human epithelial cells, in vivo

    NASA Astrophysics Data System (ADS)

    Larios-Rodriguez, E.; Rangel-Ayon, C.; Castillo, S. J.; Zavala, G.; Herrera-Urbina, R.

    2011-09-01

    Healthy epithelial cells, in vivo, have the ability to synthesize gold nanoparticles when aqueous tetrachloroauric acid is made to react with human skin. Neither a reducing agent nor a protecting chemical is needed for this bio-synthesis method. The first indication of gold nanoparticle formation is the staining of the skin, which turns deep purple. Stereoscopic optical micrographs of human skin tissue in contact with aqueous tetrachloroauric acid clearly show the staining of the epithelial cells. The UV-Vis spectrum of these epithelial cells shows an absorption band with a maximum at 553 nm. This absorption peak is within the wavelength region where the surface plasmon resonance (SPR) band of aqueous colloidal gold exhibits a maximum. Transmission electron micrographs show that gold nanoparticles synthesized by epithelial cells have sizes between 1 and 100 nm. The electron diffraction pattern of these nanoparticles reveals a crystalline structure whose interplanar distances correspond to fcc metallic gold. Transmission electron micrographs of ultra-thin (70 nm thick) slices of epithelial cells clearly and undoubtedly demonstrate that gold nanoparticles are inside the cell. According to high resolution transmission electron micrographs of intracellular single gold nanoparticles, they have the shape of a polyhedron.

  1. Bio-synthesis of gold nanoparticles by human epithelial cells, in vivo.

    PubMed

    Larios-Rodriguez, E; Rangel-Ayon, C; Castillo, S J; Zavala, G; Herrera-Urbina, R

    2011-09-01

    Healthy epithelial cells, in vivo, have the ability to synthesize gold nanoparticles when aqueous tetrachloroauric acid is made to react with human skin. Neither a reducing agent nor a protecting chemical is needed for this bio-synthesis method. The first indication of gold nanoparticle formation is the staining of the skin, which turns deep purple. Stereoscopic optical micrographs of human skin tissue in contact with aqueous tetrachloroauric acid clearly show the staining of the epithelial cells. The UV-Vis spectrum of these epithelial cells shows an absorption band with a maximum at 553 nm. This absorption peak is within the wavelength region where the surface plasmon resonance (SPR) band of aqueous colloidal gold exhibits a maximum. Transmission electron micrographs show that gold nanoparticles synthesized by epithelial cells have sizes between 1 and 100 nm. The electron diffraction pattern of these nanoparticles reveals a crystalline structure whose interplanar distances correspond to fcc metallic gold. Transmission electron micrographs of ultra-thin (70 nm thick) slices of epithelial cells clearly and undoubtedly demonstrate that gold nanoparticles are inside the cell. According to high resolution transmission electron micrographs of intracellular single gold nanoparticles, they have the shape of a polyhedron. PMID:21817787

  2. pH-sensitive pullulan-based nanoparticle carrier for adriamycin to overcome drug-resistance of cancer cells.

    PubMed

    Guo, Hua; Liu, Yuanyuan; Wang, Yan; Wu, Jing; Yang, Xiaoying; Li, Rongshan; Wang, Yinsong; Zhang, Ning

    2014-10-13

    Urocanic acid was conjugated to pullulan to synthesize O-urocanyl pullulan (URPA) with degree of substitution (DS) of 8.2%. URPA nanoparticles prepared by dialysis method had spherical shapes and a mean diameter of 156.8 ± 16.8 nm. Adriamycin (ADR) was successfully loaded into URPA nanoparticles and exhibited pH-sensitive in vitro release property. MTT assay showed that ADR-loaded URPA (ADR/URPA) nanoparticles had a significant higher toxicity against drug resistant MCF-7/ADR cells than free ADR, and the reversal index reached up to 9.6. The results of flow cytometry and confocal microscopy showed that URPA nanoparticles efficiently enhanced accumulation and retention of ADR in MCF-7/ADR cells and successfully delivered ADR into cell nucleus. The reversal effect of ADR/URPA nanoparticles on the drug resistance of MCF-7/ADR cells was perhaps related with their cell entry and intracellular drug release mechanisms.

  3. Stem cell tracking using iron oxide nanoparticles.

    PubMed

    Bull, Elizabeth; Madani, Seyed Yazdan; Sheth, Roosey; Seifalian, Amelia; Green, Mark; Seifalian, Alexander M

    2014-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI) and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored.

  4. Drug-loaded nanoparticles induce gene expression in human pluripotent stem cell derivatives

    PubMed Central

    Gajbhiye, Virendra; Escalante, Leah; Chen, Guojun; Laperle, Alex; Zheng, Qifeng; Steyer, Benjamin; Gong, Shaoqin; Saha, Krishanu

    2014-01-01

    Tissue engineering and advanced manufacturing of human stem cells requires a suite of tools to control gene expression spatiotemporally in culture. Inducible gene expression systems offer cell-extrinsic control, typically through addition of small molecules, but small molecule inducers typically contain few functional groups for further chemical modification. Doxycycline (DXC), a potent small molecule inducer of tetracycline (Tet) transgene systems, was conjugated to a hyperbranched dendritic polymer (Boltorn H40) and subsequently reacted with polyethylene glycol (PEG). The resulting PEG-H40-DXC nanoparticle exhibited pH-sensitive drug release behavior and successfully controlled gene expression in stem-cell-derived fibroblasts with a Tet-On system. While free DXC inhibited fibroblast proliferation and matrix metalloproteinase (MMP) activity, PEG-H40-DXC nanoparticles maintained higher fibroblast proliferation levels and MMP activity. The results demonstrate that the PEG-H40-DXC nanoparticle system provides an effective tool to controlling gene expression in human stem cell derivatives. PMID:24232694

  5. Cell Surface-based Sensing with Metallic Nanoparticles

    PubMed Central

    Jiang, Ziwen; Rotello, Vincent M.

    2015-01-01

    Metallic nanoparticles provide versatile scaffolds for biosensing applications. In this review, we focus on the use of metallic nanoparticles for cell surface sensings. Examples of the use of both specific recognition and array-based “chemical nose” approaches to cell surface sensing will be discussed. PMID:25853985

  6. Designer nanoparticle: nanobiotechnology tool for cell biology

    NASA Astrophysics Data System (ADS)

    Thimiri Govinda Raj, Deepak B.; Khan, Niamat Ali

    2016-09-01

    This article discusses the use of nanotechnology for subcellular compartment isolation and its application towards subcellular omics. This technology review significantly contributes to our understanding on use of nanotechnology for subcellular systems biology. Here we elaborate nanobiotechnology approach of using superparamagnetic nanoparticles (SPMNPs) optimized with different surface coatings for subcellular organelle isolation. Using pulse-chase approach, we review that SPMNPs interacted differently with the cell depending on its surface functionalization. The article focuses on the use of functionalized-SPMNPs as a nanobiotechnology tool to isolate high quality (both purity and yield) plasma membranes and endosomes or lysosomes. Such nanobiotechnology tool can be applied in generating subcellular compartment inventories. As a future perspective, this strategy could be applied in areas such as immunology, cancer and stem cell research.

  7. Genetically Programmed Clusters of Gold Nanoparticles for Cancer Cell-Targeted Photothermal Therapy.

    PubMed

    Oh, Mi Hwa; Yu, Jeong Heon; Kim, Insu; Nam, Yoon Sung

    2015-10-14

    Interpretations of the interactions of nanocarriers with biological cells are often complicated by complex synthesis of materials, broad size distribution, and heterogeneous surface chemistry. Herein, the major capsid proteins of an icosahedral T7 phage (55 nm in diameter) are genetically engineered to display a gold-binding peptide and a prostate cancer cell-binding peptide in a tandem sequence. The genetically modified phage attracts gold nanoparticles (AuNPs) to form a cluster of gold nanoparticles (about 70 nanoparticles per phage). The cluster of AuNPs maintains cell-targeting functionality and exhibits excellent dispersion stability in serum. Under a very low light irradiation (60 mW cm(-2)), only targeted AuNP clusters kill the prostate cancer cells in minutes (not in other cell types), whereas neither nontargeted AuNP clusters nor citrate-stabilized AuNPs cause any significant cell death. The result suggests that the prostate cancer cell-targeted clusters of AuNPs are targeted to only prostate cancer cells and, when illuminated, generate local heating to more efficiently and selectively kill the targeted cancer cells. Our strategy can be generalized to target other types of cells and assemble other kinds of nanoparticles for a broad range of applications. PMID:26413999

  8. Rat alveolar type I cells proliferate, express OCT-4, and exhibit phenotypic plasticity in vitro.

    PubMed

    Gonzalez, Robert F; Allen, Lennell; Dobbs, Leland G

    2009-12-01

    Alveolar type I (TI) cells are large, squamous cells that cover 95-99% of the internal surface area of the lung. Although TI cells are believed to be terminally differentiated, incapable of either proliferation or phenotypic plasticity, TI cells in vitro both proliferate and express phenotypic markers of other differentiated cell types. Rat TI cells isolated in purities of >99% proliferate in culture, with a sixfold increase in cell number before the cells reach confluence; >50% of the cultured TI cells are Ki67+. At cell densities of 1-2 cells/well, approximately 50% of the cells had the capacity to form colonies. Under the same conditions, type II cells do not proliferate. Cultured TI cells express RTI40 and aquaporin 5, phenotypic markers of the TI cell phenotype. By immunofluorescence, Western blotting, and Q-PCR, TI cells express OCT-4A (POU5F1), a transcription factor associated with maintenance of the pluripotent state in stem cells. Based on the expression patterns of various marker proteins, TI cells are distinct from either of two recently described putative pulmonary multipotent cell populations, the bronchoalveolar stem cell or the OCT-4+ stem/progenitor cell. Although TI cells in adult rat lung tissue do not express either surfactant protein C (SP-C) or CC10, respective markers of the TII and Clara cell phenotypes, in culture TI cells can be induced to express both SP-C and CC10. Together, the findings that TI cells proliferate and exhibit phenotypic plasticity in vitro raise the possibility that TI cells may have similar properties in vivo. PMID:19717550

  9. Protein Corona Influences Cellular Uptake of Gold Nanoparticles by Phagocytic and Nonphagocytic Cells in a Size-Dependent Manner.

    PubMed

    Cheng, Xiaju; Tian, Xin; Wu, Anqing; Li, Jianxiang; Tian, Jian; Chong, Yu; Chai, Zhifang; Zhao, Yuliang; Chen, Chunying; Ge, Cuicui

    2015-09-23

    The interaction at nanobio is a critical issue in designing safe nanomaterials for biomedical applications. Recent studies have reported that it is nanoparticle-protein corona rather than bare nanoparticle that determines the nanoparticle-cell interactions, including endocytic pathway and biological responses. Here, we demonstrate the effects of protein corona on cellular uptake of different sized gold nanoparticles in different cell lines. The experimental results show that protein corona significantly decreases the internalization of Au NPs in a particle size- and cell type-dependent manner. Protein corona exhibits much more significant inhibition on the uptake of large-sized Au NPs by phagocytic cell than that of small-sized Au NPs by nonphagocytic cell. The endocytosis experiment indicates that different endocytic pathways might be responsible for the differential roles of protein corona in the interaction of different sized Au NPs with different cell lines. Our findings can provide useful information for rational design of nanomaterials in biomedical application.

  10. Manipulating directional cell motility using intracellular superparamagnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Bradshaw, Michael; Clemons, Tristan D.; Ho, Diwei; Gutiérrez, Lucía; Lázaro, Francisco J.; House, Michael J.; St. Pierre, Timothy G.; Fear, Mark W.; Wood, Fiona M.; Iyer, K. Swaminathan

    2015-03-01

    This study investigated the ability for magnetic nanoparticles to influence cellular migration in the presence of an external magnetic field. We found that the direction of migrating keratinocytes can be controlled and the migration speed of fibroblasts can be increased with the internalisation of these nanoparticles in the presence of a magnetic field. The possibility of shepherding cells towards a region of interest through the use of internalized nanoparticles is an attractive prospect for cell tracking, cell therapies, and tissue engineering applications.This study investigated the ability for magnetic nanoparticles to influence cellular migration in the presence of an external magnetic field. We found that the direction of migrating keratinocytes can be controlled and the migration speed of fibroblasts can be increased with the internalisation of these nanoparticles in the presence of a magnetic field. The possibility of shepherding cells towards a region of interest through the use of internalized nanoparticles is an attractive prospect for cell tracking, cell therapies, and tissue engineering applications. Electronic supplementary information (ESI) available: Nanoparticle characterisation, supporting experimental data, video time course study of cellular uptake of the nanoparticles and complete experimental details are all provided in the ESI. See DOI: 10.1039/c4nr06594h

  11. Bisphosphonamidate Clodronate Prodrug Exhibits Selective Cytotoxic Activity Against Melanoma Cell Lines

    PubMed Central

    Webster, Marie R.; Kamat, Chandrashekhar; Connis, Nick; Zhao, Ming; Weeraratna, Ashani T.; Rudek, Michelle A.; Hann, Christine L.; Freel Meyers, Caren L.

    2014-01-01

    Bisphosphonates are used clinically to treat disorders of calcium metabolism and malignant bone disease and are known to inhibit cancer cell growth, adhesion, and invasion. However, clinical use of these agents for the treatment of extraskeletal disease is limited due to low cell permeability. We recently described a bisphosphonamidate prodrug strategy for efficient intracellular release of bisphosphonates, including clodronate (CLO), in NSCLC cells. To evaluate anticancer activity of this prodrug class across many cancer cell types, the bisphosphonamidate clodronate prodrug (CLO prodrug) was screened against the NCI-60 cell line panel, and was found to exhibit selectivity toward melanoma cell lines. Here, we confirm efficient cellular uptake and intracellular activation of this prodrug class in melanoma cells. We further demonstrate inhibition of melanoma cell proliferation, induction of apoptosis, and an anti-tumor effect of CLO prodrug in a xenograft model. These data suggest a novel therapeutic application for the CLO prodrug and potential to selectively target melanoma cells. PMID:24310621

  12. Cytokine-induced memory-like natural killer cells exhibit enhanced responses against myeloid leukemia.

    PubMed

    Romee, Rizwan; Rosario, Maximillian; Berrien-Elliott, Melissa M; Wagner, Julia A; Jewell, Brea A; Schappe, Timothy; Leong, Jeffrey W; Abdel-Latif, Sara; Schneider, Stephanie E; Willey, Sarah; Neal, Carly C; Yu, Liyang; Oh, Stephen T; Lee, Yi-Shan; Mulder, Arend; Claas, Frans; Cooper, Megan A; Fehniger, Todd A

    2016-09-21

    Natural killer (NK) cells are an emerging cellular immunotherapy for patients with acute myeloid leukemia (AML); however, the best approach to maximize NK cell antileukemia potential is unclear. Cytokine-induced memory-like NK cells differentiate after a brief preactivation with interleukin-12 (IL-12), IL-15, and IL-18 and exhibit enhanced responses to cytokine or activating receptor restimulation for weeks to months after preactivation. We hypothesized that memory-like NK cells exhibit enhanced antileukemia functionality. We demonstrated that human memory-like NK cells have enhanced interferon-γ production and cytotoxicity against leukemia cell lines or primary human AML blasts in vitro. Using mass cytometry, we found that memory-like NK cell functional responses were triggered against primary AML blasts, regardless of killer cell immunoglobulin-like receptor (KIR) to KIR-ligand interactions. In addition, multidimensional analyses identified distinct phenotypes of control and memory-like NK cells from the same individuals. Human memory-like NK cells xenografted into mice substantially reduced AML burden in vivo and improved overall survival. In the context of a first-in-human phase 1 clinical trial, adoptively transferred memory-like NK cells proliferated and expanded in AML patients and demonstrated robust responses against leukemia targets. Clinical responses were observed in five of nine evaluable patients, including four complete remissions. Thus, harnessing cytokine-induced memory-like NK cell responses represents a promising translational immunotherapy approach for patients with AML.

  13. Cytokine-induced memory-like natural killer cells exhibit enhanced responses against myeloid leukemia.

    PubMed

    Romee, Rizwan; Rosario, Maximillian; Berrien-Elliott, Melissa M; Wagner, Julia A; Jewell, Brea A; Schappe, Timothy; Leong, Jeffrey W; Abdel-Latif, Sara; Schneider, Stephanie E; Willey, Sarah; Neal, Carly C; Yu, Liyang; Oh, Stephen T; Lee, Yi-Shan; Mulder, Arend; Claas, Frans; Cooper, Megan A; Fehniger, Todd A

    2016-09-21

    Natural killer (NK) cells are an emerging cellular immunotherapy for patients with acute myeloid leukemia (AML); however, the best approach to maximize NK cell antileukemia potential is unclear. Cytokine-induced memory-like NK cells differentiate after a brief preactivation with interleukin-12 (IL-12), IL-15, and IL-18 and exhibit enhanced responses to cytokine or activating receptor restimulation for weeks to months after preactivation. We hypothesized that memory-like NK cells exhibit enhanced antileukemia functionality. We demonstrated that human memory-like NK cells have enhanced interferon-γ production and cytotoxicity against leukemia cell lines or primary human AML blasts in vitro. Using mass cytometry, we found that memory-like NK cell functional responses were triggered against primary AML blasts, regardless of killer cell immunoglobulin-like receptor (KIR) to KIR-ligand interactions. In addition, multidimensional analyses identified distinct phenotypes of control and memory-like NK cells from the same individuals. Human memory-like NK cells xenografted into mice substantially reduced AML burden in vivo and improved overall survival. In the context of a first-in-human phase 1 clinical trial, adoptively transferred memory-like NK cells proliferated and expanded in AML patients and demonstrated robust responses against leukemia targets. Clinical responses were observed in five of nine evaluable patients, including four complete remissions. Thus, harnessing cytokine-induced memory-like NK cell responses represents a promising translational immunotherapy approach for patients with AML. PMID:27655849

  14. A Biphasic Ligand Exchange Reaction on Cdse Nanoparticles: Introducing Undergraduates to Functionalizing Nanoparticles for Solar Cells

    ERIC Educational Resources Information Center

    Zemke, Jennifer M.; Franz, Justin

    2016-01-01

    Semiconductor nanoparticles, including cadmium selenide (CdSe) particles, are attractive as light harvesting materials for solar cells. In the undergraduate laboratory, the size-tunable optical and electronic properties can be easily investigated; however, these nanoparticles (NPs) offer another platform for application-based tunability--the NP…

  15. Curcumin associated magnetite nanoparticles inhibit in vitro melanoma cell growth.

    PubMed

    de Souza, Fernanda França; dos Santos, Michelly Christine; dos Passos, Debora Cristina Silva; Lima, Emilia Celma de Oliveira; Guillo, Lidia Andreu

    2011-09-01

    Curcumin is a natural product possessing therapeutic properties but the low water solubility of this compound limits its use. We have successfully incorporated curcumin into a bilayer of dodecanoic acid attached to magnetite nanoparticles in an effort to maximize solubility and delivery efficiency. Curcumin/magnetite nanoparticles were characterized using diffused reflectance infra-red fourier transform spectroscopy (DRIFTS) and X-ray powder diffraction (XRD). Moreover curcumin associated magnetite nanoparticles inhibited in vitro melanoma cell growth. An inhibitory concentration (IC50) of 66.0 +/- 3.0 microM (48 +/- 2.2 microg-iron/mL) was observed for the curcumin/magnetite nanoparticles. Fluorescent microscopy revealed that curcumin associated magnetite nanoparticles were internalized by the melanoma cells and remained in the cytoplasm. The curcumin/magnetic nanoparticles synthesized in this study possess magnetic and water solubility properties making this a novel curcumin formulation with therapeutic potential.

  16. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    PubMed Central

    2011-01-01

    Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis. PMID:27502666

  17. Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

    NASA Astrophysics Data System (ADS)

    Yuan, Hengguang; Hu, Shanglian; Huang, Peng; Song, Hua; Wang, Kan; Ruan, Jing; He, Rong; Cui, Daxiang

    2011-12-01

    Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

  18. Cancer cells recovering from damage exhibit mitochondrial restructuring and increased aerobic glycolysis

    SciTech Connect

    Akakura, Shin; Ostrakhovitch, Elena; Sanokawa-Akakura, Reiko; Tabibzadeh, Siamak

    2014-06-13

    Highlights: • Some cancer cells recover from severe damage that causes cell death in majority of cells. • Damage-Recovered (DR) cancer cells show reduced mitochondria, mDNA and mitochondrial enzymes. • DR cells show increased aerobic glycolysis, ATP, cell proliferation, and resistance to damage. • DR cells recovered from in vivo damage also show increased glycolysis and proliferation rate. - Abstract: Instead of relying on mitochondrial oxidative phosphorylation, most cancer cells rely heavily on aerobic glycolysis, a phenomenon termed as “the Warburg effect”. We considered that this effect is a direct consequence of damage which persists in cancer cells that recover from damage. To this end, we studied glycolysis and rate of cell proliferation in cancer cells that recovered from severe damage. We show that in vitro Damage-Recovered (DR) cells exhibit mitochondrial structural remodeling, display Warburg effect, and show increased in vitro and in vivo proliferation and tolerance to damage. To test whether cancer cells derived from tumor microenvironment can show similar properties, we isolated Damage-Recovered (T{sup DR}) cells from tumors. We demonstrate that T{sup DR} cells also show increased aerobic glycolysis and a high proliferation rate. These findings show that Warburg effect and its consequences are induced in cancer cells that survive severe damage.

  19. Au-ZnO hybrid nanoparticles exhibiting strong charge-transfer-induced SERS for recyclable SERS-active substrates.

    PubMed

    Liu, Liping; Yang, Haitao; Ren, Xiao; Tang, Jin; Li, Yongfeng; Zhang, Xiangqun; Cheng, Zhaohua

    2015-03-12

    Flower-shaped Au-ZnO hybrid nanoparticles have been prepared via seeding growth and subsequent wet-chemical etching of Au-ZnO core-shell nanoparticles. The etched Au-ZnO hybrid nanoparticles have shown a stronger surface-enhanced Raman scattering (SERS) signal of the nontotally symmetric (b2) vibrational modes of PATP molecules than Au nanoparticles alone, which is attributed to the chemical enhancement effect of the ZnO layer which is greatly excited by the localized surface plasmon resonance (LSPR) of Au cores. Further, the mechanism of the LSPR-enhanced charge transfer (CT) effect has been proved by the SERS spectra of PATP molecules excited using different laser sources from 325 to 785 nm. Moreover, the photocatalytic experimental results indicated that Au-ZnO hybrid nanoparticles are promising as biologically compatible and recyclable SERS-active platforms for different molecular species.

  20. Biogenic magnetic nanoparticles from Burkholderia sp. YN01 exhibiting intrinsic peroxidase-like activity and their applications.

    PubMed

    Pan, Yu; Li, Na; Mu, Jianshuai; Zhou, Runhong; Xu, Yan; Cui, Daizong; Wang, Yan; Zhao, Min

    2015-01-01

    A novel bacterial strain containing biogenic magnetic nanoparticles (BMNPs) was isolated from the sediments of Songhua River in Harbin, China, and was identified as Burkholderia sp. YN01. Extracted BMNPs from YN01 were characterized as pure face-centered cubic Fe3O4 with an average size of 80 nm through transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The hysteresis parameters of the BMNP samples such as Bc and Bcr and ratios Mrs/Ms were deduced as 35.6 mT, 43.2 mT, and 0.47, respectively, indicating that the BMNPs exhibit a ferromagnetic behavior. This is the first report concerning on biogenic Fe3O4 NPs produced in Burkholderia genus. Significantly, the BMNPs were proved to possess intrinsic peroxidase-like activity that could catalyze the oxidation of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. Kinetic analysis indicates that the catalytic behavior is in accord with typical Michaelis-Menten kinetics and follows ping-pong mechanism. The catalytic constants (K cat) were 6.5 × 10(4) s(-1) and 0.78 × 10(4) s(-1) with H2O2 and TMB as substrate, respectively, which was higher than that of horseradish peroxidase (HRP). Electron spin resonance (ESR) spectroscopy experiments showed that the BMNPs could catalyze H2O2 to produce hydroxyl radicals. The origin of peroxidase-like activity is also associated with their ability to transfer electron between electrode and H2O2 according to an electrochemical study. As a novel peroxidase mimetic, the BMNPs were employed to offer a simple, sensitive, and selective colorimetric method for H2O2 and glucose determination, and the BMNPs could efficiently catalyze the degradation of phenol and Congo red dye. PMID:25030455

  1. Hsp70 as an indicator of stress in the cells after contact with nanoparticles

    NASA Astrophysics Data System (ADS)

    Hardilová, Šárka; Havrdová, Markéta; Panáček, Aleš; Kvítek, Libor; Zbořil, Radek

    2015-05-01

    conditions. The study was done on two types of mouse fibroblasts NIH-3T3 and L929. While NIH-3T3 cells exhibit stress response proportional to the concentration of silver nanoparticles, for L929 cells this was not observed.

  2. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    PubMed

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. PMID:27207037

  3. Ligand engineering of nanoparticle solar cells

    NASA Astrophysics Data System (ADS)

    Voros, Marton

    Semiconductor nanoparticles (NP) are promising materials to build cheap and efficient solar cells. One of the key challenges in their utilization for solar energy conversion is the control of NP surfaces and ligand-NP interfaces. Recent experiments have shown that by carefully choosing the ligands terminating the NPs, one can tailor electronic and optical absorption properties of NP assemblies, along with their transport properties. By using density functional theory based methods, we investigated how the opto-electronic properties of lead chalcogenide NPs may be tuned by using diverse organic and inorganic ligands. We interpreted experiments, and we showed that an essential prerequisite to avoid detrimental trap states is to ensure charge balance at the ligand-NP interface, possibly with the help of hydrogen treatment Work supported by the Center for Advanced Solar Photophysics, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences.

  4. Juglans mandshurica Maxim extracts exhibit antitumor activity on HeLa cells in vitro.

    PubMed

    Xin, Nian; Hasan, Murtaza; Li, Wei; Li, Yan

    2014-04-01

    The present study examined the potential application of Juglans mandshurica Maxim extracts (HT) for cancer therapy by assessing their anti‑proliferative activity, reduction of telomerase activity, induction of apoptosis and cell cycle arrest in S phase in HeLa cells. From the perspective of using HT as a herbal medicine, photomicroscopy and florescent microscopy techniques were utilized to characterize the effect of the extracts on telomerase activity and cell morphology. Flow cytometry was employed to study apoptosis and cell cycle of HeLa cells, and DNA laddering was performed. The results showed that HT inhibited cell proliferation and telomerase activity, induced apoptosis and caused S phase arrest of HeLa cells in vitro. HT inhibited HeLa cell proliferation significantly, and the highest inhibition rate was 83.7%. A trap‑silver staining assay showed that HT was capable of markedly decreasing telomerase activity of HeLa cells and this inhibition was enhanced in a time‑ and dose‑dependent manner. Results of a Hoechst 33258 staining assay showed that HeLa cells treated by HT induced cell death. Through DNA agarose gel electrophoresis, DNA ladders of HeLa cells treated with HT were observed, indicating apoptosis. In conclusion, the present study demonstrated that HT exhibited anti‑tumor effects comprising the inhibition of growth and telomerase activity as well as apoptosis and cell cycle arrest in HeLa cells.

  5. Imaging of Biological Cells Using Luminescent Silver Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kravets, Vira; Almemar, Zamavang; Jiang, Ke; Culhane, Kyle; Machado, Rosa; Hagen, Guy; Kotko, Andriy; Dmytruk, Igor; Spendier, Kathrin; Pinchuk, Anatoliy

    2016-01-01

    The application of luminescent silver nanoparticles as imaging agents for neural stem and rat basophilic leukemia cells was demonstrated. The experimental size dependence of the extinction and emission spectra for silver nanoparticles were also studied. The nanoparticles were functionalized with fluorescent glycine dimers. Spectral position of the resonance extinction and photoluminescence emission for particles with average diameters ranging from 9 to 32 nm were examined. As the particle size increased, the spectral peaks for both extinction and the intrinsic emission of silver nanoparticles shifted to the red end of the spectrum. The intrinsic photoluminescence of the particles was orders of magnitude weaker and was spectrally separated from the photoluminescence of the glycine dimer ligands. The spectral position of the ligand emission was independent of the particle size; however, the quantum yield of the nanoparticle-ligand system was size-dependent. This was attributed to the enhancement of the ligand's emission caused by the local electric field strength's dependence on the particle size. The maximum quantum yield determined for the nanoparticle-ligand complex was (5.2 ± 0.1) %. The nanoparticles were able to penetrate cell membranes of rat basophilic leukemia and neural stem cells fixed with paraformaldehyde. Additionally, toxicity studies were performed. It was found that towards rat basophilic leukemia cells, luminescent silver nanoparticles had a toxic effect in the silver atom concentration range of 10-100 μM.

  6. Cell-specific cytotoxicity of dextran-stabilized magnetite nanoparticles.

    PubMed

    Ding, Jing; Tao, Ke; Li, Jiyu; Song, Sheng; Sun, Kang

    2010-08-01

    Cytotoxicity of dextran-hybridized magnetite nanoparticles which were prepared by a novel polyol method was evaluated by incubation with four different kinds of cells, including rat liver cells BRL 3A, renal cells NRK, astrocyte and periphery blood mononuclear cells (PBMC). The study was designed not only to evaluate their cytotoxicity but also to reflect the interaction between nanoparticles and related cells in their circulation processes. By fluorescent-activated cell sorting technique, it was found that the cytotoxicity of the nanoparticles is cell-specific. Under the concentrations in our study (0-128 mg/mL), the nanoparticles lead to the apoptosis of PBMC in a concentration-dependant manner, but have almost no influence on the other kinds of cells. TEM images demonstrate that the nanoparticles were endocytosed by BRL 3A, NRK and astrocyte, and result in the apoptosis of PBMC without the observation of the uptaking process. The results suggest that the related cells in nanoparticles cycling process should also be concerned for the cytotoxicity evaluation.

  7. Uptake and cytotoxicity of chitosan nanoparticles in human liver cells

    SciTech Connect

    Loh, Jing Wen; Yeoh, George; Saunders, Martin; Lim, Lee-Yong

    2010-12-01

    Despite extensive research into the biomedical and pharmaceutical applications of nanoparticles, and the liver being the main detoxifying organ in the human body, there are limited studies which delineate the hepatotoxicity of nanoparticles. This paper reports on the biological interactions between liver cells and chitosan nanoparticles, which have been widely recognised as biocompatible. Using the MTT assay, human liver cells were shown to tolerate up to 4 h of exposure to 0.5% w/v of chitosan nanoparticles (18 {+-} 1 nm, 7.5 {+-} 1.0 mV in culture medium). At nanoparticle concentrations above 0.5% w/v, cell membrane integrity was compromised as evidenced by leakage of alanine transaminase into the extracellular milieu, and there was a dose-dependent increase in CYP3A4 enzyme activity. Uptake of chitosan nanoparticles into the cell nucleus was observed by confocal microscopic analysis after 4 h exposure with 1% w/v of chitosan nanoparticles. Electron micrographs further suggest necrotic or autophagic cell death, possibly caused by cell membrane damage and resultant enzyme leakage.

  8. Gold nanoparticle-enhanced electroporation for leukemia cell transfection.

    PubMed

    Huang, Shuyan; Zu, Yingbo; Wang, Shengnian

    2014-01-01

    Electroporation serves as an attractive nonviral gene delivery approach for its effectiveness, operational simplicity, and no restrictions of probe or cell type. The commercial electroporation systems have been widely adopted in research and clinics with protocols usually compromising appropriate transfection efficiency and cell viability. By introducing gold nanoparticles (AuNPs), we demonstrated greatly enhanced performance of electroporation from two aspects: the highly conductive, naked AuNPs help reduce the potential drop consumed by the electroporation solution so that the majority of the applied voltage of an electric pulse is truly imposed on cells with enhanced field strength; AuNPs with targeting ligands (e.g., transferrin-AuNPs or Tf-AuNPs) are bound to the cell membrane, working as virtual microelectrodes to create pores on cells with limited opening area while from many different sites. The addition of AuNPs during electroporation therefore benefits not only quicker recovery and better survival of cells but also more efficient uptake of the subjected probes. Such enhancement was successfully confirmed on a chronic myeloid leukemia cell line (i.e., K562 cells) in both a commercial batch electroporation system and a homemade flow system with pWizGFP plasmid DNA probes. The efficiency was found to be dependent on the size, concentration, and mixing ratio of free AuNPs/Tf-AuNPs. An equivalent mixture of free AuNPs and Tf-AuNPs exhibited the best enhancement with the transfection efficiency increase of two to threefold at a minimum sacrifice of the cell viability.

  9. Magnetic nanoparticles to recover cellular organelles and study the time resolved nanoparticle-cell interactome throughout uptake.

    PubMed

    Bertoli, Filippo; Davies, Gemma-Louise; Monopoli, Marco P; Moloney, Micheal; Gun'ko, Yurii K; Salvati, Anna; Dawson, Kenneth A

    2014-08-27

    Nanoparticles in contact with cells and living organisms generate quite novel interactions at the interface between the nanoparticle surface and the surrounding biological environment. However, a detailed time resolved molecular level description of the evolving interactions as nanoparticles are internalized and trafficked within the cellular environment is still missing and will certainly be required for the emerging arena of nanoparticle-cell interactions to mature. In this paper promising methodologies to map out the time resolved nanoparticle-cell interactome for nanoparticle uptake are discussed. Thus silica coated magnetite nanoparticles are presented to cells and their magnetic properties used to isolate, in a time resolved manner, the organelles containing the nanoparticles. Characterization of the recovered fractions shows that different cell compartments are isolated at different times, in agreement with imaging results on nanoparticle intracellular location. Subsequently the internalized nanoparticles can be further isolated from the recovered organelles, allowing the study of the most tightly nanoparticle-bound biomolecules, analogous to the 'hard corona' that so far has mostly been characterized in extracellular environments. Preliminary data on the recovered nanoparticles suggest that significant portion of the original corona (derived from the serum in which particles are presented to the cells) is preserved as nanoparticles are trafficked through the cells.

  10. Synthesis of CZTS Nanoparticles for Low-Cost Solar Cells.

    PubMed

    Kim, Donguk; Kim, Minha; Shim, Joongpyo; Kim, Doyoung; Choi, Wonseok; Park, Yong Seob; Choi, Youngkwan; Lee, Jaehyeong

    2016-05-01

    In this work, uniformly sized Cu2ZnSnS4 (CZTS) nanoparticles with easy control of chemical composition were synthesized and printable ink containing CZTS nanoparticles was prepared for low-cost-solar cell applications. In addition, we studied the effects of synthesis conditions, such as reaction temperature and time, on properties of the CZTS nanoparticles. For CZTS nanoparticles synthesis process, the reactants were mixed as the 2:1:1:4 molar ratios. The reaction temperature and time was varied from 220 degrees C to 320 degrees C and from 3 hours to 5 hours, respectively. The crystal structure and morphology of CZTS nanoparticles prepared under the various conditions were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDS) was used for compositional analysis of the CZTS nanoparticles. PMID:27483876

  11. Endocytosis and exocytosis of nanoparticles in mammalian cells

    PubMed Central

    Oh, Nuri; Park, Ji-Ho

    2014-01-01

    Engineered nanoparticles that can be injected into the human body hold tremendous potential to detect and treat complex diseases. Understanding of the endocytosis and exocytosis mechanisms of nanoparticles is essential for safe and efficient therapeutic application. In particular, exocytosis is of significance in the removal of nanoparticles with drugs and contrast agents from the body, while endocytosis is of great importance for the targeting of nanoparticles in disease sites. Here, we review the recent research on the endocytosis and exocytosis of functionalized nanoparticles based on various sizes, shapes, and surface chemistries. We believe that this review contributes to the design of safe nanoparticles that can efficiently enter and leave human cells and tissues. PMID:24872703

  12. Porous Silicon Nanoparticle Photosensitizers for Singlet Oxygen and Their Phototoxicity Against Cancer Cells

    PubMed Central

    Xiao, Ling; Gu, Luo; Howell, Stephen B.; Sailor, Michael J.

    2011-01-01

    Porous Si nanoparticles, prepared from electrochemically etched single crystal Si wafers, function as photosensitizers to generate 1O2 in ethanol and in aqueous media. The preparation conditions for the porous Si nanoparticles were optimized to maximize (1) the yield of material; (2) its quantum yield of 1O2 production; and (3) its in vitro degradation properties. The optimal formulation was determined to consist of nanoparticles 146 ± 7 nm in diameter, with nominal pore sizes of 12 ± 4 nm. The quantum yield for 1O2 production is 0.10 ± 0.02 in ethanol and 0.17 ± 0.01 in H2O. HeLa or NIH-3T3 cells treated with 100 µg/mL porous Si nanoparticles and exposed to 60 J/cm2 white light (infrared filtered, 100 mW/cm2 for 10 min) exhibit ~ 45% cell death, while controls containing no nanoparticles show 10% or 25% cell death, respectively. The dark control experiment yields < 10% cytotoxicity for either cell type. PMID:21452822

  13. Toxicity Study of Silver Nanoparticles Synthesized from Suaeda monoica on Hep-2 Cell Line.

    PubMed

    Satyavani, Kaliyamurthi; Gurudeeban, Selvaraj; Ramanathan, Thiruganasambandam; Balasubramanian, Thangavel

    2012-01-01

    Recently there has been fabulous excitement in the nano-biotechnological area for the study of nanoparticles synthesis using some natural biological system, which has led the growth advanced nanomaterials. This intention made us to assess the biologically synthesized silver nanoparticles from the leaf of Suaeda monoica (S.monoica) using 1 mM silver nitrate. The leaf extract of S.monoica incubated with 1 mM silver nitrate solution and characterized by UV- spectrometer and AFM. The effect of synthesized silver nanoparticles on Human Epidermoid Larynx Carcinoma cell line was evaluated by the MTT colorimetric technique. As a result we observed gradual change in the colour of extract from greenish to brown. The synthesized silver nanoparticles confirmed by UV at 430 nm and spherical shape identified in the range of 31 nm under AFM. The effect of silver nanoparticles on Human Epidermoid Larynx Carcinoma cell line exhibits a dose-dependent toxicity for the cell tested and the viability of Hep-2 cells decreased to 50 % (IC(50)) at the concentration of 500 nM. Further findings will be determined the exact mechanisms of this cost effective Nano-treatments.

  14. Enhanced apoptotic effects of dihydroartemisinin-aggregated gelatin and hyaluronan nanoparticles on human lung cancer cells.

    PubMed

    Sun, Qian; Teong, Benjamin; Chen, I-Fen; Chang, Shwu Jen; Gao, Jimin; Kuo, Shyh-Ming

    2014-04-01

    Recent studies suggest that dihydroartemisinin (DHA), a derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has anticancer properties. Due to poor water solubility, poor oral activity, and a short plasma half-life, large doses of DHA have to be injected to achieve the necessary bioavailability. This study examined increasing DHA bioavailability by encapsulating DHA within gelatin (GEL) or hyaluronan (HA) nanoparticles via an electrostatic field system. Observations from transmission electron microscopy show that DHA in GEL and HA nanoparticles formed GEL/DHA and HA/DHA aggregates that were approximately 30-40 nm in diameter. The entrapment efficiencies for DHA were approximately 13 and 35% for the GEL/DHA and HA/DHA aggregates, respectively. The proliferation of A549 cells was inhibited by the GEL/DHA and HA/DHA aggregates. Fluorescent annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining displayed low background staining with annexin V-FITC or PI on DHA-untreated cells. In contrast, annexin V-FITC and PI stains dramatically increased when the cells were incubated with GEL/DHA and HA/DHA aggregates. These results suggest that DHA-aggregated GEL and HA nanoparticles exhibit higher anticancer proliferation activities than DHA alone in A549 cells most likely due to the greater aqueous dispersion after hydrophilic GEL or HA nanoparticles aggregation. These results demonstrate that DHA can aggregate with nanoparticles in an electrostatic field environment to form DHA nanosized aggregates. PMID:24039154

  15. Cationic surface modification of PLG nanoparticles offers sustained gene delivery to pulmonary epithelial cells.

    PubMed

    Baoum, Abdulgader; Dhillon, Navneet; Buch, Shilpa; Berkland, Cory

    2010-05-01

    Biodegradable polymeric nanoparticles are currently being explored as a nonviral gene delivery system; however, many obstacles impede the translation of these nanomaterials. For example, nanoparticles delivered systemically are inherently prone to adsorbing serum proteins and agglomerating as a result of their large surface/volume ratio. What is desired is a simple procedure to prepare nanoparticles that may be delivered locally and exhibit minimal toxicity while improving entry into cells for effectively delivering DNA. The objective of this study was to optimize the formulation of poly(D,L-lactide-co-glycolide) (PLG) nanoparticles for gene delivery performance to a model of the pulmonary epithelium. Using a simple solvent diffusion technique, the chemistry of the particle surface was varied by using different coating materials that adsorb to the particle surface during formation. A variety of cationic coating materials were studied and compared to more conventional surfactants used for PLG nanoparticle fabrication. Nanoparticles (approximately 200 nm) efficiently encapsulated plasmids encoding for luciferase (80-90%) and slowly released the same for 2 weeks. In A549 alveolar lung epithelial cells, high levels of gene expression appeared at day 5 for certain positively charged PLG particles and gene expression was maintained for at least 2 weeks. In contrast, PEI gene expression ended at day 5. PLG particles were also significantly less cytotoxic than PEI suggesting the use of these vehicles for localized, sustained gene delivery to the pulmonary epithelium.

  16. Long-Term Tracking Mesenchymal Stem Cell Differentiation with Photostable Fluorescent Nanoparticles.

    PubMed

    Liu, Shiying; Tay, Li Min; Anggara, Raditya; Chuah, Yon Jin; Kang, Yuejun

    2016-05-18

    Mesenchymal stem cells (MSCs) have proved to be a promising and abundant cell source for tissue and organ repair in regenerative medicine. However, the cell fate, distribution and migration of these transplanted cells are still unclear due to the limited tracking methods. It is desirable to develop a biocompatible and photostable probe to label the MSCs for long-term tracking without affecting the cell proliferation and potency. Herein we apply a recently developed nanoprobe system, in which di(thiophene-2-yl)-diketopyrrolopyrrole (DPP) is covalently linked in the middle of polycaprolactone (PCL) forming the PCL-DPP-PCL polymer complex. Although the PCL-DPP-PCL nanoparticles uptaken by the MSCs did not affect the cell viability, it was interesting that they exhibited different effects on the multilineage potency of the MSCs in the subsequent differentiation in vitro. Specifically, we found that the PCL-DPP-PCL labeling was unfavorable to the MSC osteogenic differentiation, whereas the labeled MSCs exhibited the same adipogenic and chondrogenic differentiations compared to the unlabeled controls as verified by gene expressions and histological staining. Furthermore, the PCL-DPP-PCL nanoparticles remained strong fluorescence intensity even after 4 weeks of differentiation. This study indicated that PCL-DPP-PCL nanoparticles could be used for long-term cell tracing in MSC differentiation into adipogenic and chondrogenic lineages. PMID:27124820

  17. Circulating tumor cells exhibit a biologically aggressive cancer phenotype accompanied by selective resistance to chemotherapy.

    PubMed

    Pavese, Janet M; Bergan, Raymond C

    2014-10-01

    With prostate cancer (PCa), circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) portend a poor clinical prognosis. Their unknown biology precludes rational therapeutic design. We demonstrate that CTC and DTC cell lines, established from mice bearing human PCa orthotopic implants, exhibit increased cellular invasion in vitro, increased metastasis in mice, and express increased epithelial to mesenchymal transition biomarkers. Further, they are selectively resistant to growth inhibition by mitoxantrone-like agents. These findings demonstrate that CTC formation is accompanied by phenotypic progression without obligate reversion. Their increased metastatic potential, selective therapeutic resistance, and differential expression of potential therapeutic targets provide a rational basis to test further interventions.

  18. Coating nanoparticles with cell membranes for targeted drug delivery.

    PubMed

    Gao, Weiwei; Zhang, Liangfang

    2015-01-01

    Targeted delivery allows drug molecules to preferentially accumulate at the sites of action and thus holds great promise to improve therapeutic index. Among various drug-targeting approaches, nanoparticle-based delivery systems offer some unique strengths and have achieved exciting preclinical and clinical results. Herein, we aim to provide a review on the recent development of cell membrane-coated nanoparticle system, a new class of biomimetic nanoparticles that combine both the functionalities of cellular membranes and the engineering flexibility of synthetic nanomaterials for effective drug delivery and novel therapeutics. This review is particularly focused on novel designs of cell membrane-coated nanoparticles as well as their underlying principles that facilitate the purpose of drug targeting. Three specific areas are highlighted, including: (i) cell membrane coating to prolong nanoparticle circulation, (ii) cell membrane coating to achieve cell-specific targeting and (iii) cell membrane coating for immune system targeting. Overall, cell membrane-coated nanoparticles have emerged as a novel class of targeted nanotherapeutics with strong potentials to improve on drug delivery and therapeutic efficacy for treatment of various diseases.

  19. Dedifferentiation derived cells exhibit phenotypic and functional characteristics of epidermal stem cells.

    PubMed

    Zhang, Cuiping; Fu, Xiaobing; Chen, Peng; Bao, Xiaoxia; Li, Fu; Sun, Xiaoyan; Lei, Yonghong; Cai, Sa; Sun, Tongzhu; Sheng, Zhiyong

    2010-05-01

    Differentiated epidermal cells can dedifferentiate into stem cells or stem cell-like cells in vivo. In this study, we report the isolation and characterization of dedifferentiation-derived cells. Epidermal sheets eliminated of basal stem cells were transplanted onto the skin wounds in 47 nude athymic (BALB/c-nu/nu) mice. After 5 days, cells negative for CK10 but positive for CK19 and beta1-integrin emerged at the wound-neighbouring side of the epidermal sheets. Furthermore, the percentages of CK19 and beta1-integrin+ cells detected by flow cytometric analysis were increased after grafting (P < 0.01) and CK10+ cells in grafted sheets decreased (P < 0.01). Then we isolated these cells on the basis of rapid adhesion to type IV collagen and found that there were 4.56% adhering cells (dedifferentiation-derived cells) in the grafting group within 10 min. The in vitro phenotypic assays showed that the expressions of CK19, beta1-integrin, Oct4 and Nanog in dedifferentiation-derived cells were remarkably higher than those in the control group (differentiated epidermal cells) (P < 0.01). In addition, the results of the functional investigation of dedifferentiation-derived cells demonstrated: (1) the numbers of colonies consisting of 5-10 cells and greater than 10 cells were increased 5.9-fold and 6.7-fold, respectively, as compared with that in the control (P < 0.01); (2) more cells were in S phase and G2/M phase of the cell cycle (proliferation index values were 21.02% in control group, 45.08% in group of dedifferentiation); (3) the total days of culture (28 days versus 130 days), the passage number of cells (3 passages versus 20 passages) and assumptive total cell output (1 x 10(5) cells versus 1 x 10(12) cells) were all significantly increased and (4) dedifferentiation-derived cells, as well as epidermal stem cells, were capable of regenerating a skin equivalent, but differentiated epidermal cells could not. These results suggested that the characteristics of

  20. Genotoxicity of Superparamagnetic Iron Oxide Nanoparticles in Granulosa Cells

    PubMed Central

    Pöttler, Marina; Staicu, Andreas; Zaloga, Jan; Unterweger, Harald; Weigel, Bianca; Schreiber, Eveline; Hofmann, Simone; Wiest, Irmi; Jeschke, Udo; Alexiou, Christoph; Janko, Christina

    2015-01-01

    Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5) were treated with SPIONs, either coated with lauric acid (SEONLA) only, or additionally with a protein corona of bovine serum albumin (BSA; SEONLA-BSA), or with dextran (SEONDEX). Both micronuclei testing and the detection of γH2A.X revealed no genotoxic effects of SEONLA-BSA, SEONDEX or SEONLA. Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system. PMID:26540051

  1. Head and neck cancer cell lines exhibit differential mitochondrial repair deficiency in response to 4NQO.

    PubMed

    Kim, Michael M; Glazer, Chad A; Mambo, Elizabeth; Chatterjee, Aditi; Zhao, Ming; Sidransky, David; Califano, Joseph A

    2006-02-01

    Constituents of tobacco can cause DNA adduct formation and are implicated in head and neck squamous cell cancer (HNSC) development. We investigated the capacity of HNSC cell lines to repair mitochondrial DNA (mtDNA) damage induced by a DNA adduct-forming agent. HNSC cell lines underwent 4-nitroquinoline 1-oxide (4NQO) exposure with subsequent rescue with normal media. Real-time quantitative PCR for nuclear DNA (nDNA) and mtDNA was performed. mtDNA to nDNA ratios were calculated and standardized to mock-treated cells to assess mtDNA repair ability. Two of three tested cancer cell lines exposed to 4NQO exhibited consistent decreases in mtDNA/nDNA ratios throughout the different repair timepoints. At 24 h mtDNA/nDNA ratios of JHU-O19 and JHU-O22 decreased to 63% and 60% of controls, respectively. Conversely, a control keratinocyte cell line exhibited overall increases in mtDNA/nDNA ratios compared to baseline suggesting intact DNA repair mechanisms. By using a DNA adduct formation and repair model featuring 4NQO and HNSC cell lines, we have implicated faulty mtDNA repair as having a potential role in HNSC.

  2. Mesenchymal Stem Cells Exhibit Regulated Exocytosis in Response to Chemerin and IGF

    PubMed Central

    Kumar, J. Dinesh; Holmberg, Chris; Balabanova, Silvia; Borysova, Lyudmyla; Burdyga, Ted; Beynon, Robert; Dockray, Graham J.; Varro, Andrea

    2015-01-01

    Mesenchymal stem cells (MSCs) play important roles in tissue repair and cancer progression. Our recent work suggests that some mesenchymal cells, notably myofibroblasts exhibit regulated exocytosis resembling that seen in neuroendocrine cells. We now report that MSCs also exhibit regulated exocytosis. Both a G-protein coupled receptor agonist, chemerin, and a receptor tyrosine kinase stimulant, IGF-II, evoked rapid increases in secretion of a marker protein, TGFβig-h3. The calcium ionophore, ionomycin, also rapidly increased secretion of TGFβig-h3 while inhibitors of translation (cycloheximide) or secretory protein transport (brefeldin A) had no effect, indicating secretion from preformed secretory vesicles. Inhibitors of the chemerin and IGF receptors specifically reduced the secretory response. Confocal microscopy of MSCs loaded with Fluo-4 revealed chemerin and IGF-II triggered intracellular Ca2+ oscillations requiring extracellular calcium. Immunocytochemistry showed co-localisation of TGFβig-h3 and MMP-2 to secretory vesicles, and transmission electron-microscopy showed dense-core secretory vesicles in proximity to the Golgi apparatus. Proteomic studies on the MSC secretome identified 64 proteins including TGFβig-h3 and MMP-2 that exhibited increased secretion in response to IGF-II treatment for 30min and western blot of selected proteins confirmed these data. Gene ontology analysis of proteins exhibiting regulated secretion indicated functions primarily associated with cell adhesion and in bioassays chemerin increased adhesion of MSCs and adhesion, proliferation and migration of myofibroblasts. Thus, MSCs exhibit regulated exocytosis that is compatible with an early role in tissue remodelling. PMID:26513261

  3. Buffalo (Bubalus bubalis) term amniotic-membrane-derived cells exhibited mesenchymal stem cells characteristics in vitro.

    PubMed

    Ghosh, Kaushalya; Kumar, Rajesh; Singh, Jarnail; Gahlawat, S K; Kumar, Dharmendra; Selokar, Naresh Lalaji; Yadav, S P; Gulati, B R; Yadav, P S

    2015-10-01

    Recent studies suggested that placentae amniotic membrane is a valuable source of stem cells in human as well as in livestock species. Advantages of amnion over other sources of stem cells included abundant availability, ethically non-objectionable and non-invasive source. The aim of the present study was the isolation, culture and characterization of amniotic-membrane-derived mesenchymal stem cells from term placentae collected postpartum in buffalo. We have observed that both presumptive epithelial-like and fibroblast-like cells were cultured and maintained from term amnion. These cells were shown the positive expression of pluripotency markers (OCT-4, SOX-2, NANOG, TERT), mesenchymal stem cell markers (CD29, CD44, CD105) and negative for haematopoietic marker (CD34) genes at different passages. In addition, these cells were also positive for alkaline phosphatase staining. Stem-ness potential of any stem cells is determined by their potential to differentiate into specific lineages of cell type. In the present study, we have successfully differentiated the amniotic-membrane-derived cells into adipogenic, chondrogenic and osteogenic lineages of cells in vitro. In conclusion, the results of this study demonstrate that amniotic-membrane-derived cells expressed pluripotent and mesenchymal stem cells markers and have propensity to differentiate into cells of mesenchymal lineage cell type upon directed differentiation in vitro.

  4. Size-dependent cytotoxicity of europium doped NaYF ₄ nanoparticles in endothelial cells.

    PubMed

    Chen, Shizhu; Zhang, Cuimiao; Jia, Guang; Duan, Jianlei; Wang, Shuxiang; Zhang, Jinchao

    2014-10-01

    Lanthanide-doped sodium yttrium fluoride (NaYF4) nanoparticles exhibit novel optical properties which make them be widely used in various fields. The extensive applications increase the chance of human exposure to these nanoparticles and thus raise deep concerns regarding their riskiness. In the present study, we have synthesized europium doped NaYF4 (NaYF4:Eu(3+)) nanoparticles with three diameters and used endothelial cells (ECs) as a cell model to explore the potential toxic effect. The cell viability, cytomembrane integrity, cellular uptake, intracellular localization, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis detection, caspase-3 activity and expression of inflammatory gene were studied. The results indicated that these nanoparticles could be uptaken into ECs and decrease the cell viability, induce the intracellular lactate dehydrogenase (LDH) release, increase the ROS level, and decrease the cell MMP in a size-dependent manner. Besides that, the cells were suffered to apoptosis with the caspase-3 activation, and the inflammation specific gene expressions (ICAM1 and VCAM1) were also increased. Our results suggest that the damage pathway may be related to the ROS generation and mitochondrial damage. The results provide novel evidence to elucidate their toxicity mechanisms and may be helpful for more rational applications of these compounds in the future.

  5. Fibroblasts Cultured on Nanowires Exhibit Low Motility, Impaired Cell Division, and DNA Damage

    PubMed Central

    Persson, Henrik; Købler, Carsten; Mølhave, Kristian; Samuelson, Lars; Tegenfeldt, Jonas O; Oredsson, Stina; Prinz, Christelle N

    2013-01-01

    Nanowires are commonly used as tools for interfacing living cells, acting as biomolecule-delivery vectors or electrodes. It is generally assumed that the small size of the nanowires ensures a minimal cellular perturbation, yet the effects of nanowires on cell migration and proliferation remain largely unknown. Fibroblast behaviour on vertical nanowire arrays is investigated, and it is shown that cell motility and proliferation rate are reduced on nanowires. Fibroblasts cultured on long nanowires exhibit failed cell division, DNA damage, increased ROS content and respiration. Using focused ion beam milling and scanning electron microscopy, highly curved but intact nuclear membranes are observed, showing no direct contact between the nanowires and the DNA. The nanowires possibly induce cellular stress and high respiration rates, which trigger the formation of ROS, which in turn results in DNA damage. These results are important guidelines to the design and interpretation of experiments involving nanowire-based transfection and electrical characterization of living cells. PMID:23813871

  6. Fibroblasts cultured on nanowires exhibit low motility, impaired cell division, and DNA damage.

    PubMed

    Persson, Henrik; Købler, Carsten; Mølhave, Kristian; Samuelson, Lars; Tegenfeldt, Jonas O; Oredsson, Stina; Prinz, Christelle N

    2013-12-01

    Nanowires are commonly used as tools for interfacing living cells, acting as biomolecule-delivery vectors or electrodes. It is generally assumed that the small size of the nanowires ensures a minimal cellular perturbation, yet the effects of nanowires on cell migration and proliferation remain largely unknown. Fibroblast behaviour on vertical nanowire arrays is investigated, and it is shown that cell motility and proliferation rate are reduced on nanowires. Fibroblasts cultured on long nanowires exhibit failed cell division, DNA damage, increased ROS content and respiration. Using focused ion beam milling and scanning electron microscopy, highly curved but intact nuclear membranes are observed, showing no direct contact between the nanowires and the DNA. The nanowires possibly induce cellular stress and high respiration rates, which trigger the formation of ROS, which in turn results in DNA damage. These results are important guidelines to the design and interpretation of experiments involving nanowire-based transfection and electrical characterization of living cells.

  7. NK cells activated by Interleukin-4 in cooperation with Interleukin-15 exhibit distinctive characteristics.

    PubMed

    Kiniwa, Tsuyoshi; Enomoto, Yutaka; Terazawa, Natsumi; Omi, Ai; Miyata, Naoko; Ishiwata, Kenji; Miyajima, Atsushi

    2016-09-01

    Natural killer (NK) cells are known to be activated by Th1-type cytokines, such as IL-2, -12, or -18, and they secrete a large amount of IFN-γ that accelerates Th1-type responses. However, the roles of NK cells in Th2-type responses have remained unclear. Because IL-4 acts as an initiator of Th2-type responses, we examined the characteristics of NK cells in mice overexpressing IL-4. In this study, we report that IL-4 overexpression induces distinctive characteristics of NK cells (B220(high)/CD11b(low)/IL-18Rα(low)), which are different from mature conventional NK (cNK) cells (B220(low)/CD11b(high)/IL-18Rα(high)). IL-4 overexpression induces proliferation of tissue-resident macrophages, which contributes to NK cell proliferation via production of IL-15. These IL-4-induced NK cells (IL4-NK cells) produce higher levels of IFN-γ, IL-10, and GM-CSF, and exhibit high cytotoxicity compared with cNK cells. Furthermore, incubation of cNK cells with IL-15 and IL-4 alters their phenotype to that similar to IL4-NK cells. Finally, parasitic infection, which typically causes strong Th2-type responses, induces the development of NK cells with characteristics similar to IL4-NK cells. These IL4-NK-like cells do not develop in IL-4Rα KO mice by parasitic infection. Collectively, these results suggest a novel role of IL-4 in immune responses through the induction of the unique NK cells. PMID:27551096

  8. Nanoparticle-Based ARV Drug Combinations for Synergistic Inhibition of Cell-Free and Cell-Cell HIV Transmission.

    PubMed

    Jiang, Yonghou; Cao, Shijie; Bright, Danielle K; Bever, Alaina M; Blakney, Anna K; Suydam, Ian T; Woodrow, Kim A

    2015-12-01

    Nanocarrier-based drug delivery systems are playing an emerging role in human immunodeficiency virus (HIV) chemoprophylaxis and treatment due to their ability to alter the pharmacokinetics and improve the therapeutic index of various antiretroviral (ARV) drug compounds used alone and in combination. Although several nanocarriers have been described for combination delivery of ARV drugs, measurement of drug-drug activities facilitated by the use of these nanotechnology platforms has not been fully investigated for topical prevention. Here, we show that physicochemically diverse ARV drugs can be encapsulated within polymeric nanoparticles to deliver multidrug combinations that provide potent HIV chemoprophylaxis in relevant models of cell-free, cell-cell, and mucosal tissue infection. In contrast to existing approaches that coformulate ARV drug combinations together in a single nanocarrier, we prepared single-drug-loaded nanoparticles that were subsequently combined upon administration. ARV drug-nanoparticles were prepared using emulsion-solvent evaporation techniques to incorporate maraviroc (MVC), etravirine (ETR), and raltegravir (RAL) into poly(lactic-co-glycolic acid) (PLGA) nanoparticles. We compared the antiviral potency of the free and formulated drug combinations for all pairwise and triple drug combinations against both cell-free and cell-associated HIV-1 infection in vitro. The efficacy of ARV-drug nanoparticle combinations was also assessed in a macaque cervicovaginal explant model using a chimeric simian-human immunodeficiency virus (SHIV) containing the reverse transcriptase (RT) of HIV-1. We observed that our ARV-NPs maintained potent HIV inhibition and were more effective when used in combinations. In particular, ARV-NP combinations involving ETR-NP exhibited significantly higher antiviral potency and dose-reduction against both cell-free and cell-associated HIV-1 BaL infection in vitro. Furthermore, ARV-NP combinations that showed large dose

  9. Dimers of melampomagnolide B exhibit potent anticancer activity against hematological and solid tumor cells

    PubMed Central

    Janganati, Venumadhav; Ponder, Jessica; Jordan, Craig T.; Borrelli, Michael J.; Penthala, Narsimha Reddy; Crooks, Peter A.

    2016-01-01

    A series of novel carbamate and carbonate dimers of melampomagnolide B (MMB) have been synthesized by reaction of the MMB-triazole carbamate synthon 6 with various terminal diamino and dihydroxy alkanes. The resulting dimeric products 7b, 7c and 7f were selected and evaluated for anticancer activity against a panel of 60 human hematological and solid tumor cell lines. The most active compounds, 7b, 7c and 7f, exhibited GI50 values in the range 250-780 nM against the majority of leukemia cell lines in the tumor cell panel. Specifically, compounds 7b and 7f exhibited potent growth inhibition against non-small cell lung cancer cell lines NCI-H522 (GI50 = 160 nM) and HOP-92 (GI50 = 170 nM), respectively. Also, compound 7f also potently inhibited the growth of melanoma cell lines LOX IMVI, MALME-3M, and UACC-62 (GI50 values = 170, 190 and 190 nM, respectively); breast cancer cell line MDA-MB-468 (GI50 = 190 nM); colon cancer cell line HCT-116 (GI50 = 190 nM); and renal cancer cell line RXF 393 (GI50 = 160 nM). Compound 7f and the simple dicarbonate dimer of MMB (8) showed anticancer activity 300-fold and 1 × 106-fold, respectively, more cytotoxic than 7f and DMAPT at a concentration of 10 μM against rat 9L-SF gliosarcoma cells. The dimeric compounds 7a-7j & 8 were also screened for antileukemic activity against M9-ENL1 acute myelogenous leukemia (AML) cells and primary AML cell specimens. These compounds exhibited two to twelve-fold more potent antileukemic activity (EC50 = 0.5-2.9 μM) against the M9-ENL1 cell line when compared to parthenolide (EC50 = 6.0 μM). The dimeric analogues were also active against the primary AML cell specimens in the nanomolar to lower micromolar range and exhibited two to ten-fold more potent antileukemic activity (EC50 = 0.86-4.2 μM) when compared to parthenolide (EC50 = 2.5-16 μM). Thus, dimer 7f exhibited promising anticancer activity against a variety of both hematological and solid human tumor cell lines, while dimer 8 was

  10. Nanoparticle-labeled stem cells: a novel therapeutic vehicle

    PubMed Central

    El-Sadik, Abir O; El-Ansary, Afaf; Sabry, Sherif M

    2010-01-01

    Nanotechnology has been described as a general purpose technology. It has already generated a range of inventions and innovations. Development of nanotechnology will provide clinical medicine with a range of new diagnostic and therapeutic opportunities such as medical imaging, medical diagnosis, drug delivery, and cancer detection and management. Nanoparticles such as manganese, polystyrene, silica, titanium oxide, gold, silver, carbon, quantum dots, and iron oxide have received enormous attention in the creation of new types of analytical tools for biotechnology and life sciences. Labeling of stem cells with nanoparticles overcame the problems in homing and fixing stem cells to their desired site and guiding extension of stem cells to specific directions. Although the biologic effects of some nanoparticles have already been assessed, information on toxicity and possible mechanisms of various particle types remains inadequate. The aim of this review is to give an overview of the mechanisms of internalization and distribution of nanoparticles inside stem cells, as well as the influence of different types of nanoparticles on stem cell viability, proliferation, differentiation, and cytotoxicity, and to assess the role of nanoparticles in tracking the fate of stem cells used in tissue regeneration. PMID:22291483

  11. Tumor-derived endothelial cells exhibit aberrant Rho-mediated mechanosensing and abnormal angiogenesis in vitro.

    PubMed

    Ghosh, Kaustabh; Thodeti, Charles K; Dudley, Andrew C; Mammoto, Akiko; Klagsbrun, Michael; Ingber, Donald E

    2008-08-12

    Tumor blood vessels exhibit abnormal structure and function that cause disturbed blood flow and high interstitial pressure, which impair delivery of anti-cancer agents. Past efforts to normalize the tumor vasculature have focused on inhibition of soluble angiogenic factors, such as VEGF; however, capillary endothelial (CE) cell growth and differentiation during angiogenesis are also influenced by mechanical forces conveyed by the extracellular matrix (ECM). Here, we explored the possibility that tumor CE cells form abnormal vessels because they lose their ability to sense and respond to these physical cues. These studies reveal that, in contrast to normal CE cells, tumor-derived CE cells fail to reorient their actin cytoskeleton when exposed to uniaxial cyclic strain, exhibit distinct shape sensitivity to variations in ECM elasticity, exert greater traction force, and display an enhanced ability to retract flexible ECM substrates and reorganize into tubular networks in vitro. These behaviors correlate with a constitutively high level of baseline activity of the small GTPase Rho and its downstream effector, Rho-associated kinase (ROCK). Moreover, decreasing Rho-mediated tension by using the ROCK inhibitor, Y27632, can reprogram the tumor CE cells so that they normalize their reorientation response to uniaxial cyclic strain and their ability to form tubular networks on ECM gels. Abnormal Rho-mediated sensing of mechanical cues in the tumor microenvironment may therefore contribute to the aberrant behaviors of tumor CE cells that result in the development of structural abnormalities in the cancer microvasculature.

  12. Cancer-initiating cells derived from established cervical cell lines exhibit stem-cell markers and increased radioresistance

    PubMed Central

    2012-01-01

    Background Cancer-initiating cells (CICs) are proposed to be responsible for the generation of metastasis and resistance to therapy. Accumulating evidences indicates CICs are found among different human cancers and cell lines derived from them. Few studies address the characteristics of CICs in cervical cancer. We identify biological features of CICs from four of the best-know human cell lines from uterine cervix tumors. (HeLa, SiHa, Ca Ski, C-4 I). Methods Cells were cultured as spheres under stem-cell conditions. Flow cytometry was used to detect expression of CD34, CD49f and CD133 antigens and Hoechst 33342 staining to identify side population (SP). Magnetic and fluorescence-activated cell sorting was applied to enrich and purify populations used to evaluate tumorigenicity in nude mice. cDNA microarray analysis and in vitro radioresistance assay were carried out under standard conditions. Results CICs, enriched as spheroids, were capable to generate reproducible tumor phenotypes in nu-nu mice and serial propagation. Injection of 1 × 103 dissociated spheroid cells induced tumors in the majority of animals, whereas injection of 1 × 105 monolayer cells remained nontumorigenic. Sphere-derived CICs expressed CD49f surface marker. Gene profiling analysis of HeLa and SiHa spheroid cells showed up-regulation of CICs markers characteristic of the female reproductive system. Importantly, epithelial to mesenchymal (EMT) transition-associated markers were found highly expressed in spheroid cells. More importantly, gene expression analysis indicated that genes required for radioresistance were also up-regulated, including components of the double-strand break (DSB) DNA repair machinery and the metabolism of reactive oxygen species (ROS). Dose-dependent radiation assay indicated indeed that CICs-enriched populations exhibit an increased resistance to ionizing radiation (IR). Conclusions We characterized a self-renewing subpopulation of CICs found among four well known human

  13. Hyaluronic acid modified mesoporous carbon nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells

    NASA Astrophysics Data System (ADS)

    Wan, Long; Jiao, Jian; Cui, Yu; Guo, Jingwen; Han, Ning; Di, Donghua; Chang, Di; Wang, Pu; Jiang, Tongying; Wang, Siling

    2016-04-01

    In this paper, hyaluronic acid (HA) functionalized uniform mesoporous carbon spheres (UMCS) were synthesized for targeted enzyme responsive drug delivery using a facile electrostatic attraction strategy. This HA modification ensured stable drug encapsulation in mesoporous carbon nanoparticles in an extracellular environment while increasing colloidal stability, biocompatibility, cell-targeting ability, and controlled cargo release. The cellular uptake experiments of fluorescently labeled mesoporous carbon nanoparticles, with or without HA functionalization, demonstrated that HA-UMCS are able to specifically target cancer cells overexpressing CD44 receptors. Moreover, the cargo loaded doxorubicin (DOX) and verapamil (VER) exhibited a dual pH and hyaluronidase-1 responsive release in the tumor microenvironment. In addition, VER/DOX/HA-UMCS exhibited a superior therapeutic effect on an in vivo HCT-116 tumor in BALB/c nude mice. In summary, it is expected that HA-UMCS will offer a new method for targeted co-delivery of drugs to tumors overexpressing CD44 receptors.

  14. Naïve and memory B cells exhibit distinct biochemical responses following BCR engagement.

    PubMed

    Moens, Leen; Kane, Alisa; Tangye, Stuart G

    2016-09-01

    Immunological memory is characterized by the rapid reactivation of memory B cells that produce large quantities of high-affinity antigen-specific antibodies. This contrasts the response of naïve B cells, and the primary immune response, which is much slower and of lower affinity. Memory responses are critical for protection against infectious diseases and form the basis of most currently available vaccines. Although we have known about the phenomenon of long-lived memory for centuries, the biochemical differences underlying these diverse responses of naïve and memory B cells is incompletely resolved. Here we investigated the nature of B-cell receptor (BCR) signaling in human splenic naïve, IgM(+) memory and isotype-switched memory B cells following multivalent BCR crosslinking. We observed comparable rapid and transient phosphorylation kinetics for proximal (phosphotyrosine and spleen tyrosine kinase) and propagation (B-cell linker, phospholipase Cγ2) signaling components in these different B-cell subsets. However, the magnitude of activation of downstream components of the BCR signaling pathway were greater in memory compared with naïve cells. Although no differences were observed in the magnitude of Ca(2+) mobilization between subsets, IgM(+) memory B cells exhibited a more rapid Ca(2+) mobilization and a greater depletion of the Ca(2+) endoplasmic reticulum stores, while IgG(+) memory B cells had a prolonged Ca(2+) uptake. Collectively, our findings show that intrinsic signaling features of B-cell subsets contribute to the robust response of human memory B cells over naïve B cells. This has implications for our understanding of memory B-cell responses and provides a framework to modulate these responses in the setting of vaccination and immunopathologies, such as immunodeficiency and autoimmunity. PMID:27101923

  15. Carbohydrate-Based Nanocarriers Exhibiting Specific Cell Targeting with Minimum Influence from the Protein Corona.

    PubMed

    Kang, Biao; Okwieka, Patricia; Schöttler, Susanne; Winzen, Svenja; Langhanki, Jens; Mohr, Kristin; Opatz, Till; Mailänder, Volker; Landfester, Katharina; Wurm, Frederik R

    2015-06-15

    Whenever nanoparticles encounter biological fluids like blood, proteins adsorb on their surface and form a so-called protein corona. Although its importance is widely accepted, information on the influence of surface functionalization of nanocarriers on the protein corona is still sparse, especially concerning how the functionalization of PEGylated nanocarriers with targeting agents will affect protein corona formation and how the protein corona may in turn influence the targeting effect. Herein, hydroxyethyl starch nanocarriers (HES-NCs) were prepared, PEGylated, and modified on the outer PEG layer with mannose to target dendritic cells (DCs). Their interaction with human plasma was then studied. Low overall protein adsorption with a distinct protein pattern and high specific affinity for DC binding were observed, thus indicating an efficient combination of "stealth" and targeting behavior.

  16. Proliferating versus differentiating stem and cancer cells exhibit distinct midbody-release behaviour

    PubMed Central

    Ettinger, Andreas W.; Wilsch-Bräuninger, Michaela; Marzesco, Anne-Marie; Bickle, Marc; Lohmann, Annett; Maliga, Zoltan; Karbanová, Jana; Corbeil, Denis; Hyman, Anthony A.; Huttner, Wieland B.

    2011-01-01

    The central portion of the midbody, a cytoplasmic bridge between nascent daughter cells at the end of cell division, has generally been thought to be retained by one of the daughter cells, but has, recently, also been shown to be released into the extracellular space. The significance of midbody-retention versus -release is unknown. Here we show, by quantitatively analysing midbody-fate in various cell lines under different growth conditions, that the extent of midbody-release is significantly greater in stem cells than cancer-derived cells. Induction of cell differentiation is accompanied by an increase in midbody-release. Knockdown of the endosomal sorting complex required for transport family members, Alix and tumour-suppressor gene 101, or of their interaction partner, centrosomal protein 55, impairs midbody-release, suggesting mechanistic similarities to abscission. Cells with such impaired midbody-release exhibit enhanced responsiveness to a differentiation stimulus. Taken together, midbody-release emerges as a characteristic feature of cells capable of differentiation. PMID:22009035

  17. Cells surviving fractional killing by TRAIL exhibit transient but sustainable resistance and inflammatory phenotypes

    PubMed Central

    Flusberg, Deborah A.; Roux, Jérémie; Spencer, Sabrina L.; Sorger, Peter K.

    2013-01-01

    When clonal populations of human cells are exposed to apoptosis-inducing agents, some cells die and others survive. This fractional killing arises not from mutation but from preexisting, stochastic differences in the levels and activities of proteins regulating apoptosis. Here we examine the properties of cells that survive treatment with agonists of two distinct death receptors, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and anti-FasR antibodies. We find that “survivor” cells are highly resistant to a second ligand dose applied 1 d later. Resistance is reversible, resetting after several days of culture in the absence of death ligand. “Reset” cells appear identical to drug-naive cells with respect to death ligand sensitivity and gene expression profiles. TRAIL survivors are cross-resistant to activators of FasR and vice versa and exhibit an NF-κB–dependent inflammatory phenotype. Remarkably, reversible resistance is induced in the absence of cell death when caspase inhibitors are present and can be sustained for 1 wk or more, also without cell death, by periodic ligand exposure. Thus stochastic differences in cell state can have sustained consequences for sen­sitivity to prodeath ligands and acquisition of proinflammatory phenotypes. The important role played by periodicity in TRAIL exposure for induction of opposing apoptosis and survival mechanisms has implications for the design of optimal therapeutic agents and protocols. PMID:23699397

  18. Perylene-labeled silica nanoparticles: synthesis and characterization of three novel silica nanoparticle species for live-cell imaging.

    PubMed

    Blechinger, Julia; Herrmann, Rudolf; Kiener, Daniel; García-García, F Javier; Scheu, Christina; Reller, Armin; Bräuchle, Christoph

    2010-11-01

    The increasing exposure of humans to nanoscaled particles requires well-defined systems that enable the investigation of the toxicity of nanoparticles on the cellular level. To facilitate this, surface-labeled silica nanoparticles, nanoparticles with a labeled core and a silica shell, and a labeled nanoparticle network-all designed for live-cell imaging-are synthesized. The nanoparticles are functionalized with perylene derivatives. For this purpose, two different perylene species containing one or two reactive silica functionalities are prepared. The nanoparticles are studied by transmission electron microscopy, widefield and confocal fluorescence microscopy, as well as by fluorescence spectroscopy in combination with fluorescence anisotropy, in order to characterize the size and morphology of the nanoparticles and to prove the success and homogeneity of the labeling. Using spinning-disc confocal measurements, silica nanoparticles are demonstrated to be taken up by HeLa cells, and they are clearly detectable inside the cytoplasm of the cells.

  19. Dynamic Chiral Nanoparticle Assemblies and Specific Chiroplasmonic Analysis of Cancer Cells.

    PubMed

    Zhao, Yuan; Yang, Yaxin; Zhao, Jing; Weng, Ping; Pang, Qingfeng; Song, Qijun

    2016-06-01

    Fabricated Ag@Au core-shell nanoparticle (CS NP) assemblies exhibit pronounced and reverse chiral bisignate plasmonic signals spanning 400 to 580 nm, in comparison to Ag NP assemblies. The time-dependent chiro-optical response of assemblies that shift with shell deposition is systematically recorded. Chiral Ag@Au CS NP assemblies first achieve the special discrimination of circulating tumor cells with HER2 overexpression. PMID:27115447

  20. Antibody Conjugated Magnetic Iron Oxide Nanoparticles for Cancer Cell Separation in Fresh Whole Blood

    PubMed Central

    Xu, Hengyi; Aguilar, Zoraida P.; Yang, Lily; Kuang, Min; Duan, Hongwei; Xiong, Yonghua; Wei, Hua; Wang, Andrew

    2011-01-01

    A highly efficient process using iron oxide magnetic nanoparticles (IO)-based immunomagnetic separation of tumor cells from fresh whole blood has been developed. The process involved polymer coated 30 nm IO that was modified with antibodies (Ab) against human epithelial growth factor receptor 2 (anti-HER2 or anti-HER2/neu) forming IO-Ab. HER2 is a cell membrane protein that is over expressed in several types of human cancer cells. Using a HER2/neu over expressing human breast cancer cell line, SK-BR3, as a model cell, the IO-Ab was used to separate 73.6 % (with a maximum capture of 84%) of SK-BR3 cells that were spiked in 1 mL of fresh human whole blood. The IO-Ab preferentially bound to SK-BR3 cells over normal cells found in blood due to the high level of HER2/neu receptor on the cancer cells unlike the normal cell surfaces. The results showed that the nanosized magnetic nanoparticles exhibited an enrichment factor (cancer cells over normal cells) of 1:10,000,000 in a magnetic field (with gradient of 100 T/m) through the binding of IO-Ab on the cell surface that resulted in the preferential capture of the cancer cells. This research holds promise for efficient separation of circulating cancer cells in fresh whole blood. PMID:21920599

  1. Nanoparticles meet cell membranes: probing nonspecific interactions using model membranes.

    PubMed

    Chen, Kai Loon; Bothun, Geoffrey D

    2014-01-21

    Nanotoxicity studies have shown that both carbon-based and inorganic engineered nanoparticles can be toxic to microorganisms. Although the pathways for cytotoxicity are diverse and dependent upon the nature of the engineered nanoparticle and the chemical environment, numerous studies have provided evidence that direct contact between nanoparticles and bacterial cell membranes is necessary for cell inactivation or damage, and may in fact be a primary mechanism for cytotoxicity. The propensities for nanoparticles to attach to and disrupt cell membranes are still not well understood due to the heterogeneous and dynamic nature of biological membranes. Model biological membranes can be employed for systematic investigations of nanoparticle-membrane interactions. In this article, current and emerging experimental approaches to identify the key parameters that control the attachment of ENPs on model membranes and the disruption of membranes by ENPs will be discussed. This critical information will help enable the "safe-by-design" production of engineered nanoparticles that are nontoxic or biocompatible, and also allow for the design of antimicrobial nanoparticles for environmental and biomedical applications.

  2. Cell Membrane-Cloaked Nanoparticles for Targeted Therapeutics

    NASA Astrophysics Data System (ADS)

    Luk, Brian Tsengchi

    The advent of nanoparticle-based delivery systems has made a significant impact on clinical patient outcomes. In recent decades, myriad nanoparticle-based therapeutic agents have been developed for the treatment and management of ailments such as cancer, diabetes, pain, bacterial infections, and asthma, among many others. Nanotherapeutics offer many distinct advantages over conventional free drug formulations. For example, nanoparticles are able to accumulate at tumor sites by extravasation through leaky vasculature at tumor sites via the enhanced permeability and retention (EPR) effect; nanoparticles can also be tailored to have desirable characteristics, such as prolonged circulation in the blood stream, improved drug encapsulation, and sustained or triggered drug release. Currently, a growing number of nanoformulations with favorable pharmacological profiles and promising efficacy are being used in clinical trials for the treatment of various cancers. Building on the success of these encouraging clinical results, new engineering strategies have emerged that combine synthetic nanoparticles with natural biomaterials to create nature-inspired biomimetic delivery systems. The work presented in this dissertation focuses on the biointerfacing between synthetic and natural materials, namely in the manifestation of cell membrane-coated nanoparticles. By exploiting the natural functionalities of source cell membranes, cell membrane-cloaked nanoparticles have huge potential in the delivery of therapeutic agents for a variety of applications. The first portion of this thesis will focus on understanding the fundamentals underlying cell membrane coating on synthetic nanoparticles. First introduced in 2011, cell membrane-cloaked nanoparticles showed immediate promise in drug delivery applications, but further understanding was necessary to be able to harness the full potential of the membrane coating platform. The first section provides further insight into the interfacial

  3. Eu/Tb codoped spindle-shaped fluorinated hydroxyapatite nanoparticles for dual-color cell imaging

    NASA Astrophysics Data System (ADS)

    Ma, Baojin; Zhang, Shan; Qiu, Jichuan; Li, Jianhua; Sang, Yuanhua; Xia, Haibing; Jiang, Huaidong; Claverie, Jerome; Liu, Hong

    2016-06-01

    Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500-580 nm) can be decreased to the benefit of the emission in the red region (580-720 nm), thus reaching a balanced dual color emission. Using MC3T3-E1 cells co-cultured with Eu/Tb codoped FAp nanoparticles, it is observed that the nanoparticles are cytocompatible even at a concentration as high as 800 μg ml-1. The Eu/Tb codoped FAp nanoparticles are located in the cytoplasm and can be monitored by dual color--green and red imaging with a single excitation light at 488 nm. At a concentration of 200 μg ml-1, the cytoplasm is saturated in 8 hours, and Eu/Tb codoped FAp nanoparticles retain their fluorescence for at least 3 days. The cytocompatible Eu/Tb codoped FAp nanoparticles with unique dual color emission will be of great use for cell and tissue imaging.Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500-580 nm) can be decreased to the benefit of the emission in the

  4. Synthesis and characterization of jacalin-gold nanoparticles conjugates as specific markers for cancer cells.

    PubMed

    Marangoni, Valeria S; Paino, Ieda M; Zucolotto, Valtencir

    2013-12-01

    New nanobiocomposites that combine nanoparticles and biomolecules have been shown very relevant for medical applications. Recently, cancer diagnostics and treatment have benefited from the development of nanobiocomposites, in which metallic or magnetic nanoparticles are conjugated with specific biomolecules for selective cell uptake. Despite recent advances in this area, the biomedical applications of these materials are still limited by the low efficiency of functionalization, low stability, among other factors. In this study, we report the synthesis of jacalin-conjugated gold nanoparticles, a nanoconjugate with potential application in medical areas, especially for cancer diagnosis. Jacalin is a lectin protein and it was employed due to its ability to recognize the Galβ1-3GalNAc disaccharide, which is highly expressed in tumor cells. Gold nanoparticles (AuNPs) were synthesized in the presence of generation 4 polyamidoamine dendrimer (PAMAM G4) and conjugated with fluorescein isothiocyanate (FITC)-labeled jacalin. The AuNPs/jacalin nanoconjugates were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and vibrational spectroscopy (FTIR). We also performed an investigation using isothermal titration calorimetry (ITC) and fluorescence quenching measurements to understand the interactions occurring between the AuNPs and jacalin, which revealed that the nanoconjugate formation is driven by an entropic process with good affinity. Furthermore, in vitro tests revealed that the AuNPs/jacalin-FITC nanoconjugates exhibited higher affinity for leukemic K562 cells than for healthy mononuclear blood cells, which could be useful for biomedical applications, including cancer cells imaging.

  5. Bifunctional magnetic-fluorescent nanoparticles: synthesis, characterization, and cell imaging.

    PubMed

    Lu, Yanjiao; Zheng, Yang; You, Shusen; Wang, Feng; Gao, Zhuo; Shen, Jie; Yang, Wantai; Yin, Meizhen

    2015-03-11

    A new type of bifunctional magnetic-fluorescent Fe3O4@SiO2-PDI-PAA/Ca(2+) nanoparticles has been prepared by coating PDI-cored star polymers (PDI-PAA) onto the surface of Fe3O4@SiO2 core-shell nanostructures. The morphology and properties of the composite nanoparticles are investigated by transmission electron microscopy, ultraviolet-visible spectrometry, fluorescence spectrometry, and vibrating sample magnetometry. The composite nanoparticles display a strong red emission and superparamagnetic behavior at room temperature. The cell viability and uptake assays reveal good biocompatibility of these hybrid nanoparticles. Hence, the composite nanoparticles are of potential to be further explored as therapeutic vector in biomedical field. PMID:25691125

  6. Bifunctional magnetic-fluorescent nanoparticles: synthesis, characterization, and cell imaging.

    PubMed

    Lu, Yanjiao; Zheng, Yang; You, Shusen; Wang, Feng; Gao, Zhuo; Shen, Jie; Yang, Wantai; Yin, Meizhen

    2015-03-11

    A new type of bifunctional magnetic-fluorescent Fe3O4@SiO2-PDI-PAA/Ca(2+) nanoparticles has been prepared by coating PDI-cored star polymers (PDI-PAA) onto the surface of Fe3O4@SiO2 core-shell nanostructures. The morphology and properties of the composite nanoparticles are investigated by transmission electron microscopy, ultraviolet-visible spectrometry, fluorescence spectrometry, and vibrating sample magnetometry. The composite nanoparticles display a strong red emission and superparamagnetic behavior at room temperature. The cell viability and uptake assays reveal good biocompatibility of these hybrid nanoparticles. Hence, the composite nanoparticles are of potential to be further explored as therapeutic vector in biomedical field.

  7. Delivering nanoparticles to lungs while avoiding liver and spleen through adsorption on red blood cells.

    PubMed

    Anselmo, Aaron C; Gupta, Vivek; Zern, Blaine J; Pan, Daniel; Zakrewsky, Michael; Muzykantov, Vladimir; Mitragotri, Samir

    2013-12-23

    Nanoparticulate drug delivery systems are one of the most widely investigated approaches for developing novel therapies for a variety of diseases. However, rapid clearance and poor targeting limit their clinical utility. Here, we describe an approach to harness the flexibility, circulation, and vascular mobility of red blood cells (RBCs) to simultaneously overcome these limitations (cellular hitchhiking). A noncovalent attachment of nanoparticles to RBCs simultaneously increases their level in blood over a 24 h period and allows transient accumulation in the lungs, while reducing their uptake by liver and spleen. RBC-adsorbed nanoparticles exhibited ∼3-fold increase in blood persistence and ∼7-fold higher accumulation in lungs. RBC-adsorbed nanoparticles improved lung/liver and lung/spleen nanoparticle accumulation by over 15-fold and 10-fold, respectively. Accumulation in lungs is attributed to mechanical transfer of particles from the RBC surface to lung endothelium. Independent tracing of both nanoparticles and RBCs in vivo confirmed that RBCs themselves do not accumulate in lungs. Attachment of anti-ICAM-1 antibody to the exposed surface of NPs that were attached to RBCs led to further increase in lung targeting and retention over 24 h. Cellular hitchhiking onto RBCs provides a new platform for improving the blood pharmacokinetics and vascular delivery of nanoparticles while simultaneously avoiding uptake by liver and spleen, thus opening the door for new applications.

  8. Nanoparticle distribution in polymer solar cells

    NASA Astrophysics Data System (ADS)

    Kirby, B. J.; Kiel, J. W.; Maranville, B. B.; Majkrzak, C. F.; Mackay, M. E.

    2010-03-01

    Polymer based solar cells (PSC) hold the promise of cheap, versatile devices for harnessing solar energy. A widely studied PSC is poly-3-hexylthiophene (P3HT) blended with [6,6] - phenyl-C61 - butyric acid methyl ester (PCBM) nanoparticles. The acceptor PCBM is needed to inhibit exciton recombination, thus, proper PCBM distribution is critical for photovoltaic performance. However, determining this distribution is challenging, as PCBM is extremely difficult to distinguish from P3HT via standard techniques like microscopy or x-ray diffraction. Neutron scattering presents a solution, as the scattering potential for PCBM is ˜5 x that of P3HT. Thus, we have studied PCBM:P3HT thin film samples using neutron reflectometry, which is sensitive to the compositional depth profile.[1] Measurements were conducted both with a weak scatterer (air) and then with a strong scatterer (D2O) backing the sample, such that the depth profile could be calculated from the reflectometry data with no fitting parameters, and/or model fitted with virtually no ambiguity. We find that PCBM aggregates near the substrate and surface interfaces of the P3HT film, implying that the PCBM is not optimally distributed for best photovoltaic performance. In general, this work demonstrates the extreme utility of neutron reflectometry for studying this class of materials. [1] Kiel, et al. Soft Matter, DOI:10.1039/B920979D (2009).

  9. Nanoparticle accumulation and transcytosis in brain endothelial cell layers

    NASA Astrophysics Data System (ADS)

    Ye, Dong; Raghnaill, Michelle Nic; Bramini, Mattia; Mahon, Eugene; Åberg, Christoffer; Salvati, Anna; Dawson, Kenneth A.

    2013-10-01

    The blood-brain barrier (BBB) is a selective barrier, which controls and limits access to the central nervous system (CNS). The selectivity of the BBB relies on specialized characteristics of the endothelial cells that line the microvasculature, including the expression of intercellular tight junctions, which limit paracellular permeability. Several reports suggest that nanoparticles have a unique capacity to cross the BBB. However, direct evidence of nanoparticle transcytosis is difficult to obtain, and we found that typical transport studies present several limitations when applied to nanoparticles. In order to investigate the capacity of nanoparticles to access and transport across the BBB, several different nanomaterials, including silica, titania and albumin- or transferrin-conjugated gold nanoparticles of different sizes, were exposed to a human in vitro BBB model of endothelial hCMEC/D3 cells. Extensive transmission electron microscopy imaging was applied in order to describe nanoparticle endocytosis and typical intracellular localisation, as well as to look for evidence of eventual transcytosis. Our results show that all of the nanoparticles were internalised, to different extents, by the BBB model and accumulated along the endo-lysosomal pathway. Rare events suggestive of nanoparticle transcytosis were also observed for several of the tested materials.The blood-brain barrier (BBB) is a selective barrier, which controls and limits access to the central nervous system (CNS). The selectivity of the BBB relies on specialized characteristics of the endothelial cells that line the microvasculature, including the expression of intercellular tight junctions, which limit paracellular permeability. Several reports suggest that nanoparticles have a unique capacity to cross the BBB. However, direct evidence of nanoparticle transcytosis is difficult to obtain, and we found that typical transport studies present several limitations when applied to nanoparticles. In

  10. Detecting polymeric nanoparticles with coherent anti-stokes Raman scattering microscopy in tissues exhibiting fixative-induced autofluorescence

    NASA Astrophysics Data System (ADS)

    Garrett, N. L.; Godfrey, L.; Lalatsa, A.; Serrano, D. R.; Uchegbu, I. F.; Schatzlein, A.; Moger, J.

    2015-03-01

    Recent advances in pharmaceutical nanotechnology have enabled the development of nano-particulate medicines with enhanced drug performance. Although the fate of these nano-particles can be macroscopically tracked in the body (e.g. using radio-labeling techniques), there is little information about the sub-cellular scale mechanistic processes underlying the particle-tissue interactions, or how these interactions may correlate with pharmaceutical efficacy. To rationally engineer these nano-particles and thus optimize their performance, these mechanistic interactions must be fully understood. Coherent Anti-Stokes Raman scattering (CARS) microscopy provides a label-free means for visualizing biological samples, but can suffer from a strong non-resonant background in samples that are prepared using aldehyde-based fixatives. We demonstrate how formalin fixative affects the detection of polymeric nanoparticles within kidneys following oral administration using CARS microscopy, compared with samples that were snap-frozen. These findings have implications for clinical applications of CARS for probing nanoparticle distribution in tissue biopsies.

  11. Dye-doped organosilicate nanoparticles as cell-preserving labels for photoacoustic signal generation.

    PubMed

    Ramirez-Perez, Francisco I; Gutiérrez-Juárez Gerardo; Bok, Sangho; Gangopadhyay, Keshab; Gangopadhyay, Shubhra; Baker, Gary A; Polo-Parada, Luis

    2014-11-01

    Nanoparticle-assisted ultrasound generation by pulsed laser or photoacoustic (PA) techniques has been employed in the study of several tissues both in vivo and in vitro. Among the many applications of this technology, the detection of few cells in vitro is of particular interest. However, the toxicity induced by laser irradiation used for PA signal generation, whether in the absence or the presence of PA enhancers, within single isolated cells has not yet been investigated in detail. Herein, we report our studies of the cellular health of two different nanoparticle-labeled cell lines one hour after being subjected to a single laser pulse in vitro. We selected for this study an Hs936 skin epithelial melanoma cell line, which can be naturally detected photoacoustically, as well as a T47D human mammary breast gland epithelial cell line which has proven difficult to detect photoacoustically due to the absence of natural melanin. We have evaluated the amplitude of the PA signal derived from these two cell types, unlabeled and labeled with nanoparticles of two types (gold nanoparticles, AuNPs, or rhodamine 6G-doped organosilicate nanoparticles, R6G-NPOs), and assessed their health one hour subsequent to laser treatment. The current work corroborates previous findings that, for unlabeled cells, Hs936 produces a detectable PA signal whereas the T47D line does not. Cells labeled with AuNPs or R6G-NPOs produced a detectable PA signal of similar amplitude for the two cell lines. A significant number of Hs936 cells (both unlabeled cells and those labeled with AuNPs) exhibited cell nuclei alterations, as revealed by DAPI staining conducted an hour after photo treatment. Remarkably, the T47D cells suffered damage only when labeled with AuNPs. A significant finding, the R6G-NPOs proved capable of non-destructive PA signal generation in both cell types. Our findings advocate a transformational path forward for the use of dye-doped silicate nanoparticles in cell-compatible PA

  12. Nanoparticle facilitated extracellular electron transfer in microbial fuel cells.

    PubMed

    Jiang, Xiaocheng; Hu, Jinsong; Lieber, Alexander M; Jackan, Charles S; Biffinger, Justin C; Fitzgerald, Lisa A; Ringeisen, Bradley R; Lieber, Charles M

    2014-11-12

    Microbial fuel cells (MFCs) have been the focus of substantial research interest due to their potential for long-term, renewable electrical power generation via the metabolism of a broad spectrum of organic substrates, although the low power densities have limited their applications to date. Here, we demonstrate the potential to improve the power extraction by exploiting biogenic inorganic nanoparticles to facilitate extracellular electron transfer in MFCs. Simultaneous short-circuit current recording and optical imaging on a nanotechnology-enabled platform showed substantial current increase from Shewanella PV-4 after the formation of cell/iron sulfide nanoparticle aggregates. Detailed characterization of the structure and composition of the cell/nanoparticle interface revealed crystalline iron sulfide nanoparticles in intimate contact with and uniformly coating the cell membrane. In addition, studies designed to address the fundamental mechanisms of charge transport in this hybrid system showed that charge transport only occurred in the presence of live Shewanella, and moreover demonstrated that the enhanced current output can be attributed to improved electron transfer at cell/electrode interface and through the cellular-networks. Our approach of interconnecting and electrically contacting bacterial cells through biogenic nanoparticles represents a unique and promising direction in MFC research and has the potential to not only advance our fundamental knowledge about electron transfer processes in these biological systems but also overcome a key limitation in MFCs by constructing an electrically connected, three-dimensional cell network from the bottom-up.

  13. Metal nanoparticles amplify photodynamic effect on skin cells in vitro

    NASA Astrophysics Data System (ADS)

    Bauer, Brigitte; Chen, Si; Käll, Mikael; Gunnarsson, Linda; Ericson, Marica B.

    2011-03-01

    We report on an investigation aimed to increase the efficiency of photodynamic therapy (PDT) through the influence of localized surface plasmon resonances (LSPR's) in metal nanoparticles. PDT is based on photosensitizers that generate singlet oxygen at the tumour site upon exposure to visible light. Although PDT is a well-established treatment for skin cancer, a major drawback is the low quantum yield for singlet-oxygen production. This motivates the development of novel methods that enhance singlet oxygen generation during treatment. In this context, we study the photodynamic effect on cultured human skin cells in the presence or absence of gold nanoparticles with well established LSPR and field-enhancement properties. The cultured skin cells were exposed to protoporphyrin IX and gold nanoparticles and subsequently illuminated with red light. We investigated the differences in cell viability by tuning different parameters, such as incubation time and light dose. In order to find optimal parameters for specific targeting of tumour cells, we compared normal human epidermal keratinocytes with a human squamous skin cancer cell line. The study indicates significantly enhanced cell death in the presence of nanoparticles and important differences in treatment efficiency between normal and tumour cells. These results are thus promising and clearly motivate further development of nanoparticle enhanced clinical PDT treatment.

  14. Human Endometrial Side Population Cells Exhibit Genotypic, Phenotypic and Functional Features of Somatic Stem Cells

    PubMed Central

    Cervelló, Irene; Gil-Sanchis, Claudia; Mas, Aymara; Delgado-Rosas, Francisco; Martínez-Conejero, José Antonio; Galán, Amparo; Martínez-Romero, Alicia; Martínez, Sebastian; Navarro, Ismael; Ferro, Jaime; Horcajadas, José Antonio; Esteban, Francisco José; O'Connor, José Enrique; Pellicer, Antonio; Simón, Carlos

    2010-01-01

    During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC. PMID:20585575

  15. Enhanced magnetic resonance imaging and staining of cancer cells using ferrimagnetic H-ferritin nanoparticles with increasing core size

    PubMed Central

    Cai, Yao; Cao, Changqian; He, Xiaoqing; Yang, Caiyun; Tian, Lanxiang; Zhu, Rixiang; Pan, Yongxin

    2015-01-01

    Purpose This study is to demonstrate the nanoscale size effect of ferrimagnetic H-ferritin (M-HFn) nanoparticles on magnetic properties, relaxivity, enzyme mimetic activities, and application in magnetic resonance imaging (MRI) and immunohistochemical staining of cancer cells. Materials and methods M-HFn nanoparticles with different sizes of magnetite cores in the range of 2.7–5.3 nm were synthesized through loading different amounts of iron into recombinant human H chain ferritin (HFn) shells. Core size, crystallinity, and magnetic properties of those M-HFn nanoparticles were analyzed by transmission electron microscope and low-temperature magnetic measurements. The MDA-MB-231 cancer cells were incubated with synthesized M-HFn nanoparticles for 24 hours in Dulbecco’s Modified Eagle’s Medium. In vitro MRI of cell pellets after M-HFn labeling was performed at 7 T. Iron uptake of cells was analyzed by Prussian blue staining and inductively coupled plasma mass spectrometry. Immunohistochemical staining by using the peroxidase-like activity of M-HFn nanoparticles was carried out on MDA-MB-231 tumor tissue paraffin sections. Results The saturation magnetization (Ms), relaxivity, and peroxidase-like activity of synthesized M-HFn nanoparticles were monotonously increased with the size of ferrimagnetic cores. The M-HFn nanoparticles with the largest core size of 5.3 nm exhibit the strongest saturation magnetization, the highest peroxidase activity in immunohistochemical staining, and the highest r2 of 321 mM−1 s−1, allowing to detect MDA-MB-231 breast cancer cells as low as 104 cells mL−1. Conclusion The magnetic properties, relaxivity, and peroxidase-like activity of M-HFn nanoparticles are size dependent, which indicates that M-HFn nanoparticles with larger magnetite core can significantly enhance performance in MRI and staining of cancer cells. PMID:25878496

  16. Immobilization of gold nanoparticles on cell culture surfaces for safe and enhanced gold nanoparticle-mediated laser transfection.

    PubMed

    Kalies, Stefan; Heinemann, Dag; Schomaker, Markus; Gentemann, Lara; Meyer, Heiko; Ripken, Tammo

    2014-01-01

    In comparison to standard transfection methods, gold nanoparticle-mediated laser transfection has proven to be a versatile alternative. This is based on its minor influence on cell viability and its high efficiency, especially for the delivery of small molecules like small interfering RNA. However, in order to transfer it to routine usage, a safety aspect is of major concern: The avoidance of nanoparticle uptake by the cells is desired. The immobilization of the gold nanoparticles on cell culture surfaces can address this issue. In this study, we achieved this by silanization of the appropriate surfaces and the binding of gold nanoparticles to them. Comparable perforation efficiencies to the previous approaches of gold nanoparticle-mediated laser transfection with free gold nanoparticles are demonstrated. The uptake of the immobilized particles by the cells is unlikely. Consequently, these investigations offer the possibility of bringing gold nanoparticle-mediated laser transfection closer to routine usage.

  17. Laser-targeted photofabrication of gold nanoparticles inside cells.

    PubMed

    Smith, Nicholas I; Mochizuki, Kentaro; Niioka, Hirohiko; Ichikawa, Satoshi; Pavillon, Nicolas; Hobro, Alison J; Ando, Jun; Fujita, Katsumasa; Kumagai, Yutaro

    2014-10-09

    Nanoparticle manipulation is of increasing interest, since they can report single molecule-level measurements of the cellular environment. Until now, however, intracellular nanoparticle locations have been essentially uncontrollable. Here we show that by infusing a gold ion solution, focused laser light-induced photoreduction allows in situ fabrication of gold nanoparticles at precise locations. The resulting particles are pure gold nanocrystals, distributed throughout the laser focus at sizes ranging from 2 to 20 nm, and remain in place even after removing the gold solution. We demonstrate the spatial control by scanning a laser beam to write characters in gold inside a cell. Plasmonically enhanced molecular signals could be detected from nanoparticles, allowing their use as nano-chemical probes at targeted locations inside the cell, with intracellular molecular feedback. Such light-based control of the intracellular particle generation reaction also offers avenues for in situ plasmonic device creation in organic targets, and may eventually link optical and electron microscopy.

  18. Nanoparticle-GFP "chemical nose" sensor for cancer cell identification.

    PubMed

    Moyano, Daniel F; Rotello, Vincent M

    2013-01-01

    Nanoparticle-based sensor arrays have been used to distinguish a wide range of bio-related molecules through pattern recognition. This "chemical nose" approach uses nanoparticles as receptors to selectively identify the analytes, while a transducer reports the binding through a readable signal (fluorescence). Here we describe a procedure that uses functionalized gold nanoparticles as receptors and green fluorescent protein (GFP) as the transducer to identify and differentiate cell state (normal, cancerous, and metastatic), an important tool in early diagnosis and treatment of tumors.

  19. Nanogel-quantum dot hybrid nanoparticles for live cell imaging

    SciTech Connect

    Hasegawa, Urara; Nomura, Shin-ichiro M.; Kaul, Sunil C.; Hirano, Takashi; Akiyoshi, Kazunari; E-mail: akiyoshi.org@tmd.ac.jp

    2005-06-17

    We report here a novel carrier of quantum dots (QDs) for intracellular labeling. Monodisperse hybrid nanoparticles (38 nm in diameter) of QDs were prepared by simple mixing with nanogels of cholesterol-bearing pullulan (CHP) modified with amino groups (CHPNH{sub 2}). The CHPNH{sub 2}-QD nanoparticles were effectively internalized into the various human cells examined. The efficiency of cellular uptake was much higher than that of a conventional carrier, cationic liposome. These hybrid nanoparticles could be a promising fluorescent probe for bioimaging.

  20. Infectious dengue vesicles derived from CD61+ cells in acute patient plasma exhibited a diaphanous appearance

    PubMed Central

    Hsu, Alan Yi-Hui; Wu, Shang-Rung; Tsai, Jih-Jin; Chen, Po-Lin; Chen, Ya-Ping; Chen, Tsai-Yun; Lo, Yu-Chih; Ho, Tzu-Chuan; Lee, Meed; Chen, Min-Ting; Chiu, Yen-Chi; Perng, Guey Chuen

    2015-01-01

    The levels of neutralizing antibody to a pathogen are an effective indicator to predict efficacy of a vaccine in trial. And yet not all the trial vaccines are in line with the theory. Using dengue virus (DENV) to investigate the viral morphology affecting the predictive value, we evaluated the viral morphology in acute dengue plasma compared to that of Vero cells derived DENV. The virions in plasma were infectious and heterogeneous in shape with a “sunny-side up egg” appearance, viral RNA was enclosed with CD61+ cell-derived membrane interspersed by the viral envelope protein, defined as dengue vesicles. The unique viral features were also observed from ex vivo infected human bone marrow. Dengue vesicles were less efficiently neutralized by convalescent patient serum, compared to virions produced from Vero cells. Our results exhibit a reason why potencies of protective immunity fail in vivo and significantly impact dengue vaccine and drug development. PMID:26657027

  1. Arbovirus-Derived piRNAs Exhibit a Ping-Pong Signature in Mosquito Cells

    PubMed Central

    Vodovar, Nicolas; Bronkhorst, Alfred W.; van Cleef, Koen W. R.; Miesen, Pascal; Blanc, Hervé; van Rij, Ronald P.; Saleh, Maria-Carla

    2012-01-01

    The siRNA pathway is an essential antiviral mechanism in insects. Whether other RNA interference pathways are involved in antiviral defense remains unclear. Here, we report in cells derived from the two main vectors for arboviruses, Aedes albopictus and Aedes aegypti, the production of viral small RNAs that exhibit the hallmarks of ping-pong derived piwi-associated RNAs (piRNAs) after infection with positive or negative sense RNA viruses. Furthermore, these cells produce endogenous piRNAs that mapped to transposable elements. Our results show that these mosquito cells can initiate de novo piRNA production and recapitulate the ping-pong dependent piRNA pathway upon viral infection. The mechanism of viral-piRNA production is discussed. PMID:22292064

  2. Infectious dengue vesicles derived from CD61+ cells in acute patient plasma exhibited a diaphanous appearance.

    PubMed

    Hsu, Alan Yi-Hui; Wu, Shang-Rung; Tsai, Jih-Jin; Chen, Po-Lin; Chen, Ya-Ping; Chen, Tsai-Yun; Lo, Yu-Chih; Ho, Tzu-Chuan; Lee, Meed; Chen, Min-Ting; Chiu, Yen-Chi; Perng, Guey Chuen

    2015-12-11

    The levels of neutralizing antibody to a pathogen are an effective indicator to predict efficacy of a vaccine in trial. And yet not all the trial vaccines are in line with the theory. Using dengue virus (DENV) to investigate the viral morphology affecting the predictive value, we evaluated the viral morphology in acute dengue plasma compared to that of Vero cells derived DENV. The virions in plasma were infectious and heterogeneous in shape with a "sunny-side up egg" appearance, viral RNA was enclosed with CD61+ cell-derived membrane interspersed by the viral envelope protein, defined as dengue vesicles. The unique viral features were also observed from ex vivo infected human bone marrow. Dengue vesicles were less efficiently neutralized by convalescent patient serum, compared to virions produced from Vero cells. Our results exhibit a reason why potencies of protective immunity fail in vivo and significantly impact dengue vaccine and drug development.

  3. Dendritic Cells Differentiated from Human Umbilical Cord Blood-Derived Monocytes Exhibit Tolerogenic Characteristics.

    PubMed

    Kim, Sun Kyung; Yun, Cheol-Heui; Han, Seung Hyun

    2015-12-01

    Human umbilical cord blood (UCB) is rich in diverse hematopoietic stem cells that are competent to differentiate into various cell types with immunological compatibility at transplantation. Thus, UCB is a potential source for the preparation of dendritic cells (DCs) to be used for cell therapy against inflammatory disorders or cancers. However, the immunological properties of UCB-derived DCs are not fully characterized. In this study, we investigated the phenotypes and functions of UCB monocyte-derived DCs (UCB-DCs) in comparison with those of adult peripheral blood (APB) monocyte-derived DCs (APB-DCs). UCB-DCs contained less CD1a(+) DCs, which is known as immunostimulatory DCs, than APB-DCs. UCB-DCs exhibited lower expression of CD80, MHC proteins, and DC-SIGN, but higher endocytic activity, than APB-DCs. Lipopolysaccharide stimulation of UCB-DCs minimally augmented the expression of maturation markers and production of interleukin (IL)-12 and tumor necrosis factor (TNF)-α, but potently expressed IL-10. When UCB-DCs were cocultured with CD14(+) cell-depleted allogeneic peripheral blood mononuclear cells, they weakly induced the proliferation, surface expression of activation markers, and interferon (IFN)-γ production of T lymphocytes compared with APB-DCs. UCB possessed higher levels of prostaglandin E2 (PGE2) than APB, which might be responsible for tolerogenic phenotypes and functions of UCB-DCs. Indeed, APB-DCs prepared in the presence of PGE2 exhibited CD1a(-)CD14(+) phenotypes with tolerogenic properties, including weak maturation, impaired IL-12 production, and negligible T lymphocyte activation as UCB-DCs did. Taken together, we suggest that UCB-DCs have tolerogenic properties, which might be due to PGE2 highly sustained in UCB.

  4. Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells

    NASA Astrophysics Data System (ADS)

    Li, Jing; Ma, Fang-Kui; Dang, Qi-Feng; Liang, Xing-Guo; Chen, Xi-Guang

    2014-12-01

    A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles (GCNPs), was developed for specific recognition and interaction with glucose transporters (Gluts) over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan (CS), and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of (187.9 ± 3.8) nm and a zeta potential of (- 15.43 ± 0.31) mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin (DOX) could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-loaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline (pH 7.4). In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.

  5. Nanoparticle derived contacts for photovoltaic cells

    SciTech Connect

    Ginley, D.S.

    1999-10-20

    Contacts are becoming increasingly important as PV devices move to higher efficiency and lower cost. The authors present an approach to developing contacts using nanoparticle-based precursors. Both elemental, alloy and compound nanoparticles can be employed for contacts. Ink based approaches can be utilized at low temperatures and utilize direct write techniques such as ink jet and screen printing. The ability to control the composition of the nanoparticle allows improved control of the contact metallurgy and the potential for thermodynamically stable interfaces. A key requirement is the ability to control the interface between particles and between particles and the substrate. The authors illustrate some of these principals with recent results on Al, Cu and (Hg,Cu)Te. They show that for the elemental materials control of the surface can prevent oxide formation and act as glue to control the reactivity of the nanoparticles.

  6. Vaccinium corymbosum L. (blueberry) extracts exhibit protective action against cadmium toxicity in Saccharomyces cerevisiae cells.

    PubMed

    Oprea, Eliza; Ruta, Lavinia L; Nicolau, Ioana; Popa, Claudia V; Neagoe, Aurora D; Farcasanu, Ileana C

    2014-01-01

    Blueberries (Vaccinium corymbosum L.) are a rich source of antioxidants and their consumption is believed to contribute to food-related protection against oxidative stress. In the present study, the chemoprotective action of blueberry extracts against cadmium toxicity was investigated using a cadmium-hypersensitive strain of Saccharomyces cerevisiae. Four varieties of blueberries were used in the study, and it was found that the extracts with high content of total anthocyanidins exhibited significant protective effect against the toxicity of cadmium and H2O2. Both the blueberry extracts and pure cyanidin exhibited protective effects against cadmium in a dose-dependent manner, but without significantly interfering with the cadmium accumulation by the yeast cells. The results imply that the blueberry extracts might be a potentially valuable food supplement for individuals exposed to high cadmium.

  7. Know thy nano neighbor. Plasmonic versus electron charging effects of metal nanoparticles in dye-sensitized solar cells.

    PubMed

    Choi, Hyunbong; Chen, Wei Ta; Kamat, Prashant V

    2012-05-22

    Neighboring metal nanoparticles influence photovoltaic and photocatalytic behavior of semiconductor nanostructures either through Fermi level equilibration by accepting electrons or inducing localized surface plasmon effects. By employing SiO(2)- and TiO(2)-capped Au nanoparticles we have identified the mechanism with which the performance of dye-sensitized solar cells (DSSC) is influenced by the neighboring metal nanoparticles. The efficiency of an N719 dye-sensitized solar cell (9.3%) increased to 10.2% upon incorporation of 0.7% Au@SiO(2) and to 9.8% upon loading of 0.7% Au@TiO(2) nanoparticles. The plasmonic effect as monitored by introducing Au@SiO(2) in DSSC produces higher photocurrent. However, Au nanoparticles undergo charge equilibration with TiO(2) nanoparticles and shift the apparent Fermi level of the composite to more negative potentials. As a result, Au@TiO(2) nanoparticle-embedded DSSC exhibit higher photovoltage. A better understanding of these two effects is crucial in exploiting the beneficial aspects of metal nanoparticles in photovoltaics.

  8. Cytotoxic Effect of Lipophilic Bismuth Dimercaptopropanol Nanoparticles on Epithelial Cells.

    PubMed

    Rene, Hernandez-Delgadillo; Badireddy, Appala Raju; José, Martínez-Sanmiguel Juan; Francisco, Contreras-Cordero Juan; Israel, Martinez-Gonzalez Gustavo; Isela, Sánchez-Nájera Rosa; Chellam, Shankararaman; Claudio, Cabral-Romero

    2016-01-01

    Bismuth nanoparticles have many interesting properties to be applied in biomedical and medicinal sectors, however their safety in humans have not been comprehensively investigated. The objective of this research was to determine the cytotoxic effect of bismuth dimercaptopropanol nanoparticles (BisBAL NPs) on epithelial cells. The nanoparticles are composed of 18.7 nm crystallites on average and have a rhombohedral structure, agglomerating into chains-like or clusters of small nanoparticles. Based on MTT viability assay and fluorescence microscopy, cytotoxicity was not observed on monkey kidney cells after growing with 5 µM of BisBAL NPs for 24 h. Employing same techniques, identical results were obtained with human epithelial cells (HeLa), showing a not strain-dependent phenomenon. The absence of toxic effects on epithelial cells growing with BisBAL NPs was corroborated with long-time experiments (24-72 hrs.), showing no difference in comparison with growing control (cells without nanoparticles). Further, genotoxicity assays, comet assay and fluorescent microscopy and electrophoresis in bromide-stained agarose gel revealed no damage to genomic DNA of MA104 cells after 24 h. of exposition to BisBAL NPs. Finally, the effect of bismuth nanoparticles on protein synthesis was studied in cells growing with BisBAL NPs for 24 h. SDS-PAGE assays showed no difference between treated and untreated cells, suggesting that BisBAL NPs did not interfere with protein synthesis. Hence BisBAL NPs do not appear to exert cytotoxic effects suggesting their biological compatibility with epithelial cells.

  9. Cytotoxic Effect of Lipophilic Bismuth Dimercaptopropanol Nanoparticles on Epithelial Cells.

    PubMed

    Rene, Hernandez-Delgadillo; Badireddy, Appala Raju; José, Martínez-Sanmiguel Juan; Francisco, Contreras-Cordero Juan; Israel, Martinez-Gonzalez Gustavo; Isela, Sánchez-Nájera Rosa; Chellam, Shankararaman; Claudio, Cabral-Romero

    2016-01-01

    Bismuth nanoparticles have many interesting properties to be applied in biomedical and medicinal sectors, however their safety in humans have not been comprehensively investigated. The objective of this research was to determine the cytotoxic effect of bismuth dimercaptopropanol nanoparticles (BisBAL NPs) on epithelial cells. The nanoparticles are composed of 18.7 nm crystallites on average and have a rhombohedral structure, agglomerating into chains-like or clusters of small nanoparticles. Based on MTT viability assay and fluorescence microscopy, cytotoxicity was not observed on monkey kidney cells after growing with 5 µM of BisBAL NPs for 24 h. Employing same techniques, identical results were obtained with human epithelial cells (HeLa), showing a not strain-dependent phenomenon. The absence of toxic effects on epithelial cells growing with BisBAL NPs was corroborated with long-time experiments (24-72 hrs.), showing no difference in comparison with growing control (cells without nanoparticles). Further, genotoxicity assays, comet assay and fluorescent microscopy and electrophoresis in bromide-stained agarose gel revealed no damage to genomic DNA of MA104 cells after 24 h. of exposition to BisBAL NPs. Finally, the effect of bismuth nanoparticles on protein synthesis was studied in cells growing with BisBAL NPs for 24 h. SDS-PAGE assays showed no difference between treated and untreated cells, suggesting that BisBAL NPs did not interfere with protein synthesis. Hence BisBAL NPs do not appear to exert cytotoxic effects suggesting their biological compatibility with epithelial cells. PMID:27398446

  10. Three dimensional spheroid cell culture for nanoparticle safety testing.

    PubMed

    Sambale, Franziska; Lavrentieva, Antonina; Stahl, Frank; Blume, Cornelia; Stiesch, Meike; Kasper, Cornelia; Bahnemann, Detlef; Scheper, Thomas

    2015-07-10

    Nanoparticles are widely employed for many applications and the number of consumer products, incorporating nanotechnology, is constantly increasing. A novel area of nanotechnology is the application in medical implants. The widespread use of nanoparticles leads to their higher prevalence in our environment. This, in turn, raises concerns regarding potential risks to humans. Previous studies have shown possible hazardous effects of some nanoparticles on mammalian cells grown in two-dimensional (2D) cultures. However, 2D in vitro cell cultures display several disadvantages such as changes in cell shape, cell function, cell responses and lack of cell-cell contacts. For this reason, the development of better models for mimicking in vivo conditions is essential. In the present work, we cultivated A549 cells and NIH-3T3 cells in three-dimensional (3D) spheroids and investigated the effects of zinc oxide (ZnO-NP) and titanium dioxide nanoparticles (TiO2-NP). The results were compared to cultivation in 2D monolayer culture. A549 cells in 3D cell culture formed loose aggregates which were more sensitive to the toxicity of ZnO-NP in comparison to cells grown in 2D monolayers. In contrast, NIH-3T3 cells showed a compact 3D spheroid structure and no differences in the sensitivity of the NIH-3T3 cells to ZnO-NP were observed between 2D and 3D cultures. TiO2-NP were non-toxic in 2D cultures but affected cell-cell interaction during 3D spheroid formation of A549 and NIH-3T3 cells. When TiO2-NP were directly added during spheroid formation in the cultures of the two cell lines tested, several smaller spheroids were formed instead of a single spheroid. This effect was not observed if the nanoparticles were added after spheroid formation. In this case, a slight decrease in cell viability was determined only for A549 3D spheroids. The obtained results demonstrate the importance of 3D cell culture studies for nanoparticle safety testing, since some effects cannot be revealed in 2D

  11. Daunomycin-loaded superparamagnetic iron oxide nanoparticles: Preparation, magnetic targeting, cell cytotoxicity, and protein delivery research.

    PubMed

    Liu, Min-Chao; Jin, Shu-Fang; Zheng, Min; Wang, Yan; Zhao, Peng-Liang; Tang, Ding-Tong; Chen, Jiong; Lin, Jia-Qi; Wang, Xia-Hong; Zhao, Ping

    2016-08-01

    The clinical use of daunomycin is restricted by dose-dependent toxicity and low specificity against cancer cells. In the present study, modified superparamagnetic iron oxide nanoparticles were employed to load daunomycin and the drug-loaded nanospheres exhibited satisfactory size and smart pH-responsive release. The cellular uptake efficiency, targeted cell accumulation, and cell cytotoxicity experimental results proved that the superparamagnetic iron oxide nanoparticle-loading process brings high drug targeting without decreasing the cytotoxicity of daunomycin. Moreover, a new concern for the evaluation of nanophase drug delivery's effects was considered, with monitoring the interactions between human serum albumin and the drug-loaded nanospheres. Results from the multispectroscopic techniques and molecular modeling calculation elucidate that the drug delivery has detectable deleterious effects on the frame conformation of protein, which may affect its physiological function. PMID:27288463

  12. Human T-cell leukemia virus types I and II exhibit different DNase I protection patterns.

    PubMed

    Altman, R; Harrich, D; Garcia, J A; Gaynor, R B

    1988-04-01

    Human T-cell leukemia virus types I (HTLV-I) and II (HTLV-II) are human retroviruses which normally infect T-lymphoid cells. HTLV-I infection is associated with adult T-cell leukemia-lymphoma, and HTLV-II is associated with an indolent form of hairy-cell leukemia. To identify potential transcriptional regulatory elements of these two related human retroviruses, we performed DNase I footprinting of both the HTLV-I and HTLV-II long terminal repeats (LTRs) by using extracts prepared from uninfected T cells, HTLV-I and HTLV-II transformed T cells, and HeLa cells. Five regions of the HTLV-I LTR and three regions of the HTLV-II LTR showed protection by DNase I footprinting. All three of the 21-base-pair repeats previously shown to be important in HTLV transcriptional regulation were protected in the HTLV-I LTR, whereas only one of these repeats was protected in the HTLV-II LTR. Several regions exhibited altered protection in extracts prepared from lymphoid cells as compared with HeLa cells, but there were minimal differences in the protection patterns between HTLV-infected and uninfected lymphoid extracts. A number of HTLV-I and HTLV-II LTR fragments which contained regions showing protection in DNase I footprinting were able to function as inducible enhancer elements in transient CAT gene expression assays in the presence of the HTLV-II tat protein. The alterations in the pattern of the cellular proteins which bind to the HTLV-I and HTLV-II LTRs may in part be responsible for differences in the transcriptional regulation of these two related viruses.

  13. Silver nanoparticles-coated glass frits for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Li, Yingfen; Gan, Weiping; Li, Biyuan

    2016-04-01

    Silver nanoparticles-coated glass frit composite powders for silicon solar cells were prepared by electroless plating. Silver colloids were used as the activating agent of glass frits. The products were characterized by X-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. The characterization results indicated that silver nanoparticles with the melting temperature of 838 °C were uniformly deposited on glass frit surface. The particle size of silver nanoparticles could be controlled by adjusting the [Ag(NH3)2]NO3 concentration. The as-prepared composite powders were applied in the front side metallization of silicon solar cells. Compared with those based on pure glass frits, the solar cells containing the composite powders had the denser silver electrodes and the better silver-silicon ohmic contacts. Furthermore, the photovoltaic performances of solar cells were improved after the electroless plating.

  14. Mice lacking TrkB in parvalbumin-positive cells exhibit sexually dimorphic behavioral phenotypes.

    PubMed

    Lucas, Elizabeth K; Jegarl, Anita; Clem, Roger L

    2014-11-01

    Activity-dependent brain-derived neurotrophic factor (BDNF) signaling through receptor tyrosine kinase B (TrkB) is required for cued fear memory consolidation and extinction. Although BDNF is primarily secreted from glutamatergic neurons, TrkB is expressed by other genetically defined cells whose contributions to the behavioral effects of BDNF remain poorly understood. Parvalbumin (PV)-positive interneurons, which are highly enriched in TrkB, are emerging as key regulators of fear memory expression. We therefore hypothesized that activity-dependent BDNF signaling in PV-interneurons may modulate emotional learning. To test this hypothesis, we utilized the LoxP/Cre system for conditional deletion of TrkB in PV-positive cells to examine the impact of cell-autonomous BDNF signaling on Pavlovian fear conditioning and extinction. However, behavioral abnormalities indicative of vestibular dysfunction precluded the use of homozygous conditional knockouts in tests of higher cognitive functioning. While vestibular dysfunction was apparent in both sexes, female conditional knockouts exhibited an exacerbated phenotype, including extreme motor hyperactivity and circling behavior, compared to their male littermates. Heterozygous conditional knockouts were spared of vestibular dysfunction. While fear memory consolidation was unaffected in heterozygotes of both sexes, males exhibited impaired extinction consolidation compared to their littermate controls. Our findings complement evidence from human and rodent studies suggesting that BDNF signaling promotes consolidation of extinction and point to PV-positive neurons as a discrete population that mediates these effects in a sex-specific manner.

  15. Mice lacking TrkB in parvalbumin-positive cells exhibit sexually dimorphic behavioral phenotypes

    PubMed Central

    Lucas, Elizabeth K.; Jegarl, Anita; Clem, Roger L.

    2016-01-01

    Activity-dependent brain-derived neurotrophic factor (BDNF) signaling through receptor tyrosine kinase B (TrkB) is required for cued fear memory consolidation and extinction. Although BDNF is primarily secreted from glutamatergic neurons, TrkB is expressed by other genetically defined cells whose contributions to the behavioral effects of BDNF remain poorly understood. Parvalbumin (PV)-positive interneurons, which are highly enriched in TrkB, are emerging as key regulators of fear memory expression. We therefore hypothesized that activity-dependent BDNF signaling in PV-interneurons may modulate emotional learning. To test this hypothesis, we utilized the LoxP/Cre system for conditional deletion of TrkB in PV-positive cells to examine the impact of cell-autonomous BDNF signaling on Pavlovian fear conditioning and extinction. However, behavioral abnormalities indicative of vestibular dysfunction precluded the use of homozygous conditional knockouts in tests of higher cognitive functioning. While vestibular dysfunction was apparent in both sexes, female conditional knockouts exhibited an exacerbated phenotype, including extreme motor hyperactivity and circling behavior, compared to their male littermates. Heterozygous conditional knockouts were spared of vestibular dysfunction. While fear memory consolidation was unaffected in heterozygotes of both sexes, males exhibited impaired extinction consolidation compared to their littermate controls. Our findings complement evidence from human and rodent studies suggesting that BDNF signaling promotes consolidation of extinction and point to PV-positive neurons as a discrete population that mediates these effects in a sex-specific manner. PMID:25127683

  16. Hematopoietic stem cells from NOD mice exhibit autonomous behavior and a competitive advantage in allogeneic recipients.

    PubMed

    Chilton, Paula M; Rezzoug, Francine; Ratajczak, Mariusz Z; Fugier-Vivier, Isabelle; Ratajczak, Janina; Kucia, Magda; Huang, Yiming; Tanner, Michael K; Ildstad, Suzanne T

    2005-03-01

    Type 1 diabetes is a systemic autoimmune disease that can be cured by transplantation of hematopoietic stem cells (HSCs) from disease-resistant donors. Nonobese diabetic (NOD) mice have a number of features that distinguish them as bone marrow transplant recipients that must be understood prior to the clinical application of chimerism to induce tolerance. In the present studies, we characterized NOD HSCs, comparing their engraftment characteristics to HSCs from disease-resistant strains. Strikingly, NOD HSCs are significantly enhanced in engraftment potential compared with HSCs from disease-resistant donors. Unlike HSCs from disease-resistant strains, they do not require graft-facilitating cells to engraft in allogeneic recipients. Additionally, they exhibit a competitive advantage when coadministered with increasing numbers of syngeneic HSCs, produce significantly more spleen colony-forming units (CFU-Ss) in vivo in allogeneic recipients, and more granulocyte macrophage-colony-forming units (CFU-GMs) in vitro compared with HSCs from disease-resistant controls. NOD HSCs also exhibit significantly enhanced chemotaxis to a stromal cell-derived factor 1 (SDF-1) gradient and adhere significantly better on primary stroma. This enhanced engraftment potential maps to the insulin-dependent diabetes locus 9 (Idd9) locus, and as such the tumor necrosis factor (TNF) receptor family as well as ski/sno genes may be involved in the mechanism underlying the autonomy of NOD HSCs. These findings may have important implications to understand the evolution of autoimmune disease and impact on potential strategies for cure. PMID:15522953

  17. Toxicity of Cerium Oxide Nanoparticles in Human Lung Cancer Cells

    SciTech Connect

    Weisheng, Lin; Huang, Yue-wern; Zhou, Xiao Dong; Ma, Yinfa

    2006-12-31

    With the fast development of nanotechnology, the nanomaterials start to cause people's attention for potential toxic effect. In this paper, the cytotoxicity and oxidative stress caused by 20-nm cerium oxide (CeO2) nanoparticles in cultured human lung cancer cells was investigated. The sulforhodamine B method was employed to assess cell viability after exposure to 3.5, 10.5, and 23.3 μg/ml of CeO2 nanoparticles for 24, 48, and 72 h. Cell viability decreased significantly as a function of nanoparticle dose and exposure time. Indicators of oxidative stress and cytotoxicity, including total reactive oxygen species, glutathione, malondialdehyde, α-tocopherol, and lactate dehydrogenase, were quantitatively assessed. It is concluded from the results that free radicals generated by exposure to 3.5 to 23.3 μg/ml CeO2 nanoparticles produce significant oxidative stress in the cells, as reflected by reduced glutathione and α-tocopherol levels; the toxic effects of CeO2 nanoparticles are dose dependent and time dependent; elevated oxidative stress increases the production of malondialdehyde and lactate dehydrogenase, which are indicators of lipid peroxidation and cell membrane damage, respectively.

  18. UCP2- and non-UCP2-mediated electric current in eukaryotic cells exhibits different properties.

    PubMed

    Wang, Ruihua; MoYung, K C; Zhang, M H; Poon, Karen

    2015-12-01

    Using live eukaryotic cells, including cancer cells, MCF-7 and HCT-116, normal hepatocytes and red blood cells in anode and potassium ferricyanide in cathode of MFC could generate bio-based electric current. Electrons and protons generated from the metabolic reaction in both cytosol and mitochondria contributing to the leaking would mediate the generation of electric current. Both resveratrol (RVT) and 2,4-dinitrophenol (DNP) used to induce proton leak in mitochondria were found to promote electric current production in all cells except red blood cells without mitochondria. Proton leak might be important for electric current production by bringing the charge balance in cells to enhance the further electron leak. The induced electric current by RVT can be blocked by Genipin, an inhibitor of UCP2-mediated proton leak, while that induced by DNP cannot. RVT could reduce reactive oxygen species (ROS) level in cells better than that of DNP. In addition, RVT increased mitochondrial membrane potential (MMP), while DNP decreased it. Results highly suggested the existence of at least two types of electric current that showed different properties. They included UCP2-mediated and non-UCP2-mediated electric current. UCP2-mediated electric current exhibited higher reactive oxygen species (ROS) reduction effect per unit electric current production than that of non-UCP2-mediated electric current. Higher UCP2-mediated electric current observed in cancer cells might contribute to the mechanism of drug resistence. Correlation could not be established between electric current production with either ROS and MMP without distinguishing the types of electric current.

  19. A Novel, Potent, Small Molecule AKT Inhibitor Exhibits Efficacy against Lung Cancer Cells In Vitro

    PubMed Central

    Dinavahi, Saketh S.; Prasanna, Rajagopalan; Dharmarajan, Sriram; Perumal, Yogeeswari; Viswanadha, Srikant

    2015-01-01

    Purpose Anomalies of Akt regulation, including overexpression in lung cancer, impart resistance to conventional chemotherapy and radiation, thereby implicating this kinase as a therapeutic intervention point. A novel scaffold of Akt inhibitors was developed through virtual screening of chemical databases available at Birla Institute of Technology and Science, Pilani, Hyderabad, based on docking studies using Maestro. A benzothienopyrimidine derivative (BIA-6) was identified as a potential lead molecule that inhibited Akt1 enzyme activity with an IC50 of 256 nM. Materials and Methods BIA-6 was tested for in vitro Akt1 inhibition using a fluorescence resonance energy transfer kit. Anti-proliferative activity was tested in NCI-H460, A549, NCI-H1975, and NCI-H2170 cell lines. The effect of the compound on p-Akt (S473) was estimated. Results BIA-6 allosterically caused a dose dependent reduction of growth of cell lines with a half maximal growth inhibition (GI50) range of 0.49 μM to 6.6 μM. Cell cycle analysis indicated that BIA-6 caused a G1 phase arrest at < 100 nM but led to apoptosis at higher doses. BIA-6 also exhibited synergism with standard chemotherapeutic agents. Conclusion BIA-6 is a novel, allosteric Akt inhibitor with potent anti-cancer activity in lung cancer cell lines, that effectively blocks the phosphoinositide-3 kinase/Akt pathway with a high margin selectivity towards normal cells. PMID:25687876

  20. Hepatitis B virus X protein mutants exhibit distinct biological activities in hepatoma Huh7 cells

    SciTech Connect

    Liu Xiaohong; Zhang Shuhui; Lin Jing; Zhang Shunmin; Feitelson, Mark A.; Gao Hengjun; Zhu Minghua

    2008-09-05

    The role of the hepatitis B virus X protein (HBx) in hepatocarcinogenesis remains controversial. To investigate the biological impact of hepatitis B virus x gene (HBx) mutation on hepatoma cells, plasmids expressing the full-length HBx or HBx deletion mutants were constructed. The biological activities in these transfectants were analyzed by a series of assays. Results showed that HBx3'-20 and HBx3'-40 amino acid deletion mutants exhibited an increase in cellular proliferation, focus formation, tumorigenicity, and invasive growth and metastasis through promotion of the cell cycle from G0/G1 to the S phase, when compared with the full-length HBx. In contrast, HBx3'-30 amino acid deletion mutant repressed cell proliferation by blocking in G1 phase. The expression of P53, p21{sup WAF1}, p14{sup ARF}, and MDM2 proteins was regulated by expression of HBx mutants. In conclusions, HBx variants showed different effects and functions on cell proliferation and invasion by regulation of the cell cycle progression and its associated proteins expression.

  1. Firefly luciferase and RLuc8 exhibit differential sensitivity to oxidative stress in apoptotic cells.

    PubMed

    Czupryna, Julie; Tsourkas, Andrew

    2011-01-01

    Over the past decade, firefly Luciferase (fLuc) has been used in a wide range of biological assays, providing insight into gene regulation, protein-protein interactions, cell proliferation, and cell migration. However, it has also been well established that fLuc activity can be highly sensitive to its surrounding environment. In this study, we found that when various cancer cell lines (HeLa, MCF-7, and 293T) stably expressing fLuc were treated with staurosporine (STS), there was a rapid loss in bioluminescence. In contrast, a stable variant of Renilla luciferase (RLuc), RLuc8, exhibited significantly prolonged functionality under the same conditions. To identify the specific underlying mechanism(s) responsible for the disparate sensitivity of RLuc8 and fLuc to cellular stress, we conducted a series of inhibition studies that targeted known intracellular protein degradation/modification pathways associated with cell death. Interestingly, these studies suggested that reactive oxygen species, particularly hydrogen peroxide (H(2)O(2)), was responsible for the diminution of fLuc activity. Consistent with these findings, the direct application of H(2)O(2) to HeLa cells also led to a reduction in fLuc bioluminescence, while H(2)O(2) scavengers stabilized fLuc activity. Comparatively, RLuc8 was far less sensitive to ROS. These observations suggest that fLuc activity can be substantially altered in studies where ROS levels become elevated and can potentially lead to ambiguous or misleading findings.

  2. Anionic polymers and 10 nm Fe₃O₄@UA wound dressings support human foetal stem cells normal development and exhibit great antimicrobial properties.

    PubMed

    Grumezescu, Alexandru Mihai; Holban, Alina Maria; Andronescu, Ecaterina; Mogoşanu, George Dan; Vasile, Bogdan Stefan; Chifiriuc, Mariana Carmen; Lazar, Veronica; Andrei, Eugen; Constantinescu, Andrei; Maniu, Horia

    2014-03-25

    The aims of this study were the development, characterization and bioevaluation of a novel biocompatible, resorbable and bio-active wound dressing prototype, based on anionic polymers (sodium alginate--AlgNa, carboximethylcellulose--CMC) and magnetic nanoparticles loaded with usnic acid (Fe₃O₄@UA). The antimicrobial activity was tested against Staphylococcus aureus grown in biofilms. The biocompatibility testing model included an endothelial cell line from human umbilical vein and human foetal progenitor cells derived from the amniotic fluid, that express a wide spectrum of surface molecules involved in different vascular functions and inflammatory response, and may be used as skin regenerative support. The obtained results demonstrated that CMC/Fe₃O₄@UA and AlgNa/Fe₃O₄@UA are exhibiting structural and functional properties that recommend them for further applications in the biomedical field. They could be used alone or coated with different bio-active compounds, such as Fe₃O₄@UA, for the development of novel, multifunctional porous materials used in tissues regeneration, as antimicrobial substances releasing devices, providing also a mechanical support for the eukaryotic cells adhesion, and exhibiting the advantage of low cytotoxicity on human progenitor cells. The great antimicrobial properties exhibited by the newly synthesized nano-bioactive coatings are recommending them as successful candidates for improving the implanted devices surfaces used in regenerative medicine. PMID:23994366

  3. Anionic polymers and 10 nm Fe₃O₄@UA wound dressings support human foetal stem cells normal development and exhibit great antimicrobial properties.

    PubMed

    Grumezescu, Alexandru Mihai; Holban, Alina Maria; Andronescu, Ecaterina; Mogoşanu, George Dan; Vasile, Bogdan Stefan; Chifiriuc, Mariana Carmen; Lazar, Veronica; Andrei, Eugen; Constantinescu, Andrei; Maniu, Horia

    2014-03-25

    The aims of this study were the development, characterization and bioevaluation of a novel biocompatible, resorbable and bio-active wound dressing prototype, based on anionic polymers (sodium alginate--AlgNa, carboximethylcellulose--CMC) and magnetic nanoparticles loaded with usnic acid (Fe₃O₄@UA). The antimicrobial activity was tested against Staphylococcus aureus grown in biofilms. The biocompatibility testing model included an endothelial cell line from human umbilical vein and human foetal progenitor cells derived from the amniotic fluid, that express a wide spectrum of surface molecules involved in different vascular functions and inflammatory response, and may be used as skin regenerative support. The obtained results demonstrated that CMC/Fe₃O₄@UA and AlgNa/Fe₃O₄@UA are exhibiting structural and functional properties that recommend them for further applications in the biomedical field. They could be used alone or coated with different bio-active compounds, such as Fe₃O₄@UA, for the development of novel, multifunctional porous materials used in tissues regeneration, as antimicrobial substances releasing devices, providing also a mechanical support for the eukaryotic cells adhesion, and exhibiting the advantage of low cytotoxicity on human progenitor cells. The great antimicrobial properties exhibited by the newly synthesized nano-bioactive coatings are recommending them as successful candidates for improving the implanted devices surfaces used in regenerative medicine.

  4. Quercetin conjugated superparamagnetic magnetite nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy applications.

    PubMed

    Kumar, S Rajesh; Priyatharshni, S; Babu, V N; Mangalaraj, D; Viswanathan, C; Kannan, S; Ponpandian, N

    2014-12-15

    The magnetic nanoparticles attract increasing interest due to their opportunities in cancer therapy and used as drug carriers for several other diseases. The present study investigates the quercetin conjugated superparamagnetic Fe3O4 nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy. A simple precipitation method was used to prepare the dextran coated Fe3O4 nanoparticles and the anticancer flavonoid quercetin was conjugated on the surface via carboxylic/amine group using nanoprecipitation method. The structural, morphological and the magnetic properties of the prepared materials were studied by using X-ray diffractometer (XRD), Fourier transformed infer-red spectrometer (FTIR), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The MTT (3-(4,5-dimethylthiahiazol-2-yl)-2,5-diphenyl tetrazolium) assay of dextran coated Fe3O4 nanoparticles did not exhibit notable toxicity against MCF7 cells, whereas the cytotoxicity of quercetin conjugated Fe3O4 nanoparticles increased significantly in comparison with pure quercetin. The incubation of MCF-7 cells with quercetin conjugated Fe3O4 nanoparticles (QCMNPs) shows significant changes in cellular morphology observed through fluorescent microscopy. The results validate the prepared quercetin conjugated Fe3O4 nanoparticles are promising anticancer agents for targeted drug delivery. PMID:25278361

  5. Quercetin conjugated superparamagnetic magnetite nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy applications.

    PubMed

    Kumar, S Rajesh; Priyatharshni, S; Babu, V N; Mangalaraj, D; Viswanathan, C; Kannan, S; Ponpandian, N

    2014-12-15

    The magnetic nanoparticles attract increasing interest due to their opportunities in cancer therapy and used as drug carriers for several other diseases. The present study investigates the quercetin conjugated superparamagnetic Fe3O4 nanoparticles for in-vitro analysis of breast cancer cell lines for chemotherapy. A simple precipitation method was used to prepare the dextran coated Fe3O4 nanoparticles and the anticancer flavonoid quercetin was conjugated on the surface via carboxylic/amine group using nanoprecipitation method. The structural, morphological and the magnetic properties of the prepared materials were studied by using X-ray diffractometer (XRD), Fourier transformed infer-red spectrometer (FTIR), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The MTT (3-(4,5-dimethylthiahiazol-2-yl)-2,5-diphenyl tetrazolium) assay of dextran coated Fe3O4 nanoparticles did not exhibit notable toxicity against MCF7 cells, whereas the cytotoxicity of quercetin conjugated Fe3O4 nanoparticles increased significantly in comparison with pure quercetin. The incubation of MCF-7 cells with quercetin conjugated Fe3O4 nanoparticles (QCMNPs) shows significant changes in cellular morphology observed through fluorescent microscopy. The results validate the prepared quercetin conjugated Fe3O4 nanoparticles are promising anticancer agents for targeted drug delivery.

  6. Antitumor effect of TRAIL on oral squamous cell carcinoma using magnetic nanoparticle-mediated gene expression.

    PubMed

    Miao, Leiying; Liu, Chao; Ge, Jiuyu; Yang, Weidong; Liu, Jinzhong; Sun, Weibin; Yang, Bai; Zheng, Changyu; Sun, Hongchen; Hu, Qingang

    2014-07-01

    We developed a new magnetic nanovector to improve the efficiency and targeting of transgene therapy for oral squamous cell carcinoma (OSCC). Positively charged polymer PEI-modified Fe(3)O(4) magnetic nanoparticles were tested as gene transfer vectors in the presence of a magnetic field. The Fe(3)O(4) nanoparticles were prepared by a co-precipitation method and had good dispersibility in water. These nanoparticles modified by PEI were combined with negatively charged pACTERT-EGFP via electrostatic interaction. The transfection efficiency of the magnetic nano-gene vector with the magnetic field was determined by a fluorescence-inverted microscope and flow cytometry. The results showed significant improvement compared with the control group (p < 0.05). The magnetic complexes also exhibited up to 6-times higher transfection efficiency compared with commonly used PEI or lipofectin. On the basis of these results, the antitumor effect with suicide gene therapy using pACTERT-TRAIL in vitro and vivo was evaluated. In vitro apoptosis was determined with the Annexin V-FITC Apoptosis Detection Kit. The results suggested that PEI-modified Fe(3)O(4) nanoparticles could mediate the killing of Tca83 cells. Furthermore, treatment with pACTERT-TRAIL delivered by magnetic nanoparticles showed a significant cytostatic effect through the induction of apoptosis in a xenograft model. This indicates that magnetic nano-gene vectors could improve the transgene efficiency for Tca83 cells and could exhibit antitumor functions with the plasmid pACTERT-TRAIL. This may be a new way to treat OSCC.

  7. Drug-loaded nanoparticles induce gene expression in human pluripotent stem cell derivatives

    NASA Astrophysics Data System (ADS)

    Gajbhiye, Virendra; Escalante, Leah; Chen, Guojun; Laperle, Alex; Zheng, Qifeng; Steyer, Benjamin; Gong, Shaoqin; Saha, Krishanu

    2013-12-01

    Tissue engineering and advanced manufacturing of human stem cells requires a suite of tools to control gene expression spatiotemporally in culture. Inducible gene expression systems offer cell-extrinsic control, typically through addition of small molecules, but small molecule inducers typically contain few functional groups for further chemical modification. Doxycycline (DXC), a potent small molecule inducer of tetracycline (Tet) transgene systems, was conjugated to a hyperbranched dendritic polymer (Boltorn H40) and subsequently reacted with polyethylene glycol (PEG). The resulting PEG-H40-DXC nanoparticle exhibited pH-sensitive drug release behavior and successfully controlled gene expression in stem-cell-derived fibroblasts with a Tet-On system. While free DXC inhibited fibroblast proliferation and matrix metalloproteinase (MMP) activity, PEG-H40-DXC nanoparticles maintained higher fibroblast proliferation levels and MMP activity. The results demonstrate that the PEG-H40-DXC nanoparticle system provides an effective tool to controlling gene expression in human stem cell derivatives.Tissue engineering and advanced manufacturing of human stem cells requires a suite of tools to control gene expression spatiotemporally in culture. Inducible gene expression systems offer cell-extrinsic control, typically through addition of small molecules, but small molecule inducers typically contain few functional groups for further chemical modification. Doxycycline (DXC), a potent small molecule inducer of tetracycline (Tet) transgene systems, was conjugated to a hyperbranched dendritic polymer (Boltorn H40) and subsequently reacted with polyethylene glycol (PEG). The resulting PEG-H40-DXC nanoparticle exhibited pH-sensitive drug release behavior and successfully controlled gene expression in stem-cell-derived fibroblasts with a Tet-On system. While free DXC inhibited fibroblast proliferation and matrix metalloproteinase (MMP) activity, PEG-H40-DXC nanoparticles maintained

  8. Preparation of iron oxide-entrapped chitosan nanoparticles for stem cell labeling.

    PubMed

    Chaleawlert-Umpon, Saowaluk; Mayen, Varissaporn; Manotham, Krissanapong; Pimpha, Nuttaporn

    2010-01-01

    This study intended to prepare iron oxide nanoparticle-entrapped chitosan (CS) nanoparticles for stem cell labeling. The nanoparticles were synthesized by polymerizing iron oxide nanoparticle-associated methacrylic acid monomer in the presence of CS. TEM revealed that the well-defined iron oxide nanoparticles were successfully encapsulated inside the CS nanoparticles. The effect of CS at different [NH(2)]/[COOH] molar ratios on particle size, surface charge, thermal stability and magnetic properties was determined systematically. Internalization and localization of the coated nanoparticles were evaluated by atomic absorption spectrometry and confocal laser scanning microscopy. The Kusa O cell line was chosen as a stem cell model. Interestingly, the uptake of iron oxide-entrapped CS nanoparticles was remarkably enhanced under magnetization and the nanoparticles were mostly located inside cellular compartments. It can be concluded that the iron oxide-entrapped CS nanoparticles have a strong potential for stem cell labeling. PMID:20537238

  9. Encapsulation of honokiol into self-assembled pectin nanoparticles for drug delivery to HepG2 cells.

    PubMed

    Zhang, Yuxia; Chen, Tong; Yuan, Pei; Tian, Rui; Hu, Wenjing; Tang, Yalan; Jia, Yuntao; Zhang, Liangke

    2015-11-20

    Self-assembled pectin nanoparticles was prepared and evaluated for delivering the hydrophobic drug, honokiol (HK), to HepG2 cells. These hydrophobic drug-loaded nanoparticles were developed without using any surfactant and organic solvent. Hydroxypropyl-β-cyclodextrin (HCD) was used to fabricate an inclusion complex with HK (HKHCD) to increase the solubility of the drug and thus facilitate its encapsulation and dispersion in the pectin nanoparticles. Investigation of the in vitro release indicated that the drug-loaded nanoparticles exhibited a higher drug release rate than free honokiol and an effective sustained-release. Cytotoxicity, cell apoptosis and cellular uptake studies further confirmed that the pectin nanoparticles with galactose residues generated higher cytotoxicity than free honokiol on HepG2 cells which highly expressed asialoglycoprotein receptors (ASGR). Nevertheless, these findings were not observed in ASGR-negative A549 cells under similar condition. Therefore, pectin nanoparticles demonstrated a specific active targeting ability to ASGR-positive HepG2 cells and could be used as a potential drug carrier for treatment of liver-related tumors. PMID:26344251

  10. Novel STAT3 phosphorylation inhibitors exhibit potent growth suppressive activity in pancreatic and breast cancer cells

    PubMed Central

    Lin, Li; Hutzen, Brian; Zuo, Mingxin; Ball, Sarah; Deangelis, Stephanie; Foust, Elizabeth; Pandit, Bulbul; Ihnat, Michael A.; Shenoy, Satyendra S.; Kulp, Samuel; Li, Pui-Kai; Li, Chenglong; Fuchs, James; Lin, Jiayuh

    2010-01-01

    The constitutive activation of Signal Transducer and Activator of Transcription 3 (STAT3) is frequently detected in most types of human cancer where it plays important roles in survival, drug-resistance, angiogenesis, and other functions. Targeting constitutive STAT3 signaling is thus an attractive therapeutic approach for these cancers. We have recently developed novel small molecule STAT3 inhibitors known as FLLL31 and FLLL32, which are derived from curcumin (the primary bioactive compound of turmeric). These compounds are designed to bind selectively to Janus Kinase 2 (JAK2) and the STAT3 SH2 domain, which serves crucial roles in STAT3 dimerization and signal transduction. Here we show that FLLL31 and FLLL32 are effective inhibitors of STAT3 phosphorylation, DNA binding activity, and transactivation in vitro, leading to the impediment of multiple oncogenic processes and the induction of apoptosis in pancreatic and breast cancer cell lines. FLLL31 and FLLL32 also inhibit colony formation in soft agar, cell invasion, and exhibit synergy with the anti-cancer drug doxorubicin against breast cancer cells. In addition, we show that FLLL32 can inhibit the induction of STAT3 phosphorylation by Interferon-α (IFNα) and Interleukin-6 (IL-6) in breast cancer cells. We also demonstrate that administration of FLLL32 can inhibit tumor growth and vascularity in chicken embryo xenografts as well as substantially reduce tumor volumes in mouse xenografts. Our findings highlight the potential of these new compounds and their efficacy in targeting pancreatic and breast cancers that exhibit constitutive STAT3 signaling. PMID:20215512

  11. Nanoparticle-Delivered Antisense MicroRNA-21 Enhances the Effects of Temozolomide on Glioblastoma Cells.

    PubMed

    Ananta, Jeyarama S; Paulmurugan, Ramasamy; Massoud, Tarik F

    2015-12-01

    Glioblastoma (GBM) generally exhibits high IC50 values for its standard drug treatment, temozolomide (TMZ). MicroRNA-21 (miR-21) is an oncomiR overexpressed in GBM, thus controlling important aspects of glioma biology. We hypothesized that PLGA nanoparticles carrying antisense miR-21 to glioblastoma cells might beneficially knock down endogenous miR-21 prior to TMZ treatment. PLGA nanoparticles encapsulating antisense miR-21 were effective in intracellular delivery and sustained silencing (p < 0.01) of miR-21 function in U87 MG, LN229, and T98G cells. Prior antisense miR-21 delivery significantly reduced the number of viable cells (p < 0.001), and increased (1.6-fold) cell cycle arrest at G2/M phase upon TMZ treatment in U87 MG cells. There was overexpression of the miR-21 target genes PTEN (by 67%) and caspase-3 (by 15%) upon cotreatment. This promising PLGA nanoparticle-based platform for antisense miR-21 delivery to GBM is an effective cotherapeutic strategy in cell culture, warranting the need for further studies prior to future clinical translation. PMID:26559642

  12. Salinomycin encapsulated nanoparticles as a targeting vehicle for glioblastoma cells.

    PubMed

    Tığlı Aydın, R Seda; Kaynak, Gökçe; Gümüşderelioğlu, Menemşe

    2016-02-01

    Salinomycin has been introduced as a novel alternative to traditional anti-cancer drugs. The aim of this study was to test a strategy designed to deliver salinomycin to glioblastoma cells in vitro. Salinomycin-encapsulated polysorbate 80-coated poly(lactic-co-glycolic acid) nanoparticles (P80-SAL-PLGA) were prepared and characterized with respect to particle size, morphology, thermal properties, drug encapsulation efficiency and controlled salinomycin-release behaviour. The in vitro cellular uptake of P80-SAL-PLGA (5 and 10 µM) or uncoated nanoparticles was assessed in T98G human glioblastoma cells, and the cell viability was investigated with respect to anti-growth activities. SAL, which was successfully transported to T98G glioblastoma cells via P80 coated nanoparticles (∼14% within 60 min), greatly decreased (p < 0.01) the cellular viability of T98G cells. Substantial morphological changes were observed in the T98G cells with damaged actin cytoskeleton. Thus, P80-SAL-PLGA nanoparticles induced cell death, suggesting a potential therapeutic role for this salinomycin delivery system in the treatment of human glioblastoma. PMID:26476239

  13. Cell outer membrane mimetic chitosan nanoparticles: preparation, characterization and cytotoxicity.

    PubMed

    Zhao, Jing; Liang, Fei; Kong, Lingheng; Zheng, Lina; Fan, Tao

    2015-01-01

    A negatively charged copolymer poly (MPC-co-AMPS) of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 2-acrylamide-2-methyl propane sulfonic acid (AMPS) was designed and synthesized. Chitosan nanoparticles with cell outer membrane mimetic structure were prepared by electrostatic interaction between the sulfonic acid groups of poly (MPC-co-AMPS) and the protonated amino groups of chitosan. Effects of factors on influencing the particle size, distribution, and stability were investigated. The experimental results showed that cell membrane mimetic chitosan nanoparticles with controllable and homogeneous size ranged from 100 to 300 nm were prepared at the concentration of 0.1-2.0 mg/mL and the charge ratio of 0.5-1.1. Chitosan nanoparticles prepared can exist stably for more than 45 days when placed at 4 °C and pH < 7.5. The cytotoxicity of the chitosan nanoparticles reduced significantly after surface modification with cell membrane mimetic structure, meeting the basic requirements of biomedical materials. The results suggest cell membrane mimetic chitosan nanoparticles prepared with polyanion and polycation obtain good biological compatibility and immune stealth ability, which has important academic significance and great application prospects.

  14. Impact of protein modification on the protein corona on nanoparticles and nanoparticle-cell interactions.

    PubMed

    Treuel, Lennart; Brandholt, Stefan; Maffre, Pauline; Wiegele, Sarah; Shang, Li; Nienhaus, G Ulrich

    2014-01-28

    Recent studies have firmly established that cellular uptake of nanoparticles is strongly affected by the presence and the physicochemical properties of a protein adsorption layer around these nanoparticles. Here, we have modified human serum albumin (HSA), a serum protein often used in model studies of protein adsorption onto nanoparticles, to alter its surface charge distribution and investigated the consequences for protein corona formation around small (radius ∼5 nm), dihydrolipoic acid-coated quantum dots (DHLA-QDs) by using fluorescence correlation spectroscopy. HSA modified by succinic anhydride (HSAsuc) to generate additional carboxyl groups on the protein surface showed a 3-fold decreased binding affinity toward the nanoparticles. A 1000-fold enhanced affinity was observed for HSA modified by ethylenediamine (HSAam) to increase the number of amino functions on the protein surface. Remarkably, HSAsuc formed a much thicker protein adsorption layer (8.1 nm) than native HSA (3.3 nm), indicating that it binds in a distinctly different orientation on the nanoparticle, whereas the HSAam corona (4.6 nm) is only slightly thicker. Notably, protein binding to DHLA-QDs was found to be entirely reversible, independent of the modification. We have also measured the extent and kinetics of internalization of these nanoparticles without and with adsorbed native and modified HSA by HeLa cells. Pronounced variations were observed, indicating that even small physicochemical changes of the protein corona may affect biological responses.

  15. Glial cells, but not neurons, exhibit a controllable response to a localized inflammatory microenvironment in vitro.

    PubMed

    Sommakia, Salah; Rickus, Jenna L; Otto, Kevin J

    2014-01-01

    The ability to design long-lasting intracortical implants hinges on understanding the factors leading to the loss of neuronal density and the formation of the glial scar. In this study, we modify a common in vitro mixed cortical culture model using lipopolysaccharide (LPS) to examine the responses of microglia, astrocytes, and neurons to microwire segments. We also use dip-coated polyethylene glycol (PEG), which we have previously shown can modulate impedance changes to neural microelectrodes, to control the cellular responses. We find that microglia, as expected, exhibit an elevated response to LPS-coated microwire for distances of up to 150 μm, and that this elevated response can be mitigated by co-depositing PEG with LPS. Astrocytes exhibit a more complex, distance-dependent response, whereas neurons do not appear to be affected by the type or magnitude of glial response within this in vitro model. The discrepancy between our in vitro responses and typically observed in vivo responses suggest the importance of using a systems approach to understand the responses of the various brain cell types in a chronic in vivo setting, as well as the necessity of studying the roles of cell types not native to the brain. Our results further indicate that the loss of neuronal density observed in vivo is not a necessary consequence of elevated glial activation. PMID:25452724

  16. Photothermal Therapy of Cancer Cells mediated by Blue Hydrogel Nanoparticles

    NASA Astrophysics Data System (ADS)

    Curry, Taeyjuana; Epstein, Tamir; Kopelman, Raoul

    2012-02-01

    Coomassie Blue dye has been covalently linked into a polyacrylamide nanoparticle matrix, so as to form nontoxic, biologically compatible, biodegradable and cell-specific targetable nanoparticles for photothermal therapy (PTT) of cancer. The nanoparticles were found to be approximately 80-95 nm in diameter, with an absorbance value of 0.52. Using an inexpensive, low intensity LED array light source (590nm, 25mW/cm2), with 20 minute excitation times, at 37^o, PTT induced hyperthermia/thermolysis in HeLa cells, in vitro, resulting in virtually complete cell death when observed 3 hours after exposure. These multifunctional particles have been previously used in cancer delineation, for surgery, and in photoacoustic imaging studies; the addition of the PTT function now enables a multi-pronged medical approach to cancer.

  17. Photothermal Therapy of Cancer Cells mediated by Blue Hydrogel Nanoparticles

    NASA Astrophysics Data System (ADS)

    Curry, Taeyjuana; Epstein, Tamir; Kopelman, Raoul

    2012-10-01

    Coomassie Blue dye has been covalently linked into a polyacrylamide nanoparticle matrix, so as to form nontoxic, biologically compatible, biodegradable and cell-specific targetable nanoparticles for photothermal therapy (PTT) of cancer. The nanoparticles were found to be approximately 80-95 nm in diameter, with an absorbance value of 0.52. Using an inexpensive, low intensity LED array light source (590nm, 25mW/cm^2), with 20 minute excitation times, at 37 , PTT induced hyperthermia/thermolysis in HeLa cells, in vitro, resulting in virtually complete cell death when observed 3 hours after exposure. These multifunctional particles have been previously used in cancer delineation, for surgery, and in photoacoustic imaging studies; the addition of the PTT function now enables a multi-pronged medical approach to cancer.

  18. Metallic nanoparticle deposition techniques for enhanced organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Cacha, Brian Joseph Gonda

    Energy generation via organic photovoltaic (OPV) cells provide many advantages over alternative processes including flexibility and price. However, more efficient OPVs are required in order to be competitive for applications. One way to enhance efficiency is through manipulation of exciton mechanisms within the OPV, for example by inserting a thin film of bathocuproine (BCP) and gold nanoparticles between the C60/Al and ZnPc/ITO interfaces, respectively. We find that BCP increases efficiencies by 330% due to gains of open circuit voltage (Voc) by 160% and short circuit current (Jsc) by 130%. However, these gains are complicated by the anomalous photovoltaic effect and an internal chemical potential. Exploration in the tuning of metallic nanoparticle deposition on ITO was done through four techniques. Drop casting Ag nanoparticle solution showed arduous control on deposited morphology. Spin-coating deposited very low densities of nanoparticles. Drop casting and spin-coating methods showed arduous control on Ag nanoparticle morphology due to clustering and low deposition density, respectively. Sputtered gold on glass was initially created to aid the adherence of Ag nanoparticles but instead showed a quick way to deposit aggregated gold nanoparticles. Electrodeposition of gold nanoparticles (AuNP) proved a quick method to tune nanoparticle morphology on ITO substrates. Control of deposition parameters affected AuNP size and distribution. AFM images of electrodeposited AuNPs showed sizes ranging from 39 to 58 nm. UV-Vis spectroscopy showed the presence of localized plasmon resonance through absorption peaks ranging from 503 to 614 nm. A linear correlation between electrodeposited AuNP size and peak absorbance was seen with a slope of 3.26 wavelength(nm)/diameter(nm).

  19. Evidence that high-migration drug-surviving MOLT4 leukemia cells exhibit cancer stem cell-like properties.

    PubMed

    Huang, Xiaoxing; Xiong, Meng; Jin, Yujie; Deng, Chaohua; Xu, Hui; An, Changqing; Hao, Ling; Yang, Xiangyong; Deng, Xinzhou; Tu, Zhenbo; Li, Xinran; Xiao, Ruijing; Zhang, Qiuping

    2016-07-01

    Leukemia represents a spectrum of hematological malignancies threatening human health. Resistance to treatments and metastasis of leukemia are the main causes of death in patients. Leukemia stem cells (LSCs) are the initiating cells of leukemia as well as the main source of drug resistance, invasion and metastasis. Consequently, eliminating LSCs is a prerequisite to eradicate leukemia. Preliminary studies in our laboratory have shown that chemokines and their related receptors play an important role in the drug resistance and metastasis of leukemic cells. In this study, we obtained high migration drug-surviving (short term) MOLT4 cells (hMDSCs-MOLT4) with treatment of doxorubicin (DOX) after Transwell assay. Then we detected stem cell-associated molecular markers on hMDSCs-MOLT4 cells and the parental MOLT4 cells by FCM, QPCR, western blotting, H&E staining and immunohisto-chemistry experimental techniques in vitro and in vivo. Moreover, we explored its impact on drug resistance and tumor formation. Then we found that compared with the parental MOLT4 cells, the mRNA expression levels of stem cell-related factors Sox2, Oct4, C-myc, Klf4, Nanog, Bmi-1, CXCR4 are increased in hMDSCs-MOLT4 cells, together with the protein expression levels of Sox2, Oct4, Klf4, Nanog, CXCR4 and CD34. Our results indicated that hMDSCs-MOLT4 cells exhibited strong drug resistance and certain cancer stem cell-like characteristics. It is the first indication that the targeting stemness factors such as Sox2, Oct4, Klf4, Nanog and CXCR4 may represent plausible options for eliminating T-ALL stem-like cells. The present findings shed light on the relationship between drug-tolerant leukemic cells and cancer stem cells.

  20. Human mesenchymal stem cells are sensitive to abnormal gravity and exhibit classic apoptotic features.

    PubMed

    Meng, Rui; Xu, Hui-yun; Di, Sheng-meng; Shi, Dong-yan; Qian, Ai-rong; Wang, Jin-fu; Shang, Peng

    2011-02-01

    The aim of the present study was to investigate the effects of abnormal gravity on human mesenchymal stem cells (hMSCs). Strong magnetic field and magnetic field gradient generate a magnetic force that can add to or subtract from the gravitational force. In this study, this is defined as a high-magneto-gravitational environment (HMGE). The HMGE provides three apparent gravity levels, i.e. hypogravity (μg), hypergravity (2g) and normal gravity with strong magnetic field (1g) conditions. After hMSCs were subject to HMGE for 12 h, the proliferation, morphology, structure and apoptosis were investigated. Results showed that the proliferation of hMSCs was inhibited under μg condition. The abnormal gravity induced morphologic characteristics of apoptosis cells, such as cell shrinkage, membrane blebbing, nuclear chromatin condensation and margination, decreased cell viability, and increased caspase-3/7 activity. The rate of apoptosis under μg condition is up to 56.95%. The F-actin stress fibers and microtubules were disrupted under abnormal gravity condition. Under μg-condition, the expression of p53 at mRNA and protein levels was up-regulated more than 9- and 6 folds, respectively. The Pifithrin-α, an specific inhibitor of p53, inhibited the apoptosis and prevented the disruption of cytoskeleton induced by abnormal gravity. These results implied that hMSCs were sensitive to abnormal gravity and exhibited classic apoptotic features, which might be associated with p53 signaling.

  1. Heritability of in vitro phenotypes exhibited by murine adipose-derived stromal cells.

    PubMed

    Jiang, Zixuan; Harrison, David E; Parsons, Makayla E; McClatchy, Susan; Jacobs, Lawrence; Pazdro, Robert

    2016-10-01

    Adipose-derived stromal cells (ADSCs) exhibit significant potential as therapeutic agents to promote tissue regeneration. Success of ADSC-based therapies is dependent upon efficient cell expansion in vitro as well as postinjection survival in the caustic milieu of damaged tissue. Genetic background regulates ADSC proliferative capacity and stress resistance, but the extent of the genetic effect size is not completely defined. The present study aimed to quantify phenotypic ranges and heritability of in vitro ADSC characteristics. ADSCs were isolated from mice representing 16 genetically diverse inbred mouse strains, including 12 classical inbred strains and four wild-derived strains. Cells were grown in vitro, and proliferative capacity and oxidative stress resistance were assessed. The fold change for ADSC growth ranged from 0.87 (BALB/cByJ) to 23.60 (POHN/DehJ), relative to original seeding density. The heritability of proliferative capacity was estimated to be 0.6462 (p = 9.967 × 10(-15)), and this phenotype was not associated with other ADSC traits. Cell viability following H2O2 treatment ranged from 39.81 % (CAST/EiJ) to 91.60 % (DBA/2 J), and the heritability of this phenotype was calculated as 0.6146 (p = 1.22 × 10(-12)). Relationships between cell viability and weight of the donor fat pad were also discovered. Donor genetic background is a major determinant of in vitro ADSC phenotypes. This study supports the development of forward genetics strategies to identify genes that underlie ADSC phenotypic diversity, which will inform efforts to improve cell-based therapies.

  2. Using silica nanoparticles for modifying sulfonated poly(phthalazinone ether ketone) membrane for direct methanol fuel cell: A significant improvement on cell performance

    NASA Astrophysics Data System (ADS)

    Su, Yu-Huei; Liu, Ying-Ling; Sun, Yi-Ming; Lai, Juin-Yih; Guiver, Michael D.; Gao, Yan

    Sulfonated poly(phthalazinone ether ketone) (sPPEK) with a degree of sulfonation of 1.23 was mixed with silica nanoparticles to form hybrid materials for using as proton exchange membranes. The nanoparticles were found homogeneously dispersed in the polymer matrix and a high 30 phr (parts per hundred resin) loading of silica nanoparticles can be achieved. The hybrid membranes exhibited improved swelling behavior, thermal stability, and mechanical properties. The methanol crossover behavior of the membrane was also depressed such that these membranes are suitable for a high methanol concentration in feed (3 M) in cell test. The membrane with 5 phr silica nanoparticles showed an open cell potential of 0.6 V and an optimum power density of 52.9 mW cm -2 at a current density of 264.6 mA cm -2, which is better than the performance of the pristine sPPEK membrane and Nafion ® 117.

  3. Differential nanoreprotoxicity of silver nanoparticles in male somatic cells and spermatogonial stem cells

    PubMed Central

    Zhang, Xi-Feng; Choi, Yun-Jung; Han, Jae Woong; Kim, Eunsu; Park, Jung Hyun; Gurunathan, Sangiliyandi; Kim, Jin-Hoi

    2015-01-01

    Background Silver nanoparticles (AgNPs) possess unique physical, chemical, and biological properties. AgNPs have been increasingly used as anticancer, antiangiogenic, and antibacterial agents for the treatment of bacterial infections in open wounds as well as in ointments, bandages, and wound dressings. The present study aimed to investigate the effects of two different sizes of AgNPs (10 nm and 20 nm) in male somatic Leydig (TM3) and Sertoli (TM4) cells and spermatogonial stem cells (SSCs). Methods Here, we demonstrate a green and simple method for the synthesis of AgNPs using Bacillus cereus culture supernatants. The synthesized AgNPs were characterized using ultraviolet and visible absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM). The toxicity of the synthesized AgNPs was evaluated by the effects on cell viability, metabolic activity, oxidative stress, apoptosis, and expression of genes encoding steroidogenic and tight junction proteins. Results AgNPs inhibited the viability and proliferation of TM3 and TM4 cells in a dose- and size-dependent manner by damaging cell membranes and inducing the generation of reactive oxygen species, which in turn affected SSC growth on TM3 and TM4 as feeder cells. Small AgNPs (10 nm) were more cytotoxic than medium-sized nanoparticles (20 nm). TEM revealed the presence of AgNPs in the cell cytoplasm and nucleus, and detected mitochondrial damage and enhanced formation of autosomes and autolysosomes in the AgNP-treated cells. Flow cytometry analysis using Annexin V/propidium iodide staining showed massive cell death by apoptosis or necrosis. Real-time polymerase chain reaction and western blot analyses indicated that in TM3 and TM4 cells, AgNPs activated the p53, p38, and pErk1/2 signaling pathways and significantly downregulated the expression of genes related to testosterone synthesis (TM3) and tight junctions (TM4). Furthermore, the exposure of TM3

  4. Screening of nanoparticle embryotoxicity using embryonic stem cells.

    PubMed

    Campagnolo, Luisa; Fenoglio, Ivana; Massimiani, Micol; Magrini, Andrea; Pietroiusti, Antonio

    2013-01-01

    Due to the increasing use of engineered nanoparticles in many consumer products, rapid and economic tests for evaluating possible adverse effects on human health are urgently needed. In the present chapter the use of mouse embryonic stem cells as a valuable tool to in vitro screen nanoparticle toxicity on embryonic tissues is described. This in vitro method is a modification of the embryonic stem cell test, which has been widely used to screen soluble chemical compounds for their embryotoxic potential. The test offers an alternative to animal experimentation, reducing experimental costs and ethical issues.

  5. Red Blood Cell Membrane-Cloaked Nanoparticles For Drug Delivery

    NASA Astrophysics Data System (ADS)

    Carpenter, Cody Westcott

    Herein we describe the development of the Red Blood Cell coated nanoparticle, RBC-NP. Purified natural erythrocyte membrane is used to coat drug-loaded poly(lacticco-glycolic acid) (PLGA). Synthetic PLGA co-polymer is biocompatible and biodegradable and has already received US FDA approval for drug-delivery and diagnostics. This work looks specifically at the retention of immunosuppressive proteins on RBC-NPs, right-sidedness of natural RBC membranes interfacing with synthetic polymer nanoparticles, sustained and retarded drug release of RBC-NPs as well as further surface modification of RBC-NPs for increased targeting of model cancer cell lines.

  6. Single metallic nanoparticle imaging for protein detection in cells.

    PubMed

    Cognet, L; Tardin, C; Boyer, D; Choquet, D; Tamarat, P; Lounis, B

    2003-09-30

    We performed a visualization of membrane proteins labeled with 10-nm gold nanoparticles in cells, using an all-optical method based on photothermal interference contrast. The high sensitivity of the method and the stability of the signals allows 3D imaging of individual nanoparticles without the drawbacks of photobleaching and blinking inherent to fluorescent markers. A simple analytical model is derived to account for the measurements of the signal amplitude and the spatial resolution. The photothermal interference contrast method provides an efficient, reproducible, and promising way to visualize low amounts of proteins in cells by optical means. PMID:13679586

  7. Polymeric Nanoparticles for Targeted Radiosensitization of Prostate Cancer Cells

    PubMed Central

    Menon, Jyothi U.; Tumati, Vasu; Hsieh, Jer-Tsong; Nguyen, Kytai T.; Saha, Debabrata

    2014-01-01

    One of the many issues of using radiosensitizers in a clinical setting is timing daily radiation treatments to coincide with peak drug concentration in target tissue. To overcome this deficit, we have synthesized a novel nanoparticle system consisting of poly (lactic-co-glycolic acid) (PLGA) nanoparticles conjugated with prostate cancer cell penetrating peptide-R11 and encapsulated with a potent radio-sensitizer 8-dibenzothiophen-4-yl-2-morpholin-4-yl-chromen-4-one (NU7441) to allow prostate cancer-specific targeting and sustained delivery over 3 weeks. Preliminary characterization studies showed that the R11-conjugated nanoparticles (R11-NU7441 NPs) had an average size of about 274 ± 80 nm and were stable for up to 5 days in de-ionized water and serum. The nanoparticles were cytocompatible with immortalized prostate cells (PZ-HPV-7). Further, the particles showed a bi-phasic release of encapsulated NU7441 and were taken up by PC3 prostate cancer cells in a dose- and magnetic field-dependent manner while not being taken up in non-prostate cancer cell lines. In addition, R11-NU7441 NPs were effective radiation sensitizers of prostate cancer cell lines in vitro. These results thus demonstrate the potential of R11-conjugated PLGA NPs as novel platforms for targeted radiosensitization of prostate cancer cells. PMID:25088162

  8. Toxicity of Calcium Hydroxide Nanoparticles on Murine Fibroblast Cell Line

    PubMed Central

    Dianat, Omid; Azadnia, Sina; Mozayeni, Mohammad Ali

    2015-01-01

    Introduction: One of the major contributing factors, which may cause failure of endodontic treatment, is the presence of residual microorganisms in the root canal system. For years, most dentists have been using calcium hydroxide (CH) as the intracanal medicament between treatment sessions to eliminate remnant microorganisms. Reducing the size of CH particles into nanoparticles enhances the penetration of this medicament into dentinal tubules and increases their antimicrobial efficacy. This in vitro study aimed to compare the cytotoxicity of CH nanoparticles and conventional CH on fibroblast cell line using the Mosmann’s Tetrazolium Toxicity (MTT) assay. Methods and Materials: This study was conducted on L929 murine fibroblast cell line by cell culture and evaluation of the direct effect of materials on the cultured cells. Materials were evaluated in two groups of 10 samples each at 24, 48 and 72 h. At each time point, 10 samples along with 5 positive and 5 negative controls were evaluated. The samples were transferred into tubes and exposed to fibroblast cells. The viability of cells was then evaluated. The Two-way ANOVA was used for statistical analysis and the level of significance was set at 0.05. Results: Cytotoxicity of both materials decreased over time and for conventional CH was lower than that of nanoparticles. However, this difference was not statistically significant (P>0.05). Conclusion: The cytotoxicity of CH nanoparticles was similar to that of conventional CH. PMID:25598810

  9. Facile synthesis of Cu2CoSnS4 nanoparticles exhibiting red-edge-effect: Application in hybrid photonic devices

    NASA Astrophysics Data System (ADS)

    Murali, Banavoth; Krupanidhi, S. B.

    2013-10-01

    Cu2CoSnS4 (CCTS) quaternary semiconducting nanoparticles with size distribution from 20 nm to 60 nm were synthesized by one-pot low temperature time and surfactant dependent hydrothermal route. Nanoparticles were characterized structurally and optically. Excitation dependent fluorescence exhibited a dynamic stoke shift referring to the Red-Edge-Effect with peak shifting by a greater magnitude (>100 nm) towards red side, in all the samples. Hybrid devices, fabricated from CCTS nanoparticle inorganic counterparts benefitting from the conjugation of organic P3HT polymer matrix, were demonstrated for photodetection under infra-red and A.M 1.5 solar light illuminations. Faster rise and decay constants of 37 ms and 166 ms, with one order photocurrent amplification from 1.6 × 10-6 A in the dark to 6.55 × 10-5 A, upon the 18.50 mW cm-2 IR lamp illumination, make CCTS a potential candidate for photodetector and photovoltaic applications.

  10. Synthetic and biogenic magnetite nanoparticles for tracking of stem cells and dendritic cells

    NASA Astrophysics Data System (ADS)

    Schwarz, Sebastian; Fernandes, Fabiana; Sanroman, Laura; Hodenius, Michael; Lang, Claus; Himmelreich, Uwe; Schmitz-Rode, Thomas; Schueler, Dirk; Hoehn, Mathias; Zenke, Martin; Hieronymus, Thomas

    2009-05-01

    Accurate delivery of cells to target organs is critical for success of cell-based therapies with stem cells or immune cells such as antigen-presenting dendritic cells (DC). Labeling with contrast agents before implantation provides a powerful means for monitoring cellular migration using magnetic resonance imaging (MRI). In this study, we investigated the uptake of fully synthesized or bacterial magnetic nanoparticles (MNPs) into hematopoietic Flt3 + stem cells and DC from mouse bone marrow. We show that (i) uptake of both synthetic and biogenic nanoparticles into cells endow magnetic activity and (ii) low numbers of MNP-loaded cells are readily detected by MRI.

  11. Cell labeling with magnetic nanoparticles: Opportunity for magnetic cell imaging and cell manipulation

    PubMed Central

    2013-01-01

    This tutorial describes a method of controlled cell labeling with citrate-coated ultra small superparamagnetic iron oxide nanoparticles. This method may provide basically all kinds of cells with sufficient magnetization to allow cell detection by high-resolution magnetic resonance imaging (MRI) and to enable potential magnetic manipulation. In order to efficiently exploit labeled cells, quantify the magnetic load and deliver or follow-up magnetic cells, we herein describe the main requirements that should be applied during the labeling procedure. Moreover we present some recommendations for cell detection and quantification by MRI and detail magnetic guiding on some real-case studies in vitro and in vivo. PMID:24564857

  12. Antimicrobial efficacy and ocular cell toxicity from silver nanoparticles

    PubMed Central

    Santoro, Colleen M.; Duchsherer, Nicole L.

    2009-01-01

    Silver in various forms has long been recognized for antimicrobial properties, both in biomedical devices and in eyes. However, soluble drugs used on the ocular surface are rapidly cleared through tear ducts and eventually ingested, resulting in decreased efficacy of the drug on its target tissue and potential concern for systemic side effects. Silver nanoparticles were studied as a source of anti-microbial silver for possible controlled-release contact lens controlled delivery formulations. Silver ion release over a period of several weeks from nanoparticle sources of various sizes and doses in vitro was evaluated in vitro against Pseudomonas aeruginosa strain PA01. Mammalian cell viability and cytokine expression in response to silver nanoparticle exposure is evaluated using corneal epithelial cells and eye-associated macrophages cultured in vitro in serum-free media. Minimal microcidal and cell toxic effects were observed for several silver nanoparticle suspensions and aqueous extraction times for bulk total silver concentrations commensurate with comparative silver ion (e.g., Ag+(aq)) toxicity. This indicates that (1) silver particles themselves are not microcidal under conditions tested, and (2) insufficient silver ion is generated from these particles at these loadings to produce observable biological effects in these in vitro assays. If dosing allows substantially increased silver particle loading in the lens, the bactericidal efficacy of silver nanoparticles in vitro is one possible approach to limiting bacterial colonization problems associated with extended-wear contact lenses. PMID:19865601

  13. Pomegranate ellagitannin-derived compounds exhibit antiproliferative and antiaromatase activity in breast cancer cells in vitro.

    PubMed

    Adams, Lynn S; Zhang, Yanjun; Seeram, Navindra P; Heber, David; Chen, Shiuan

    2010-01-01

    Estrogen stimulates the proliferation of breast cancer cells and the growth of estrogen-responsive tumors. The aromatase enzyme, which converts androgen to estrogen, plays a key role in breast carcinogenesis. The pomegranate fruit, a rich source of ellagitannins (ET), has attracted recent attention due to its anticancer and antiatherosclerotic properties. On consumption, pomegranate ETs hydrolyze, releasing ellagic acid, which is then converted to 3,8-dihydroxy-6H-dibenzo[b,d]pyran-6-one ("urolithin") derivatives by gut microflora. The purpose of this study was to investigate the antiaromatase activity and inhibition of testosterone-induced breast cancer cell proliferation by ET-derived compounds isolated from pomegranates. A panel of 10 ET-derived compounds including ellagic acid, gallagic acid, and urolithins A and B (and their acetylated, methylated, and sulfated analogues prepared in our laboratory) were examined for their ability to inhibit aromatase activity and testosterone-induced breast cancer cell proliferation. Using a microsomal aromatase assay, we screened the panel of ET-derived compounds and identified six with antiaromatase activity. Among these, urolithin B (UB) was shown to most effectively inhibit aromatase activity in a live cell assay. Kinetic analysis of UB showed mixed inhibition, suggesting more than one inhibitory mechanism. Proliferation assays also determined that UB significantly inhibited testosterone-induced MCF-7aro cell proliferation. The remaining test compounds also exhibited antiproliferative activity, but to a lesser degree than UB. These studies suggest that pomegranate ET-derived compounds have potential for the prevention of estrogen-responsive breast cancers.

  14. Human immune cell targeting of protein nanoparticles - caveospheres

    NASA Astrophysics Data System (ADS)

    Glass, Joshua J.; Yuen, Daniel; Rae, James; Johnston, Angus P. R.; Parton, Robert G.; Kent, Stephen J.; de Rose, Robert

    2016-04-01

    Nanotechnology has the power to transform vaccine and drug delivery through protection of payloads from both metabolism and off-target effects, while facilitating specific delivery of cargo to immune cells. However, evaluation of immune cell nanoparticle targeting is conventionally restricted to monocultured cell line models. We generated human caveolin-1 nanoparticles, termed caveospheres, which were efficiently functionalized with monoclonal antibodies. Using this platform, we investigated CD4+ T cell and CD20+ B cell targeting within physiological mixtures of primary human blood immune cells using flow cytometry, imaging flow cytometry and confocal microscopy. Antibody-functionalization enhanced caveosphere binding to targeted immune cells (6.6 to 43.9-fold) within mixed populations and in the presence of protein-containing fluids. Moreover, targeting caveospheres to CCR5 enabled caveosphere internalization by non-phagocytic CD4+ T cells--an important therapeutic target for HIV treatment. This efficient and flexible system of immune cell-targeted caveosphere nanoparticles holds promise for the development of advanced immunotherapeutics and vaccines.

  15. Fission yeast with DNA polymerase delta temperature-sensitive alleles exhibits cell division cycle phenotype.

    PubMed Central

    Francesconi, S; Park, H; Wang, T S

    1993-01-01

    DNA polymerases alpha and delta are essential enzymes believed to play critical roles in initiation and replication of chromosome DNA. In this study, we show that the genes for Schizosaccharomyces pombe (S.pombe) DNA polymerase alpha and delta (pol alpha+ and pol delta+) are essential for cell viability. Disruption of either the pol alpha+ or pol delta+ gene results in distinct terminal phenotypes. The S.pombe pol delta+ gene is able to complement the thermosensitive cdc2-2 allele of Saccharomyces cerevisiae (S.cerevisiae) at the restrictive temperature. By random mutagenesis in vitro, we generated three pol delta conditional lethal alleles. We replaced the wild type chromosomal copy of pol delta+ gene with the mutagenized sequence and characterized the thermosensitive alleles in vivo. All three thermosensitive mutants exhibit a typical cell division cycle (cdc) terminal phenotype similar to that of the disrupted pol delta+ gene. Flow cytometric analysis showed that at the nonpermissive temperature all three mutants were arrested in S phase of the cell cycle. The three S.pombe conditional pol delta alleles were recovered and sequenced. The mutations causing the thermosensitive phenotype are missense mutations. The altered amino acid residues are uniquely conserved among the known polymerase delta sequences. Images PMID:8367300

  16. Congenital amegakaryocytic thrombocytopenia iPS cells exhibit defective MPL-mediated signaling

    PubMed Central

    Hirata, Shinji; Takayama, Naoya; Jono-Ohnishi, Ryoko; Endo, Hiroshi; Nakamura, Sou; Dohda, Takeaki; Nishi, Masanori; Hamazaki, Yuhei; Ishii, Ei-ichi; Kaneko, Shin; Otsu, Makoto; Nakauchi, Hiromitsu; Kunishima, Shinji; Eto, Koji

    2013-01-01

    Congenital amegakaryocytic thrombocytopenia (CAMT) is caused by the loss of thrombopoietin receptor–mediated (MPL-mediated) signaling, which causes severe pancytopenia leading to bone marrow failure with onset of thrombocytopenia and anemia prior to leukopenia. Because Mpl–/– mice do not exhibit the human disease phenotype, we used an in vitro disease tracing system with induced pluripotent stem cells (iPSCs) derived from a CAMT patient (CAMT iPSCs) and normal iPSCs to investigate the role of MPL signaling in hematopoiesis. We found that MPL signaling is essential for maintenance of the CD34+ multipotent hematopoietic progenitor (MPP) population and development of the CD41+GPA+ megakaryocyte-erythrocyte progenitor (MEP) population, and its role in the fate decision leading differentiation toward megakaryopoiesis or erythropoiesis differs considerably between normal and CAMT cells. Surprisingly, complimentary transduction of MPL into normal or CAMT iPSCs using a retroviral vector showed that MPL overexpression promoted erythropoiesis in normal CD34+ hematopoietic progenitor cells (HPCs), but impaired erythropoiesis and increased aberrant megakaryocyte production in CAMT iPSC–derived CD34+ HPCs, reflecting a difference in the expression of the transcription factor FLI1. These results demonstrate that impaired transcriptional regulation of the MPL signaling that normally governs megakaryopoiesis and erythropoiesis underlies CAMT. PMID:23908116

  17. Collective optical Kerr effect exhibited by an integrated configuration of silicon quantum dots and gold nanoparticles embedded in ion-implanted silica.

    PubMed

    Torres-Torres, C; López-Suárez, A; Can-Uc, B; Rangel-Rojo, R; Tamayo-Rivera, L; Oliver, A

    2015-07-24

    The study of the third-order optical nonlinear response exhibited by a composite containing gold nanoparticles and silicon quantum dots nucleated by ion implantation in a high-purity silica matrix is presented. The nanocomposites were explored as an integrated configuration containing two different ion-implanted distributions. The time-resolved optical Kerr gate and z-scan techniques were conducted using 80 fs pulses at a 825 nm wavelength; while the nanosecond response was investigated by a vectorial two-wave mixing method at 532 nm with 1 ns pulses. An ultrafast purely electronic nonlinearity was associated to the optical Kerr effect for the femtosecond experiments, while a thermal effect was identified as the main mechanism responsible for the nonlinear optical refraction induced by nanosecond pulses. Comparative experimental tests for examining the contribution of the Au and Si distributions to the total third-order optical response were carried out. We consider that the additional defects generated by consecutive ion irradiations in the preparation of ion-implanted samples do not notably modify the off-resonance electronic optical nonlinearities; but they do result in an important change for near-resonant nanosecond third-order optical phenomena exhibited by the closely spaced nanoparticle distributions. PMID:26135968

  18. Lymphoid Organ-Resident Dendritic Cells Exhibit Unique Transcriptional Fingerprints Based on Subset and Site

    PubMed Central

    Elpek, Kutlu G.; Bellemare-Pelletier, Angelique; Malhotra, Deepali; Reynoso, Erika D.; Lukacs-Kornek, Veronika; DeKruyff, Rosemarie H.; Turley, Shannon J.

    2011-01-01

    Lymphoid organ-resident DC subsets are thought to play unique roles in determining the fate of T cell responses. Recent studies focusing on a single lymphoid organ identified molecular pathways that are differentially operative in each DC subset and led to the assumption that a given DC subset would more or less exhibit the same genomic and functional profiles throughout the body. Whether the local milieu in different anatomical sites can also influence the transcriptome of DC subsets has remained largely unexplored. Here, we interrogated the transcriptional relationships between lymphoid organ-resident DC subsets from spleen, gut- and skin-draining lymph nodes, and thymus of C57BL/6 mice. For this purpose, major resident DC subsets including CD4 and CD8 DCs were sorted at high purity and gene expression profiles were compared using microarray analysis. This investigation revealed that lymphoid organ-resident DC subsets exhibit divergent genomic programs across lymphoid organs. Interestingly, we also found that transcriptional and biochemical properties of a given DC subset can differ between lymphoid organs for lymphoid organ-resident DC subsets, but not plasmacytoid DCs, suggesting that determinants of the tissue milieu program resident DCs for essential site-specific functions. PMID:21886840

  19. Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells.

    PubMed

    Loos, Cornelia; Syrovets, Tatiana; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

    2014-02-01

    Activation of the mammalian target of rapamycin (mTOR) has been implicated in anticancer drug resistance, type 2 diabetes, and aging. Here, we show that surface functionalization of polystyrene nanoparticles with amino groups (PS-NH2), but not with carboxyl groups (PS-COOH), induces G2 cell-cycle arrest and inhibition of proliferation in three leukemia cell lines. Besides, PS-NH2 inhibit angiogenesis and proliferation of leukemia cells xenografted onto the chick chorioallantoic membrane. At the molecular level, PS-NH2 inhibit, whereas PS-COOH activate mTOR signaling in leukemia cells. Consistently, PS-NH2 block activation of the mTOR downstream targets, Akt and p70 ribosomal S6 kinase 1, and induce overexpression of the cell-cycle regulator p21(Cip1/Waf1) and degradation of cyclin B1. After addition, both types of particles rapidly induce autophagy in leukemia cells. Yet, only in PS-NH2-treated cells, acidic vesicular organelles show elevated pH and impaired processing of procathepsin B. Moreover, solely in PS-NH2-treated cells, autophagy is followed by permeabilization of acidic vesicular organelles and induction of apoptosis. By contrast, primary macrophages, which do not exhibit activated mTOR signaling, proved relatively resistant to PS-NH2-induced toxicity. These data indicate that functionalized nanoparticles can be used to control activation of mTOR signaling pathways, and to influence proliferation and viability of malignant cells.

  20. Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells.

    PubMed

    Loos, Cornelia; Syrovets, Tatiana; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

    2014-02-01

    Activation of the mammalian target of rapamycin (mTOR) has been implicated in anticancer drug resistance, type 2 diabetes, and aging. Here, we show that surface functionalization of polystyrene nanoparticles with amino groups (PS-NH2), but not with carboxyl groups (PS-COOH), induces G2 cell-cycle arrest and inhibition of proliferation in three leukemia cell lines. Besides, PS-NH2 inhibit angiogenesis and proliferation of leukemia cells xenografted onto the chick chorioallantoic membrane. At the molecular level, PS-NH2 inhibit, whereas PS-COOH activate mTOR signaling in leukemia cells. Consistently, PS-NH2 block activation of the mTOR downstream targets, Akt and p70 ribosomal S6 kinase 1, and induce overexpression of the cell-cycle regulator p21(Cip1/Waf1) and degradation of cyclin B1. After addition, both types of particles rapidly induce autophagy in leukemia cells. Yet, only in PS-NH2-treated cells, acidic vesicular organelles show elevated pH and impaired processing of procathepsin B. Moreover, solely in PS-NH2-treated cells, autophagy is followed by permeabilization of acidic vesicular organelles and induction of apoptosis. By contrast, primary macrophages, which do not exhibit activated mTOR signaling, proved relatively resistant to PS-NH2-induced toxicity. These data indicate that functionalized nanoparticles can be used to control activation of mTOR signaling pathways, and to influence proliferation and viability of malignant cells. PMID:24331713

  1. Optical micromanipulation of nanoparticles and cells inside living zebrafish.

    PubMed

    Johansen, Patrick Lie; Fenaroli, Federico; Evensen, Lasse; Griffiths, Gareth; Koster, Gerbrand

    2016-01-01

    Regulation of biological processes is often based on physical interactions between cells and their microenvironment. To unravel how and where interactions occur, micromanipulation methods can be used that offer high-precision control over the duration, position and magnitude of interactions. However, lacking an in vivo system, micromanipulation has generally been done with cells in vitro, which may not reflect the complex in vivo situation inside multicellular organisms. Here using optical tweezers we demonstrate micromanipulation throughout the transparent zebrafish embryo. We show that different cells, as well as injected nanoparticles and bacteria can be trapped and that adhesion properties and membrane deformation of endothelium and macrophages can be analysed. This non-invasive micromanipulation inside a whole-organism gives direct insights into cell interactions that are not accessible using existing approaches. Potential applications include screening of nanoparticle-cell interactions for cancer therapy or tissue invasion studies in cancer and infection biology. PMID:26996121

  2. Optical micromanipulation of nanoparticles and cells inside living zebrafish

    PubMed Central

    Johansen, Patrick Lie; Fenaroli, Federico; Evensen, Lasse; Griffiths, Gareth; Koster, Gerbrand

    2016-01-01

    Regulation of biological processes is often based on physical interactions between cells and their microenvironment. To unravel how and where interactions occur, micromanipulation methods can be used that offer high-precision control over the duration, position and magnitude of interactions. However, lacking an in vivo system, micromanipulation has generally been done with cells in vitro, which may not reflect the complex in vivo situation inside multicellular organisms. Here using optical tweezers we demonstrate micromanipulation throughout the transparent zebrafish embryo. We show that different cells, as well as injected nanoparticles and bacteria can be trapped and that adhesion properties and membrane deformation of endothelium and macrophages can be analysed. This non-invasive micromanipulation inside a whole-organism gives direct insights into cell interactions that are not accessible using existing approaches. Potential applications include screening of nanoparticle-cell interactions for cancer therapy or tissue invasion studies in cancer and infection biology. PMID:26996121

  3. Optical micromanipulation of nanoparticles and cells inside living zebrafish

    NASA Astrophysics Data System (ADS)

    Johansen, Patrick Lie; Fenaroli, Federico; Evensen, Lasse; Griffiths, Gareth; Koster, Gerbrand

    2016-03-01

    Regulation of biological processes is often based on physical interactions between cells and their microenvironment. To unravel how and where interactions occur, micromanipulation methods can be used that offer high-precision control over the duration, position and magnitude of interactions. However, lacking an in vivo system, micromanipulation has generally been done with cells in vitro, which may not reflect the complex in vivo situation inside multicellular organisms. Here using optical tweezers we demonstrate micromanipulation throughout the transparent zebrafish embryo. We show that different cells, as well as injected nanoparticles and bacteria can be trapped and that adhesion properties and membrane deformation of endothelium and macrophages can be analysed. This non-invasive micromanipulation inside a whole-organism gives direct insights into cell interactions that are not accessible using existing approaches. Potential applications include screening of nanoparticle-cell interactions for cancer therapy or tissue invasion studies in cancer and infection biology.

  4. Microenvironments and different nanoparticle dynamics in living cells revealed by a standard nanoparticle.

    PubMed

    Pack, Chan Gi; Song, Mi Ryoung; Tae, Eunju Lee; Hiroshima, Michio; Byun, Kyung Hee; Kim, Jun Sung; Sako, Yasushi

    2012-11-10

    For quantitative analysis of nanoparticle diffusions and submicro-environments in living cells, use of newly synthesized silica-based fluorescent nanoparticle (Si-FNP) as a standard nanoprobe is successfully demonstrated. The appropriate characteristics of a standard probe were fully analyzed in vitro by single molecule detection, transmission electron microscopy, and dynamic light scattering. Using fluorescence correlation analysis in single living cells, we quantitatively compared the diffusional properties of the standard Si-FNP with a diameter of 50 nm, peptide coated Si-FNP, streptavidin coated Qdot, and GFP molecule which have different sizes and surface properties. The result demonstrates that the standard Si-FNP without coat is minimally trapped in the vesicles in the process of cellular endocytosis. Interestingly, a large proportion of Si-FNP introduced into the cells by electroporation diffuses freely in the cells during a cell cycle suggesting free diffusing NPs are hardly trapped in the vesicles. The simple but highly sensitive method will provide insight into strategies to understanding the hydrodynamic process of nanoparticle delivery into living cells as well as the cellular microenvironment in the view of submicro-size.

  5. Cytotoxic effect of silver nanoparticles synthesized from Padina tetrastromatica on breast cancer cell line

    NASA Astrophysics Data System (ADS)

    Gnana Selvi, B. Clara; Madhavan, J.; Santhanam, Amutha

    2016-09-01

    In recent years researchers were attracted towards marine sources due to the presence of active components in it. Seaweeds were widely used in pharmaceutical research for their known biological activities. The biological synthesis method of silver nanoparticles (AgNPs) using Padina tetrastromatica seaweed extract and their cytotoxicity against breast cancer MCF-7 cells was reported in this study. The synthesized AgNPs using seaweed extract were subjected to x-ray diffraction, UV–visible spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscope, energy dispersive x-ray, zeta potential to elucidate the structural, morphology, size as well as surface potential parameters. An absorption peak at 430 nm in UV-visible spectrum reveals the excitation and surface plasmon resonance of AgNPs. FE-SEM micrographs exhibits the biosynthesized AgNPs, which are pre-dominantly round shaped and the size ranges between 40–50 nm. The zeta potential value of ‑27.6 mV confirms the stable nature of biosynthesized silver nanoparticles. Furthermore, the biological synthesized Ag NPs exhibited a dose-dependent cytotoxicity against human breast cancer cell (MCF-7) and the inhibitory concentration (IC50) was found for AgNPs against MCF-7 at 24 h incubation. Biological method of synthesizing silver nanoparticles shows a environmental friendly property which helps in effective electrifying usage in many fields.

  6. Cytotoxic effect of silver nanoparticles synthesized from Padina tetrastromatica on breast cancer cell line

    NASA Astrophysics Data System (ADS)

    Gnana Selvi, B. Clara; Madhavan, J.; Santhanam, Amutha

    2016-09-01

    In recent years researchers were attracted towards marine sources due to the presence of active components in it. Seaweeds were widely used in pharmaceutical research for their known biological activities. The biological synthesis method of silver nanoparticles (AgNPs) using Padina tetrastromatica seaweed extract and their cytotoxicity against breast cancer MCF-7 cells was reported in this study. The synthesized AgNPs using seaweed extract were subjected to x-ray diffraction, UV-visible spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscope, energy dispersive x-ray, zeta potential to elucidate the structural, morphology, size as well as surface potential parameters. An absorption peak at 430 nm in UV-visible spectrum reveals the excitation and surface plasmon resonance of AgNPs. FE-SEM micrographs exhibits the biosynthesized AgNPs, which are pre-dominantly round shaped and the size ranges between 40-50 nm. The zeta potential value of -27.6 mV confirms the stable nature of biosynthesized silver nanoparticles. Furthermore, the biological synthesized Ag NPs exhibited a dose-dependent cytotoxicity against human breast cancer cell (MCF-7) and the inhibitory concentration (IC50) was found for AgNPs against MCF-7 at 24 h incubation. Biological method of synthesizing silver nanoparticles shows a environmental friendly property which helps in effective electrifying usage in many fields.

  7. Cell adhesion and proliferation on polyethylene grafted with Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Kasálková, N. Slepičková; Slepička, P.; Kolská, Z.; Sajdl, P.; Bačáková, L.; Rimpelová, S.; Švorčík, V.

    2012-02-01

    Plasma treatment and subsequent Au nano-particles grafting of polyethylene (PE) lead to changes in surface morphology, roughness and wettability, significantly increasing the attractiveness of the material for cells. The PE samples were exposed to argon plasma. Plasma modified PE was chemically grafted by immersion to biphenyldithiol and consequently into solution of Au nano-particles. Changes in chemical structure of the modified PE were studied using X-ray Photoelectron Spectroscopy (XPS) and electrokinetic analysis ( ζ-potential). The surface wettability of the modified PE samples was examined by measurement of the contact angle by standard goniometry. The surface morphology of the plasma modified PE and that grafted with Au nano-particles was studied by Atomic Force Microscopy (AFM). The modified PE samples were seeded with rat vascular smooth muscle cells (VSMCs) and their adhesion and proliferation were studied. Chemically bounded biphenyldithiol increases the number of the incorporated gold nano-particles and changes sample surface properties. The presence of the biphenyldithiol and the gold nano-particles on the PE surface influences dramatically adhesion and proliferation of VSMCs.

  8. Gold nanoparticles delivery in mammalian live cells: a critical review

    PubMed Central

    Lévy, Raphaël; Shaheen, Umbreen; Cesbron, Yann; Sée, Violaine

    2010-01-01

    Functional nanomaterials have recently attracted strong interest from the biology community, not only as potential drug delivery vehicles or diagnostic tools, but also as optical nanomaterials. This is illustrated by the explosion of publications in the field with more than 2,000 publications in the last 2 years (4,000 papers since 2000; from ISI Web of Knowledge, ‘nanoparticle and cell’ hit). Such a publication boom in this novel interdisciplinary field has resulted in papers of unequal standard, partly because it is challenging to assemble the required expertise in chemistry, physics, and biology in a single team. As an extreme example, several papers published in physical chemistry journals claim intracellular delivery of nanoparticles, but show pictures of cells that are, to the expert biologist, evidently dead (and therefore permeable). To attain proper cellular applications using nanomaterials, it is critical not only to achieve efficient delivery in healthy cells, but also to control the intracellular availability and the fate of the nanomaterial. This is still an open challenge that will only be met by innovative delivery methods combined with rigorous and quantitative characterization of the uptake and the fate of the nanoparticles. This review mainly focuses on gold nanoparticles and discusses the various approaches to nanoparticle delivery, including surface chemical modifications and several methods used to facilitate cellular uptake and endosomal escape. We will also review the main detection methods and how their optimum use can inform about intracellular localization, efficiency of delivery, and integrity of the surface capping. PMID:22110850

  9. Nanocomposite of tin sulfide nanoparticles with reduced graphene oxide in high-efficiency dye-sensitized solar cells.

    PubMed

    Yang, Bo; Zuo, Xueqin; Chen, Peng; Zhou, Lei; Yang, Xiao; Zhang, Haijun; Li, Guang; Wu, Mingzai; Ma, Yongqing; Jin, Shaowei; Chen, Xiaoshuang

    2015-01-14

    A nanocomposite of SnS2 nanoparticles with reduced graphene oxide (SnS2@RGO) had been successfully synthesized as a substitute conventional Pt counter electrode (CE) in a dye-sensitized solar cell (DSSC) system. The SnS2 nanoparticles were uniformly dispersed onto graphene sheets, which formed a nanosized composite system. The effectiveness of this nanocomposite exhibited remarkable electrocatalytic properties upon reducing the triiodide, owning to synergistic effects of SnS2 nanoparticles dispersed on graphene sheet and improved conductivity. Consequently, the DSSC equipped with SnS2@RGO nanocomposite CE achieved power conversion efficiency (PCE) of 7.12%, which was higher than those of SnS2 nanoparticles (5.58%) or graphene sheet alone (3.73%) as CEs and also comparable to the value (6.79%) obtained with pure Pt CE as a reference.

  10. Dietary Phenolic Acids Act as Effective Antioxidants in Membrane Models and in Cultured Cells, Exhibiting Proapoptotic Effects in Leukaemia Cells

    PubMed Central

    Zambonin, Laura; Caliceti, Cristiana; Vieceli Dalla Sega, Francesco; Fiorentini, Diana; Hrelia, Silvana; Landi, Laura; Prata, Cecilia

    2012-01-01

    Caffeic, syringic, and protocatechuic acids are phenolic acids derived directly from food intake or come from the gut metabolism of polyphenols. In this study, the antioxidant activity of these compounds was at first evaluated in membrane models, where caffeic acid behaved as a very effective chain-breaking antioxidant, whereas syringic and protocatechuic acids were only retardants of lipid peroxidation. However, all three compounds acted as good scavengers of reactive species in cultured cells subjected to exogenous oxidative stress produced by low level of H2O2. Many tumour cells are characterised by increased ROS levels compared with their noncancerous counterparts. Therefore, we investigated whether phenolic acids, at low concentrations, comparable to those present in human plasma, were able to decrease basal reactive species. Results show that phenolic acids reduced ROS in a leukaemia cell line (HEL), whereas no effect was observed in normal cells, such as HUVEC. The compounds exhibited no toxicity to normal cells while they decreased proliferation in leukaemia cells, inducing apoptosis. In the debate on optimal ROS-manipulating strategies in cancer therapy, our work in leukaemia cells supports the antioxidant ROS-depleting approach. PMID:22792417

  11. Do cancer cells in human and meristematic cells in plant exhibit similar responses toward plant extracts with cytotoxic activities?

    PubMed

    Khalifa, Noha S; Barakat, Hoda S; Elhallouty, Salwa; Salem, Dina

    2015-01-01

    We examined the effect of water extracts of Persea americana fruit, and of the leaves of Tabernamontana divericata, Nerium oleander and Annona cherimolia (positive control) on Vicia faba root cells. We had confirmed in our previously published data the cytotoxicity of these plant extracts on four human cancer cell lines: liver (HepG-2), lung (A549), colon (HT-29) and breast (MCF-7). Vicia faba roots were soaked in plant extracts at dilutions of 100, 1,250, 2,500, 5,000, 10,000, 20,000 ppm for 4 and 24 h. All treatments resulted in a significant reduction in the mitotic index in a dose dependant manner. Root cells treated with T. divericata, N. oleander and A. cherimolia exhibited a decrease in prophase cell percentage, increase in micronuclei and chromosomal abnormalities as concentration increased. The P. americana treatment showed the highest cytotoxic effect on cancer cells, prophase cell percentage increased linearly with the applied concentration and no micronuclei were detected. This study shows that root tip assay of beans can be used in initial screening for new plant extracts to validate their use as candidates for containing active cytotoxic agents against malignant cells. This will greatly help in exploring new plant extracts as drugs for cancer treatment. PMID:24705601

  12. Targeting myeloid cells using nanoparticles to improve cancer immunotherapy.

    PubMed

    Amoozgar, Zohreh; Goldberg, Michael S

    2015-08-30

    While nanoparticles have traditionally been used to deliver cytotoxic drugs directly to tumors to induce cancer cell death, emerging data suggest that nanoparticles are likely to generate a larger impact on oncology through the delivery of agents that can stimulate antitumor immunity. Tumor-targeted nanocarriers have generally been used to localize chemotherapeutics to tumors and thus decrease off-target toxicity while enhancing efficacy. Challengingly, tumor heterogeneity and evolution render tumor-intrinsic approaches likely to succumb to relapse. The immune system offers exquisite specificity, cytocidal potency, and long-term activity that leverage an adaptive memory response. For this reason, the ability to manipulate immune cell specificity and function would be desirable, and nanoparticles represent an exciting means by which to perform such manipulation. Dendritic cells and tumor-associated macrophages are cells of the myeloid lineage that function as natural phagocytes, so they naturally take up nanoparticles. Dendritic cells direct the specificity and potency of cellular immune responses that can be targeted for cancer vaccines. Herein, we discuss the specific criteria needed for efficient vaccine design, including but not limited to the route of administration, size, morphology, surface charge, targeting ligands, and nanoparticle composition. In contrast, tumor-associated macrophages are critical mediators of immunosuppression whose trans-migratory abilities can be exploited to localize therapeutics to the tumor core and which can be directly targeted for elimination or for repolarization to a tumor suppressive phenotype. It is likely that a combination of targeting dendritic cells to stimulate antitumor immunity and tumor-associated macrophages to reduce immune suppression will impart significant benefits and result in durable antitumor responses.

  13. Cancer cell response to nanoparticles: criticality and optimality.

    PubMed

    Patra, Hirak Kumar; Dasgupta, Anjan Kr

    2012-08-01

    A stochastic variation in size and electrical parameters is common in nanoparticles. Synthesizing gold nanoparticles with a varying range of size and zeta potential, we show that there is clustering at certain regions of hydrodynamic diameter and zeta potentials that can be classified using k-clustering technique. A cluster boundary was observed around 50 nm, a size known for its optimal response to cells. However, neither size nor zeta potential alone determined the optimal cellular response (e.g., percentage cell survival) induced by such nanoparticles. A complex interplay prevails between size, zeta potential, nature of surface functionalization, and extent of adhesion of the cell to a solid matrix. However, it follows that the ratio of zeta potential to surface area, which scales as the electrical field (by Gaussian law), serves as an appropriate indicator for optimal cellular response. The phase plot spanned by fractional survival and effective electric field (charge density) indicates a positive correlation between mean cell survival and the magnitude of the electric field. The phase plot spanned by fractional survival and effective electric field (charge density) associated with the nanosurface shows a bifurcation behavior. Wide variation of cell survival response is observed at certain critical values of the surface charge density, whereas in other ranges the cellular response is well behaved and more predictable. Existence of phase points near the critical region corresponds to wide fluctuation of nanoparticle-induced response, for small changes in the nanosurface property. Smaller nanoparticles with low zeta potential (e.g., those conjugated with arginine) can have such an attribute (i.e., higher electrical field strength), and eventually they cause more cell death. The study may help in optimal design of nanodrugs. PMID:22094123

  14. The role of surface charge on the uptake and biocompatibility of hydroxyapatite nanoparticles with osteoblast cells

    NASA Astrophysics Data System (ADS)

    Chen, Liang; Mccrate, Joseph M.; C-M Lee, James; Li, Hao

    2011-03-01

    The objective of this study is to evaluate the effect of hydroxyapatite (HAP) nanoparticles with different surface charges on the cellular uptake behavior and in vitro cell viability and proliferation of MC3T3-E1 cell lines (osteoblast). The nanoparticles' surface charge was varied by surface modification with two carboxylic acids: 12-aminododecanoic acid (positive) and dodecanedioic acid (negative). The untreated HAP nanoparticles and dodecanoic acid modified HAP nanoparticles (neutral) were used as the control. X-ray diffraction (XRD) revealed that surface modifications by the three carboxylic acids did not change the crystal structure of HAP nanoparticles; Fourier transform infrared spectroscopy (FT-IR) confirmed the adsorption and binding of the carboxylic acids on the HAP nanoparticles' surfaces; and zeta potential measurement confirmed that the chemicals successfully modified the surface charge of HAP nanoparticles in water based solution. Transmission electron microscopy (TEM) images showed that positively charged, negatively charged and untreated HAP nanoparticles, with similar size and shape, all penetrated into the cells and cells had more uptake of HAP nanoparticles with positive charge compared to those with negative charge, which might be attributed to the attractive or repulsive interaction between the negatively charged cell membrane and positively/negatively charged HAP nanoparticles. The neutral HAP nanoparticles could not penetrate the cell membrane due to their larger size. MTT assay and LDH assay results indicated that as compared with the polystyrene control, greater cell viability and cell proliferation were measured on MC3T3-E1 cells treated with the three kinds of HAP nanoparticles (neutral, positive, and untreated), among which positively charged HAP nanoparticles showed the strongest improvement for cell viability and cell proliferation. In summary, the surface charge of HAP nanoparticles can be modified to influence the cellular uptake of

  15. Genotoxicity of Superparamagnetic Iron Oxide Nanoparticles in Granulosa Cells.

    PubMed

    Pöttler, Marina; Staicu, Andreas; Zaloga, Jan; Unterweger, Harald; Weigel, Bianca; Schreiber, Eveline; Hofmann, Simone; Wiest, Irmi; Jeschke, Udo; Alexiou, Christoph; Janko, Christina

    2015-01-01

    Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5) were treated with SPIONs, either coated with lauric acid (SEONLA) only, or additionally with a protein corona of bovine serum albumin (BSA; SEON(LA-BSA)), or with dextran (SEON(DEX)). Both micronuclei testing and the detection of γH2A.X revealed no genotoxic effects of SEON(LA-BSA), SEON(DEX) or SEON(LA). Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system. PMID:26540051

  16. Optical injection of gold nanoparticles into living cells.

    PubMed

    Li, Miao; Lohmüller, Theobald; Feldmann, Jochen

    2015-01-14

    The controlled injection of nanoscopic objects into living cells with light offers promising prospects for the development of novel molecular delivery strategies or intracellular biosensor applications. Here, we show that single gold nanoparticles from solution can be patterned on the surface of living cells with a continuous wave laser beam. In a second step, we demonstrate how the same particles can then be injected into the cells through a combination of plasmonic heating and optical force. We find that short exposure times are sufficient to perforate the cell membrane and inject the particles into cells with a survival rate of >70%.

  17. Cardiac Adipose-Derived Stem Cells Exhibit High Differentiation Potential to Cardiovascular Cells in C57BL/6 Mice.

    PubMed

    Nagata, Hiroki; Ii, Masaaki; Kohbayashi, Eiko; Hoshiga, Masaaki; Hanafusa, Toshiaki; Asahi, Michio

    2016-02-01

    Adipose-derived stem cells (AdSCs) have recently been shown to differentiate into cardiovascular lineage cells. However, little is known about the fat tissue origin-dependent differences in AdSC function and differentiation potential. AdSC-rich cells were isolated from subcutaneous, visceral, cardiac (CA), and subscapular adipose tissue from mice and their characteristics analyzed. After four different AdSC types were cultured with specific differentiation medium, immunocytochemical analysis was performed for the assessment of differentiation into cardiovascular cells. We then examined the in vitro differentiation capacity and therapeutic potential of AdSCs in ischemic myocardium using a mouse myocardial infarction model. The cell density and proliferation activity of CA-derived AdSCs were significantly increased compared with the other adipose tissue-derived AdSCs. Immunocytochemistry showed that CA-derived AdSCs had the highest appearance rates of markers for endothelial cells, vascular smooth muscle cells, and cardiomyocytes among the AdSCs. Systemic transfusion of CA-derived AdSCs exhibited the highest cardiac functional recovery after myocardial infarction and the high frequency of the recruitment to ischemic myocardium. Moreover, long-term follow-up of the recruited CA-derived AdSCs frequently expressed cardiovascular cell markers compared with the other adipose tissue-derived AdSCs. Cardiac adipose tissue could be an ideal source for isolation of therapeutically effective AdSCs for cardiac regeneration in ischemic heart diseases. Significance: The present study found that cardiac adipose-derived stem cells have a high potential to differentiate into cardiovascular lineage cells (i.e., cardiomyocytes, endothelial cells, and vascular smooth muscle cells) compared with stem cells derived from other adipose tissue such as subcutaneous, visceral, and subscapular adipose tissue. Notably, only a small number of supracardiac adipose-derived stem cells that were

  18. Integrated Anti-Icing Property of Super-Repellency and Electrothermogenesis Exhibited by PEDOT:PSS/Cyanoacrylate Composite Nanoparticles.

    PubMed

    Matsubayashi, Takeshi; Tenjimbayashi, Mizuki; Manabe, Kengo; Komine, Masatsugu; Navarrini, Walter; Shiratori, Seimei

    2016-09-14

    Ice formation causes numerous problems in many industrial fields as well as in our daily life. Various functional anti-ice coatings have been extensively studied during the past several decades; however, the development of feasible ice-repellent surfaces with long-term stability has been found to be extremely difficult. Here, we report the conductive superhydrophobic coatings with freezing rain repellency that simultaneously possess electrothermogenic ability to rapidly melt newly formed frosts due to the Joule heat. The obtained films have high mechanical flexibility and abrasion resistance produced by composite nanoparticles of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) embedded in ethyl cyanoacrylate. In addition, excellent water repellency (corresponding contact angle >160°) and efficient heating ability (with an estimated energy consumption as low as 260.8 °C cm(2)/W) generated by applying voltage through the conductive film surface have been demonstrated. The proposed concept of combining super-repellency with electrothermal heating may provide a new strategy of addressing problems related to ice formation. PMID:27540638

  19. Comparative evaluation of the impact on endothelial cells induced by different nanoparticle structures and functionalization

    PubMed Central

    Müller, Ines; Ernst, Peter; Schäfer, Miriam; Rosman, Christina; Schick, Isabel; Köhler, Oskar; Oehring, Hartmut; Breus, Vladimir V; Basché, Thomas; Sönnichsen, Carsten; Tremel, Wolfgang

    2015-01-01

    Summary In the research field of nanoparticles, many studies demonstrated a high impact of the shape, size and surface charge, which is determined by the functionalization, of nanoparticles on cell viability and internalization into cells. This work focused on the comparison of three different nanoparticle types to give a better insight into general rules determining the biocompatibility of gold, Janus and semiconductor (quantum dot) nanoparticles. Endothelial cells were subject of this study, since blood is the first barrier after intravenous nanoparticle application. In particular, stronger effects on the viability of endothelial cells were found for nanoparticles with an elongated shape in comparison to spherical ones. Furthermore, a positively charged nanoparticle surface (NH2, CyA) leads to the strongest reduction in cell viability, whereas neutral and negatively charged nanoparticles are highly biocompatible to endothelial cells. These findings are attributed to a rapid internalization of the NH2-functionalized nanoparticles in combination with the damage of intracellular membranes. Interestingly, the endocytotic pathway seems to be a size-dependent process whereas nanoparticles with a size of 20 nm are internalized by caveolae-mediated endocytosis and nanoparticles with a size of 40 nm are taken up by clathrin-mediated internalization and macropinocytosis. Our results can be summarized to formulate five general rules, which are further specified in the text and which determine the biocompatibility of nanoparticles on endothelial cells. Our findings will help to design new nanoparticles with optimized properties concerning biocompatibility and uptake behavior with respect to the respective intended application. PMID:25821668

  20. Water soluble nanoporous nanoparticle for in vivo targeted drug delivery and controlled release in B cells tumor context

    NASA Astrophysics Data System (ADS)

    de Angelis, F.; Pujia, A.; Falcone, C.; Iaccino, E.; Palmieri, C.; Liberale, C.; Mecarini, F.; Candeloro, P.; Luberto, L.; de Laurentiis, A.; Das, G.; Scala, G.; di Fabrizio, E.

    2010-10-01

    Multitasking nanoparticles are gaining great attention for smart drug delivery systems. The exploration of the nano-scale opens new concrete opportunities for revealing new properties and undiscovered cell-particle interactions. Here we present a biodegradable nanoporous silicon nanoparticle that can be successfully employed for in vivo targeted drug delivery and sustained release. The bare nanoporous nanocarriers can be accurately designed and fabricated with an effective control of porosity, surface chemistry and particle size, up to a few nm. The proposed nanoparticles exhibit several remarkable features including high payload, biodegradability, no toxicity, and multiple loading in water without the need of additional chemical reagents at room temperature. The targeting strategy is based on phage display technology that was successfully used to discover cell surface binding peptide for murine B lymphoma A20 cell line. The peptide used in combination with the nanoporous nanoparticles allows an efficient in vivo targeting, a sustained release and a sensible therapeutic effect.Multitasking nanoparticles are gaining great attention for smart drug delivery systems. The exploration of the nano-scale opens new concrete opportunities for revealing new properties and undiscovered cell-particle interactions. Here we present a biodegradable nanoporous silicon nanoparticle that can be successfully employed for in vivo targeted drug delivery and sustained release. The bare nanoporous nanocarriers can be accurately designed and fabricated with an effective control of porosity, surface chemistry and particle size, up to a few nm. The proposed nanoparticles exhibit several remarkable features including high payload, biodegradability, no toxicity, and multiple loading in water without the need of additional chemical reagents at room temperature. The targeting strategy is based on phage display technology that was successfully used to discover cell surface binding peptide for

  1. Effects of As2O3 nanoparticles on cell growth and apoptosis of NB4 cells

    PubMed Central

    DONG, XIAOYAN; MA, NING; LIU, MENGMENG; LIU, ZILING

    2015-01-01

    The aim of the present study was to explore the preparation of arsenic trioxide (As2O3) nanoparticles and examine the antitumor effects of these nanoparticles on NB4 cells. As2O3 nanoparticles were prepared using the sol-gel method and characterized using transmission electron microscopy and energy dispersive spectroscopy. The results indicated that the As2O3 nanoparticles prepared in the present study were round or elliptical, well dispersed and had an ~40-nm or <10-nm diameter. The antitumor effects of As2O3 nanoparticles at various concentrations were analyzed by flow cytometry and the MTT assay, and were compared with those of traditional As2O3 solution. At the same concentration and incubation time (48 h), the survival rate of cells treated with As2O3 nanoparticles was significantly lower than that of cells treated with the As2O3 solution. The growth inhibition rate under both treatments was time- and dose-dependent. In addition, at the same concentration and incubation time, the apoptosis rate of the cells treated with As2O3 nanoparticles was significantly higher than that of the cells treated with the As2O3 solution. Furthermore, As2O3 nanoparticles resulted in a greater reduction in the expression of the anti-apoptotic protein B-cell lymphoma 2 compared with the As2O3 solution. In conclusion, As2O3 nanoparticles, prepared using the sol-gel method, were found to produce a stronger cytotoxic effect on tumor cells than that produced by the As2O3 solution, possibly by inhibiting Bcl-2 expression. PMID:26622477

  2. Mutagenic Effects of Iron Oxide Nanoparticles on Biological Cells

    PubMed Central

    Dissanayake, Niluka M.; Current, Kelley M.; Obare, Sherine O.

    2015-01-01

    In recent years, there has been an increased interest in the design and use of iron oxide materials with nanoscale dimensions for magnetic, catalytic, biomedical, and electronic applications. The increased manufacture and use of iron oxide nanoparticles (IONPs) in consumer products as well as industrial processes is expected to lead to the unintentional release of IONPs into the environment. The impact of IONPs on the environment and on biological species is not well understood but remains a concern due to the increased chemical reactivity of nanoparticles relative to their bulk counterparts. This review article describes the impact of IONPs on cellular genetic components. The mutagenic impact of IONPs may damage an organism’s ability to develop or reproduce. To date, there has been experimental evidence of IONPs having mutagenic interactions on human cell lines including lymphoblastoids, fibroblasts, microvascular endothelial cells, bone marrow cells, lung epithelial cells, alveolar type II like epithelial cells, bronchial fibroblasts, skin epithelial cells, hepatocytes, cerebral endothelial cells, fibrosarcoma cells, breast carcinoma cells, lung carcinoma cells, and cervix carcinoma cells. Other cell lines including the Chinese hamster ovary cells, mouse fibroblast cells, murine fibroblast cells, Mytilus galloprovincialis sperm cells, mice lung cells, murine alveolar macrophages, mice hepatic and renal tissue cells, and vero cells have also shown mutagenic effects upon exposure to IONPs. We further show the influence of IONPs on microorganisms in the presence and absence of dissolved organic carbon. The results shed light on the transformations IONPs undergo in the environment and the nature of the potential mutagenic impact on biological cells. PMID:26437397

  3. PEG-templated mesoporous silica nanoparticles exclusively target cancer cells

    NASA Astrophysics Data System (ADS)

    Morelli, Catia; Maris, Pamela; Sisci, Diego; Perrotta, Enrico; Brunelli, Elvira; Perrotta, Ida; Panno, Maria Luisa; Tagarelli, Antonio; Versace, Carlo; Casula, Maria Francesca; Testa, Flaviano; Andò, Sebastiano; Nagy, Janos B.; Pasqua, Luigi

    2011-08-01

    Mesoporous silica nanoparticles (MSNs) have been proposed as DNA and drug delivery carriers, as well as efficient tools for fluorescent cell tracking. The major limitation is that MSNs enter cells regardless of a target-specific functionalization. Here we show that non functionalized MSNs, synthesized using a PEG surfactant-based interfacial synthesis procedure, do not enter cells, while a highly specific, receptor mediated, cellular internalization of folic acid (FOL) grafted MSNs (MSN-FOL), occurs exclusively in folate receptor (FR) expressing cells. Neither the classical clathrin pathway nor macropinocytosis is involved in the MSN endocytic process, while fluorescent MSNs (MSN-FITC) enter cells through aspecific, caveolae-mediated, endocytosis. Moreover, internalized particles seem to be mostly exocytosed from cells within 96 h. Finally, cisplatin (Cp) loaded MSN-FOL were tested on cancerous FR-positive (HeLa) or normal FR-negative (HEK293) cells. A strong growth arrest was observed only in HeLa cells treated with MSN-FOL-Cp. The results presented here show that our mesoporous nanoparticles do not enter cells unless opportunely functionalized, suggesting that they could represent a promising vehicle for drug targeting applications.Mesoporous silica nanoparticles (MSNs) have been proposed as DNA and drug delivery carriers, as well as efficient tools for fluorescent cell tracking. The major limitation is that MSNs enter cells regardless of a target-specific functionalization. Here we show that non functionalized MSNs, synthesized using a PEG surfactant-based interfacial synthesis procedure, do not enter cells, while a highly specific, receptor mediated, cellular internalization of folic acid (FOL) grafted MSNs (MSN-FOL), occurs exclusively in folate receptor (FR) expressing cells. Neither the classical clathrin pathway nor macropinocytosis is involved in the MSN endocytic process, while fluorescent MSNs (MSN-FITC) enter cells through aspecific, caveolae

  4. Carbon composites with metal nanoparticles for Alcohol fuel cells

    NASA Astrophysics Data System (ADS)

    Ventrapragada, Lakshman; Siddhardha, R. S.; Podilla, Ramakrishna; Muthukumar, V. S.; Creager, Stephen; Rao, A. M.; Ramamurthy, Sai Sathish

    2015-03-01

    Graphene due to its high surface area and superior conductivity has attracted wide attention from both industrial and scientific communities. We chose graphene as a substrate for metal nanoparticle deposition for fuel cell applications. There are many chemical routes for fabrication of metal-graphene composites, but they have an inherent disadvantage of low performance due to the usage of surfactants, that adsorb on their surface. Here we present a design for one pot synthesis of gold nanoparticles and simultaneous deposition on graphene with laser ablation of gold strip and functionalized graphene. In this process there are two natural advantages, the nanoparticles are synthesized without any surfactants, therefore they are pristine and subsequent impregnation on graphene is linker free. These materials are well characterized with electron microscopy to find their morphology and spectroscopic techniques like Raman, UV-Vis. for functionality. This gold nanoparticle decorated graphene composite has been tested for its electrocatalytic oxidation of alcohols for alkaline fuel cell applications. An electrode made of this composite showed good stability for more than 200 cycles of operation and reported a low onset potential of 100 mV more negative, an important factor for direct ethanol fuel cells.

  5. Effect of Fe3O4 Nanoparticles on Skin Tumor Cells and Dermal Fibroblasts

    PubMed Central

    Alili, Lirija; Chapiro, Swetlana; Marten, Gernot U.; Schmidt, Annette M.; Zanger, Klaus; Brenneisen, Peter

    2015-01-01

    Iron oxide (Fe3O4) nanoparticles have been used in many biomedical approaches. The toxicity of Fe3O4 nanoparticles on mammalian cells was published recently. Though, little is known about the viability of human cells after treatment with Fe3O4 nanoparticles. Herein, we examined the toxicity, production of reactive oxygen species, and invasive capacity after treatment of human dermal fibroblasts (HDF) and cells of the squamous tumor cell line (SCL-1) with Fe3O4 nanoparticles. These nanoparticles had an average size of 65 nm. Fe3O4 nanoparticles induced oxidative stress via generation of reactive oxygen species (ROS) and subsequent initiation of lipid peroxidation. Furthermore, the question was addressed of whether Fe3O4 nanoparticles affect myofibroblast formation, known to be involved in tumor invasion. Herein, Fe3O4 nanoparticles prevent the expression alpha-smooth muscle actin and therefore decrease the number of myofibroblastic cells. Moreover, our data show in vitro that concentrations of Fe3O4 nanoparticles, which are nontoxic for normal cells, partially reveal a ROS-triggered cytotoxic but also a pro-invasive effect on the fraction of squamous cancer cells surviving the treatment with Fe3O4 nanoparticles. The data herein show that the Fe3O4 nanoparticles appear not to be adequate for use in therapeutic approaches against cancer cells, in contrast to recently published data with cerium oxide nanoparticles. PMID:26090418

  6. Photothermal therapy of cancer cells using magnetic carbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Vardarajan, V.; Gu, L.; Kanneganti, A.; Mohanty, S. K.; Koymen, A. R.

    2011-03-01

    Photothermal therapy offers a solution for the destruction of cancer cells without significant collateral damage to otherwise healthy cells. Several attempts are underway in using carbon nanoparticles (CNPs) and nanotubes due to their excellent absorption properties in the near-infrared spectrum of biological window. However, minimizing the required number of injected nanoparticles, to ensure minimal cytotoxicity, is a major challenge. We report on the introduction of magnetic carbon nanoparticles (MCNPs) onto cancer cells, localizing them in a desired region by applying an external magnetic field and irradiating them with a near-infrared laser beam. The MCNPs were prepared in Benzene, using an electric plasma discharge, generated in the cavitation field of an ultrasonic horn. The CNPs were made ferromagnetic by use of Fe-electrodes to dope the CNPs, as confirmed by magnetometry. Transmission electron microscopy measurements showed the size distribution of these MCNPs to be in the range of 5-10 nm. For photothermal irradiation, a tunable continuous wave Ti: Sapphire laser beam was weakly focused on to the cell monolayer under an inverted fluorescence microscope. The response of different cell types to photothermal irradiation was investigated. Cell death in the presence of both MCNPs and laser beam was confirmed by morphological changes and propidium iodide fluorescence inclusion assay. The results of our study suggest that MCNP based photothermal therapy is a promising approach to remotely guide photothermal therapy.

  7. Glass frits coated with silver nanoparticles for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Li, Yingfen; Gan, Weiping; Zhou, Jian; Li, Biyuan

    2015-06-01

    Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.

  8. In vitro cell imaging using multifunctional small sized KGdF4:Yb3+,Er3+ upconverting nanoparticles synthesized by a one-pot solvothermal process

    NASA Astrophysics Data System (ADS)

    Wong, Hon-Tung; Tsang, Ming-Kiu; Chan, Chi-Fai; Wong, Ka-Leung; Fei, Bin; Hao, Jianhua

    2013-03-01

    Multifunctional KGdF4:18%Yb3+,2%Er3+ nanoparticles with upconversion fluorescence and paramagnetism are synthesized. The average sizes of the nanoparticles capped with branched polyethyleneimine (PEI) and 6-aminocaproic acid (6AA) are ~14 and ~13 nm, respectively. Our KGdF4 host does not exhibit any phase change with the decrease of particle size, which can prevent the detrimental significant decrease in upconversion luminescence caused by this effect observed in the well-known NaYF4 host. The branched PEI and 6AA capping ligands endow our nanoparticles with water-dispersibility and biocompatibility, which can favor internalization of our nanoparticles into the cytoplasm of HeLa cells and relatively high cell viability. The strong upconversion luminescence detected at the cytoplasm of HeLa cells incubated with the branched PEI-capped nanoparticles is probably attributed to the reported high efficiency of cellular uptake. The magnetic mass susceptibility of our nanoparticle is 8.62 × 10-5 emu g-1 Oe-1. This is the highest value ever reported in trivalent rare-earth ion-doped KGdF4 nanoparticles of small size (<=14 nm), and is very close to that of nanoparticles used as T1 contrast agents in magnetic resonance imaging. These suggest the potential of our KGdF4:Yb3+,Er3+ nanoparticles as small-sized multifunctional bioprobes.

  9. Memory and effector CD8 T-cell responses after nanoparticle vaccination of melanoma patients.

    PubMed

    Speiser, Daniel E; Schwarz, Katrin; Baumgaertner, Petra; Manolova, Vania; Devevre, Estelle; Sterry, Wolfram; Walden, Peter; Zippelius, Alfred; Conzett, Katrin Baumann; Senti, Gabriela; Voelter, Verena; Cerottini, Jean-Philippe; Guggisberg, David; Willers, Jörg; Geldhof, Christine; Romero, Pedro; Kündig, Thomas; Knuth, Alexander; Dummer, Reinhard; Trefzer, Uwe; Bachmann, Martin F

    2010-10-01

    Induction of cytotoxic CD8 T-cell responses is enhanced by the exclusive presentation of antigen through dendritic cells, and by innate stimuli, such as toll-like receptor ligands. On the basis of these 2 principles, we designed a vaccine against melanoma. Specifically, we linked the melanoma-specific Melan-A/Mart-1 peptide to virus-like nanoparticles loaded with A-type CpG, a ligand for toll-like receptor 9. Melan-A/Mart-1 peptide was cross-presented, as shown in vitro with human dendritic cells and in HLA-A2 transgenic mice. A phase I/II study in stage II-IV melanoma patients showed that the vaccine was well tolerated, and that 14/22 patients generated ex vivo detectable T-cell responses, with in part multifunctional T cells capable to degranulate and produce IFN-γ, TNF-α, and IL-2. No significant influence of the route of immunization (subcutaneous versus intradermal) nor dosing regimen (weekly versus daily clusters) could be observed. It is interesting to note that, relatively large fractions of responding specific T cells exhibited a central memory phenotype, more than what is achieved by other nonlive vaccines. We conclude that vaccination with CpG loaded virus-like nanoparticles is associated with a human CD8 T-cell response with properties of a potential long-term immune protection from the disease. PMID:20842051

  10. Metal nanoparticles enhanced optical absorption in thin film solar cells

    NASA Astrophysics Data System (ADS)

    Xie, Wanlu; Liu, Fang; Qu, Di; Xu, Qi; Huang, Yidong

    2011-12-01

    The plasmonic enhanced absorption for thin film solar cells with silver nanoparticles (NPs) deposited on top of the amorphous silicon film (a-Si:H) solar cells and embedded inside the active layer of organic solar cells (OSCs) has been simulated and analyzed. Obvious optical absorption enhancement is obtained not only at vertical incidence but also at oblique incidence. By properly adjusting the period and size of NPs, an increased absorption enhancement of about 120% and 140% is obtained for a-Si:H solar cells and OSCs, respectively.

  11. Enhanced reactive oxygen species overexpression by CuO nanoparticles in poorly differentiated hepatocellular carcinoma cells

    NASA Astrophysics Data System (ADS)

    Kung, Mei-Lang; Hsieh, Shu-Ling; Wu, Chih-Chung; Chu, Tian-Huei; Lin, Yu-Chun; Yeh, Bi-Wen; Hsieh, Shuchen

    2015-01-01

    Copper oxide nanoparticles (CuO NPs) are known to exhibit toxic effects on a variety of cell types and organs. To determine the oxidative impact of CuO NPs on hepatocellular carcinoma (HCC) cells, well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) cells were exposed to CuO NPs. Cell viability assay showed that the median inhibition concentration (IC50) for SK-Hep-1 and HepG2 cells was 25 μg ml-1 and 85 μg ml-1, respectively. Cellular fluorescence intensity using DCFH-DA staining analysis revealed significant intracellular reactive oxygen species (ROS) generation of up to 242% in SK-Hep-1 cells, compared with 86% in HepG2 cells. HPLC analysis demonstrated that a CuO NP treatment caused cellular GSH depletion of 58% and a GSH/GSSG ratio decrease to ~0.1 in SK-Hep-1 cells. The oxidative stress caused by enhanced superoxide anion production was observed in both HepG2 (146%) and SK-Hep-1 (192%) cells. The Griess assay verified that CuO NPs induced NO production (170%) in SK-Hep-1 cells. Comet assay and western blot further demonstrated that CuO NPs induced severe DNA strand breakage (70%) in SK-Hep-1 cells and caused DNA damage via increased γ-H2AX levels. These results suggest that well-differentiated HepG2 cells possess a robust antioxidant defense system against CuO NP-induced ROS stress and exhibit more tolerance to oxidative stress. Conversely, poorly differentiated SK-Hep-1 cells exhibited a deregulated antioxidant defense system that allowed accumulation of CuO NP-induced ROS and resulted in severe cytotoxicity.Copper oxide nanoparticles (CuO NPs) are known to exhibit toxic effects on a variety of cell types and organs. To determine the oxidative impact of CuO NPs on hepatocellular carcinoma (HCC) cells, well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) cells were exposed to CuO NPs. Cell viability assay showed that the median inhibition concentration (IC50) for SK-Hep-1 and HepG2 cells was 25 μg ml-1 and 85 μg ml-1, respectively

  12. Single-cell imaging detection of nanobarcoded nanoparticle biodistributions in tissues for nanomedicine

    NASA Astrophysics Data System (ADS)

    Eustaquio, Trisha; Cooper, Christy L.; Leary, James F.

    2011-03-01

    In nanomedicine, biodistribution studies are critical to evaluate the safety and efficacy of nanoparticles. Currently, extensive biodistribution studies are hampered by the limitations of bulk tissue and single-cell imaging techniques. To ameliorate these limitations, we have developed a novel method for single nanoparticle detection that incorporates a conjugated oligonucleotide as a "nanobarcode" for detection via in situ PCR. This strategy magnifies the detection signal from single nanoparticles, facilitating rapid evaluation of nanoparticle uptake by cell type over larger areas. The nanobarcoding method can enable precise analysis of nanoparticle biodistributions and expedite translation of these nanoparticles to the clinic.

  13. Core-shell polymer nanoparticles for prevention of GSH drug detoxification and cisplatin delivery to breast cancer cells

    NASA Astrophysics Data System (ADS)

    Surnar, Bapurao; Sharma, Kavita; Jayakannan, Manickam

    2015-10-01

    Platinum drug delivery against the detoxification of cytoplasmic thiols is urgently required for achieving efficacy in breast cancer treatment that is over expressed by glutathione (GSH, thiol-oligopeptide). GSH-resistant polymer-cisplatin core-shell nanoparticles were custom designed based on biodegradable carboxylic functional polycaprolactone (PCL)-block-poly(ethylene glycol) diblock copolymers. The core of the nanoparticle was fixed as 100 carboxylic units and the shell part was varied using various molecular weight poly(ethylene glycol) monomethyl ethers (MW of PEGs = 100-5000 g mol-1) as initiator in the ring-opening polymerization. The complexation of cisplatin aquo species with the diblocks produced core-shell nanoparticles of 75 nm core with precise size control the particles up to 190 nm. The core-shell nanoparticles were found to be stable in saline solution and PBS and they exhibited enhanced stability with increase in the PEG shell thickness at the periphery. The hydrophobic PCL layer on the periphery of the cisplatin core behaved as a protecting layer against the cytoplasmic thiol residues (GSH and cysteine) and exhibited <5% of drug detoxification. In vitro drug-release studies revealed that the core-shell nanoparticles were ruptured upon exposure to lysosomal enzymes like esterase at the intracellular compartments. Cytotoxicity studies were performed both in normal wild-type mouse embryonic fibroblast cells (Wt-MEFs), and breast cancer (MCF-7) and cervical cancer (HeLa) cell lines. Free cisplatin and polymer drug core-shell nanoparticles showed similar cytotoxicity effects in the HeLa cells. In MCF-7 cells, the free cisplatin drug exhibited 50% cell death whereas complete cell death (100%) was accomplished by the polymer-cisplatin core-shell nanoparticles. Confocal microscopic images confirmed that the core-shell nanoparticles were taken up by the MCF-7 and HeLa cells and they were accumulated both at the cytoplasm as well at peri

  14. Imaging circulating cells and lymphoid tissues with iron oxide nanoparticles.

    PubMed

    Elias, Andrew; Tsourkas, Andrew

    2009-01-01

    The use of nanometer-sized iron oxide nanoparticles and micron-sized iron oxide particles as magnetic resonance (MR) contrast agents has garnered a high degree of interest in diverse areas of biology and medicine. Applications such as cell tracking, molecular imaging, gene detection, and lymphography are being explored to provide insight into disease mechanisms, monitor therapeutic efficacy, and facilitate diagnostic imaging. What makes iron oxide so appealing is a number of favorable properties including high detectability by MR, biodegradability and low toxicity. Here we describe the recent progress on the use of magnetic nanoparticles in imaging circulating cells and lymphoid tissues. The study of the lymph system and the biodistribution of various circulating immune cells is important in the diagnosis, prognosis, and treatment of a wide range of diseases and is expected to have a profound effect on patient outcome.

  15. Nanoparticles-cell association predicted by protein corona fingerprints

    NASA Astrophysics Data System (ADS)

    Palchetti, S.; Digiacomo, L.; Pozzi, D.; Peruzzi, G.; Micarelli, E.; Mahmoudi, M.; Caracciolo, G.

    2016-06-01

    In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface chemistry (unmodified and PEGylated) to investigate the relationships between NP physicochemical properties (nanoparticle size, aggregation state and surface charge), protein corona fingerprints (PCFs), and NP-cell association. We found out that none of the NPs' physicochemical properties alone was exclusively able to account for association with human cervical cancer cell line (HeLa). For the entire library of NPs, a total of 436 distinct serum proteins were detected. We developed a predictive-validation modeling that provides a means of assessing the relative significance of the identified corona proteins. Interestingly, a minor fraction of the HC, which consists of only 8 PCFs were identified as main promoters of NP association with HeLa cells. Remarkably, identified PCFs have several receptors with high level of expression on the plasma membrane of HeLa cells.In a physiological environment (e.g., blood and interstitial fluids) nanoparticles (NPs) will bind proteins shaping a ``protein corona'' layer. The long-lived protein layer tightly bound to the NP surface is referred to as the hard corona (HC) and encodes information that controls NP bioactivity (e.g. cellular association, cellular signaling pathways, biodistribution, and toxicity). Decrypting this complex code has become a priority to predict the NP biological outcomes. Here, we use a library of 16 lipid NPs of varying size (Ø ~ 100-250 nm) and surface

  16. Interaction of Biofunctionalized Nanoparticles with Receptors on Cell Surfaces: MC Simulations

    NASA Astrophysics Data System (ADS)

    Dormidontova, Elena; Wang, Shihu

    2015-03-01

    One of the areas of active development of modern nanomedicine is drug/gene delivery and imaging application of nanoparticles functionalized by ligands, aptamers or antibodies capable of specific interactions with cell surface receptors. Being a complex multifunctional system different structural aspects of nanoparticles affect their interactions with cell surfaces and the surface properties of cells can be different (e.g. density, distribution and mobility of receptors). Computer simulations allow a systematic investigation of the influence of multiple factors and provide a unified platform for the comparison. Using Monte Carlo simulations we investigate the influence of the nanoparticle properties (nanoparticle size, polymer tether length, polydispersity, density, ligand energy, valence and density) on nanoparticle-cell surface interactions and make predictions regarding favorable nanoparticle design for achieving multiple ligand-receptor binding. We will also discuss the implications of nanoparticle design on the selectivity of attachment to cells with high receptor density while ``ignoring'' cells with a low density of receptors.

  17. Polystyrene nanoparticles internalization in human gastric adenocarcinoma cells.

    PubMed

    Forte, Maurizio; Iachetta, Giuseppina; Tussellino, Margherita; Carotenuto, Rosa; Prisco, Marina; De Falco, Maria; Laforgia, Vincenza; Valiante, Salvatore

    2016-03-01

    The increase in the use of nanoparticles, as a promising tool for drug delivery or as a food additive, raises questions about their interaction with biological systems, especially in terms of evoked responses. In this work, we evaluated the kinetics of uptake of 44 nm (NP44) and 100 nm (NP100) unmodified polystyrene nanoparticles (PS-NPs) in gastric adenocarcinoma (AGS) cells, as well as the endocytic mechanism involved, and the effect on cell viability and gene expression of genes involved in cell cycle regulation and inflammation processes. We showed that NP44 accumulate rapidly and more efficiently in the cytoplasm of AGS compared to NP100; both PS-NPs showed an energy dependent mechanism of internalization and a clathrin-mediated endocytosis pathway. Dose response treatments revealed a non-linear curve. PS-NPs also affected cell viability, inflammatory gene expression and cell morphology. NP44 strongly induced an up-regulation of IL-6 and IL-8 genes, two of the most important cytokines involved in gastric pathologies. Our study suggests that parameters such as time, size and concentration of NPs must be taken carefully into consideration during the development of drug delivery systems based on NPs and for the management of nanoparticles associated risk factors. PMID:26585375

  18. Controlling the hydrophilicity and contact resistance of fuel cell bipolar plate surfaces using layered nanoparticle assembly

    NASA Astrophysics Data System (ADS)

    Wang, Feng

    Hybrid nanostructured coatings exhibiting the combined properties of electrical conductivity and surface hydrophilicity were obtained by using Layer-by-Layer (LBL) assembly of cationic polymer, silica nanospheres, and carbon nanoplatelets. This work demonstrates that by controlling the nanoparticle zeta (zeta) potential through the suspension parameters (pH, organic solvent type and amount, and ionic content) as well as the assembly sequence, the nanostructure and composition of the coatings may be adjusted to optimize the desired properties. Two types of silica nanospheres were evaluated as the hydrophilic component: X-TecRTM 3408 from Nano-X Corporation, with a diameter of about 20 nm, and polishing silica from Electron Microscopy Supply, with diameter of about 65 nm. Graphite nanoplatelets with a thickness of 5~10nm (Aquadag RTM E from Acheson Industries) were used as electrically conductive filler. A cationic copolymer of acrylamide and a quaternary ammonium salt (SuperflocRTM C442 from Cytec Corporation) was used as the binder for the negatively charged nanoparticles. Coatings were applied to gold-coated stainless steel substrates presently used a bipolar plate material for proton exchange membrane (PEM) fuel cells. Coating thickness was found to vary nearly linearly with the number of polymer-nanoparticle layers deposited while a monotonic increase in coating contact resistance was observed for all heterogeneous and pure silica coatings. Thickness increased if the difference in the oppositely charged zeta potentials of the adsorbing components was enhanced through alcohol addition. Interestingly, an opposite effect was observed if the zeta potential difference was increased through pH variation. This previously undocumented difference in adsorption behavior is herein related to changes to the surface chemical heterogeneity of the nanoparticles. Coating contact resistance and surface wettability were found to have a more subtle dependence on the assembly

  19. Tumor-targeted Chlorotoxin-coupled Nanoparticles for Nucleic Acid Delivery to Glioblastoma Cells: A Promising System for Glioblastoma Treatment.

    PubMed

    Costa, Pedro M; Cardoso, Ana L; Mendonça, Liliana S; Serani, Angelo; Custódia, Carlos; Conceição, Mariana; Simões, Sérgio; Moreira, João N; Pereira de Almeida, Luís; Pedroso de Lima, Maria C

    2013-06-18

    The present work aimed at the development and application of a lipid-based nanocarrier for targeted delivery of nucleic acids to glioblastoma (GBM). For this purpose, chlorotoxin (CTX), a peptide reported to bind selectively to glioma cells while showing no affinity for non-neoplastic cells, was covalently coupled to liposomes encapsulating antisense oligonucleotides (asOs) or small interfering RNAs (siRNAs). The resulting targeted nanoparticles, designated CTX-coupled stable nucleic acid lipid particles (SNALPs), exhibited excellent features for in vivo application, namely small size (<180 nm) and neutral surface charge. Cellular association and internalization studies revealed that attachment of CTX onto the liposomal surface enhanced particle internalization into glioma cells, whereas no significant internalization was observed in noncancer cells. Moreover, nanoparticle-mediated miR-21 silencing in U87 human GBM and GL261 mouse glioma cells resulted in increased levels of the tumor suppressors PTEN and PDCD4, caspase 3/7 activation and decreased tumor cell proliferation. Preliminary in vivo studies revealed that CTX enhances particle internalization into established intracranial tumors. Overall, our results indicate that the developed targeted nanoparticles represent a valuable tool for targeted nucleic acid delivery to cancer cells. Combined with a drug-based therapy, nanoparticle-mediated miR-21 silencing constitutes a promising multimodal therapeutic approach towards GBM.Molecular Therapy-Nucleic Acids (2013) 2, e100; doi:10.1038/mtna.2013.30; published online 18 June 2013.

  20. Polyethylenimine-coated SPION exhibits potential intrinsic anti-metastatic properties inhibiting migration and invasion of pancreatic tumor cells.

    PubMed

    Mulens-Arias, Vladimir; Rojas, José Manuel; Pérez-Yagüe, Sonia; Morales, María del Puerto; Barber, Domingo F

    2015-10-28

    Due to its aggressive behavior, pancreatic cancer is one of the principal causes of cancer-related deaths. The highly metastatic potential of pancreatic tumor cells demands the development of more effective anti-metastatic approaches for this disease. Although polyethylenimine-coated superparamagnetic iron oxide nanoparticles (PEI-coated SPIONs) have been studied for their utility as transfection agents, little is known of their effect on tumor cell biology. Here we demonstrated that PEI-coated SPIONs have potent inhibitory effects on pancreatic tumor cell migration/invasion, through inhibition of Src kinase and decreased expression of MT1-MMP and MMP2 metalloproteinases. When treated with PEI-coated SPIONs, the pancreatic tumor cell line Pan02 showed reduced invadosome density and thus, a decrease in their ability to invade through basement membrane. These nanoparticles temporarily downmodulated microRNA-21, thereby upregulating the cell migration inhibitors PTEN, PDCD4 and Sprouty-1. PEI-coated SPIONs thus show intrinsic, possibly anti-metastatic properties for modulating pancreatic tumor cell migration machinery, which indicates their potential as anti-metastatic agents for treatment of pancreatic cancer.

  1. Glyco-gold nanoparticle shapes enhance carbohydrate-protein interactions in mammalian cells

    NASA Astrophysics Data System (ADS)

    Sangabathuni, Sivakoti; Vasudeva Murthy, Raghavendra; Chaudhary, Preeti Madhukar; Surve, Manalee; Banerjee, Anirban; Kikkeri, Raghavendra

    2016-06-01

    Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions.Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03008d

  2. Evaluating mononuclear cells as nanoparticle delivery vehicles for the treatment of breast tumors

    NASA Astrophysics Data System (ADS)

    Murton, Jaclyn K.; Hu, Chelin; Ahmed, Mona M.; Hathaway, Helen J.; Nysus, Monique; Anderson Daniels, Tamara; Norenberg, Jeffrey P.; Adolphi, Natalie L.

    2015-08-01

    In breast cancer, certain types of circulating immune cells respond to long-range chemical signals from tumors by leaving the blood stream to actively infiltrate tumor tissue. The aim of this study was to evaluate whether immune cells could be used to deliver therapeutic nanoparticles into breast tumors in mice. Mononuclear splenocytes (MS) were harvested from donor mice, labeled with Indium-111, injected intravenously into immune-competent recipient mice (3 tumor-bearing and 3 control), and imaged longitudinally by SPECT/CT. For comparison, the biodistribution of bonemarrow derived macrophages (BMDM) in one pair of mice was also imaged. Quantitative analysis of the SPECT images demonstrates that, after 24 hours, the concentration of MS detected in mammary tumors is more than 3-fold higher than the concentration detected in normal mammary glands. The ratio of MS concentration in mammary tissue to MS concentration in non-target tissues (muscle, lung, heart, liver, spleen, and kidney) was enhanced in tumor-bearing mice (compared to controls), with statistical significance achieved for mammary/muscle (p<0.01), mammary/lung (p<0.05), and mammary/kidney (p<0.05). By contrast, BMDM did not show a different affinity for tumors relative to normal mammary tissue. MS were incubated with 100 nm red fluorescent nanoparticles, and flow cytometry demonstrated that ~35% of the MS population exhibited strong phagocytic uptake of the nanoparticles. After intravenous injection into tumor-bearing mice, fluorescence microscopy images of tumor sections show qualitatively that nanoparticle-loaded MS retain the ability to infiltrate mammary tumors. Taken together, these results suggest that MS carriers are capable of actively targeting therapeutic nanoparticles to breast tumors.

  3. The effects of different size gold nanoparticles on mechanical properties of vascular smooth muscle cells under mechanical stretching

    NASA Astrophysics Data System (ADS)

    Kieu, Tri Minh

    Nanotechnology is an emerging and promising frontier for medicine and biomedical research due to its potential for applications such as drug delivery, imaging enhancement, and cancer treatment. While these materials may possess significant possibilities, the effects of these particles in the body and how the particles affect the cells is not fully understood. In this study, vascular smooth muscle cells (VSMCs) will be exposed to 5 and 20 nm diameter citrate AuNPs under mechanical conditions. The cytotoxicity properties of these particles will be investigated using LDH and MTT assays. Atomic force microscopy will be used to study how the size of the nanoparticles affect the mechanical properties of the VSMCs. Immunofluorescence staining for alpha actin will also be performed to enhance understanding of the phenotypic shift. The LDH and MTT cytotoxicity assay results demonstrated that neither 5 nor 20 nm diameter nanoparticles are cytotoxic to the cells. However, the mechanical properties and cell morphology of the VSMCs was altered. Under static conditions, both AuNP treatments decreased the mechanical properties of the cells. The size of the nanoparticles had a softening effect on elastic modulus of the cell and sign of a synthetic phenotype was observed. The VSMCs subjected to mechanical stretching exhibited higher elastic modulus compared to the static experimental groups. Again, both AuNPs treatments decreased the mechanical properties of the cells and signs of more synthetic phenotype was seen. However, the size of the nanoparticles did not have any influence on cell's elastic modulus unlike the static treated cells. The mechanical testing condition provided a better look at how these particles would affect the cells in vivo. While the nanoparticles are not cytotoxic to the VSMCs, they are altering the mechanical properties and phenotype of the cell.

  4. Nanoparticle scaffolds for syngas-fed solid oxide fuel cells

    SciTech Connect

    Boldrin, Paul; Ruiz-Trejo, Enrique; Yu, Jingwen; Gruar, Robert I.; Tighe, Christopher J.; Chang, Kee-Chul; Ilavsky, Jan; Darr, Jawwad A.; Brandon, Nigel

    2014-12-17

    Incorporation of nanoparticles into devices such as solid oxide fuel cells (SOFCs) may provide benefits such as higher surface areas or finer control over microstructure. However, their use with traditional fabrication techniques such as screen-printing is problematic. Here, we show that mixing larger commercial particles with nanoparticles allows traditional ink formulation and screen-printing to be used while still providing benefits of nanoparticles such as increased porosity and lower sintering temperatures. SOFC anodes were produced by impregnating ceria–gadolinia (CGO) scaffolds with nickel nitrate solution. The scaffolds were produced from inks containing a mixture of hydrothermally-synthesised nanoparticle CGO, commercial CGO and polymeric pore formers. The scaffolds were heat-treated at either 1000 or 1300 °C, and were mechanically stable. In situ ultra-small X-ray scattering (USAXS) shows that the nanoparticles begin sintering around 900–1000 °C. Analysis by USAXS and scanning electron microscopy (SEM) revealed that the low temperature heat-treated scaffolds possessed higher porosity. Impregnated scaffolds were used to produce symmetrical cells, with the lower temperature heat-treated scaffolds showing improved gas diffusion, but poorer charge transfer. Using these scaffolds, lower temperature heat-treated cells of Ni–CGO/200 μm YSZ/CGO-LSCF performed better at 700 °C (and below) in hydrogen, and performed better at all temperatures using syngas, with power densities of up to 0.15 W cm-2 at 800 °C. This approach has the potential to allow the use of a wider range of materials and finer control over microstructure.

  5. Nanoparticle scaffolds for syngas-fed solid oxide fuel cells

    DOE PAGESBeta

    Boldrin, Paul; Ruiz-Trejo, Enrique; Yu, Jingwen; Gruar, Robert I.; Tighe, Christopher J.; Chang, Kee-Chul; Ilavsky, Jan; Darr, Jawwad A.; Brandon, Nigel

    2014-12-17

    Incorporation of nanoparticles into devices such as solid oxide fuel cells (SOFCs) may provide benefits such as higher surface areas or finer control over microstructure. However, their use with traditional fabrication techniques such as screen-printing is problematic. Here, we show that mixing larger commercial particles with nanoparticles allows traditional ink formulation and screen-printing to be used while still providing benefits of nanoparticles such as increased porosity and lower sintering temperatures. SOFC anodes were produced by impregnating ceria–gadolinia (CGO) scaffolds with nickel nitrate solution. The scaffolds were produced from inks containing a mixture of hydrothermally-synthesised nanoparticle CGO, commercial CGO and polymericmore » pore formers. The scaffolds were heat-treated at either 1000 or 1300 °C, and were mechanically stable. In situ ultra-small X-ray scattering (USAXS) shows that the nanoparticles begin sintering around 900–1000 °C. Analysis by USAXS and scanning electron microscopy (SEM) revealed that the low temperature heat-treated scaffolds possessed higher porosity. Impregnated scaffolds were used to produce symmetrical cells, with the lower temperature heat-treated scaffolds showing improved gas diffusion, but poorer charge transfer. Using these scaffolds, lower temperature heat-treated cells of Ni–CGO/200 μm YSZ/CGO-LSCF performed better at 700 °C (and below) in hydrogen, and performed better at all temperatures using syngas, with power densities of up to 0.15 W cm-2 at 800 °C. This approach has the potential to allow the use of a wider range of materials and finer control over microstructure.« less

  6. Effect of carbon nanoparticles on renal epithelial cell structure, barrier function, and protein expression.

    PubMed

    Blazer-Yost, Bonnie L; Banga, Amiraj; Amos, Adam; Chernoff, Ellen; Lai, Xianyin; Li, Cheng; Mitra, Somenath; Witzmann, Frank A

    2011-09-01

    To assess effects of carbon nanoparticle (CNP) exposure on renal epithelial cells, fullerenes (C(60)), single-walled carbon nanotubes (SWNT), and multi-walled carbon nanotubes (MWNT) were incubated with a confluent renal epithelial line for 48 h. At low concentrations, CNP-treated cells exhibited significant decreases in transepithelial electrical resistance (TEER) but no changes in hormone-stimulated ion transport or CNP-induced toxicity or stress responses as measured by lactate dehydrogenase or cytokine release. The changes in TEER, manifested as an inverse relationship with CNP concentration, were mirrored by an inverse correlation between dose and changes in protein expression. Lower, more physiologically relevant, concentrations of CNP have the most profound effects on barrier cell function and protein expression. These results indicate an impact of CNPs on renal epithelial cells at concentrations lower than have been previously studied and suggest caution with regard to increasing CNP levels entering the food chain due to increasing environmental pollution. PMID:21067278

  7. Epirubicin loaded to pre-polymerized poly(butyl cyanoacrylate) nanoparticles: preparation and in vitro evaluation in human lung adenocarcinoma cells.

    PubMed

    Yordanov, Georgi; Evangelatov, Alexander; Skrobanska, Ralica

    2013-07-01

    This article describes the preparation of epirubicin-loaded nanoparticles, prepared by loading of the drug in pre-polymerized poly(butyl cyanoacrylate) nanoparticles, their physicochemical characterization and in vitro evaluation on human lung adenocarcinoma (A549) cells. Nanoparticles were also coated in aqueous dispersions with two different non-ionic surfactants (Pluronic F68 and Polysorbate 80). All particles were spherical in shape, with monomodal size distributions. The zeta-potentials at pH 7.4 increased with augmentation of the particle drug content. The increased drug content was found to correlate with the initial concentration of the drug, used for the particle preparation. In vitro studies on A549 cells showed that the drug-loaded nanoparticles, as well as the combinations of free drug and empty nanoparticles, exhibited higher cytotoxicity than the free drug alone. The presence of surfactants also resulted in increased cytotoxicity. Fluorescent imaging of epirubicin internalization by the adenocarcinoma cells revealed that the free drug was predominantly localized in the cell nucleus, while a cytoplasmic localization was observed for the nanoparticle-bound drug formulations, suggesting the probability of nanoparticle endocytosis. Thus the hereby presented results could be useful for development of nanoparticle-based anthracycline formulations for treatment of lung adenocarcinoma. PMID:23466549

  8. Quantification of single-cell nanoparticle concentrations and the distribution of these concentrations in cell population.

    PubMed

    Rashkow, Jason T; Patel, Sunny C; Tappero, Ryan; Sitharaman, Balaji

    2014-05-01

    Quantification of nanoparticle uptake into cells is necessary for numerous applications in cellular imaging and therapy. Herein, synchrotron X-ray fluorescence (SXRF) microscopy, a promising tool to quantify elements in plant and animal cells, was employed to quantify and characterize the distribution of titanium dioxide (TiO2) nanosphere uptake in a population of single cells. These results were compared with average nanoparticle concentrations per cell obtained by widely used inductively coupled plasma mass spectrometry (ICP-MS). The results show that nanoparticle concentrations per cell quantified by SXRF were of one to two orders of magnitude greater compared with ICP-MS. The SXRF results also indicate a Gaussian distribution of the nanoparticle concentration per cell. The results suggest that issues relevant to the field of single-cell analysis, the limitation of methods to determine physical parameters from large population averages leading to potentially misleading information and the lack of any information about the cellular heterogeneity are equally relevant for quantification of nanoparticles in cell populations. PMID:24554576

  9. Low dose of amino-modified nanoparticles induces cell cycle arrest.

    PubMed

    Kim, Jong Ah; Åberg, Christoffer; de Cárcer, Guillermo; Malumbres, Marcos; Salvati, Anna; Dawson, Kenneth A

    2013-09-24

    The interaction of nanoscaled materials with biological systems is currently the focus of a fast-growing area of investigation. Though many nanoparticles interact with cells without acute toxic responses, amino-modified polystyrene nanoparticles are known to induce cell death. We have found that by lowering their dose, cell death remains low for several days while, interestingly, cell cycle progression is arrested. In this scenario, nanoparticle uptake, which we have recently shown to be affected by cell cycle progression, develops differently over time due to the absence of cell division. This suggests that the same nanoparticles can trigger different pathways depending on exposure conditions and the dose accumulated.

  10. Non-specific internalization of laser ablated pure gold nanoparticles in pancreatic tumor cell.

    PubMed

    Sobhan, M A; Sreenivasan, V K A; Withford, M J; Goldys, E M

    2012-04-01

    We investigate the intracellular uptake of 7.3 nm, 21.2 nm and 31.3 nm average size pure colloidal gold nanoparticles synthesized using femtosecond laser ablation technique in pure water. Dark-field imaging, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) was used to assess the uptake of these pure gold nanoparticles in the pancreatic tumor cell line. We show that these ligand-free gold nanoparticles are non-toxic to these cells. The nanoparticles and cell images indicated that unmodified gold nanoparticles interacted with the cells, despite negative surface charge on both the cells and the nanoparticles. We also demonstrate that the uptake of the gold nanoparticles is size-dependent.

  11. Sticky Patches on Lipid Nanoparticles Enable the Selective Targeting and Killing of Untargetable Cancer Cells.

    PubMed

    Sempkowski, Michelle; Zhu, Charles; Menzenski, Monica Zofia; Kevrekidis, Ioannis G; Bruchertseifer, Frank; Morgenstern, Alfred; Sofou, Stavroula

    2016-08-23

    Effective targeting by uniformly functionalized nanoparticles is limited to cancer cells expressing at least two copies of targeted receptors per nanoparticle footprint (approximately ≥2 × 10(5) receptor copies per cell); such a receptor density supports the required multivalent interaction between the neighboring receptors and the ligands from a single nanoparticle. To enable selective targeting below this receptor density, ligands on the surface of lipid vesicles were displayed in clusters that were designed to form at the acidic pH of the tumor interstitium. Vesicles with clustered HER2-targeting peptides within such sticky patches (sticky vesicles) were compared to uniformly functionalized vesicles. On HER2-negative breast cancer cells MDA-MB-231 and MCF7 {expressing (8.3 ± 0.8) × 10(4) and (5.4 ± 0.9) × 10(4) HER2 copies per cell, respectively}, only the sticky vesicles exhibited detectable specific targeting (KD ≈ 49-69 nM); dissociation (0.005-0.009 min(-1)) and endocytosis rates (0.024-0.026 min(-1)) were independent of HER2 expression for these cells. MDA-MB-231 and MCF7 were killed only by sticky vesicles encapsulating doxorubicin (32-40% viability) or α-particle emitter (225)Ac (39-58% viability) and were not affected by uniformly functionalized vesicles (>80% viability). Toxicities on cardiomyocytes and normal breast cells (expressing HER2 at considerably lower but not insignificant levels) were not observed, suggesting the potential of tunable clustered ligand display for the selective killing of cancer cells with low receptor densities. PMID:27468779

  12. Intracellular Uptake and Trafficking of Difluoroboron Dibenzoylmethane-Poly(lactic acid) Nanoparticles in HeLa Cells

    PubMed Central

    Contreras, Janette; Xie, Jiansong; Chen, Yin Jie; Pei, Hua; Zhang, Guoqing; Fraser, Cassandra L.; Hamm-Alvarez, Sarah F.

    2010-01-01

    In this study, nanoparticles based on difluoroboron dibenzoylmethane-poly(lactic acid) (BF2dbmPLA) are prepared. Polylactic acid or polylactide is a commonly used degradable polymer, while the boron dye possesses a large extinction coefficient, high emission quantum yield, 2-photon absorption, and sensitivity to the surrounding environment. BF2dbmPLA exhibits molecular weight-dependent emission properties, and can be formulated as stable nanoparticles, suggesting that its unique optical properties may be useful in multiple contexts for probing intracellular environments. Here we show that BF2dbmPLA nanoparticles are internalized into cultured HeLa cells by endocytosis, and that within the cellular milieu they retain their fluorescence properties. BF2dbmPLA nanoparticles are photostable, resisting laser-induced photobleaching under conditions that destroy the fluorescence of a common photostable probe, LysoTracker™ blue. Their endocytosis is also lipid raft-dependent, as evidenced by their significant co-localization with cholera toxin B subunit in membrane compartments after uptake, and their sensitivity of uptake to methyl-β-cyclodextrin. Additionally, BF2dbmPLA nanoparticle endocytosis utilizes microtubules and actin filaments. Internalized BF2dbmPLA nanoparticles do not accumulate in acidic late endosomes and lysosomes, but within a perinuclear non-lysosomal compartment. These findings demonstrate the feasibility of using novel BF2dbmPLA nanoparticles exhibiting diverse emission properties for in situ, live cell imaging, and suggest that their endogenous uptake occurs through a lipid-raft dependent endocytosis mechanism. PMID:20420413

  13. Effects of silver nanoparticles and gold nanoparticles on IL-2, IL-6, and TNF-α production via MAPK pathway in leukemic cell lines.

    PubMed

    Parnsamut, C; Brimson, S

    2015-01-01

    Silver nanopaticles (AgNPs) and gold nanoparticles (AuNPs) have various applications in medical healthcare and various biological properties such as anti-inflammation, anti-cancer, and anti-angiogenesis. In this study, we investigated the effect of AgNPs and AuNPs on cytokine production via the mitogen-activated protein kinase pathway in leukemic cell lines (T-lymphocytic Jurkat and monocytic U937 cells). We found that both AgNPs and AuNPs inhibited cell proliferation of leukemic cell lines. AgNPs inhibited TNF-α, while AuNPs inhibited interleukin-2 production in Jurkat cells, in which inhibition of cytokines is involved in the extracellular-signal regulated protein kinase but not the c-Jun N-terminal kinase pathway. In U937 cells, AuNPs inhibited interleukin-6 but stimulated TNF-α production in a concentration-dependent manner through the c-Jun N-terminal kinase but not the extracellular-signal regulated protein kinase pathway. Our study showed that each leukemic cell line treated with nanoparticles exhibited a distinct signaling pathway response to inhibit or stimulate cytokine production, leading to anti-cell proliferation. The effects of AgNPs and AuNPs on leukemic cell lines may have a significant impact on leukemia treatment in the future. PMID:25966134

  14. GpIIb/IIIa+ subpopulation of rat megakaryocyte progenitor cells exhibits high responsiveness to human thrombopoietin.

    PubMed

    Kato, T; Horie, K; Hagiwara, T; Maeda, E; Tsumura, H; Ohashi, H; Miyazaki, H

    1996-08-01

    The recently cloned factor thrombopoietin (TPO) has been shown to exhibit megakaryocyte colony-stimulating activity in vitro. In this investigation, to further evaluate the action of TPO on megakaryocyte progenitor cells (colony-forming units-megakaryocyte [CFU-MK]), GpIIb/IIIa+ and GpIIb/IIIa- populations of CFU-MK were prepared from rat bone marrow cells based on their reactivity with P55 antibody, a monoclonal antibody against rat GpIIb/IIIa, and their responsiveness to recombinant human TPO (rhTPO) and recombinant rat interleukin-3 (rrIL-3) was examined using a megakaryocyte colony-forming assay (Meg-CSA). rhTPO supported only megakaryocyte colony growth from both fractions in a dose-dependent fashion. The mean colony size observed with the GpIIb/IIIa+ population was smaller than that seen with the GpIIb/IIIa- population. With the optimal concentration of either rhTPO or rrIL-3, similar numbers of megakaryocyte colonies were formed from the GpIIb/IIIa+ population previously shown to be highly enriched for CFU-MK. In contrast, the maximum number of megakaryocyte colonies from the GpIIb/IIIa- population stimulated by rhTPO was only 24.2% of that achieved with rrIL-3. Morphologic analysis of rhTPO-promoted megakaryocyte colonies from the GpIIb/IIIa+ population showed that the average colony size was smaller but that the mean diameter of individual megakaryocytes was larger than in megakaryocyte colonies promoted with rrIL-3. rhTPO plus rrIL-3, each at suboptimal concentrations, had an additive effect on proliferation of CFU-MK in the GpIIb/IIIa+ fraction, whereas rhTPO plus murine IL-6 or murine granulocyte-macrophage colony-stimulating factor (mG-M-CSF) modestly but significantly reduced megakaryocyte colony growth. These results indicate that TPO preferentially acts on GpIIb/IIIa+ late CFU-MK with lower proliferative capacity and interacts with some other cytokines in CFU-MK development. PMID:8765496

  15. Influence of HepG2 cell shape on nanoparticle uptake.

    PubMed

    Prats-Mateu, Batirtze; Ertl, Peter; Toca-Herrera, José Luis

    2014-08-01

    Cell mechanics provides insights in cell responses to external stress, which is an important parameter known to influence a variety of cell functions. Understanding the interdependence between mechanical stimulus, cell shape and function is essential in controlling cell culture microenvironment. In this paper, we report on the effect of cationic and anionic interfaces on cell shape and nanoparticle uptake activity of hepatocellular carcinoma cells HepG2. The shape of HepG2 cells changed from a round-like shape to a spread-like form exhibiting lamellar protrusions by incubating them on coated polystyrene well plates with polystyrene sulfonate and poly-ethylene imine (PEI), respectively. This change in shape of HepG2 cells did not influence the uptake of 49-nm particles (which entered the cells by diffusion). However, the internalization of 240-nm diameter particles was larger on cells seeded on cationic PEI. Particle uptake was measured at 4°C and 37°C; the optimal incubation time was 6 h. Cell shape and particle uptake were monitored by fluorescence and confocal microscopy. Quantification of particle internalization was carried out with flow cytometry.

  16. Polylactide-based Paclitaxel-loaded Nanoparticles Fabricated by Dispersion Polymerization: Characterization, Evaluation in Cancer Cell Lines, and Preliminary Biodistribution Studies

    PubMed Central

    Adesina, Simeon K.; Holly, Alesia; Kramer-Marek, Gabriela; Capala, Jacek; Akala, Emmanuel O.

    2015-01-01

    The macromonomer method was used to prepare crosslinked, paclitaxel-loaded polylactide-polyethylene glycol (stealth) nanoparticles using free-radical dispersion polymerization. The method can facilitate the attachment of other molecules to the nanoparticle surface to make it multifunctional. Proton NMR and FT-IR spectra confirm the synthesis of polylactide macromonomer and crosslinking agent. Formation of stealth nanoparticles was confirmed by scanning and transmission electron microscopy. The drug release isotherm of paclitaxel-loaded nanoparticles shows that the encapsulated drug is released over 7 days. In vitro cytotoxicity assay in selected breast and ovarian cancer cell lines reveal that the blank nanoparticle is biocompatible compared to medium-only treated controls. In addition, the paclitaxel-loaded nanoparticles exhibit similar cytotoxicity compared to paclitaxel in solution. Confocal microscopy reveals that the nanoparticles are internalized by MCF-7 breast cancer cells within one hour. Preliminary biodistribution studies also show nanoparticle accumulation in tumour xenograft model. The nanoparticles are suitable for the controlled delivery of bioactive agents. PMID:24961596

  17. Use of nanoparticles for targeted, noninvasive thermal destruction of malignant cells.

    PubMed

    Cherukuri, Paul; Curley, Steven A

    2010-01-01

    Shortwave (MHz range) radiofrequency (RF) energy is nonionizing, penetrates deeply into biological tissues with no adverse side effects, and heats metallic nanoparticles efficiently. Targeted delivery of these nanoparticles to cancer cells should result in hyperthermic cytotoxicity upon exposure to a focused, noninvasive RF field. We have demonstrated that gold nanoparticles conjugated with cetuximab (C225) are quickly internalized by Panc-1 (pancreatic adenocarcinoma) and Difi (colorectal adenocarcinoma) cancer cells overexpressing epidermal growth factor receptor (EGFR). Panc-1 or Difi cells treated with naked gold nanoparticles or nonspecific IgG-conjugated gold nanoparticles demonstrated minimal intracellular uptake of gold nanoparticles by transmission electron microscopy (TEM). In contrast, there were dense concentrations of cytoplasmic vesicles containing gold nanoparticles following treatment with cetuximab-conjugated gold nanoparticles. Exposure of cells to a noninvasive RF field produced nearly 100% cytotoxicity in cells treated with the cetuximab-conjugated gold nanoparticles, but significantly lower levels of cytotoxicity in the two control groups (p < 0.00012). Treatment of a breast cancer cell line (CAMA-1) that does not express EGFR with cetuximab-conjugated gold nanoparticles produced no enhanced cytotoxicity following treatment in the RF field. Conjugation of cancer cell-directed targeting agents to gold nanoparticles may represent an effective and cancer-specific therapy to treat numerous types of human malignant disease using noninvasive RF hyperthermia. PMID:20217608

  18. Targeting cancer stem cells by using the nanoparticles

    PubMed Central

    Hong, In-Sun; Jang, Gyu-Beom; Lee, Hwa-Yong; Nam, Jeong-Seok

    2015-01-01

    Cancer stem cells (CSCs) have been shown to be markedly resistant to conventional cancer treatments such as chemotherapy and radiation therapy. Therefore, therapeutic strategies that selectively target CSCs will ultimately lead to better cancer treatments. Currently, accessible conventional therapeutic agents mainly eliminate the bulk tumor but do not eliminate CSCs. Therefore, the discovery and improvement of CSC-targeting therapeutic agents are necessary. Nanoparticles effectively inhibit multiple types of CSCs by targeting specific signaling pathways (Wnt/β-catenin, Notch, transforming growth factor-β, and hedgehog signaling) and/or specific markers (aldehyde dehydrogenases, CD44, CD90, and CD133) critically involved in CSC function and maintenance. In this review article, we summarized a number of findings to provide current information about their therapeutic potential of nanoparticles in various cancer cell types and CSCs. PMID:26425092

  19. A multifunctional core-shell nanoparticle for dendritic cell-based cancer immunotherapy

    NASA Astrophysics Data System (ADS)

    Cho, Nam-Hyuk; Cheong, Taek-Chin; Min, Ji Hyun; Wu, Jun Hua; Lee, Sang Jin; Kim, Daehong; Yang, Jae-Seong; Kim, Sanguk; Kim, Young Keun; Seong, Seung-Yong

    2011-10-01

    Dendritic cell-based cancer immunotherapy requires tumour antigens to be delivered efficiently into dendritic cells and their migration to be monitored in vivo. Nanoparticles have been explored as carriers for antigen delivery, but applications have been limited by the toxicity of the solvents used to make nanoparticles, and by the need to use transfection agents to deliver nanoparticles into cells. Here we show that an iron oxide-zinc oxide core-shell nanoparticle can deliver carcinoembryonic antigen into dendritic cells while simultaneously acting as an imaging agent. The nanoparticle-antigen complex is efficiently taken up by dendritic cells within one hour and can be detected in vitro by confocal microscopy and in vivo by magnetic resonance imaging. Mice immunized with dendritic cells containing the nanoparticle-antigen complex showed enhanced tumour antigen specific T-cell responses, delayed tumour growth and better survival than controls.

  20. Microfluidic Synthesis of Hybrid Nanoparticles with Controlled Lipid Layers: Understanding Flexibility-Regulated Cell-Nanoparticle Interaction.

    PubMed

    Zhang, Lu; Feng, Qiang; Wang, Jiuling; Zhang, Shuai; Ding, Baoquan; Wei, Yujie; Dong, Mingdong; Ryu, Ji-Young; Yoon, Tae-Young; Shi, Xinghua; Sun, Jiashu; Jiang, Xingyu

    2015-10-27

    The functionalized lipid shell of hybrid nanoparticles plays an important role for improving their biocompatibility and in vivo stability. Yet few efforts have been made to critically examine the shell structure of nanoparticles and its effect on cell-particle interaction. Here we develop a microfluidic chip allowing for the synthesis of structurally well-defined lipid-polymer nanoparticles of the same sizes, but covered with either lipid-monolayer-shell (MPs, monolayer nanoparticles) or lipid-bilayer-shell (BPs, bilayer nanoparticles). Atomic force microscope and atomistic simulations reveal that MPs have a lower flexibility than BPs, resulting in a more efficient cellular uptake and thus anticancer effect than BPs do. This flexibility-regulated cell-particle interaction may have important implications for designing drug nanocarriers.

  1. Silver Nanoparticle Enhanced Freestanding Thin-Film Silicon Solar Cells

    NASA Astrophysics Data System (ADS)

    Winans, Joshua David

    As the supply of fossil fuels diminishes in quantity the demand for alternative energy sources will consistently increase. Solar cells are an environmentally friendly and proven technology that suffer in sales due to a large upfront cost. In order to help facilitate the transition from fossil fuels to photovoltaics, module costs must be reduced to prices well below $1/Watt. Thin-film solar cells are more affordable because of the reduced materials costs, but lower in efficiency because less light is absorbed before passing through the cell. Silver nanoparticles placed at the front surface of the solar cell absorb and reradiate the energy of the light in ways such that more of the light ends being captured by the silicon. Silver nanoparticles can do this because they have free electron clouds that can take on the energy of an incident photon through collective action. This bulk action of the electrons is called a plasmon. This work begins by discussing the economics driving the need for reduced material use, and the pros and cons of taking this step. Next, the fundamental theory of light-matter interaction is briefly described followed by an introduction to the study of plasmonics. Following that we discuss a traditional method of silver nanoparticle formation and the initial experimental studies of their effects on the ability of thin-film silicon to absorb light. Then, Finite-Difference Time-Domain simulation software is used to simulate the effects of nanoparticle morphology and size on the scattering of light at the surface of the thin-film.

  2. Cell Labeling and Targeting with Superparamagnetic Iron Oxide Nanoparticles.

    PubMed

    Tefft, Brandon J; Uthamaraj, Susheil; Harburn, J Jonathan; Klabusay, Martin; Dragomir-Daescu, Dan; Sandhu, Gurpreet S

    2015-10-19

    Targeted delivery of cells and therapeutic agents would benefit a wide range of biomedical applications by concentrating the therapeutic effect at the target site while minimizing deleterious effects to off-target sites. Magnetic cell targeting is an efficient, safe, and straightforward delivery technique. Superparamagnetic iron oxide nanoparticles (SPION) are biodegradable, biocompatible, and can be endocytosed into cells to render them responsive to magnetic fields. The synthesis process involves creating magnetite (Fe3O4) nanoparticles followed by high-speed emulsification to form a poly(lactic-co-glycolic acid) (PLGA) coating. The PLGA-magnetite SPIONs are approximately 120 nm in diameter including the approximately 10 nm diameter magnetite core. When placed in culture medium, SPIONs are naturally endocytosed by cells and stored as small clusters within cytoplasmic endosomes. These particles impart sufficient magnetic mass to the cells to allow for targeting within magnetic fields. Numerous cell sorting and targeting applications are enabled by rendering various cell types responsive to magnetic fields. SPIONs have a variety of other biomedical applications as well including use as a medical imaging contrast agent, targeted drug or gene delivery, diagnostic assays, and generation of local hyperthermia for tumor therapy or tissue soldering.

  3. Magnetic field-magnetic nanoparticle culture system used to grow in vitro murine embryonic stem cells.

    PubMed

    de Freitas, Erika Regina Leal; Soares, Paula Roberta Otaviano; de Santos, Rachel Paula; dos Santos, Regiane Lopes; Porfírio, Elaine Paulucio; Báo, Sônia N; Lima, Emília Celma Oliveira; Guillo, Lídia Andreu

    2011-01-01

    The in vitro growth of embryonic stem cells (ESCs) is usually obtained in the presence of murine embryonic fibroblasts (MEF), but new methods for in vitro expansion of ESCs should be developed due to their potential clinical use. This study aims to establish a culture system to expand and maintain ESCs in the absence of MEF by using murine embryonic stem cells (mECS) as a model of embryonic stem cell. Magnetic nanoparticles (MNPs) were used for growing mESCs in the presence of an external magnetic field, creating the magnetic field-magnetic nanoparticle (MF-MNP) culture system. The growth characteristics were evaluated showing a doubling time slightly higher for mESCs cultivated in the presence of the system than in the presence of the MEF. The undifferentiated state was characterized by RT-PCR, immunofluorescence, alkaline phosphatase activity and electron microscopy. Murine embryonic stem cells cultivated in presence of the MF-MNP culture system exhibited Oct-4 and Nanog expression and high alkaline phosphatase activity. Ultrastructural morphology showed that the MF-MNP culture system did not interfere with processes that cause structural changes in the cytoplasm or nucleus. The MF-MNP culture system provides a tool for in vitro expansion of mESCs and could contribute to studies that aim the therapeutic use of embryonic stem cells. PMID:21446404

  4. Nanoparticle analysis of cancer cells by light transmission spectroscopy.

    PubMed

    Sun, N; Johnson, J; Stack, M S; Szajko, J; Sander, C; Rebuyon, R; Deatsch, A; Easton, J; Tanner, C E; Ruggiero, S T

    2015-09-01

    We have measured the optical properties of cancer and normal whole cells and lysates using light transmission spectroscopy (LTS). LTS provides both the optical extinction coefficient in the wavelength range from 220 to 1100nm and (by spectral inversion using a Mie model) the particle distribution density in the size range from 1 to 3000nm. Our current work involves whole cells and lysates of cultured human oral cells in liquid suspension. We found systematic differences in the optical extinction between cancer and normal whole cells and lysates, which translate to different particle size distributions (PSDs) for these materials. Specifically, we found that cancer cells have distinctly lower concentrations of nanoparticles with diameters less than 100nm and have higher concentrations of particles with diameters from 100 to 1000nm-results that hold for both whole cells and lysates. We also found a power-law dependence of particle density with diameter over several orders of magnitude.

  5. Magnetic Resonance Imaging of Human-Derived Amniotic Membrane Stem Cells Using PEGylated Superparamagnetic Iron Oxide Nanoparticles

    PubMed Central

    Naseroleslami, Maryam; Parivar, Kazem; Khoei, Samideh; Aboutaleb, Nahid

    2016-01-01

    Objective The label and detection of cells injected into target tissues is an area of focus for researchers. Iron oxide nanoparticles can be used to label cells as they have special characteristics. The purpose of this study is to examine the effects of iron oxide nanoparticles on human-derived amniotic membrane stem cell (hAMCs) survival and to investigate the magnetic properties of these nanoparticles with increased contrast in magnetic resonance imaging (MRI). Materials and Methods In this experimental study, we initially isolated mesenchymal stem cells from amniotic membranes and analyzed them by flow cytometry. In addition, we synthesized superparamagnetic iron oxide nanoparticles (SPIONs) and characterized them by various methods. The SPIONs were incubated with hAMCs at concentrations of 25-800 μg/mL. The cytotoxicity of nanoparticles on hAMCs was measured by the MTT assay. Next, we evaluated the effectiveness of the magnetic nanoparticles as MRI contrast agents. Solutions of SPION were prepared in water at different iron concentrations for relaxivity measurements by a 1.5 Tesla clinical MRI instrument. Results The isolated cells showed an adherent spindle shaped morphology. Polyethylene glycol (PEG)-coated SPIONs exhibited a spherical morphology. The average particle size was 20 nm and magnetic saturation was 60 emu/g. Data analysis showed no significant reduction in the percentage of viable cells (97.86 ± 0.41%) after 72 hours at the 125 μg/ml concentration compared with the control. The relaxometry results of this SPION showed a transverse relaxivity of 6.966 (μg/ml.s)-1 Conclusion SPIONs coated with PEG used in this study at suitable concentrations had excellent labeling efficiency and biocompatibility for hAMCs. PMID:27602314

  6. Magnetic Resonance Imaging of Human-Derived Amniotic Membrane Stem Cells Using PEGylated Superparamagnetic Iron Oxide Nanoparticles

    PubMed Central

    Naseroleslami, Maryam; Parivar, Kazem; Khoei, Samideh; Aboutaleb, Nahid

    2016-01-01

    Objective The label and detection of cells injected into target tissues is an area of focus for researchers. Iron oxide nanoparticles can be used to label cells as they have special characteristics. The purpose of this study is to examine the effects of iron oxide nanoparticles on human-derived amniotic membrane stem cell (hAMCs) survival and to investigate the magnetic properties of these nanoparticles with increased contrast in magnetic resonance imaging (MRI). Materials and Methods In this experimental study, we initially isolated mesenchymal stem cells from amniotic membranes and analyzed them by flow cytometry. In addition, we synthesized superparamagnetic iron oxide nanoparticles (SPIONs) and characterized them by various methods. The SPIONs were incubated with hAMCs at concentrations of 25-800 μg/mL. The cytotoxicity of nanoparticles on hAMCs was measured by the MTT assay. Next, we evaluated the effectiveness of the magnetic nanoparticles as MRI contrast agents. Solutions of SPION were prepared in water at different iron concentrations for relaxivity measurements by a 1.5 Tesla clinical MRI instrument. Results The isolated cells showed an adherent spindle shaped morphology. Polyethylene glycol (PEG)-coated SPIONs exhibited a spherical morphology. The average particle size was 20 nm and magnetic saturation was 60 emu/g. Data analysis showed no significant reduction in the percentage of viable cells (97.86 ± 0.41%) after 72 hours at the 125 μg/ml concentration compared with the control. The relaxometry results of this SPION showed a transverse relaxivity of 6.966 (μg/ml.s)-1 Conclusion SPIONs coated with PEG used in this study at suitable concentrations had excellent labeling efficiency and biocompatibility for hAMCs.

  7. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model

    PubMed Central

    Zhang, Xi-Feng; Shen, Wei; Gurunathan, Sangiliyandi

    2016-01-01

    Silver nanoparticles (AgNPs) have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with future perspectives

  8. Targeted lipid-coated nanoparticles: delivery of tumor necrosis factor-functionalized particles to tumor cells.

    PubMed

    Messerschmidt, Sylvia K E; Musyanovych, Anna; Altvater, Martin; Scheurich, Peter; Pfizenmaier, Klaus; Landfester, Katharina; Kontermann, Roland E

    2009-07-01

    Polymeric nanoparticles displaying tumor necrosis factor on their surface (TNF nanocytes) are useful carrier systems capable of mimicking the bioactivity of membrane-bound TNF. Thus, TNF nanocytes are potent activators of TNF receptor 1 and 2 leading to a striking enhancement of apoptosis. However, in vivo applications are hampered by potential systemic toxicity. Here, using TNF nanocytes as a model system, we developed a procedure to generate targeted lipid-coated particles (TLP) in which TNF activity is shielded. The TLPs generated here are composed of an inner single-chain TNF (scTNF)-functionalized, polymeric nanoparticle core surrounded by a lipid coat endowed with polyethylene glycol (PEG) for sterical stabilization and a single-chain Fv (scFv) fragment for targeting. Using a scFv directed against the tumor stroma marker fibroblast activation protein (FAP) we show that TLP and scTNF-TLP specifically bind to FAP-expressing, but not to FAP-negative cells. Lipid coating strongly reduced nonspecific binding of particles and scTNF-mediated cytotoxicity towards FAP-negative cells. In contrast, an increased cytotoxicity of TLP was observed for FAP-positive cells. Thus, through liposome encapsulation, nanoparticles carrying bioactive molecules, which are subject to nonselective uptake and activity towards various cells and tissues, can be converted into target cell-specific composite particles exhibiting a selective activity towards antigen-positive target cells. Besides safe and targeted delivery of death ligands such as TNF, TLP should be suitable for various diagnostic and therapeutic applications, which benefit from a targeted delivery of reagents embedded into the particle core or displayed on the core particle surface.

  9. Silver Nanoparticle-Mediated Cellular Responses in Various Cell Lines: An in Vitro Model.

    PubMed

    Zhang, Xi-Feng; Shen, Wei; Gurunathan, Sangiliyandi

    2016-01-01

    Silver nanoparticles (AgNPs) have attracted increased interest and are currently used in various industries including medicine, cosmetics, textiles, electronics, and pharmaceuticals, owing to their unique physical and chemical properties, particularly as antimicrobial and anticancer agents. Recently, several studies have reported both beneficial and toxic effects of AgNPs on various prokaryotic and eukaryotic systems. To develop nanoparticles for mediated therapy, several laboratories have used a variety of cell lines under in vitro conditions to evaluate the properties, mode of action, differential responses, and mechanisms of action of AgNPs. In vitro models are simple, cost-effective, rapid, and can be used to easily assess efficacy and performance. The cytotoxicity, genotoxicity, and biocompatibility of AgNPs depend on many factors such as size, shape, surface charge, surface coating, solubility, concentration, surface functionalization, distribution of particles, mode of entry, mode of action, growth media, exposure time, and cell type. Cellular responses to AgNPs are different in each cell type and depend on the physical and chemical nature of AgNPs. This review evaluates significant contributions to the literature on biological applications of AgNPs. It begins with an introduction to AgNPs, with particular attention to their overall impact on cellular effects. The main objective of this review is to elucidate the reasons for different cell types exhibiting differential responses to nanoparticles even when they possess similar size, shape, and other parameters. Firstly, we discuss the cellular effects of AgNPs on a variety of cell lines; Secondly, we discuss the mechanisms of action of AgNPs in various cellular systems, and try to elucidate how AgNPs interact with different mammalian cell lines and produce significant effects; Finally, we discuss the cellular activation of various signaling molecules in response to AgNPs, and conclude with future perspectives

  10. Imaging and radiation effects of gold nanoparticles in tumour cells

    PubMed Central

    McQuaid, Harold N.; Muir, Mark F.; Taggart, Laura E.; McMahon, Stephen J.; Coulter, Jonathan A.; Hyland, Wendy B.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.; Hirst, David G.; Botchway, Stanley W.; Currell, Fred J.

    2016-01-01

    Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events. PMID:26787230

  11. Imaging and radiation effects of gold nanoparticles in tumour cells

    NASA Astrophysics Data System (ADS)

    McQuaid, Harold N.; Muir, Mark F.; Taggart, Laura E.; McMahon, Stephen J.; Coulter, Jonathan A.; Hyland, Wendy B.; Jain, Suneil; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.; Hirst, David G.; Botchway, Stanley W.; Currell, Fred J.

    2016-01-01

    Gold nanoparticle radiosensitization represents a novel technique in enhancement of ionising radiation dose and its effect on biological systems. Variation between theoretical predictions and experimental measurement is significant enough that the mechanism leading to an increase in cell killing and DNA damage is still not clear. We present the first experimental results that take into account both the measured biodistribution of gold nanoparticles at the cellular level and the range of the product electrons responsible for energy deposition. Combining synchrotron-generated monoenergetic X-rays, intracellular gold particle imaging and DNA damage assays, has enabled a DNA damage model to be generated that includes the production of intermediate electrons. We can therefore show for the first time good agreement between the prediction of biological outcomes from both the Local Effect Model and a DNA damage model with experimentally observed cell killing and DNA damage induction via the combination of X-rays and GNPs. However, the requirement of two distinct models as indicated by this mechanistic study, one for short-term DNA damage and another for cell survival, indicates that, at least for nanoparticle enhancement, it is not safe to equate the lethal lesions invoked in the local effect model with DNA damage events.

  12. Targeted images of KB cells using folate-conjugated gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Rathinaraj, Pierson; Lee, Kyubae; Park, Soo-Young; Kang, Inn-Kyu

    2015-01-01

    Mercaptosuccinic acid-coated gold (GM) nanoparticles were prepared and characterized by transmission electron microscopy and dynamic light scattering. Folic acid (F) was then conjugated to the GM to preferentially target oral squamous cancer (KB) cells with folate receptors expressed on their membranes and facilitate the transit of the nanoparticles across the cell membrane. Finally, a fluorescence dye (Atto) was conjugated to the nanoparticles to visualize their internalization into KB cells. After culture of the cells in a medium containing GM and folate-conjugated GM (GF), the interaction of surface-modified gold nanoparticles with KB cells was studied.

  13. Effect of β-cyclodextrin on the internalization of nanoparticles into intestine epithelial cells.

    PubMed

    García-González, Lorena; Yépez-Mulía, Lilián; Ganem, Adriana

    2016-01-01

    The influence of β-cyclodextrin on the interaction and internalization of PLGA nanoparticles into intestine epithelial cells was assessed. For this purpose β-cyclodextrin was adsorbed on PLGA nanoparticles. Interaction of nanoparticles with Caco-2 cells, determined by fluorescence, was expressed as the number of particles per cell. Confocal microscopy confirmed the localization of the particles in the cell monolayer. The results showed that adsorption of β-cyclodextrin on the surface of PLGA nanoparticles reduces interaction with mucin, enhancing in this way the internalization into the Caco-2 cells.

  14. New mechanisms for non-porative ultrasound stimulation of cargo delivery to cell cytosol with targeted perfluorocarbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Soman, N. R.; Marsh, J. N.; Lanza, G. M.; Wickline, S. A.

    2008-05-01

    The cell membrane constitutes a major barrier for non-endocytotic intracellular delivery of therapeutic molecules from drug delivery vehicles. Existing approaches to breaching the cell membrane include cavitational ultrasound (with microbubbles), electroporation and cell-penetrating peptides. We report the use of diagnostic ultrasound for intracellular delivery of therapeutic bulky cargo with the use of molecularly targeted liquid perfluorocarbon (PFC) nanoparticles. To demonstrate the concept, we used a lipid with a surrogate polar head group, nanogold-DPPE, incorporated into the nanoparticle lipid monolayer. Melanoma cells were incubated with nanogold particles and this was followed by insonication with continuous wave ultrasound (2.25 MHz, 5 min, 0.6 MPa). Cells not exposed to ultrasound showed gold particles partitioned only in the outer bilayer of the cell membrane with no evidence of the intracellular transit of nanogold. However, the cells exposed to ultrasound exhibited numerous nanogold-DPPE components inside the cell that appeared polarized inside intracellular vesicles demonstrating cellular uptake and trafficking. Further, ultrasound-exposed cells manifested no incorporation of calcein or the release of lactate dehydrogenase. These observations are consistent with a mechanism that suggests that ultrasound is capable of stimulating the intracellular delivery of therapeutic molecules via non-porative mechanisms. Therefore, non-cavitational adjunctive ultrasound offers a novel paradigm in intracellular cargo delivery from PFC nanoparticles.

  15. Amorphous silica nanoparticles enhance cross-presentation in murine dendritic cells

    SciTech Connect

    Hirai, Toshiro; Yoshioka, Yasuo; Takahashi, Hideki; Ichihashi, Ko-ichi; Yoshida, Tokuyuki; Tochigi, Saeko; Nagano, Kazuya; Abe, Yasuhiro; Nabeshi, Hiromi; Yoshikawa, Tomoaki; Tsutsumi, Yasuo

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Silica nanoparticles enhanced cross-presentation. Black-Right-Pointing-Pointer Silica nanoparticles induced endosomal release of exogenous antigens. Black-Right-Pointing-Pointer Silica nanoparticle-induced cross-presentation was mediated by scavenger receptors. Black-Right-Pointing-Pointer Surface-modification may enable the manufacture of safer silica nanoparticles. -- Abstract: Nanomaterials (NMs) exhibit unique physicochemical properties and innovative functions, and they are increasingly being used in a wide variety of fields. Ensuring the safety of NMs is now an urgent task. Recently, we reported that amorphous silica nanoparticles (nSPs), one of the most widely used NMs, enhance antigen-specific cellular immune responses and may therefore aggravate immune diseases. Thus, to ensure the design of safer nSPs, investigations into the effect of nSPs on antigen presentation in dendritic cells, which are central orchestrators of the adaptive immune response, are now needed. Here, we show that nSPs with diameters of 70 and 100 nm enhanced exogenous antigen entry into the cytosol from endosomes and induced cross-presentation, whereas submicron-sized silica particles (>100 nm) did not. Furthermore, we show that surface modification of nSPs suppressed cross-presentation. Although further studies are required to investigate whether surface-modified nSPs suppress immune-modulating effects in vivo, the current results indicate that appropriate regulation of the characteristics of nSPs, such as size and surface properties, will be critical for the design of safer nSPs.

  16. Polymeric nanoparticle-based delivery of microRNA-199a-3p inhibits proliferation and growth of osteosarcoma cells.

    PubMed

    Zhang, Linlin; Lyer, Arun K; Yang, Xiaoqian; Kobayashi, Eisuke; Guo, Yuqi; Mankin, Henry; Hornicek, Francis J; Amiji, Mansoor M; Duan, Zhenfeng

    2015-01-01

    Our prior screening of microRNAs (miRs) identified that miR-199a-3p expression is reduced in osteosarcoma cells, one of the most common types of bone tumor. miR-199a-3p exhibited functions of tumor cell growth inhibition, suggesting the potential application of miR-199a-3p as an anticancer agent. In the study reported here, we designed and developed a lipid-modified dextran-based polymeric nanoparticle platform for encapsulation of miRs, and determined the efficiency and efficacy of delivering miR-199a-3p into osteosarcoma cells. In addition, another potent miR, let-7a, which also displayed tumor suppressive ability, was selected as a candidate miR for evaluation. Fluorescence microscopy studies and real-time polymerase chain reaction results showed that dextran nanoparticles could deliver both miR-199a-3p and let-7a into osteosarcoma cell lines (KHOS and U-2OS) successfully. Western blotting analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays demonstrated that dextran nanoparticles loaded with miRs could efficiently downregulate the expression of target proteins and effectively inhibit the growth and proliferation of osteosarcoma cells. These results demonstrate that a lipid-modified dextran-based polymeric nanoparticle platform may be an effective nonviral carrier for potential miR-based anticancer therapeutics. PMID:25931818

  17. 'Working' cardiomyocytes exhibiting plateau action potentials from human placenta-derived extraembryonic mesodermal cells.

    PubMed

    Okamoto, Kazuma; Miyoshi, Shunichiro; Toyoda, Masashi; Hida, Naoko; Ikegami, Yukinori; Makino, Hatsune; Nishiyama, Nobuhiro; Tsuji, Hiroko; Cui, Chang-Hao; Segawa, Kaoru; Uyama, Taro; Kami, Daisuke; Miyado, Kenji; Asada, Hironori; Matsumoto, Kenji; Saito, Hirohisa; Yoshimura, Yasunori; Ogawa, Satoshi; Aeba, Ryo; Yozu, Ryohei; Umezawa, Akihiro

    2007-07-15

    The clinical application of cell transplantation for severe heart failure is a promising strategy to improve impaired cardiac function. Recently, an array of cell types, including bone marrow cells, endothelial progenitors, mesenchymal stem cells, resident cardiac stem cells, and embryonic stem cells, have become important candidates for cell sources for cardiac repair. In the present study, we focused on the placenta as a cell source. Cells from the chorionic plate in the fetal portion of the human placenta were obtained after delivery by the primary culture method, and the cells generated in this study had the Y sex chromosome, indicating that the cells were derived from the fetus. The cells potentially expressed 'working' cardiomyocyte-specific genes such as cardiac myosin heavy chain 7beta, atrial myosin light chain, cardiac alpha-actin by gene chip analysis, and Csx/Nkx2.5, GATA4 by RT-PCR, cardiac troponin-I and connexin 43 by immunohistochemistry. These cells were able to differentiate into cardiomyocytes. Cardiac troponin-I and connexin 43 displayed a discontinuous pattern of localization at intercellular contact sites after cardiomyogenic differentiation, suggesting that the chorionic mesoderm contained a large number of cells with cardiomyogenic potential. The cells began spontaneously beating 3 days after co-cultivation with murine fetal cardiomyocytes and the frequency of beating cells reached a maximum on day 10. The contraction of the cardiomyocytes was rhythmical and synchronous, suggesting the presence of electrical communication between the cells. Placenta-derived human fetal cells may be useful for patients who cannot supply bone marrow cells but want to receive stem cell-based cardiac therapy.

  18. Biomedical Applications of Magnetic Nanoparticles: Delivering Genes and Remote Control of Cells

    NASA Astrophysics Data System (ADS)

    Dobson, Jon

    2013-03-01

    The use of magnetic micro- and nanoparticles for biomedical applications was first proposed in the 1920s as a way to measure the rehological properties of the cell's cytoplasm. Since that time, magnetic micro- and nanoparticle synthesis, coating and bio-functionalization have advanced significantly, as have the applications for these particles. Magnetic micro- and nanoparticles are now used in a variety of biomedical techniques such as targeted drug delivery, MRI contrast enhancement, gene transfection, immno-assay and cell sorting. More recently, magnetic micro- and nanoparticles have been used to investigate and manipulate cellular processes both in vitro and in vivo. This talk will focus on magnetic nanoparticle targeting to and actuation of cell surface receptors to control cell signaling cascades to control cell behavior. This technology has applications in disease therapy, cell engineering and regenerative medicine. The use of magnetic nanoparticles and oscillating magnet arrays for enhanced gene delivery will also be discussed.

  19. Biocompatible fluorescent nanoparticles for in vivo stem cell tracking

    NASA Astrophysics Data System (ADS)

    Cova, Lidia; Bigini, Paolo; Diana, Valentina; Sitia, Leopoldo; Ferrari, Raffaele; Pesce, Ruggiero Maria; Khalaf, Rushd; Bossolasco, Patrizia; Ubezio, Paolo; Lupi, Monica; Tortarolo, Massimo; Colombo, Laura; Giardino, Daniela; Silani, Vincenzo; Morbidelli, Massimo; Salmona, Mario; Moscatelli, Davide

    2013-06-01

    Efficient application of stem cells to the treatment of neurodegenerative diseases requires safe cell tracking to follow stem cell fate over time in the host environment after transplantation. In this work, for the first time, fluorescent and biocompatible methyl methacrylate (MMA)-based nanoparticles (fluoNPs) were synthesized through a free-radical co-polymerization process with a fluorescent macromonomer obtained by linking Rhodamine B and hydroxyethyl methacrylate. We demonstrate that the fluoNPs produced by polymerization of MMA-Rhodamine complexes (1) were efficient for the labeling and tracking of multipotent human amniotic fluid cells (hAFCs); (2) did not alter the main biological features of hAFCs (such as viability, cell growth and metabolic activity); (3) enabled us to determine the longitudinal bio-distribution of hAFCs in different brain areas after graft in the brain ventricles of healthy mice by a direct fluorescence-based technique. The reliability of our approach was furthermore confirmed by magnetic resonance imaging analyses, carried out by incubating hAFCs with both superparamagnetic iron oxide nanoparticles and fluoNPs. Our data suggest that these finely tunable and biocompatible fluoNPs can be exploited for the longitudinal tracking of stem cells.

  20. Preparation of human immune effector T cells containing iron-oxide nanoparticles.

    PubMed

    Iida, Hironori; Takayanagi, Kosuke; Nakanishi, Takuya; Kume, Akiko; Muramatsu, Kouji; Kiyohara, Yoshio; Akiyama, Yasuto; Osaka, Tetsuya

    2008-12-15

    Preparation of human immune T cells containing iron-oxide nanoparticles was carried out for the development of magnetically mediated immunotherapy. Peripheral blood lymphocytes (PBLs) after the incubation with magnetite nanoparticles were found to contain measurable ferric ions, which suggested the incorporation of magnetite nanoparticles. Transmission electron microscopic (TEM) study indicated that the incorporation of magnetite nanoparticles was mediated by endocytosis of PBLs. Furthermore, the effects of dosages and diameter of magnetite nanoparticles on the magnetite incorporation were investigated, and it was demonstrated that the increase in dosage promoted the incorporation of nanoparticles and the uptake into PBLs was more effective for magnetite nanoparticles, which formed smaller aggregations in medium. Finally, the demonstration of magnetite incorporation into enriched T cells and tumor antigen-specific cytotoxic T lymphocyte (CTL) line promises the achievement of magnetically mediated immunotherapy with tumor-specific CTLs containing magnetic nanoparticles.

  1. Magnetic field-guided cell delivery with nanoparticle-loaded human corneal endothelial cells.

    PubMed

    Moysidis, Stavros N; Alvarez-Delfin, Karen; Peschansky, Veronica J; Salero, Enrique; Weisman, Alejandra D; Bartakova, Alena; Raffa, Gabriella A; Merkhofer, Richard M; Kador, Karl E; Kunzevitzky, Noelia J; Goldberg, Jeffrey L

    2015-04-01

    To improve the delivery and integration of cell therapy using magnetic cell guidance for replacement of corneal endothelium, here we assess magnetic nanoparticles' (MNPs') effects on human corneal endothelial cells (HCECs) in vitro. Biocompatible, 50 nm superparamagnetic nanoparticles endocytosed by cultured HCECs induced no short- or long-term change in viability or identity. Assessment of guidance of the magnetic HCECs in the presence of different magnet shapes and field strengths showed a 2.4-fold increase in delivered cell density compared to gravity alone. After cell delivery, HCECs formed a functional monolayer, with no difference in tight junction formation between MNP-loaded and control HCECs. These data suggest that nanoparticle-mediated magnetic cell delivery may increase the efficiency of cell delivery without compromising HCEC survival, identity or function. Future studies may assess the safety and efficacy of this therapeutic modality in vivo. From the clinical editor: The authors show in this article that magnetic force facilitates the delivery of human corneal endothelial cells loaded by superparamagnetic nanoparticles to cornea, without changing their morphology, identity or functional properties. This novel idea can potentially have vast impact in the treatment of corneal endothelial dystrophies by providing self-endothelial cells after ex-vivo expansion. PMID:25596075

  2. TRAIL-coated lipid-nanoparticles overcome resistance to soluble recombinant TRAIL in non-small cell lung cancer cells

    NASA Astrophysics Data System (ADS)

    De Miguel, Diego; Gallego-Lleyda, Ana; María Ayuso, José; Erviti-Ardanaz, Sandra; Pazo-Cid, Roberto; del Agua, Celia; José Fernández, Luis; Ochoa, Ignacio; Anel, Alberto; Martinez-Lostao, Luis

    2016-05-01

    Purpose. Non-small cell lung cancer (NSCLC) is one the types of cancer with higher prevalence and mortality. Apo2-Ligand/TRAIL is a TNF family member able to induce apoptosis in tumor cells but not in normal cells. It has been tested in clinical trials against different types of human cancer including NSCLC. However, results of clinical trials have shown a limited efficacy of TRAIL-based therapies. Recently we have demonstrated that artificial lipid nanoparticles coated with bioactive Apo2L/TRAIL (LUV-TRAIL) greatly improved TRAIL cytotoxic ability being capable of killing chemoresistant hematological cancer cells. In the present work we have extended the study to NSCLC. Methods/patients. LUV-TRAIL-induced cytotoxicity was assessed on different NSCLC cell lines with different sensitivity to soluble TRAIL and on primary human tumor cells from three patients suffering from NSCLC cancer. We also tested LUV-TRAIL-cytotoxic ability in combination with several anti-tumor agents. Results. LUV-TRAIL exhibited a greater cytotoxic effect compared to soluble TRAIL both in A549 cells and primary human NSCLC cells. LUV-TRAIL-induced cell death was dependent on caspase-8 and caspase-3 activation. Moreover, combination of LUV-TRAIL with other anti-tumor agents such as flavopiridol, and SNS-032 clearly enhanced LUV-TRAIL-induced cytotoxicity against NSCLC cancer cells. Conclusion. The novel formulation of TRAIL based on displaying it on the surface of lipid nanoparticles greatly increases its anti-tumor activity and has clinical potential in cancer treatment.

  3. Cellular uptake and toxicity effects of silver nanoparticles in mammalian kidney cells.

    PubMed

    Milić, Mirta; Leitinger, Gerd; Pavičić, Ivan; Zebić Avdičević, Maja; Dobrović, Slaven; Goessler, Walter; Vinković Vrček, Ivana

    2015-06-01

    The rapid progress and early commercial acceptance of silver-based nanomaterials is owed to their biocidal activity. Besides embracing the antimicrobial potential of silver nanoparticles (AgNPs), it is imperative to give special attention to the potential adverse health effects of nanoparticles owing to prolonged exposure. Here, we report a detailed study on the in vitro interactions of citrate-coated AgNPs with porcine kidney (Pk15) cells. As uncertainty remains whether biological/cellular responses to AgNPs are solely as a result of the release of silver ions or whether the AgNPs themselves have toxic effects, we investigated the effects of Ag(+) on Pk15 cells for comparison. Next, we investigated the cellular uptake of both AgNPs and Ag(+) in Pk15 cells at various concentrations applied. The detected Ag contents in cells exposed to 50 mg l(-1) AgNPs and 50 mg l(-1) Ag(+) were 209 and 25 µg of Ag per 10(6) cells, respectively. Transmission electron microscopy (TEM) images indicated that the Pk15 cells internalized AgNPs by endocytosis. Both forms of silver, nano and ionic, decreased the number of viable Pk15 cells after 24 h in a dose-dependent manner. In spite of a significant uptake into the cells, AgNPs had only insignificant toxicity at concentrations lower than 25 mg l(-1) , whereas Ag(+) exhibited a significant decrease in cell viability at one-fifth of this concentration. The Comet assay suggested that a rather high concentration of AgNP (above 25 mg l(-1) ) is able to induce genotoxicity in Pk15 cells. Further studies must seek deeper understanding of AgNP behavior in biological media and their interactions with cellular membranes. PMID:25352480

  4. Commercial Nanoparticles for Stem Cell Labeling and Tracking

    PubMed Central

    Wang, Yaqi; Xu, Chenjie; Ow, Hooisweng

    2013-01-01

    Stem cell therapy provides promising solutions for diseases and injuries that conventional medicines and therapies cannot effectively treat. To achieve its full therapeutic potentials, the homing process, survival, differentiation, and engraftment of stem cells post transplantation must be clearly understood. To address this need, non-invasive imaging technologies based on nanoparticles (NPs) have been developed to track transplanted stem cells. Here we summarize existing commercial NPs which can act as contrast agents of three commonly used imaging modalities, including fluorescence imaging, magnetic resonance imaging and photoacoustic imaging, for stem cell labeling and tracking. Specifically, we go through their technologies, industry distributors, applications and existing concerns in stem cell research. Finally, we provide an industry perspective on the potential challenges and future for the development of new NP products. PMID:23946821

  5. Polyelectrolyte coating of ferumoxytol nanoparticles for labeling of dendritic cells

    NASA Astrophysics Data System (ADS)

    Celikkin, Nehar; Jakubcová, Lucie; Zenke, Martin; Hoss, Mareike; Wong, John Erik; Hieronymus, Thomas

    2015-04-01

    Engineered magnetic nanoparticles (MNPs) are emerging to be used as cell tracers, drug delivery vehicles, and contrast agents for magnetic resonance imaging (MRI) for enhanced theragnostic applications in biomedicine. In vitro labeling of target cell populations with MNPs and their implantation into animal models and patients shows promising outcomes in monitoring successful cell engraftment, differentiation and migration by using MRI. Dendritic cells (DCs) are professional antigen-presenting cells that initiate adaptive immune responses. Thus, DCs have been the focus of cellular immunotherapy and are increasingly applied in clinical trials. Here, we addressed the coating of different polyelectrolytes (PE) around ferumoxytol particles using the layer-by-layer technique. The impact of PE-coated ferumoxytol particles for labeling of DCs and Flt3+ DC progenitors was then investigated. The results from our studies revealed that PE-coated ferumoxytol particles can be readily employed for labeling of DC and DC progenitors and thus are potentially suitable as contrast agents for MRI tracking.

  6. Targeting and Imaging of Cancer Cells via Monosaccharide-Imprinted Fluorescent Nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Shuangshou; Yin, Danyang; Wang, Wenjing; Shen, Xiaojing; Zhu, Jun-Jie; Chen, Hong-Yuan; Liu, Zhen

    2016-03-01

    The recognition of cancer cells is a key for cancer diagnosis and therapy, but the specificity highly relies on the use of biorecognition molecules particularly antibodies. Because biorecognition molecules suffer from some apparent disadvantages, such as hard to prepare and poor storage stability, novel alternatives that can overcome these disadvantages are highly important. Here we present monosaccharide-imprinted fluorescent nanoparticles (NPs) for targeting and imaging of cancer cells. The molecularly imprinted polymer (MIP) probe was fluorescein isothiocyanate (FITC) doped silica NPs with a shell imprinted with sialic acid, fucose or mannose as the template. The monosaccharide-imprinted NPs exhibited high specificity toward the target monosaccharides. As the template monosaccharides used are over-expressed on cancer cells, these monosaccharide-imprinted NPs allowed for specific targeting cancer cells over normal cells. Fluorescence imaging of human hepatoma carcinoma cells (HepG-2) over normal hepatic cells (L-02) and mammary cancer cells (MCF-7) over normal mammary epithelial cells (MCF-10A) by these NPs was demonstrated. As the imprinting approach employed herein is generally applicable and highly efficient, monosaccharide-imprinted NPs can be promising probes for targeting cancer cells.

  7. Methods, compositions and kits for imaging cells and tissues using nanoparticles and spatial frequency heterodyne imaging

    DOEpatents

    Rose-Petruck, Christoph; Wands, Jack R.; Rand, Danielle; Derdak, Zoltan; Ortiz, Vivian

    2016-04-19

    Methods, compositions, systems, devices and kits are provided herein for preparing and using a nanoparticle composition and spatial frequency heterodyne imaging for visualizing cells or tissues. In various embodiments, the nanoparticle composition includes at least one of: a nanoparticle, a polymer layer, and a binding agent, such that the polymer layer coats the nanoparticle and is for example a polyethylene glycol, a polyelectrolyte, an anionic polymer, or a cationic polymer, and such that the binding agent that specifically binds the cells or the tissue. Methods, compositions, systems, devices and kits are provided for identifying potential therapeutic agents in a model using the nanoparticle composition and spatial frequency heterodyne imaging.

  8. Engineered nanoparticles interacting with cells: size matters

    PubMed Central

    2014-01-01

    With the rapid advancement of nanoscience and nanotechnology, detailed knowledge of interactions between engineered nanomaterials and cells, tissues and organisms has become increasingly important, especially in regard to possible hazards to human health. This review intends to give an overview of current research on nano-bio interactions, with a focus on the effects of NP size on their interactions with live cells. We summarize common techniques to characterize NP size, highlight recent work on the impact of NP size on active and passive cellular internalization and intracellular localization. Cytotoxic effects are also discussed. PMID:24491160

  9. Recombinant Nox4 cytosolic domain produced by a cell or cell-free base systems exhibits constitutive diaphorase activity

    SciTech Connect

    Nguyen, Minh Vu Chuong; Zhang, Leilei; Lhomme, Stanislas; Mouz, Nicolas

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer A comparison of two bacterial cell and cell-free protein expression systems is presented. Black-Right-Pointing-Pointer Soluble and active truncated Nox4 proteins are produced. Black-Right-Pointing-Pointer Nox4 has a constitutive diaphorase activity which is independent of cytosolic factors. Black-Right-Pointing-Pointer Isoform Nox4B is unable to initiate the first electronic transfer step. Black-Right-Pointing-Pointer Findings contribute to the understanding of the mechanism of Nox4 oxidase activity. -- Abstract: The membrane protein NADPH (nicotinamide adenine dinucleotide phosphate) oxidase Nox4 constitutively generates reactive oxygen species differing from other NADPH oxidases activity, particularly in Nox2 which needs a stimulus to be active. Although the precise mechanism of production of reactive oxygen species by Nox2 is well characterized, the electronic transfer throughout Nox4 remains unclear. Our study aims to investigate the initial electronic transfer step (diaphorase activity) of the cytosolic tail of Nox4. For this purpose, we developed two different approaches to produce soluble and active truncated Nox4 proteins. We synthesized soluble recombinant proteins either by in vitro translation or by bacteria induction. While proteins obtained by bacteria induction demonstrate an activity of 4.4 {+-} 1.7 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 20.5 {+-} 2.8 nmol/min/nmol with cytochrome c, the soluble proteins produced by cell-free expression system exhibit a diaphorase activity with a turn-over of 26 {+-} 2.6 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 48 {+-} 20.2 nmol/min/nmol with cytochrome c. Furthermore, the activity of the soluble proteins is constitutive and does not need any stimulus. We also show that the cytosolic tail of the isoform Nox4B lacking the first NADPH binding site is unable to demonstrate any diaphorase activity pointing out the

  10. SKPs derive from hair follicle precursors and exhibit properties of adult dermal stem cells.

    PubMed

    Biernaskie, Jeffrey; Paris, Maryline; Morozova, Olena; Fagan, B Matthew; Marra, Marco; Pevny, Larysa; Miller, Freda D

    2009-12-01

    Despite the remarkable regenerative capacity of mammalian skin, an adult dermal stem cell has not yet been identified. Here, we investigated whether skin-derived precursors (SKPs) might fulfill such a role. We show that SKPs derive from Sox2(+) hair follicle dermal cells and that these two cell populations are similar with regard to their transcriptome and functional properties. Both clonal SKPs and endogenous Sox2(+) cells induce hair morphogenesis, differentiate into dermal cell types, and home to a hair follicle niche upon transplantation. Moreover, hair follicle-derived SKPs self-renew, maintain their multipotency, and serially reconstitute hair follicles. Finally, grafting experiments show that follicle-associated dermal cells move out of their niche to contribute cells for dermal maintenance and wound-healing. Thus, SKPs derive from Sox2(+) follicle-associated dermal precursors and display functional properties predicted of a dermal stem cell, contributing to dermal maintenance, wound-healing, and hair follicle morphogenesis.

  11. Stable Self-Assembly of Bovine α-Lactalbumin Exhibits Target-Specific Antiproliferative Activity in Multiple Cancer Cells.

    PubMed

    Mahanta, Sailendra; Paul, Subhankar

    2015-12-30

    Self-assembly of a protein is a natural phenomenon; however, the process can be performed under a suitable condition in vitro. Since proteins are nontoxic, biodegradable, and biocompatible in nature, they are used in various industrial applications such as biocatalyst, therapeutic agent, and drug carriers. Moreover, their flexible structural state and specific activity are being used as sensors and immensely attract many new applications. However, the inherent potential of protein self-assembly for various applications is yet to be explored in detail. In this study, spherical self-assembly of bovine α-lactalbumin (nsBLA) was synthesized using an optimized ethanol-mediated desolvation process with an average diameter of approximately 300 nm. The self-assembly was found to be highly stable against thermal, pH, and proteases stress. When nsBLA was administered in various cancer cells, it demonstrated high cytotoxicity in three different cancer cells via reactive oxygen species (ROS) generation, whereas it exhibited negligible toxicity in normal human and murine cells. When nsBLA was conjugated with folic acid, it improved the cytotoxicity and perhaps mediated through enhanced cellular uptake in cancer cells through binding with folate receptors. Further, experimental results confirmed that the cancer cell death induced by nsBLA was not caused by apoptosis but a necrotic-like death mechanism. When compared with a well-known protein-based anticancer agent BAMLET (bovine α-lactalbumin made lethal against tumor cell), the self-assembled BLA clearly exhibited higher cytotoxicity to cancer cells than BAMLET. While BAMLET exhibits poor biocompatibility, our nsBLA demonstrated excellent biocompatibility to normal cells. Therefore, in this study, we prepared self-assembled α-lactalbumin that exhibits strong inherent antiproliferative potential in multiple cancer cells which can be used for efficient therapeutic approach in cancer.

  12. Physical characterization and macrophage cell uptake of mannan-coated nanoparticles.

    PubMed

    Cui, Zhengrong; Hsu, Cheng-Hsuan; Mumper, Russell J

    2003-07-01

    Previously, we reported on a cationic nanoparticle-based DNA vaccine delivery system engineered from warm oil-in-water microemulsion precursors. In these present studies, the feasibility of lyophilizing the nanoparticles and their thermal properties were investigated. Also, the binding and uptake of the nanoparticles by a macrophage cell line were studied. The nanoparticles (prior to pDNA coating) were freeze-dried with lactose or sucrose as cryoprotectants. The stability of lyophilized nanoparticles at room temperature was monitored and compared to that of the aqueous nanoparticle suspension. The thermal properties of the nanoparticles were investigated using differential scanning calorimetry (DSC). The nanoparticles, coated or uncoated with mannan as a ligand, were incubated with a mannose receptor positive (MR+) mouse macrophage cell line (J774E), at either 4 degrees C or 37 degrees C to study the binding and uptake of the nanoparticles by the cells. It was found that lactose or sucrose (1-5%, w/v) was required for successful lyophilization of the nanoparticles. After 4 months of storage, the size of lyophilized nanoparticles did not significantly increase while those in aqueous suspension grew by over 900%. Unlike its individual components, emulsifying wax (m.p., approximately 55 degrees C) and hexadecyltrimethyl ammonium bromide, the nanoparticles showed a melting point of approximately 90 degrees C. Moreover, the DSC profile of the nanoparticles was different from that of the physical mixture of emulsifying wax and CTAB. After 1 hour incubation at 37 degrees C, the uptake of mannan-coated nanoparticles was 50% higher than that of the uncoated nanoparticles. At 4 degrees C and after one hour, the binding of the mannan-coated nanoparticles by J774E was over 2-fold higher than that of the uncoated nanoparticles. This increase in J774E binding could be abolished by preincubating the cells with free mannan, suggesting that the binding and uptake were receptor

  13. Physical characterization and macrophage cell uptake of mannan-coated nanoparticles.

    PubMed

    Cui, Zhengrong; Hsu, Cheng-Hsuan; Mumper, Russell J

    2003-07-01

    Previously, we reported on a cationic nanoparticle-based DNA vaccine delivery system engineered from warm oil-in-water microemulsion precursors. In these present studies, the feasibility of lyophilizing the nanoparticles and their thermal properties were investigated. Also, the binding and uptake of the nanoparticles by a macrophage cell line were studied. The nanoparticles (prior to pDNA coating) were freeze-dried with lactose or sucrose as cryoprotectants. The stability of lyophilized nanoparticles at room temperature was monitored and compared to that of the aqueous nanoparticle suspension. The thermal properties of the nanoparticles were investigated using differential scanning calorimetry (DSC). The nanoparticles, coated or uncoated with mannan as a ligand, were incubated with a mannose receptor positive (MR+) mouse macrophage cell line (J774E), at either 4 degrees C or 37 degrees C to study the binding and uptake of the nanoparticles by the cells. It was found that lactose or sucrose (1-5%, w/v) was required for successful lyophilization of the nanoparticles. After 4 months of storage, the size of lyophilized nanoparticles did not significantly increase while those in aqueous suspension grew by over 900%. Unlike its individual components, emulsifying wax (m.p., approximately 55 degrees C) and hexadecyltrimethyl ammonium bromide, the nanoparticles showed a melting point of approximately 90 degrees C. Moreover, the DSC profile of the nanoparticles was different from that of the physical mixture of emulsifying wax and CTAB. After 1 hour incubation at 37 degrees C, the uptake of mannan-coated nanoparticles was 50% higher than that of the uncoated nanoparticles. At 4 degrees C and after one hour, the binding of the mannan-coated nanoparticles by J774E was over 2-fold higher than that of the uncoated nanoparticles. This increase in J774E binding could be abolished by preincubating the cells with free mannan, suggesting that the binding and uptake were receptor

  14. Primary rat Sertoli and interstitial cells exhibit a differential response to cadmium

    SciTech Connect

    Clough, S.R.; Welsh, M.J.; Payne, A.H.; Brown, C.D.; Brabec, M.J. )

    1990-01-01

    Two cell types central to the support of spermatogenesis, the Sertoli cell and the interstitial (Leydig) cell, were isolated from the same cohort of young male rats and challenged with cadmium chloride to compare their susceptibility to the metal. Both cell types were cultured under similar conditions, and similar biochemical endpoints were chosen to minimize experimental variability. These endpoints include the uptake of 109Cd, reduction of the vital tetrazolium dye MTT, incorporation of 3H-leucine, change in heat-stable cadmium binding capacity, and production of lactate. Using these parameters, it was observed that the Sertoli cell cultures were adversely affected in a dose-and time-dependent manner, while the interstitial cell cultures, treated with identical concentrations of CdCl2, were less affected. The 72-hr LC50's for Sertoli cells and interstitial cells were 4.1 and 19.6 microM CdCl2, respectively. Thus, different cell populations within the same tissue may differ markedly in susceptibility to a toxicant. These in vitro data suggest that the Sertoli cell, in relation to the interstitium, is particularly sensitive to cadmium. Because the Sertoli cell provides functional support for the seminiferous epithelium, the differential sensitivity of this cell type may, in part, explain cadmium-induced testicular dysfunction, particularly at doses that leave the vascular epithelium intact.

  15. Gold Nanoparticles Electroporation Enhanced Polyplex Delivery to Mammalian Cells

    PubMed Central

    Huang, Shuyan; Deshmukh, Harshavardhan; Rajagopalan, Kartik Kumar; Wang, Shengnian

    2015-01-01

    Non-viral methods have been explored as the replacement of viral systems for their low toxicity and immunogenicity. However, they have yet to reach levels competitive to their viral counterparts. In this paper, we combined physical and chemical methods to improve the performance of polyplex delivery of DNA and siRNA. Specifically, gold nanoparticles (AuNPs) were used to carry polyplex (a chemical approach) while electroporation (a physical approach) was applied for fast and direct cytosolic delivery. In this hybrid approach, cationic polymer molecules condense and/or protect genetic probes as usual while AuNPs help fix polycations to reduce their cytotoxicity and promote the transfection efficiency of electroporation. AuNPs of various sizes were first coated with polyethylenimine (PEI), which were further conjugated with DNA plasmids or siRNA molecules to form AuNPs-polyplex. The hybrid nanoparticles were then mixed with cells and introduced into cell cytosol by electroporation. The delivery efficiency was evaluated with both model anchor cells (i.e., NIH 3T3) and suspension cells (i.e., K562), together with their impact on cell viability. We found that AuNP-polyplex showed 1.5~2 folds improvement on the transfection efficiency with no significant increase of toxicity when compared to free plasmid delivery by electroporation alone. Such a combination of physical and chemical delivery concept may stimulate further exploration in the delivery of various therapeutic materials for both in vitro and in vivo applications. PMID:24777715

  16. Gold Nanoparticles-Enhanced Proton Exchange Membrane (PEM) Fuel Cell

    NASA Astrophysics Data System (ADS)

    Li, Hongfei; Pan, Cheng; Liu, Ping; Zhu, Yimei; Adzic, Radoslav; Rafailovich, Miriam

    Proton exchange membrane fuel cells have drawn great attention and been taken as a promising alternated energy source. One of the reasons hamper the wider application of PEM fuel cell is the catalytic poison effect from the impurity of the gas flow. Haruta has predicted that gold nanoparticles that are platelet shaped and have direct contact with the metal oxide substrate to be the perfect catalysts of the CO oxidization, yet the synthesis method is difficult to apply in the Fuel Cell. In our approach, thiol-functionalized gold nanoparticles were synthesized through two-phase method developed by Brust et al. We deposit these Au particles with stepped surface directly onto the Nafion membrane in the PEM fuel cell by Langmuir-Blodgett method, resulting in over 50% enhancement of the efficiency of the fuel cell. DFT calculations were conducted to understand the theory of this kind of enhancement. The results indicated that only when the particles were in direct surface contact with the membrane, where AuNPs attached at the end of the Nafion side chains, it could reduce the energy barrier for the CO oxidation that could happen at T<300K.

  17. Gold nanoparticles electroporation enhanced polyplex delivery to mammalian cells.

    PubMed

    Huang, Shuyan; Deshmukh, Harshavardhan; Rajagopalan, Kartik Kumar; Wang, Shengnian

    2014-07-01

    Nonviral methods have been explored as the replacement of viral systems for their low toxicity and immunogenicity. However, they have yet to reach levels competitive to their viral counterparts. In this paper, we combined physical and chemical methods to improve the performance of polyplex delivery of DNA and small interfering RNA. Specifically, gold nanoparticles (AuNPs) were used to carry polyplex (a chemical approach) while electroporation (a physical approach) was applied for fast and direct cytosolic delivery. In this hybrid approach, cationic polymer molecules condense and/or protect genetic probes as usual while AuNPs help fix polycations to reduce their cytotoxicity and promote the transfection efficiency of electroporation. AuNPs of various sizes were first coated with polyethylenimine, which were further conjugated with DNA plasmids or small interfering RNA molecules to form AuNPs-polyplex. The hybrid nanoparticles were then mixed with cells and introduced into cell cytosol by electroporation. The delivery efficiency was evaluated with both model anchor cells (i.e., NIH/3T3) and suspension cells (i.e., K562), together with their impact on cell viability. We found that AuNP-polyplex showed 1.5∼2 folds improvement on the transfection efficiency with no significant increase of toxicity when compared to free plasmid delivery by electroporation alone. Such a combination of physical and chemical delivery concept may stimulate further exploration in the delivery of various therapeutic materials for both in vitro and in vivo applications.

  18. Reactive oxygen species mediated DNA damage in human lung alveolar epithelial (A549) cells from exposure to non-cytotoxic MFI-type zeolite nanoparticles.

    PubMed

    Bhattacharya, Kunal; Naha, Pratap C; Naydenova, Izabela; Mintova, Svetlana; Byrne, Hugh J

    2012-12-17

    Increasing utilization of engineered nanoparticles in the field of electronics and biomedical applications demands an assessment of risk associated with deliberate or accidental exposure. Metal based nanoparticles are potentially most important of all the nanoparticles in terms of health risks. Microporous alumino-silicates and pure silicates named as zeolites and zeo-type materials with variety of structures, chemical compositions, particle sizes and morphologies have a significant number of industrial uses such as in catalysis, sorption and ion-exchange processes. In particular, the nanosized particles due to their unique properties are used in hybrid organic-inorganic materials for photography, photonics, electronics, labeling, imaging, and sensing. The aim of the current study is to investigate pure silica MFI-type zeolites nanoparticles with sizes of 50nm and 100nm (samples MFI-50 and MFI-100) under suspended conditions and their toxicological effects on human lung alveolar (A549) cells under in vitro conditions. Live cell imaging showed that the nanoparticles precipitated from the colloidal suspension of cell culture media as large agglomerates, coming in contact with the cell surface through sedimentation. A cellular proliferative capacity test showed the zeolite nanoparticles to exhibit no significant cytotoxicity below a concentration of 100μg/ml. However, both the MFI-50 and MFI-100 nanoparticles induced high intracellular reactive oxygen species (ROS) generation and elevated mitochondrial membrane potential in the A549 cells over the measured time period of 12h and at concentrations up to ≤50μg/ml. DNA fragmentation analysis using the comet assay showed that the MFI-50 and MFI-100 nanoparticles cause genotoxicity in a concentration dependent manner. Furthermore, the rate at which maximum genomic damage was caused by MFI-100 nanoparticles in the A549 cells was found to be high as compared to the MFI-50 nanoparticles. However, the damage caused by the

  19. Impacts of nanoparticles on cardiovascular diseases: modulating metabolism and function of endothelial cells.

    PubMed

    Meng, Jie; Yang, Xian-da; Jia, Lee; Liang, Xing-Jie; Wang, Chen

    2012-10-01

    Endothelial cells have very important functions, one of which is their contribution to regulating molecule and nutrient exchanges between the blood and peripheral tissues. Dysfunction of endothelial cells plays an essential role in the progression of cardiovascular diseases (CVD) such as atherosclerosis and coronary heart disease. With the recent progress of nanotechnology, increasing numbers of studies have focused on the effects of nanoparticles on CVD. In this article, we review the biological characters of endothelial cells, evaluate the impacts of nanoparticles on the behavior and functions of endothelial cells, analyze advantages and disadvantages of various nanoparticles, and discuss potential applications of nanoparticles to CVD treatment.

  20. Enhanced low-temperature power density of solid oxide fuel cell by nickel nanoparticle infiltration into pre-fired Ni/yttria-stabilized zirconia anode.

    PubMed

    Kang, Lee-Seung; Park, Jae Layng; Lee, Sungkyu; Jin, Yun-Ho; Hong, Hyun-Seon; Lee, Chan-Gi; Kim, Bum Sung

    2014-12-01

    The Ni/yttria-stabilized zirconia (YSZ) anode morphology of an anode-supported solid oxide fuel cell (SOFC) unit cell was improved by nickel nanoparticle infiltration. A colloidal route was selected for efficient fabrication of nickel metal nanoparticles and subsequent infiltration into the Ni/YSZ anode of a pre-fired SOFC unit cell. The power density of the anode-supported SOFC unit cell was measured by the potentiostatic method to investigate the effect of nickel nanoparticle infiltration. The increase in the power density of the Ni/YSZ anode with nickel nanoparticle infiltration became gradually less significant as the SOFC operating temperature increased from 700 to 800 degrees C. The improved performance of the Ni/YSZ anode with nickel nanoparticle infiltration compared to that of an anode without nickel nanoparticles is tentatively attributed to two factors: The discretely distributed nanoparticles on the nanostructured electrodes exhibited significant catalytic effects on the electrochemical performance of the electrodes, in addition to substantially increasing the triple phase boundary lengths.

  1. Comparative evaluation of novel biodegradable nanoparticles for the drug targeting to breast cancer cells.

    PubMed

    Mattu, C; Pabari, R M; Boffito, M; Sartori, S; Ciardelli, G; Ramtoola, Z

    2013-11-01

    Nanomedicine formulations such as biodegradable nanoparticles (nps) and liposomes offer several advantages over traditional routes of administration: due to their small size, nanocarriers are able to selectively accumulate inside tumours or inflammatory tissues, resulting in improved drug efficacy and reduced side effects. To further augment targeting ability of nanoparticles towards tumour cells, specific ligands or antibodies that selectively recognise biomarkers over-expressed on cancer cells, can be attached to the surface either by chemical bond or by hydrophilic/hydrophobic interactions. In the present work, Herceptin (HER), a monoclonal antibody (mAb) able to selectively recognise HER-2 over-expressing tumour cells (such as breast and ovarian cancer cells), was absorbed on the surface of nanoparticles through hydrophilic/hydrophobic interactions. Nps were prepared by a modified single emulsion solvent evaporation method with five different polymers: three commercial polyesters (poly(ε-caprolactone) (PCL), poly (D,L-lactide) (PLA) and poly (D,L-lactide-co-.glycolide) (PLGA)) and two novel biodegradable polyesterurethanes (PURs) based on Poly(ε-caprolactone) blocks, synthesised with different chain extenders (1,4-cyclohexane dimethanol (CDM) and N-Boc-serinol). Polyurethanes were introduced as matrix-forming materials for nanoparticles due to their high chemical versatility, which allows tailoring of the materials final properties by properly selecting the reagents. All nps exhibited a small size and negative surface charge, suitable for surface functionalisation with mAb through hydrophilic/hydrophobic interactions. The extent of cellular internalisation was tested on two different cell lines: MCF-7 and SK-BR-3 breast cancer cells showing a normal and a high expression of the HER-2 receptor, respectively. Paclitaxel, a model anti-neoplastic drug, was encapsulated inside all nps, and release profiles and cytotoxicity on SK-BR-3 cells were also assessed

  2. The "sweet" side of the protein corona: effects of glycosylation on nanoparticle-cell interactions.

    PubMed

    Wan, Sha; Kelly, Philip M; Mahon, Eugene; Stöckmann, Henning; Rudd, Pauline M; Caruso, Frank; Dawson, Kenneth A; Yan, Yan; Monopoli, Marco P

    2015-02-24

    The significance of a protein corona on nanoparticles in modulating particle properties and their biological interactions has been widely acknowledged. The protein corona is derived from proteins in biological fluids, many of which are glycosylated. To date, the glycans on the proteins have been largely overlooked in studies of nanoparticle-cell interactions. In this study, we demonstrate that glycosylation of the protein corona plays an important role in maintaining the colloidal stability of nanoparticles and influences nanoparticle-cell interactions. The removal of glycans from the protein corona enhances cell membrane adhesion and cell uptake of nanoparticles in comparison with the fully glycosylated form, resulting in the generation of a pro-inflammatory milieu by macrophages. This study highlights that the post-translational modification of proteins can significantly impact nanoparticle-cell interactions by modulating the protein corona properties.

  3. Silver nanoparticles-induced cytotoxicity requires ERK activation in human bladder carcinoma cells.

    PubMed

    Castiglioni, Sara; Cazzaniga, Alessandra; Perrotta, Cristiana; Maier, Jeanette A M

    2015-09-17

    Silver nanoparticles are toxic both in vitro and in vivo. We have investigated the possibility to exploit the cytotoxic potential of silver nanoparticles in T24 bladder carcinoma cells using both bare and PolyVinylPyrrolidone-coated silver nanoparticles. We show that the two types of silver nanoparticles promote morphological changes and cytoskeletal disorganization, are cytotoxic and induce cell death. These effects are due to the increased production of reactive oxygen species which are responsible, at least in part, for the sustained activation of ERK1/2. Indeed, both cytotoxicity and ERK1/2 activation are prevented by exposing the cells to the anti-oxidant N-acetylcysteine. Also blocking the ERK1/2 pathway with the MEK inhibitor PD98059 protects the cells from nanoparticles' cytotoxicity. Our findings suggest that ERK activation plays a role in silver nanoparticle-mediated cytotoxicity in T24 cells.

  4. Eco-friendly fabrication of 4% efficient organic solar cells from surfactant-free P3HT:ICBA nanoparticle dispersions.

    PubMed

    Gärtner, Stefan; Christmann, Marco; Sankaran, Sivaramakrishnan; Röhm, Holger; Prinz, Eva-Marie; Penth, Felix; Pütz, Andreas; Türeli, Akif Emre; Penth, Bernd; Baumstümmler, Bernd; Colsmann, Alexander

    2014-10-01

    Photo-active layers from non-stabilized P3HT:ICBA nanoparticles enable the fabrication of inverted organic solar cells from eco-friendly, alcoholic dispersions. Exhibiting power conversion efficiencies (PCEs) ≈4%, the devices are competitive to state-of-the-art P3HT:ICBA solar cells from chlorinated solvents. Upon thermal annealing, the short circuit current density and consequently the PCE of the inverted solar cells improve radically due to a more intimate contact of the nanoparticles and hence an enhanced charge carrier extraction.

  5. Three-Dimensional Nanocomposites: Fluidics Driven Assembly of Metal Nanoparticles on Protein Nanostructures and Their Cell-Line-Dependent Intracellular Trafficking Pattern.

    PubMed

    Srikar, R; Suresh, Dhananjay; Saranathan, Sandhya; Zambre, Ajit; Kannan, Raghuraman

    2016-05-17

    Three-dimensional nanocomposites prepared using two different families of nanomaterials holds significant relevance pertaining to biological applications. However, integration of the two distinct nanomaterials with precision to control the overall compositional homogeneity of the resulting 3D nanocomposite is a synthetic challenge. Conventional reactions result in nanocomposites with heterogeneous composition and render useless. To address this challenge, we have developed a fluidics-mediated process for controlling the interaction of nanoparticles to yield a compositional uniform multidimensional nanoparticle; as an example, we demonstrated the integration of gold nanoparticles on gelatin nanoparticles. The composition of the nanocomposite is controlled by reacting predetermined number of gold nanoparticles to a known number of thiolated gelatin nanoparticles at any given time within a defined cross-sectional area. Using the fluidics process, we developed nanocomposites of different composition: [gelatin nanoparticles-(gold nanoparticles)x] where xaverage = 2, 12, or 25. The nanocomposites were further surface conjugated with organic molecules such as fluorescent dye or polyethylene glycol (PEG) molecules. To study the biological behavior of nanocomposite, we investigated the cellular internalization and trafficking characteristics of nanocomposites in two human cancer cell lines. The nanocomposites exhibited a three-stage cellular release mechanism that enables the translocation of gold nanoparticles within various cellular compartments. In summary, the three-dimensional nanocomposite serves as a novel platform for developing well-defined protein-metal nanocomposites for potential drug delivery, sensory, and molecular imaging applications. PMID:27088307

  6. TRPV4 exhibits a functional role in cell-volume regulation.

    PubMed

    Becker, Daniel; Blase, Christopher; Bereiter-Hahn, Juergen; Jendrach, Marina

    2005-06-01

    Tight regulation of the cell volume is important for the maintenance of cellular homeostasis. In a hypotonic environment, cells swell owing to osmosis. With many vertebrate cells, swelling is followed by an active reduction of volume, a process called regulatory volume decrease (RVD). A possible participant in RVD is the non-selective cation channel TRPV4, a member of the TRP superfamily that has been shown to react to hypotonic stimuli with a conductance for Ca2+. As a model for cell-volume regulation, we used a human keratinocyte cell line (HaCaT) that produces TRPV4 endogenously. When HaCaT cells were exposed to a hypotonic solution (200 mOsm) maximal swelling was followed by RVD. During swelling and volume regulation, a strong Ca2+ influx was measured. Gd3+, an inhibitor of TRPV4, blocked RVD of HaCaT cells and the accompanying rise of cytosolic Ca2+. To define the role of TRPV4 in volume regulation, a TRPV4-EGFP fusion protein was produced in CHO cells. CHO cells are unable to undergo RVD under hypotonic conditions and do not produce TRPV4 endogenously. Fluorescence imaging revealed that recombinant TRPV4 was localized to the cell membrane. Production of TRPV4 enabled CHO cells to undergo typical RVD after hypo-osmolarity-induced cell swelling. RVD of TRPV4-transfected CHO cells was significantly reduced by Gd3+ treatment or in Ca2+-free solution. Taken together, these results show a direct participation of TRPV4 in RVD. PMID:15923656

  7. Buformin exhibits anti-proliferative and anti-invasive effects in endometrial cancer cells

    PubMed Central

    Kilgore, Joshua; Jackson, Amanda L; Clark, Leslie H; Guo, Hui; Zhang, Lu; Jones, Hannah M; Gilliam, Timothy P; Gehrig, Paola A; Zhou, Chunxiao; Bae-Jump, Victoria L

    2016-01-01

    Objective: Biguanides are anti-diabetic drugs that are thought to have anti-tumorigenic effects. Most pre-clinical studies have focused on metformin for cancer treatment and prevention; however, buformin may be potentially more potent than metformin. Given this, our goal was to evaluate the effects of buformin on cell growth, adhesion and invasion in endometrial cancer cell lines. Methods: The ECC-1 and Ishikawa endometrial cancer cell lines were used. Cell proliferation was assessed by MTT assay. Apoptosis and cell cycle analysis was performed by FITC Annexin V assay and propidium iodide staining, respectively. Adhesion was analyzed using the laminin adhesion assay. Invasion was assessed using the transwell invasion assay. The effects of buformin on the AMPK/mTOR pathway were determined by Western immunoblotting. Results: Buformin and metformin inhibited cell proliferation in a dose-dependent manner in both endometrial cancer cell lines. IC50s were 1.4-1.6 mM for metformin and 8-150 μM for buformin. Buformin induced cell cycle G1 phase arrest in the ECC-1 cells and G2 phase arrest in the Ishikawa cells. For both ECC-1 and Ishikawa cells, treatment with buformin resulted in induction of apoptosis, reduction in adhesion and invasion, activation of AMPK and inhibition of phosphorylated-S6. Buformin potentiated the anti-proliferative effects of paclitaxel in both cell lines. Conclusion: Buformin has significant anti-proliferative and anti-metastatic effects in endometrial cancer cells through modulation of the AMPK/mTOR pathway. IC50 values were lower for buformin than metformin, suggesting that buformin may be more potent for endometrial cancer treatment and worthy of further investigation. PMID:27398153

  8. Mammal-derived respiratory lipocalin allergens do not exhibit dendritic cell-activating capacity.

    PubMed

    Parviainen, S; Kinnunen, T; Rytkönen-Nissinen, M; Nieminen, A; Liukko, A; Virtanen, T

    2013-03-01

    Most mammal-derived respiratory allergens belong to the lipocalin family of proteins. Determinants of their allergenic capacity are still unknown. Innate immune cells, in particular dendritic cells, have been shown to be involved in the allergenicity of some proteins. As recognition by dendritic cells is one of the few plausible mechanisms for the allergenicity of proteins, we wanted to investigate their role in the allergenicity of lipocalin allergens. Therefore, we first incubated human monocyte-derived dendritic cells with immunologically functional recombinant allergens mouse Mus m 1, dog Can f 1 and 2, cow Bos d 2, horse Equ c 1 and natural Bos d 2. Then, the surface marker expression and cytokine production of dendritic cells and their capacity to promote T cell proliferation and Th2 immune deviation in naïve CD4(+) T cells were examined in vitro. We found that near to endotoxin-free lipocalin allergens had no effect on the activation, allostimulatory capacity or cytokine production of dendritic cells. The dendritic cells could not induce immune deviation in naïve CD4(+) T cells. In contrast, lipopolysaccharide activated the dendritic cells efficiently. However, lipocalin allergens were not able to modify the lipopolysaccharide-induced responses. We conclude that an important group of mammal-derived respiratory allergens, lipocalins, appear not to be able to activate dendritic cells, a major component involved in the allergenicity of some proteins. It is conceivable that this incapacity of lipocalin allergens to arouse innate immunity may be associated with their poor capacity to induce a strong T cell response, verified in several studies.

  9. Engineered nanoparticles mimicking cell membranes for toxin neutralization.

    PubMed

    Fang, Ronnie H; Luk, Brian T; Hu, Che-Ming J; Zhang, Liangfang

    2015-08-01

    Protein toxins secreted from pathogenic bacteria and venomous animals rely on multiple mechanisms to overcome the cell membrane barrier to inflict their virulence effect. A promising therapeutic concept toward developing a broadly applicable anti-toxin platform is to administer cell membrane mimics as decoys to sequester these virulence factors. As such, lipid membrane-based nanoparticulates are an ideal candidate given their structural similarity to cellular membranes. This article reviews the virulence mechanisms employed by toxins at the cell membrane interface and highlights the application of cell-membrane mimicking nanoparticles as toxin decoys for systemic detoxification. In addition, the implication of particle/toxin nanocomplexes in the development of toxoid vaccines is discussed.

  10. Titanium dioxide nanoparticles cause genotoxicity in human lung epithelial cells

    EPA Science Inventory

    The use of engineered nanoparticles in consumer products is steadily increasing. However, the health effects of exposure to these nanoparticles are not thoroughly understood. This study investigated the genotoxicity of six titanium dioxide and two cerium oxide nanoparticles of va...

  11. An aqueous red emitting fluorescent fluoride sensing probe exhibiting a large Stokes shift and its application in cell imaging.

    PubMed

    Hou, Peng; Chen, Song; Wang, Hongbo; Wang, Jianxiu; Voitchovsky, Kislon; Song, Xiangzhi

    2014-01-11

    A novel red emitting fluorescent probe exhibiting a 143 nm Stokes shift for the detection of fluoride ions in an aqueous solution was developed. The probe displays a rapid response, high selectivity and good sensitivity towards F(-). Application of the probe for the selective detection of intracellular F(-) has been successfully demonstrated in living cells.

  12. Manganese nanoparticle activates mitochondrial dependent apoptotic signaling and autophagy in dopaminergic neuronal cells

    SciTech Connect

    Afeseh Ngwa, Hilary; Kanthasamy, Arthi; Gu, Yan; Fang, Ning; Anantharam, Vellareddy; Kanthasamy, Anumantha G.

    2011-11-15

    The production of man-made nanoparticles for various modern applications has increased exponentially in recent years, but the potential health effects of most nanoparticles are not well characterized. Unfortunately, in vitro nanoparticle toxicity studies are extremely limited by yet unresolved problems relating to dosimetry. In the present study, we systematically characterized manganese (Mn) nanoparticle sizes and examined the nanoparticle-induced oxidative signaling in dopaminergic neuronal cells. Differential interference contrast (DIC) microscopy and transmission electron microscopy (TEM) studies revealed that Mn nanoparticles range in size from single nanoparticles ({approx} 25 nM) to larger agglomerates when in treatment media. Manganese nanoparticles were effectively internalized in N27 dopaminergic neuronal cells, and they induced a time-dependent upregulation of the transporter protein transferrin. Exposure to 25-400 {mu}g/mL Mn nanoparticles induced cell death in a time- and dose-dependent manner. Mn nanoparticles also significantly increased ROS, accompanied by a caspase-mediated proteolytic cleavage of proapoptotic protein kinase C{delta} (PKC{delta}), as well as activation loop phosphorylation. Blocking Mn nanoparticle-induced ROS failed to protect against the neurotoxic effects, suggesting the involvement of other pathways. Further mechanistic studies revealed changes in Beclin 1 and LC3, indicating that Mn nanoparticles induce autophagy. Primary mesencephalic neuron exposure to Mn nanoparticles induced loss of TH positive dopaminergic neurons and neuronal processes. Collectively, our results suggest that Mn nanoparticles effectively enter dopaminergic neuronal cells and exert neurotoxic effects by activating an apoptotic signaling pathway and autophagy, emphasizing the need for assessing possible health risks associated with an increased use of Mn nanoparticles in modern applications. -- Highlights: Black-Right-Pointing-Pointer Mn nanoparticles

  13. Dual effect of spermine on mast cell secretion exhibits different calcium and temperature requirements.

    PubMed

    Vliagoftis, H; Mak, L; Boucher, W; Theoharides, T C

    1999-09-01

    Mast cells release many biologically active molecules upon stimulation by a variety of molecules such as immunoglobulin E (IgE) and specific antigen, anaphylatoxins, as well as a number of cationic compounds which include drugs, kinins and neuropeptides. The effect of the naturally occurring polyamine spermine was studied because, even though it is polycationic, it has been implicated in the modulation of secretory processes in a variety of cells. In particular, it was previously shown that oxidation products of spermine inhibit mast cell secretion. High concentrations of spermine (5 x 10(-3) M) added at 37 degrees C induced mast cell secretion that had similar characteristics with that triggered by compound 48/80 (48/80). However, spermine inhibited mast cell secretion in a dose-dependent manner as long as it was added at 4-10 degrees C for at least 10 min in the absence of Ca++ before warming the cells to 37 degrees C and triggering them with 48/80. These findings were true both for purified rat peritoneal mast cells and for rat skin mast cells in situ. Addition of calcium after the cells had been warmed to 37 degrees C could not reverse this inhibition. The inhibition seen when spermine was added at 4 degrees C was, however, overcome if phorbol myristate acetate (PMA) or NaF, which activate PKC and G proteins respectively, were added to mast cells at 37 degrees C together with Ca++. These results indicate that polyamines could be important modulators of the activation state of mast cells and might help further define the biochemical events involved in mast cell secretion.

  14. Prostate Cancer Cell Lines under Hypoxia Exhibit Greater Stem-Like Properties

    PubMed Central

    Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Axcrona, Karol; Kvalheim, Gunnar; Stokke, Trond; Nesland, Jahn M.; Suo, Zhenhe

    2011-01-01

    Hypoxia is an important environmental change in many cancers. Hypoxic niches can be occupied by cancer stem/progenitor-like cells that are associated with tumor progression and resistance to radiotherapy and chemotherapy. However, it has not yet been fully elucidated how hypoxia influences the stem-like properties of prostate cancer cells. In this report, we investigated the effects of hypoxia on human prostate cancer cell lines, PC-3 and DU145. In comparison to normoxia (20% O2), 7% O2 induced higher expressions of HIF-1α and HIF-2α, which were associated with upregulation of Oct3/4 and Nanog; 1% O2 induced even greater levels of these factors. The upregulated NANOG mRNA expression in hypoxia was confirmed to be predominantly retrogene NANOGP8. Similar growth rates were observed for cells cultivated under hypoxic and normoxic conditions for 48 hours; however, the colony formation assay revealed that 48 hours of hypoxic pretreatment resulted in the formation of more colonies. Treatment with 1% O2 also extended the G0/G1 stage, resulting in more side population cells, and induced CD44 and ABCG2 expressions. Hypoxia also increased the number of cells positive for ABCG2 expression, which were predominantly found to be CD44bright cells. Correspondingly, the sorted CD44bright cells expressed higher levels of ABCG2, Oct3/4, and Nanog than CD44dim cells, and hypoxic pretreatment significantly increased the expressions of these factors. CD44bright cells under normoxia formed significantly more colonies and spheres compared with the CD44dim cells, and hypoxic pretreatment even increased this effect. Our data indicate that prostate cancer cells under hypoxia possess greater stem-like properties. PMID:22216200

  15. A highly sensitive and selective turn-on fluorogenic and chromogenic sensor based on BODIPY-functionalized magnetic nanoparticles for detecting lead in living cells.

    PubMed

    Son, Hyunjong; Lee, Hye Young; Lim, Jung Mi; Kang, Dongmin; Han, Won Seok; Lee, Shim Sung; Jung, Jong Hwa

    2010-10-11

    A new fluoro-chromogenic chemosensor based on BODIPY-functionalized Fe(3)O(4)@SiO(2) core/shell nanoparticles 1 has been prepared. Chemosensor 1 exhibits a high affinity and selectivity for Pb(2+) over competing metal ions tested. Moreover, confocal microscopy, and flow cytometry experiments established that 1 can be used for detecting Pb(2+) levels within living cell.

  16. B cells from African American lupus patients exhibit an activated phenotype

    PubMed Central

    Menard, Laurence C.; Habte, Sium; Gonsiorek, Waldemar; Lee, Deborah; Banas, Dana; Holloway, Deborah A.; Cunningham, Mark; Stetsko, Dawn; Casano, Francesca; Kansal, Selena; Davis, Patricia M.; Carman, Julie; Zhang, Clarence K.; Abidi, Ferva; Furie, Richard; Nadler, Steven G.; Suchard, Suzanne J.

    2016-01-01

    Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease driven by both innate and adaptive immune cells. African Americans tend to present with more severe disease at an earlier age compared with patients of European ancestry. In order to better understand the immunological differences between African American and European American patients, we analyzed the frequencies of B cell subsets and the expression of B cell activation markers from a total of 68 SLE patients and 69 normal healthy volunteers. We found that B cells expressing the activation markers CD86, CD80, PD1, and CD40L, as well as CD19+CD27–IgD– double-negative B cells, were enriched in African American patients vs. patients of European ancestry. In addition to increased expression of CD40L, surface levels of CD40 on B cells were lower, suggesting the engagement of the CD40 pathway. In vitro experiments confirmed that CD40L expressed by B cells could lead to CD40 activation and internalization on adjacent B cells. To conclude, these results indicate that, compared with European American patients, African American SLE patients present with a particularly active B cell component, possibly via the activation of the CD40/CD40L pathway. These data may help guide the development of novel therapies.

  17. B cells from African American lupus patients exhibit an activated phenotype

    PubMed Central

    Menard, Laurence C.; Habte, Sium; Gonsiorek, Waldemar; Lee, Deborah; Banas, Dana; Holloway, Deborah A.; Cunningham, Mark; Stetsko, Dawn; Casano, Francesca; Kansal, Selena; Davis, Patricia M.; Carman, Julie; Zhang, Clarence K.; Abidi, Ferva; Furie, Richard; Nadler, Steven G.; Suchard, Suzanne J.

    2016-01-01

    Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease driven by both innate and adaptive immune cells. African Americans tend to present with more severe disease at an earlier age compared with patients of European ancestry. In order to better understand the immunological differences between African American and European American patients, we analyzed the frequencies of B cell subsets and the expression of B cell activation markers from a total of 68 SLE patients and 69 normal healthy volunteers. We found that B cells expressing the activation markers CD86, CD80, PD1, and CD40L, as well as CD19+CD27–IgD– double-negative B cells, were enriched in African American patients vs. patients of European ancestry. In addition to increased expression of CD40L, surface levels of CD40 on B cells were lower, suggesting the engagement of the CD40 pathway. In vitro experiments confirmed that CD40L expressed by B cells could lead to CD40 activation and internalization on adjacent B cells. To conclude, these results indicate that, compared with European American patients, African American SLE patients present with a particularly active B cell component, possibly via the activation of the CD40/CD40L pathway. These data may help guide the development of novel therapies. PMID:27699274

  18. Rat embryo fibroblast cells expressing human papillomavirus 1a genes exhibit altered growth properties and tumorigenicity.

    PubMed Central

    Green, M; Brackmann, K H; Loewenstein, P M

    1986-01-01

    Human papillomavirus 1a (HPV1a) induces benign tumors (papillomas or warts) in humans under natural conditions of infection but has not been found to replicate significantly in cell culture or in experimental animals. To establish model systems to study the oncogenic properties and expression of HPV genes, we established cell lines by cotransfecting the 3Y1 rat fibroblast cell line with HPV1a DNA constructs containing an intact early gene region and the Tn5 neomycin resistance gene. Most cell lines selected for expression of the neomycin resistance gene by treatment with the antibiotic G-418 contained viral DNA in a high-molecular-weight form. The growth characteristics of several cell lines containing high copy numbers of HPV1a DNA were studied further. They were shown to differ from the parental cell line and from G-418-resistant cell lines that did not incorporate viral DNA in the following properties: morphological alteration, increased cell density at confluence, growth in 0.5% serum, efficient anchorage-independent growth in soft agar, and rapid formation of tumors in nude mice. Those cell lines that possessed altered growth properties and tumorigenicity were found to express abundant quantities of polyadenylated virus-specific RNA species in the cytoplasm. Images PMID:3023676

  19. Comparative cytotoxicity studies of carbon-encapsulated iron nanoparticles in murine glioma cells.

    PubMed

    Grudzinski, Ireneusz P; Bystrzejewski, Michal; Cywinska, Monika A; Kosmider, Anita; Poplawska, Magdalena; Cieszanowski, Andrzej; Fijalek, Zbigniew; Ostrowska, Agnieszka

    2014-05-01

    Carbon-encapsulated iron nanoparticles (CEINs) have recently emerged as a new class of magnetic nanomaterials with a great potential for an increasing number of biomedical applications. To address the current deficient knowledge of cellular responses due to CEIN exposures, we focused on the investigation of internalization profile and resulting cytotoxic effects of CEINs (0.0001-100 μg/ml) in murine glioma cells (GL261) in vitro. The studied CEIN samples were characterized (TEM, FT-IR, Zeta potential, Boehm titration) and examined as raw and purified nanomaterials with various surface chemistry composition. Of the four type CEINs (the mean diameter 47-56 nm) studied here, the as-synthesized raw nanoparticles (Fe@C/Fe) exhibited high cytotoxic effects on the plasma cell membrane (LDH, Calcein AM/PI) and mitochondria (MTT, JC-1) causing some pro-apoptotic evens (Annexin V/PI) in glioma cells. The effects of the purified (Fe@C) and surface-modified (Fe@C-COOH and Fe@C-(CH2)2COOH) CEINs were found in quite similar patterns; however, most of these cytotoxic events were slightly diminished compared to those induced by Fe@C/Fe. The study showed that the surface-functionalized CEINs affected the cell cycle progression in both S and G2/M phases to a greater extent compared to that of the rest of nanoparticles studied to data. Taken all together, the present results highlight the importance of the rational design of CEINs as their physicochemical features such as morphology, hydrodynamic size, impurity profiles, and especially surface characteristics are critical determinants of different cytotoxic responses.

  20. A Facile Approach to Functionalize Cell Membrane-Coated Nanoparticles

    PubMed Central

    Zhou, Hao; Fan, Zhiyuan; Lemons, Pelin K.; Cheng, Hao

    2016-01-01

    Convenient strategies to provide cell membrane-coated nanoparticles (CM-NPs) with multi-functionalities beyond the natural function of cell membranes would dramatically expand the application of this emerging class of nanomaterials. We have developed a facile approach to functionalize CM-NPs by chemically modifying live cell membranes prior to CM-NP fabrication using a bifunctional linker, succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-Maleimide). This method is particularly suitable to conjugate large bioactive molecules such as proteins on cell membranes as it establishes a strong anchorage and enable the control of linker length, a critical parameter for maximizing the function of anchored proteins. As a proof of concept, we show the conjugation of human recombinant hyaluronidase, PH20 (rHuPH20) on red blood cell (RBC) membranes and demonstrate that long linker (MW: 3400) is superior to short linker (MW: 425) for maintaining enzyme activity, while minimizing the changes to cell membranes. When the modified membranes were fabricated into RBC membrane-coated nanoparticles (RBCM-NPs), the conjugated rHuPH20 can assist NP diffusion more efficiently than free rHuPH20 in matrix-mimicking gels and the pericellular hyaluronic acid matrix of PC3 prostate cancer cells. After quenching the unreacted chemical groups with polyethylene glycol, we demonstrated that the rHuPH20 modification does not reduce the ultra-long blood circulation time of RBCM-NPs. Therefore, this surface engineering approach provides a platform to functionlize CM-NPs without sacrificing the natural function of cell membranes. PMID:27217834

  1. Geranylated 4-Phenylcoumarins Exhibit Anticancer Effects against Human Prostate Cancer Cells through Caspase-Independent Mechanism

    PubMed Central

    Suparji, Noor Shahirah; Chan, Gomathi; Sapili, Hani; Arshad, Norhafiza M.; In, Lionel L. A.; Awang, Khalijah; Hasima Nagoor, Noor

    2016-01-01

    Geranylated 4-phenylcoumarins, DMDP-1 & -2 isolated from Mesua elegans were investigated for anticancer potential against human prostate cancer cells. Treatment with DMDP-1 & -2 resulted in cell death in a time and dose dependent manner in an MTT assay on all cancer cell lines tested with the exception of lung adenocarcinoma cells. DMDP-1 showed highest cytotoxic efficacy in PC-3 cells while DMDP-2 was most potent in DU 145 cells. Flow cytometry indicated that both coumarins were successful to induce programmed cell death after 24 h treatment. Elucidation on the mode-of-action via protein arrays and western blotting demonstrated death induced without any significant expressions of caspases, Bcl-2 family proteins and cleaved PARP, thus suggesting the involvement of caspase-independent pathways. In identifying autophagy, analysis of GFP-LC3 showed increased punctate in PC-3 cells pre-treated with CQ and treated with DMDP-1. In these cells decreased expression of autophagosome protein, p62 and cathepsin B further confirmed autophagy. In contrary, the DU 145 cells pre-treated with CQ and treated with DMDP-2 has reduced GFP-LC3 punctate although the number of cells with obvious GFP-LC3 puncta was significantly increased in the inhibitor-treated cells. The increase level of p62 suggested leakage of cathepsin B into the cytosol to trigger potential downstream death mediators. This correlated with increased expression of cathepsin B and reduced expression after treatment with its inhibitor, CA074. Also auto-degradation of calpain-2 upon treatment with DMDP-1 &-2 and its inhibitor alone, calpeptin compared with the combination treatment, further confirmed involvement of calpain-2 in PC-3 and DU 145 cells. Treatment with DMDP-1 & -2 also showed up-regulation of total and phosphorylated p53 levels in a time dependent manner. Hence, DMDP-1 & -2 showed ability to activate multiple death pathways involving autophagy, lysosomal and endoplasmic reticulum death proteins which could

  2. Histone deacetylase inhibitor-induced cancer stem cells exhibit high pentose phosphate pathway metabolism

    PubMed Central

    Debeb, Bisrat G.; Lacerda, Lara; Larson, Richard; Wolfe, Adam R.; Krishnamurthy, Savitri; Reuben, James M.; Ueno, Naoto T.; Gilcrease, Michael; Woodward, Wendy A.

    2016-01-01

    Purpose We recently demonstrated that histone deacetylase (HDAC) inhibitors can “reprogram” differentiated triple-negative breast cancer cells to become quiescent stem-like cancer cells. We hypothesized that the metabolic state of such cells differs from that of their differentiated progeny. Results In untreated cells, glucose uptake was higher in ALDH+ cells than in ALDH− cells (p = 0.01) but lactate production was not different; treating ALDH− or ALDH+ cells with VA or SAHA similarly increased glucose uptake without changing lactate production but upregulated G6PD, a rate-limiting enzyme in pentose phosphate pathway metabolism. NADPH production was higher in HDAC inhibitor-treated stem-like cells than in vehicle-treated cells (p < 0.05). Two G6PD inhibitors, 6-aminonicotinamide and dehydroepiandrosterone, decreased mammosphere formation efficiency and ALDH activity and 6-aminonicotinamide reduced the VA-induced increase in ALDH+ cells. Finally, patients expressing high G6PD mRNA had significantly worse overall survival (p < 0.001), and patients with high G6PD protein showed a similar trend towards worse disease-specific survival (p = 0.06). Methods Glucose consumption, lactate and NADPH production, and reactive oxygen species generation were compared in aldehyde dehydrogenase (ALDH)-positive and –negative cells in the presence or absence of the HDAC inhibitors valproic acid (VA) or suberoylanilide hydroxamic acid (SAHA). Glucose-6-phosphate dehydrogenase (G6PD) expression was evaluated in a tissue microarray from 94 patients with node-positive invasive breast carcinoma and in two publically available databases and correlated with overall survival. Conclusions Energy metabolism in HDAC inhibitor-induced stem-like cancer cells differed sharply from that of differentiated cell types. HDAC inhibitor-induced dedifferentiation promoted metabolic reprogramming into the pentose phosphate pathway, which is targeted effectively by G6PD inhibition. These findings

  3. The Plasma Membrane Calcium Pump in Pancreatic Cancer Cells Exhibiting the Warburg Effect Relies on Glycolytic ATP*

    PubMed Central

    James, Andrew D.; Patel, Waseema; Butt, Zohra; Adiamah, Magretta; Dakhel, Raga; Latif, Ayse; Uggenti, Carolina; Swanton, Eileithyia; Imamura, Hiromi; Siriwardena, Ajith K.; Bruce, Jason I. E.

    2015-01-01

    Evidence suggests that the plasma membrane Ca2+-ATPase (PMCA), which is critical for maintaining a low intracellular Ca2+ concentration ([Ca2+]i), utilizes glycolytically derived ATP in pancreatic ductal adenocarcinoma (PDAC) and that inhibition of glycolysis in PDAC cell lines results in ATP depletion, PMCA inhibition, and an irreversible [Ca2+]i overload. We explored whether this is a specific weakness of highly glycolytic PDAC by shifting PDAC cell (MIA PaCa-2 and PANC-1) metabolism from a highly glycolytic phenotype toward mitochondrial metabolism and assessing the effects of mitochondrial versus glycolytic inhibitors on ATP depletion, PMCA inhibition, and [Ca2+]i overload. The highly glycolytic phenotype of these cells was first reversed by depriving MIA PaCa-2 and PANC-1 cells of glucose and supplementing with α-ketoisocaproate or galactose. These culture conditions resulted in a significant decrease in both glycolytic flux and proliferation rate, and conferred resistance to ATP depletion by glycolytic inhibition while sensitizing cells to mitochondrial inhibition. Moreover, in direct contrast to cells exhibiting a high glycolytic rate, glycolytic inhibition had no effect on PMCA activity and resting [Ca2+]i in α-ketoisocaproate- and galactose-cultured cells, suggesting that the glycolytic dependence of the PMCA is a specific vulnerability of PDAC cells exhibiting the Warburg phenotype. PMID:26294767

  4. NY-ESO-1 antigen-reactive T cell receptors exhibit diverse therapeutic capability.

    PubMed

    Sommermeyer, Daniel; Conrad, Heinke; Krönig, Holger; Gelfort, Haike; Bernhard, Helga; Uckert, Wolfgang

    2013-03-15

    The cancer-testis antigen NY-ESO-1 has been used as a target for different immunotherapies like vaccinations and adoptive transfer of antigen-specific cytotoxic T cells, as it is expressed in various tumor types and has limited expression in normal cells. The in vitro generation of T cells with defined antigen specificity by T cell receptor (TCR) gene transfer is an established method to create cells for immunotherapy. However, an extensive characterization of TCR which are candidates for treatment of patients is crucial for successful therapies. The TCR has to be efficiently expressed, their affinity to the desired antigen should be high enough to recognize low amounts of endogenously processed peptides on tumor cells, and the TCR should not be cross-reactive to other antigens. We characterized three NY-ESO-1 antigen-reactive cytotoxic T lymphocyte clones which were generated by different approaches of T cell priming (autologous, allogeneic), and transferred their TCR into donor T cells for more extensive evaluations. Although one TCR most efficiently bound MHC-multimers loaded with NY-ESO-1 peptide, T cells expressing this transgenic TCR were not able to recognize endogenously processed antigen. A second TCR recognized HLA-A2 independent of the bound peptide beside its much stronger recognition of NY-ESO-1 bound to HLA-A2. A third TCR displayed an intermediate but peptide-specific performance in all functional assays and, therefore, is the most promising candidate TCR for further clinical development. Our data indicate that multiple parameters of TCR gene-modified T cells have to be evaluated to identify an optimal TCR candidate for adoptive therapy.

  5. Ternary CuBiS2 nanoparticles as a sensitizer for quantum dot solar cells.

    PubMed

    Suriyawong, Nipapon; Aragaw, Belete; Shi, Jen-Bin; Lee, Ming-Way

    2016-07-01

    This work investigates the synthesis and application in solar cells of a novel solar absorber material CuBiS2. Ternary copper chalcogenide CuBiS2 nanoparticles were grown on a mesoporous TiO2 electrode by the chemical bath deposition (CBD) method. The synthesized CuBiS2 nanoparticles, size 5-10nm, have an energy gap Eg of 2.1eV. Liquid-junction quantum dot-sensitized solar cells were fabricated from the CuBiS2-sensitized electrode using a polysulfide electrolyte. Three types of counter electrodes (CEs) - Pt, Au and Cu2S - were tested. The photovoltaic performance depends on the CBD reaction time and the CE. The best cell, obtained with the Cu2S CE, exhibited the photovoltaic performance of a short-circuit current density Jsc of 6.87mA/cm(2), an open-circuit voltage Voc of 0.25V, a fill factor FF of 36% and a power conversion efficiency η of 0.62%. The present work demonstrates the feasibility of CuBiS2 as a solar energy material.

  6. Biosynthesis of gold nanoparticles using Sargassum swartzii and its cytotoxicity effect on HeLa cells

    NASA Astrophysics Data System (ADS)

    Dhas, T. Stalin; Kumar, V. Ganesh; Karthick, V.; Govindaraju, K.; Shankara Narayana, T.

    2014-12-01

    In this investigation, biological synthesis of gold nanoparticles (AuNPs) using Sargassum swartzii and its cytotoxicity against human cervical carcinoma (HeLa) cells is reported. The biological synthesis involved the reduction of chloroauric acid led to the formation of AuNPs within 5 min at 60 °C and the formation of AuNPs was confirmed using UV-vis spectrophotometer. The AuNPs were stable; spherical in shape with well-defined dimensions, and the average size of the particle is 35 nm. A zeta potential value of -27.6 mV revealed synthesized AuNPs were highly stable. The synthesized AuNPs exhibited a dose-dependent cytotoxicity against human cervical carcinoma (HeLa) cells. Furthermore, induction of apoptosis was measured by DAPI (4‧,6-Diamidino-2-phenylindole dihydrochloride) staining.

  7. ZLM-7 exhibits anti-angiogenic effects via impaired endothelial cell function and blockade of VEGF/VEGFR-2 signaling

    PubMed Central

    Su, Min; Huang, Jingjia; Li, Jijia; Qin, Xiyuan; Tang, Xiaoning; Jin, Fang; Chen, Shali; Jiang, Chuanming; Zou, Zizheng; Peng, Kunjian; Nuruzzaman, Mohammed; Zhang, Jianting; Luo, Junli; Liu, Suyou; Luo, Zhiyong

    2016-01-01

    Inhibition of angiogenesis is a promising therapeutic strategy against cancer. In this study, we reported that ZLM-7, a combretastain A-4 (CA-4) derivative, exhibited anti-angiogenic activity in vitro and in vivo. In vitro, ZLM-7 induced microtubule cytoskeletal disassembly. It decreased VEGF-induced proliferation, migration, invasion and tube formation in endothelial cells, which are critical steps in angiogenesis. In vivo, ZLM-7 significantly inhibited neovascularization in a chicken chorioallantoic membrane (CAM) model and reduced the microvessel density in tumor tissues of MCF-7 xenograft mouse model. ZLM-7 also displayed comparable antiangiogenic and anti-tumor activities associated with the lead compound CA-4, but exhibited lower toxicity compared with CA-4. The anti-angiogenic effect of ZLM-7 was exerted via blockade of VEGF/VEGFR-2 signaling. ZLM-7 treatment suppressed the expression and secretion of VEGF in endothelial cells and MCF-7 cells under hypoxia. Further, ZLM-7 suppressed the VEGF-induced phosphorylation of VEGFR-2 and its downstream signaling mediators including activated AKT, MEK and ERK in endothelial cells. Overall, these results demonstrate that ZLM-7 exhibits anti-angiogenic activities by impairing endothelial cell function and blocking VEGF/VEGFR-2 signaling, suggesting that ZLM-7 might be a potential angiogenesis inhibitor. PMID:26967559

  8. Poriferan survivin exhibits a conserved regulatory role in the interconnected pathways of cell cycle and apoptosis

    PubMed Central

    Luthringer, B; Isbert, S; Müller, W E G; Zilberberg, C; Thakur, N L; Wörheide, G; Stauber, R H; Kelve, M; Wiens, M

    2011-01-01

    Survivin orchestrates intracellular pathways during cell division and apoptosis. Its central function as mitotic regulator and inhibitor of cell death has major implications for tumor cell proliferation. Analyses in early-branching Metazoa so far propose an exclusive role of survivin as a chromosomal passenger protein, whereas only later during evolution a complementary antiapoptotic function might have arisen, concurrent with increased organismal complexity. To lift the veil on the ancestral function(s) of this key regulator, a survivin-like protein (SURVL) of one of the earliest-branching metazoan taxa was identified and functionally characterized. SURVL of the sponge Suberites domuncula shares considerable similarities with its metazoan homologs, ranging from conserved exon/intron structure to presence of protein-interaction domains. Whereas sponge tissue shows a low steady-state level, SURVL expression was significantly upregulated in rapidly proliferating primmorph cells. In addition, challenge of tissue and primmorphs with heavy metal or lipopeptide stimulated SURVL expression, concurrent with the expression of a newly discovered caspase. Complementary functional analyses in transfected HEK-293 cells revealed that heterologous expression of a SURVL–EFGP fusion not only promotes proliferation but also enhances resistance to cadmium-induced cell death. Taken together, these results suggest both a deep evolutionary conserved dual role of survivin and an equally conserved central position in the interconnected pathways of cell cycle and apoptosis. PMID:20651742

  9. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    SciTech Connect

    Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

    2014-05-02

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

  10. Sphere-derived tumor cells exhibit impaired metastasis by a host-mediated quiescent phenotype

    PubMed Central

    Bleau, Anne-Marie; Zandueta, Carolina; Redrado, Miriam; Martínez-Canarias, Susana; Larzábal, Leyre; Montuenga, Luis M.

    2015-01-01

    The spread of lung cancer cells to distant sites represents a common event associated with poor prognosis. A fraction of tumor cells named cancer stem cells (CSCs) have the ability to overcome therapeutic stress and remain quiescent. However, whether these CSCs have also the capacity to initiate and sustain metastasis remains unclear. Here, we used tumor sphere cultures (TSC) isolated from mouse and human lung cancer models to enrich for CSCs, and assessed their metastatic potential as compared to non-CSCs. As expected, TSC overexpressed a variety of stem cell markers and displayed chemoresistance. The CSC phenotype of TSC was confirmed by their higher growth ability in soft agar and tumorigenic potential in vivo, despite their reduced in vitro cell growth kinetics. Surprisingly, the appearance of spontaneous lung metastases was strongly delayed in mice injected with TSC as compared to non-TSC cells. Similarly, this finding was confirmed in several other models of metastasis, an effect associated with a retarded colonization activity. Interestingly, such delay correlated with a quiescent phenotype whose underlined mechanisms included an increase in p27 protein and lower phospho-ERK1/2 levels. Thus, these data suggest that cells enriched for CSC properties display an impaired metastatic activity, a finding with potential clinical implications. PMID:26318423

  11. Sphere-derived tumor cells exhibit impaired metastasis by a host-mediated quiescent phenotype.

    PubMed

    Bleau, Anne-Marie; Zandueta, Carolina; Redrado, Miriam; Martínez-Canarias, Susana; Larzábal, Leyre; Montuenga, Luis M; Calvo, Alfonso; Lecanda, Fernando

    2015-09-29

    The spread of lung cancer cells to distant sites represents a common event associated with poor prognosis. A fraction of tumor cells named cancer stem cells (CSCs) have the ability to overcome therapeutic stress and remain quiescent. However, whether these CSCs have also the capacity to initiate and sustain metastasis remains unclear. Here, we used tumor sphere cultures (TSC) isolated from mouse and human lung cancer models to enrich for CSCs, and assessed their metastatic potential as compared to non-CSCs. As expected, TSC overexpressed a variety of stem cell markers and displayed chemoresistance. The CSC phenotype of TSC was confirmed by their higher growth ability in soft agar and tumorigenic potential in vivo, despite their reduced in vitro cell growth kinetics. Surprisingly, the appearance of spontaneous lung metastases was strongly delayed in mice injected with TSC as compared to non-TSC cells. Similarly, this finding was confirmed in several other models of metastasis, an effect associated with a retarded colonization activity. Interestingly, such delay correlated with a quiescent phenotype whose underlined mechanisms included an increase in p27 protein and lower phospho-ERK1/2 levels. Thus, these data suggest that cells enriched for CSC properties display an impaired metastatic activity, a finding with potential clinical implications. PMID:26318423

  12. Drug loading and release on tumor cells using silk fibroin-albumin nanoparticles as carriers

    NASA Astrophysics Data System (ADS)

    Subia, B.; Kundu, S. C.

    2013-01-01

    Polymeric and biodegradable nanoparticles are frequently used in drug delivery systems. In this study silk fibroin-albumin blended nanoparticles were prepared using the desolvation method without any surfactant. These nanoparticles are easily internalized by the cells, reside within perinuclear spaces and act as carriers for delivery of the model drug methotrexate. Methotrexate loaded nanoparticles have better encapsulation efficiency, drug loading ability and less toxicity. The in vitro release behavior of methotrexate from the nanoparticles suggests that about 85% of the drug gets released after 12 days. The encapsulation and loading of a drug would depend on factors such as size, charge and hydrophobicity, which affect drug release. MTT assay and conjugation of particles with FITC demonstrate that the silk fibroin-albumin nanoparticles do not affect the viability and biocompatibility of cells. This blended nanoparticle, therefore, could be a promising nanocarrier for the delivery of drugs and other bioactive molecules.

  13. Differential uptake of nanoparticles by endothelial cells through polyelectrolytes with affinity for caveolae

    PubMed Central

    Voigt, Julia; Christensen, Jon; Shastri, V. Prasad

    2014-01-01

    Nanoparticles (NPs) constitute an important medium for the targeted delivery of cancer therapeutics. Targeting of NPs to a specific cell type is traditionally achieved through the modification of the NP surface with peptides, aptamers, or other motifs that specifically recognize a cell-surface receptor, leading to internalization of NPs via clathrin and caveolae-mediated endocytosis. We have discovered that modifying the NP surface with anionic polyelectrolytes of varying lipophilicity can regulate the uptake of lipid NPs by endothelial and epithelial cells. Furthermore, we report the finding that synthetic polyelectrolytes composed of an aromatic sulfonic acid backbone exhibit specific affinity for caveolae of endothelial cells. By exploiting the higher expression of caveolae in endothelial cells in comparison with epithelial cells, a purely physiochemical approach to the targeted uptake of lipid NPs to endothelial cells is demonstrated. The ability to confer preferential affinity for NPs to cell surface domains by varying the charge and lipophilic characteristics of an NP surface offers a general means of achieving targeted delivery without the need for receptor–ligand-type targeting strategies. PMID:24516167

  14. Differential uptake of nanoparticles by endothelial cells through polyelectrolytes with affinity for caveolae.

    PubMed

    Voigt, Julia; Christensen, Jon; Shastri, V Prasad

    2014-02-25

    Nanoparticles (NPs) constitute an important medium for the targeted delivery of cancer therapeutics. Targeting of NPs to a specific cell type is traditionally achieved through the modification of the NP surface with peptides, aptamers, or other motifs that specifically recognize a cell-surface receptor, leading to internalization of NPs via clathrin and caveolae-mediated endocytosis. We have discovered that modifying the NP surface with anionic polyelectrolytes of varying lipophilicity can regulate the uptake of lipid NPs by endothelial and epithelial cells. Furthermore, we report the finding that synthetic polyelectrolytes composed of an aromatic sulfonic acid backbone exhibit specific affinity for caveolae of endothelial cells. By exploiting the higher expression of caveolae in endothelial cells in comparison with epithelial cells, a purely physiochemical approach to the targeted uptake of lipid NPs to endothelial cells is demonstrated. The ability to confer preferential affinity for NPs to cell surface domains by varying the charge and lipophilic characteristics of an NP surface offers a general means of achieving targeted delivery without the need for receptor-ligand-type targeting strategies.

  15. Engineering of Targeted Nanoparticles for Cancer Therapy Using Internalizing Aptamers Isolated by Cell-Uptake Selection

    PubMed Central

    Xiao, Zeyu; Levy-Nissenbaum, Etgar; Alexis, Frank; Lupták, Andrej; Teply, Benjamin A.; Chan, Juliana M.; Shi, Jinjun; Digga, Elise; Cheng, Judy; Langer, Robert; Farokhzad, Omid C.

    2012-01-01

    One of the major challenges in the development of targeted nanoparticles (NPs) for cancer therapy is to discover targeting ligands that allow for differential binding and uptake by the target cancer cells. Using prostate cancer (PCa) as a model disease, we developed a cell-uptake selection strategy to isolate PCa-specific internalizing 2'-Omethyl RNA aptamers (Apts) for NP incorporation. Twelve cycles of selection and counter-selection were done to obtain a panel of internalizing Apts, which can distinguish PCa cells from non-prostate and normal prostate cells. After Apt characterization, size minimization, and conjugation of the Apts with fluorescently-labeled polymeric NPs, the NP-Apt bioconjugates exhibit PCa specificity and enhancement in cellular uptake when compared to non-targeted NPs lacking the internalizing Apts. Furthermore, when docetaxel, a chemotherapeutic agent used for the treatment of PCa, was encapsulated within the NP-Apt, a significant improvement in cytotoxicity was achieved in targeted PCa cells. Rather than isolating high-affinity Apts as reported in previous selection processes, our selection strategy was designed to enrich cancer-cell specific internalizing Apts. A similar cell-uptake selection strategy may be used to develop specific internalizing ligands for a myriad of other diseases and can potentially facilitate delivering various molecules, including drugs and siRNAs, into cells. PMID:22214176

  16. Effect of ZnO nanoparticles on nasopharyngeal cancer cells viability and respiration

    NASA Astrophysics Data System (ADS)

    Prasanth, R.; Gopinath, D.

    2013-03-01

    Development of a therapeutic drugs based on nanoparticles requires a better understanding of the mechanism of selective cyto-toxic effects of nanopaticles over cancer cells. Scanning electrochemical microscopy provides opportunity to measure the real time chemical process at cell proximity in the presence of nanoparticle. Herein, the respiration process in nasopharyngeal cancer cells is investigated with the help of scanning electrochemical microscopy. The cell viability has been tested with MTT assay. The results show that ZnO nanoparticles have time and dose dependent effect in nasopharyngeal cancer cells and the cell respiration rate decreases with time.

  17. Mitochondrial transit peptide exhibits cell penetration ability and efficiently delivers macromolecules to mitochondria.

    PubMed

    Jain, Aastha; Chugh, Archana

    2016-09-01

    Mitochondrial malfunction under various circumstances can lead to a variety of disorders. Effective targeting of macromolecules (drugs) is important for restoration of mitochondrial function and treatment of related disorders. We have designed a novel cell-penetrating mitochondrial transit peptide (CpMTP) for delivery of macromolecules to mitochondria. Comparison between properties of cell-penetrating peptides (CPPs) and mitochondrial signal sequences enabled prediction of peptides with dual ability for cellular translocation and mitochondrial localization. Among the predicted peptides, CpMTP translocates across HeLa cells and shows successful delivery of noncovalently conjugated cargo molecules to mitochondria. CpMTP may have applications in transduction and transfection of mitochondria for therapeutics.

  18. Drug-Loaded Nanoparticles from 'Ershiwuwei Shanhu' Pill Induced Cellular Swelling of SH-SY5Y Neuroblastoma Cells.

    PubMed

    Liu, Yali; Song, Xiaoping; Zheng, Siting; Luo, Yuandai; Wang, Leyu; Huang, Fukai; Qiu, Xiaozhong

    2016-03-01

    Drug-loaded nanoparticles from 'Ershiwuwei Shanhu' Pill (ESP) inducing cellular swelling of the SH-SY5Y neuroblastoma cells were investigated. Electron microscope was used to observe nanoparticles existing in the freeze-dried supernatant of 'Ershiwuwei Shanhu' Pill. Drug-free nanoparticles were obtained from the solution of drug-loaded nanoparticles via dialysis. The size and zeta potential of two kinds of nanoparticles were tested by granularmetric analysis and surface charge analysis. Results showed that nanoparticles could penetrate into cellular nucleus and caused cell swelling. CCK8 analysis implied that low concentration of drug-free nanoparticles from 'Ershiwuwei Shanhu' Pill can induce cell proliferation of the SH-SY5Y neuroblastoma cells, while drug-loaded nanoparticles can reduce cell viability through NF-κB pathway. Drug-loaded nanoparticles existed in 'Ershiwuwei Shanhu' pill might play a vital role during pharmacotherapy, which served as nanocarriers in delivering drugs into cells.

  19. Multidentate zwitterionic chitosan oligosaccharide modified gold nanoparticles: stability, biocompatibility and cell interactions

    NASA Astrophysics Data System (ADS)

    Liu, Xiangsheng; Huang, Haoyuan; Liu, Gongyan; Zhou, Wenbo; Chen, Yangjun; Jin, Qiao; Ji, Jian

    2013-04-01

    Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt conditions, wide pH range and serum or plasma containing media. The AuNPs also show strong resistance to competition from dithiothreitol (as high as 1.5 M). Moreover, the modified AuNPs demonstrate low cytotoxicity investigated by both MTT and LDH assays, and good hemocompatibility evaluated by hemolysis of human red blood cells. In addition, the intracellular fate of AuNPs was investigated by ICP-MS and TEM. It showed that the AuNPs are uptaken by cells in a concentration dependent manner, and they can escape from endosomes/lysosomes to cytosol and tend to accumulate around the nucleus after 24 h incubation but few of them are excreted out of the cells. Gold nanorods are also stabilized by this ligand, which demonstrates robust dispersion stability and excellent hemocompatibility. This kind of multidentate zwitterionic chitosan derivative could be widely used for stabilizing other inorganic nanoparticles, which will greatly improve their performance in a variety of bio-related applications.Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt

  20. Variable Nanoparticle-Cell Adhesion Strength Regulates Cellular Uptake

    NASA Astrophysics Data System (ADS)

    Yuan, Hongyan; Li, Ju; Bao, Gang; Zhang, Sulin

    2010-09-01

    In receptor-mediated endocytosis, cells exercise biochemical control over the mechanics of adhesion to engulf foreign particles, featuring a variable adhesion strength. Here we present a thermodynamic model with which we elucidate that the variable adhesion strength critically governs the cellular uptake, yielding an uptake phase diagram in the space of ligand density and particle size. We identify from the diagram an endocytosed phase with markedly high uptake, encompassed by a lower and an upper phase boundary that are set, respectively, by the enthalpic and entropic limits of the adhesion strength. The phase diagram may provide useful guidance to the rational design of nanoparticle-based therapeutic and diagnostic agents.

  1. Copper nanoparticle incorporated plasmonic organic bulk-heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Zhihai; Lee, Seung Yong; Lee, Eun-Cheol

    2014-12-01

    By embedding copper nanoparticles into poly(3,4-thylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers, the power conversion efficiency of organic bulk-heterojunction solar cell using poly(3-hexylthiophene) (P3HT) was increased from 3.58% to 3.96%, and that of the device based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  2. Extracellular galectin-3 counteracts adhesion and exhibits chemoattraction in Helicobacter pylori-infected gastric cancer cells.

    PubMed

    Subhash, Vinod Vijay; Ling, Samantha Shi Min; Ho, Bow

    2016-08-01

    Galectin-3 (Gal-3) is a β-galactoside lectin that is upregulated and rapidly secreted by gastric epithelial cells in response to Helicobacter pylori infection. An earlier study reported the involvement of H. pylori cytotoxin-associated gene A (cagA) in the expression of intracellular Gal-3. However, the role of extracellular Gal-3 and its functional significance in H. pylori-infected cells remains uncharacterized. Data presented here demonstrate secretion of Gal-3 is an initial host response event in gastric epithelial cells during H. pylori infection and is independent of CagA. Previously, Gal-3 was shown to bind to H. pylori LPS. The present study elaborates the significance of this binding, as extracellular recombinant Gal-3 (rGal-3) was shown to inhibit the adhesion of H. pylori to the gastric epithelial cells. Interestingly, a decrease in H. pylori adhesion to host cells also resulted in a decrease in apoptosis. Furthermore, the study also demonstrated a chemoattractant role of extracellular rGal-3 in the recruitment of THP-1 monocytes. This study outlines the previously unidentified roles of extracellular Gal-3 where it acts as a negative regulator of H. pylori adhesion and apoptosis in gastric epithelial cells, and as a chemoattractant to THP-1 monocytes. Our findings could contribute to the better understanding of how Gal-3 acts as a modulator under H. pylori-induced pathological conditions. PMID:27283429

  3. The natural products parthenolide and andrographolide exhibit anti-cancer stem cell activity in multiple myeloma.

    PubMed

    Gunn, Ellen J; Williams, John T; Huynh, Daniel T; Iannotti, Michael J; Han, Changho; Barrios, Francis J; Kendall, Stephen; Glackin, Carlotta A; Colby, David A; Kirshner, Julia

    2011-06-01

    Multiple myeloma (MM) is an incurable plasma cell malignancy where nearly all patients succumb to a relapse. The current preclinical models of MM target the plasma cells, constituting the bulk of the tumor, leaving the cancer stem cells to trigger a relapse. Utilizing a three-dimensional tissue culture system where cells were grown in extracellular matrix designed to reconstruct human bone marrow, we tested the anti-multiple myeloma cancer stem cell (MM-CSC) potential of two natural product inhibitors of nuclear factor κB (NFκB). Here we show that parthenolide and andrographolide are potent anti-MM-CSC agents. Both natural products demonstrated preferential toxicity toward MM-CSCs over non-tumorigenic MM cells. Addition of the bone marrow stromal compartment abrogated andrographolide activity while having no effect on parthenolide cytoxicity. This is the first report of a natural product with anti-CSC activity in myeloma, suggesting that it has the potential to improve the survival of patients with MM by eliminating the relapse-causing MM-CSCs. PMID:21417826

  4. Dunaliella salina exhibits an antileukemic immunity in a mouse model of WEHI-3 leukemia cells.

    PubMed

    Chuang, Wen-Chen; Ho, Yung-Chyuan; Liao, Jiunn-Wang; Lu, Fung-Jou

    2014-11-26

    Dunaliella salina has been shown to have antioxidant property and induce apoptotic cell death of human cancer cells in vitro. However, there is no information available on D. salina showing an antileukemia effect or immunomodulatory activity in vivo. This study applied D. salina to syngeneic leukemia-implanted mice (BALB/c and WEHI-3) to investigate its immunological and antileukemia properties. Oral administration of D. salina (184.5, 369, and 922.5 mg/kg) inhibited spleen metastasis and prolonged the survival in BALB/c mice that had received an intravenous injection of WEHI-3 cells. The results revealed that D. salina had reduced spleen enlargement in murine leukemia. It had also increased the population and proliferation of T-cells (CD3) and B-cells (CD19) following Con A/LPS treatment on flow cytometry and MTT assay, respectively. Furthermore, D. salina increased the phagocytosis of macrophages and enhanced the cytotoxicity of natural killer cells on flow cytometry and LDH assay. Moreover, D. salina enhanced the levels of interferon-γ and interleukin 2 (IL-2) but reduced the levels of IL-4 and IL-10 in leukemic mice. In conclusion, these results demonstrated that the application of D. salina had beneficial effects on WEHI-3 leukemic mice by prolonging survival via modulating the immune responses.

  5. Live cell plasma membranes do not exhibit a miscibility phase transition over a wide range of temperatures.

    PubMed

    Lee, Il-Hyung; Saha, Suvrajit; Polley, Anirban; Huang, Hector; Mayor, Satyajit; Rao, Madan; Groves, Jay T

    2015-03-26

    Lipid/cholesterol mixtures derived from cell membranes as well as their synthetic reconstitutions exhibit well-defined miscibility phase transitions and critical phenomena near physiological temperatures. This suggests that lipid/cholesterol-mediated phase separation plays a role in the organization of live cell membranes. However, macroscopic lipid-phase separation is not generally observed in cell membranes, and the degree to which properties of isolated lipid mixtures are preserved in the cell membrane remain unknown. A fundamental property of phase transitions is that the variation of tagged particle diffusion with temperature exhibits an abrupt change as the system passes through the transition, even when the two phases are distributed in a nanometer-scale emulsion. We support this using a variety of Monte Carlo and atomistic simulations on model lipid membrane systems. However, temperature-dependent fluorescence correlation spectroscopy of labeled lipids and membrane-anchored proteins in live cell membranes shows a consistently smooth increase in the diffusion coefficient as a function of temperature. We find no evidence of a discrete miscibility phase transition throughout a wide range of temperatures: 14-37 °C. This contrasts the behavior of giant plasma membrane vesicles (GPMVs) blebbed from the same cells, which do exhibit phase transitions and macroscopic phase separation. Fluorescence lifetime analysis of a DiI probe in both cases reveals a significant environmental difference between the live cell and the GPMV. Taken together, these data suggest the live cell membrane may avoid the miscibility phase transition inherent to its lipid constituents by actively regulating physical parameters, such as tension, in the membrane.

  6. Ultrasound associated uptake of chitosan nanoparticles in MC3T3-E1 cells

    NASA Astrophysics Data System (ADS)

    Wu, Junyi

    Chitosan is a natural linear polysaccharide that has been well known for its applications in drug delivery system due to its unique physicochemical and biological properties. However, challenges still remain for it to become a fully realized therapeutic agent. In this study, we investigated the uptake of chitosan nanoparticles (CNP) under the ultrasound stimulation, using a model cell culture system (MC3T3-E1 mouse pre-osteoblasts). The CNP were fabricated by an ionic gelation method and were lyophilized prior to characterization and delivery to cells. Particle size and zeta potential were measured using Dynamic Light Scattering (DLS); the efficiency of chitosan complexation was measured using the ninhydrin assay. Cytotoxicity was examined by neutral red assay within 48 hours after delivery. The effect of ultrasound (US) on the efficiency of nanoparticle delivery to the MC3T3-E1 cells was examined at 1MHz and at either 1 or 2 W/cm2. Fluorescein isothiocyanate (FITC)-conjugated-CNP were used to visualize the internalized particles within the cytosol. The uptake of FITC-CNP exhibits a dose and time dependent effect, a strong FITC fluorescence was detected at the concentration of 500microg/mL under fluorescence microscope. Ultrasound assisted uptake of FITC-CNP performed a significant positive effect at 2W/cm2 with 60s of ultrasound exposure time. CNP displayed a slightly decrease in cell viability from 25microg/mL to 100microg/mL, while higher concentration of CNP facilitates the proliferation of MC3T3-E1 cells. Less than 10% of reduction in cell viability was observed for US at 1W/cm2 and 2W/cm2 with 30s and 60s of exposure time, which suggest a mild effect of US to MC3T3-E1 cell line.

  7. Recent developments on titania nanoparticle as photocatalytic cancer cells treatment.

    PubMed

    Jukapli, Nurhidayatullaili Muhd; Bagheri, Samira

    2016-10-01

    This review provides a background, fundamental and advanced application of titania nanoparticles (TiO2) on the disinfection and killing of cancer cell through photocatalytic chemistry. It starts with the characteristic properties focused on the surface, light sensitivity, crystallinity and toxicology of TiO2 as a photocatalyst. Consequently, outline and design of photocatalytic reactor has been figured out based on the target organisms, including bacteria, viruses, fungi and cancer cells. Despite a large number of studies undertaken, limited selectivity and efficacy of TiO2 photocatalyst are still widely accepted problems. An ideal TiO2 photocatalyst should have the combined properties of highly stable reactive oxygen species yield and a greater degree of selectivity towards cancerous cell without damaging the healthy tissues. Hybridization of TiO2 with metal, metal oxide and carbon nano materials significantly improved both of stability and selectivity of TiO2, whilst maintaining its high Photodynamic reactivity. PMID:27639172

  8. Ascorbic acid delivered by mesoporous silica nanoparticles induces the differentiation of human embryonic stem cells into cardiomyocytes.

    PubMed

    Ren, Mingming; Han, Zhen; Li, Jinglai; Feng, Gang; Ouyang, Shuyuan

    2015-11-01

    Embryonic stem (ES) cells offer the potential to generate all cell types in the body, which provide a promising approach to repair tissue damage or dysfunction. In the past decade, great efforts have been made to induce the differentiation of ES cells into numerous types of cells, such as adipocytes, neurocytes and cardiomyocytes. However, the low differentiated efficiency and successful rate limit the development of induction of the differentiation of stem cells for tissue engineering. Here, we utilize ascorbic acid (AA)-loaded fluorescent TRITC-mesoporous silica nanoparticles (TMSN-AA) as a potential tool to induce the differentiation of human ES cells into cardiomyocytes. The treatment of human ES cells by TMSN-AA nanoplex arrests cell cycle at G1 phase and decreases the expression of stemness genes octamer-binding transcription factor 4 (OCT4) and sex determining region Y-box 2 (SOX2), which exhibits more significant induction efficiency of stem cell differentiation than the treatment by AA alone. Furthermore, we have tested the myocardial marker genes cardiac Troponin I (cTnI) and fetal liver kinase 1 (FLK-1), and found these genes are up-regulated by TMSN-AA nanoplex. Importantly, this work demonstrates the more efficient induction efficiency of human ES cells differentiation by the nanoparticle-drug formulation. Our studies reveal a novel approach based on MSNs as nanocarriers to induce the differentiation of human ES cells into cardiomyocytes efficiently and feasibly, and offer the potential perspectives for tissue engineering, eventually in clinical applications.

  9. Statistical detection of nanoparticles in cells by darkfield microscopy.

    PubMed

    Gnerucci, Alessio; Romano, Giovanni; Ratto, Fulvio; Centi, Sonia; Baccini, Michela; Santosuosso, Ugo; Pini, Roberto; Fusi, Franco

    2016-07-01

    In the fields of nanomedicine, biophotonics and radiation therapy, nanoparticle (NP) detection in cell models often represents a fundamental step for many in vivo studies. One common question is whether NPs have or have not interacted with cells. In this context, we propose an imaging based technique to detect the presence of NPs in eukaryotic cells. Darkfield images of cell cultures at low magnification (10×) are acquired in different spectral ranges and recombined so as to enhance the contrast due to the presence of NPs. Image analysis is applied to extract cell-based parameters (i.e. mean intensity), which are further analyzed by statistical tests (Student's t-test, permutation test) in order to obtain a robust detection method. By means of a statistical sample size analysis, the sensitivity of the whole methodology is quantified in terms of the minimum cell number that is needed to identify the presence of NPs. The method is presented in the case of HeLa cells incubated with gold nanorods labeled with anti-CA125 antibodies, which exploits the overexpression of CA125 in ovarian cancers. Control cases are considered as well, including PEG-coated NPs and HeLa cells without NPs. PMID:27381231

  10. Selective Cell Targeting with Light-Absorbing Microparticles and Nanoparticles

    PubMed Central

    Pitsillides, Costas M.; Joe, Edwin K.; Wei, Xunbin; Anderson, R. Rox; Lin, Charles P.

    2003-01-01

    We describe a new method for selective cell targeting based on the use of light-absorbing microparticles and nanoparticles that are heated by short laser pulses to create highly localized cell damage. The method is closely related to chromophore-assisted laser inactivation and photodynamic therapy, but is driven solely by light absorption, without the need for photochemical intermediates (particularly singlet oxygen). The mechanism of light-particle interaction was investigated by nanosecond time-resolved microscopy and by thermal modeling. The extent of light-induced damage was investigated by cell lethality, by cell membrane permeability, and by protein inactivation. Strong particle size dependence was found for these interactions. A technique based on light to target endogenous particles is already being exploited to treat pigmented cells in dermatology and ophthalmology. With exogenous particles, phamacokinetics and biodistribution studies are needed before the method can be evaluated against photodynamic therapy for cancer treatment. However, particles are unique, unlike photosensitizers, in that they can remain stable and inert in cells for extended periods. Thus they may be particularly useful for prelabeling cells in engineered tissue before implantation. Subsequent irradiation with laser pulses will allow control of the implanted cells (inactivation or modulation) in a noninvasive manner. PMID:12770906

  11. Morphological effect of oscillating magnetic nanoparticles in killing tumor cells

    PubMed Central

    2014-01-01

    Forced oscillation of spherical and rod-shaped iron oxide magnetic nanoparticles (MNPs) via low-power and low-frequency alternating magnetic field (AMF) was firstly used to kill cancer cells in vitro. After being loaded by human cervical cancer cells line (HeLa) and then exposed to a 35-kHz AMF, MNPs mechanically damaged cell membranes and cytoplasm, decreasing the cell viability. It was found that the concentration and morphology of the MNPs significantly influenced the cell-killing efficiency of oscillating MNPs. In this preliminary study, when HeLa cells were pre-incubated with 100 μg/mL rod-shaped MNPs (rMNP, length of 200 ± 50 nm and diameter of 50 to 120 nm) for 20 h, MTT assay proved that the cell viability decreased by 30.9% after being exposed to AMF for 2 h, while the cell viability decreased by 11.7% if spherical MNPs (sMNP, diameter of 200 ± 50 nm) were used for investigation. Furthermore, the morphological effect of MNPs on cell viability was confirmed by trypan blue assay: 39.5% rMNP-loaded cells and 15.1% sMNP-loaded cells were stained after being exposed to AMF for 2 h. It was also interesting to find that killing tumor cells at either higher (500 μg/mL) or lower (20 μg/mL) concentration of MNPs was less efficient than that achieved at 100 μg/mL concentration. In conclusion, the relatively asymmetric morphological rod-shaped MNPs can kill cancer cells more effectively than spherical MNPs when being exposed to AMF by virtue of their mechanical oscillations. PMID:24872797

  12. HIV-1-Specific CD8 T Cells Exhibit Limited Cross-Reactivity during Acute Infection.

    PubMed

    Du, Victor Y; Bansal, Anju; Carlson, Jonathan; Salazar-Gonzalez, Jesus F; Salazar, Maria G; Ladell, Kristin; Gras, Stephanie; Josephs, Tracy M; Heath, Sonya L; Price, David A; Rossjohn, Jamie; Hunter, Eric; Goepfert, Paul A

    2016-04-15

    Prior work has demonstrated that HIV-1-specific CD8 T cells can cross-recognize variant epitopes. However, most of these studies were performed in the context of chronic infection, where the presence of viral quasispecies makes it difficult to ascertain the true nature of the original antigenic stimulus. To overcome this limitation, we evaluated the extent of CD8 T cell cross-reactivity in patients with acute HIV-1 clade B infection. In each case, we determined the transmitted founder virus sequence to identify the autologous epitopes restricted by individual HLA class I molecules. Our data show that cross-reactive CD8 T cells are infrequent during the acute phase of HIV-1 infection. Moreover, in the uncommon instances where cross-reactive responses were detected, the variant epitopes were poorly recognized in cytotoxicity assays. Molecular analysis revealed that similar antigenic structures could be cross-recognized by identical CD8 T cell clonotypes mobilized in vivo, yet even subtle differences in a single TCR-accessible peptide residue were sufficient to disrupt variant-specific reactivity. These findings demonstrate that CD8 T cells are highly specific for autologous epitopes during acute HIV-1 infection. Polyvalent vaccines may therefore be required to provide optimal immune cover against this genetically labile pathogen. PMID:26983786

  13. HIV-1-specific CD8 T cells exhibit limited cross-reactivity during acute infection

    PubMed Central

    Du, Victor Y.; Bansal, Anju; Carlson, Jonathan; Salazar-Gonzalez, Jesus F.; Salazar, Maria G.; Ladell, Kristin; Gras, Stephanie; Josephs, Tracy M.; Heath, Sonya; Price, David A.; Rossjohn, Jamie; Hunter, Eric; Goepfert, Paul A.

    2016-01-01

    Prior work has demonstrated that HIV-1-specific CD8 T cells can cross-recognize variant epitopes. However, the majority of these studies were performed in the context of chronic infection, where the presence of viral quasispecies makes it difficult to ascertain the true nature of the original antigenic stimulus. To overcome this limitation, we evaluated the extent of CD8 T-cell cross-reactivity in patients with acute HIV-1 clade B infection. In each case, we determined the transmitted founder virus sequence to identify the autologous epitopes restricted by individual HLA class I molecules. Our data show that cross-reactive CD8 T cells are infrequent during the acute phase of HIV-1 infection. Moreover, in the uncommon instances where cross-reactive responses were detected, the variant epitopes were poorly recognized in cytotoxicity assays. Molecular analysis revealed that similar antigenic structures could be cross-recognized by identical CD8 T-cell clonotypes mobilized in vivo, yet even subtle differences in a single TCR-accessible peptide residue were sufficient to disrupt variant-specific reactivity. These findings demonstrate that CD8 T cells are highly specific for autologous epitopes during acute HIV-1 infection. Polyvalent vaccines may therefore be required to provide optimal immune cover against this genetically labile pathogen. PMID:26983786

  14. Next generation adoptive immunotherapy--human T cells as carriers of therapeutic nanoparticles.

    PubMed

    Mortensen, M W; Kahns, L; Hansen, T; Sorensen, P G; Björkdahl, O; Jensen, M R; Gundersen, H J G; Bjørnholm, T

    2007-12-01

    An important step in adoptive immunotherapy in general and specifically with respect to cancer treatment is the initiation of an inflammatory T cell response at the tumor site. Here we suggest a new concept for a controlled inflammatory response in which the intrinsic cytotoxic properties of T cells are upgraded with the properties of nanoparticles transfected into the T cells during the ex vivo expansion process. We report in vitro upgrading of human T cells using PEGylated boron carbide nanoparticles functionalised with a translocation peptide aimed at Boron Neutron Capture Therapy (BNCT). A key finding is that the metabolism of such upgraded human T cells were not affected by a payload of 0.13 pg boron per cell and that the nanoparticles were retained in the cell population after several cell divisions. This is vital for transporting nanoparticles by T cells to the tumor site.

  15. Protamine sulfate-nanodiamond hybrid nanoparticles as a vector for MiR-203 restoration in esophageal carcinoma cells

    NASA Astrophysics Data System (ADS)

    Cao, Minjun; Deng, Xiongwei; Su, Shishuai; Zhang, Fang; Xiao, Xiangqian; Hu, Qin; Fu, Yongwei; Yang, Burton B.; Wu, Yan; Sheng, Wang; Zeng, Yi

    2013-11-01

    We report an innovative approach for miRNA-203 delivery in esophageal cancer cells using protamine sulphate (PS)-nanodiamond (ND) nanoparticles. The efficient delivery of miR-203 significantly suppressed the proliferation and migration of cancer cells through targeting Ran and ΔNp63, exhibiting a great potential for PS@ND nanoparticles in miRNA-based cancer therapy.We report an innovative approach for miRNA-203 delivery in esophageal cancer cells using protamine sulphate (PS)-nanodiamond (ND) nanoparticles. The efficient delivery of miR-203 significantly suppressed the proliferation and migration of cancer cells through targeting Ran and ΔNp63, exhibiting a great potential for PS@ND nanoparticles in miRNA-based cancer therapy. Electronic supplementary information (ESI) available: (1) Experimental section; (2) Results: serum stability of miR-203/PS@NDs and miR-203 release curve (Fig. S1). Cytotoxicity assay of PS@NDs to Ec-109 cells (Fig. S2); confocal image and FACS analysis of intracellular uptake of cy3-labeled miR-203 (Fig. S3 and S4); real-time PCR analysis of miR-203 restoration (Fig. S5); Ran and ΔNp63 expression (Fig. S6); the sizes and zeta potentials of miRNA/PS@NDs (Table S1); the sequences of the microRNA mimics and primers (Table S2, S3 and S4). See DOI: 10.1039/c3nr04056a

  16. Photovoltaic study of dye sensitized solar cells based on TiO2, ZnO:Al3+ nanoparticles

    NASA Astrophysics Data System (ADS)

    Sánchez Godoy, H. E.; Rodríguez-Rojas, R. A.; Castañeda-Contreras, J.; Marañón-Ruiz, V. F.; Pérez-Ladrón de Guevara, H.; López-Luke, T.; De la Rosa-Cruz

    2015-10-01

    A technique to fabricate dye (rhodamine B) sensitized solar cells based on Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles are reported. The TiO2 was synthesized using the sol-gel method and the ZnO was synthesized by hydrolysis method to obtain nanoparticles of ~ 5 nm and 150 nm respectively. ZnO was doped with Al3+ in order to enhance the photovoltaic efficiency to promote the electrons mobility. The photovoltaic conversion characterization of films of TiO2, ZnO and ZnO:Al3+ nanoparticles is also reported. The generated photocurrent was measured by two methods; one of those uses a three electrode electrochemical cell and the other use an electronic array where the cells were exposed to UV lamp and the sun light. The role of the TiO2, ZnO and Al3+ doped ZnO nanoparticles is discussed to obtain a better efficiency in the generation of photocurrent (PC). The results exhibited by the electrochemical cell method, efficiencies of 0.55 (PC=187 μA/cm2) and 0.22 (PC=149 μA/cm2) for TiO2 and undoped ZnO respectively. However, when ZnO is doped with Al3+ at the higher concentration the efficiency was 0.44. While using the electronic array the results exhibited efficiencies of 0.31 (PC=45 μA/cm2) and 0.09 (PC=16 μA/cm2) for TiO2 and undoped ZnO respectively. However, when ZnO is doped with Al3+ at the higher concentration the efficiency was 0.44 and 0.48 for electrochemical cell and electronic array respectively. This shows that Al3+ enhances the photogenerated charge carriers increasing the mobility of electrons.

  17. A two-step route to planar perovskite cells exhibiting reduced hysteresis

    SciTech Connect

    Ip, Alexander H.; Adachi, Michael M.; McDowell, Jeffrey J.; Xu, Jixian; Sargent, Edward H.; Quan, Li Na; Kim, Dong Ha

    2015-04-06

    A simple two-step method was used to produce efficient planar organolead halide perovskite solar cells. Films produced using solely iodine containing precursors resulted in poor morphology and failed devices, whereas addition of chlorine to the process greatly improved morphology and resulted in dense, uniform perovskite films. This process was used to produce perovskite solar cells with a fullerene-based passivation layer. The hysteresis effect, to which planar perovskite devices are otherwise prone, was greatly suppressed through the use of this interface modifier. The combined techniques resulted in perovskite solar cells having a stable efficiency exceeding 11%. This straightforward fabrication procedure holds promise in development of various optoelectronic applications of planar perovskite films.

  18. Metre-long cell-laden microfibres exhibit tissue morphologies and functions

    NASA Astrophysics Data System (ADS)

    Onoe, Hiroaki; Okitsu, Teru; Itou, Akane; Kato-Negishi, Midori; Gojo, Riho; Kiriya, Daisuke; Sato, Koji; Miura, Shigenori; Iwanaga, Shintaroh; Kuribayashi-Shigetomi, Kaori; Matsunaga, Yukiko T.; Shimoyama, Yuto; Takeuchi, Shoji

    2013-06-01

    Artificial reconstruction of fibre-shaped cellular constructs could greatly contribute to tissue assembly in vitro. Here we show that, by using a microfluidic device with double-coaxial laminar flow, metre-long core-shell hydrogel microfibres encapsulating ECM proteins and differentiated cells or somatic stem cells can be fabricated, and that the microfibres reconstitute intrinsic morphologies and functions of living tissues. We also show that these functional fibres can be assembled, by weaving and reeling, into macroscopic cellular structures with various spatial patterns. Moreover, fibres encapsulating primary pancreatic islet cells and transplanted through a microcatheter into the subrenal capsular space of diabetic mice normalized blood glucose concentrations for about two weeks. These microfibres may find use as templates for the reconstruction of fibre-shaped functional tissues that mimic muscle fibres, blood vessels or nerve networks in vivo.

  19. Early- and late-born parvalbumin basket cell subpopulations exhibiting distinct regulation and roles in learning.

    PubMed

    Donato, Flavio; Chowdhury, Ananya; Lahr, Maria; Caroni, Pico

    2015-02-18

    Brain networks can support learning by promoting acquisition of task-relevant information or by adhering to validated rules, but the mechanisms involved are poorly understood. Upon learning, local inhibitory parvalbumin (PV)-expressing Basket cell networks can switch to opposite configurations that either favor or interfere with further learning, but how this opposite plasticity is induced and relates to distinct learning requirements has remained unclear. Here, we show that PV Basket cells consist of hitherto unrecognized subpopulations, with distinct schedules of neurogenesis, input connectivities, output target neurons, and roles in learning. Plasticity of hippocampal early-born PV neurons was recruited in rule consolidation, whereas plasticity of late-born PV neurons was recruited in new information acquisition. This involved regulation of early-born neuron plasticity specifically through excitation, and of late-born neuron plasticity specifically through inhibition. Therefore, opposite learning requirements are implemented by distinct local networks involving PV Basket cell subpopulations specifically regulated through inhibition or excitation.

  20. Chitosan-modified cobalt oxide nanoparticles stimulate TNF-α-mediated apoptosis in human leukemic cells.

    PubMed

    Chattopadhyay, Sourav; Dash, Sandeep Kumar; Kar Mahapatra, Santanu; Tripathy, Satyajit; Ghosh, Totan; Das, Balaram; Das, Debasis; Pramanik, Panchanan; Roy, Somenath

    2014-03-01

    The objective of this study was to develop chitosan-based delivery of cobalt oxide nanoparticles to human leukemic cells and investigate their specific induction of apoptosis. The physicochemical properties of the chitosan-coated cobalt oxide nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. The solubility of chitosan-coated cobalt oxide nanoparticles was higher at acidic pH, which helps to release more cobalt ions into the medium. Chitosan-coated cobalt oxide nanoparticles showed good compatibility with normal cells. However, our results showed that exposure of leukemic cells (Jurkat cells) to chitosan-coated cobalt oxide nanoparticles caused an increase in reactive oxygen species generation that was abolished by pretreatment of cells with the reactive oxygen species scavenger N-acetyl-L-cysteine. The apoptosis of Jurkat cells was confirmed by flow-cytometric analysis. Induction of TNF-α secretion was observed from stimulation of Jurkat cells with chitosan-coated cobalt oxide nanoparticles. We also tested the role of TNF-α in the induction of Jurkat cell death in the presence of TNF-α and caspase inhibitors. Treatment of leukemic cells with a blocker had a greater effect on cancer cell viability. From our findings, oxidative stress and caspase activation are involved in cancer cell death induced by chitosan-coated cobalt oxide nanoparticles.

  1. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    NASA Astrophysics Data System (ADS)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  2. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    PubMed Central

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-01-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells. PMID:26578100

  3. Antiproliferative effect of ASC-J9 delivered by PLGA nanoparticles against estrogen-dependent breast cancer cells.

    PubMed

    Verderio, Paolo; Pandolfi, Laura; Mazzucchelli, Serena; Marinozzi, Maria Rosaria; Vanna, Renzo; Gramatica, Furio; Corsi, Fabio; Colombo, Miriam; Morasso, Carlo; Prosperi, Davide

    2014-08-01

    Among polymeric nanoparticles designed for cancer therapy, PLGA nanoparticles have become one of the most popular polymeric devices for chemotherapeutic-based nanoformulations against several kinds of malignant diseases. Promising properties, including long-circulation time, enhanced tumor localization, interference with "multidrug" resistance effects, and environmental biodegradability, often result in an improvement of the drug bioavailability and effectiveness. In the present work, we have synthesized 1,7-bis(3,4-dimethoxyphenyl)-5-hydroxyhepta-1,4,6-trien-3-one (ASC-J9) and developed uniform ASC-J9-loaded PLGA nanoparticles of about 120 nm, which have been prepared by a single-emulsion process. Structural and morphological features of the nanoformulation were analyzed, followed by an accurate evaluation of the in vitro drug release kinetics, which exhibited Fickian law diffusion over 10 days. The intracellular degradation of ASC-J9-bearing nanoparticles within estrogen-dependent MCF-7 breast cancer cells was correlated to a time- and dose-dependent activity of the released drug. A cellular growth inhibition associated with a specific cell cycle G2/M blocking effect caused by ASC-J9 release inside the cytosol allowed us to put forward a hypothesis on the action mechanism of this nanosystem, which led to the final cell apoptosis. Our study was accomplished using Annexin V-based cell death analysis, MTT assessment of proliferation, radical scavenging activity, and intracellular ROS evaluation. Moreover, the intracellular localization of nanoformulated ASC-J9 was confirmed by a Raman optical imaging experiment designed ad hoc. PLGA nanoparticles and ASC-J9 proved also to be safe for a healthy embryo fibroblast cell line (3T3-L1), suggesting a possible clinical translation of this potential nanochemotherapeutic to expand the inherently poor bioavailability of hydrophobic ASC-J9 that could be proposed for the treatment of malignant breast cancer.

  4. Characterization and anticancer potential of ferulic acid-loaded chitosan nanoparticles against ME-180 human cervical cancer cell lines

    NASA Astrophysics Data System (ADS)

    Panwar, Richa; Sharma, Asvene K.; Kaloti, Mandeep; Dutt, Dharm; Pruthi, Vikas

    2016-08-01

    Ferulic acid (FA) is a widely distributed hydroxycinnamic acid found in various cereals and fruits exhibiting potent antioxidant and anticancer activities. However, due to low solubility and permeability, its availability to biological systems is limited. Non-toxic chitosan-tripolyphosphate pentasodium (CS-TPP) nanoparticles (NPs) are used to load sparingly soluble molecules and drugs, increasing their bioavailability. In the present work, we have encapsulated FA into the CS-TPP NPs to increase its potential as a therapeutic agent. Different concentrations of FA were tested to obtain optimum sized FA-loaded CS-TPP nanoparticles (FA/CS-TPP NPs) by ionic gelation method. Nanoparticles were characterized by scanning electron microscopy, Fourier transformation infrared spectroscopy (FTIR), thermogravimetric analyses and evaluated for their anticancer activity against ME-180 human cervical cancer cell lines. The FTIR spectra confirmed the encapsulation of FA and thermal analysis depicted its degradation profile. A concentration-dependent relationship between FA encapsulation efficiency and FA/CS-TPP NPs diameter was observed. Smooth and spherical FA-loaded cytocompatible nanoparticles with an average diameter of 125 nm were obtained at 40 µM FA conc. The cytotoxicity of 40 µM FA/CS-TPP NPs against ME-180 cervical cancer cell lines was found to be higher as compared to 40 µM native FA. Apoptotic morphological changes as cytoplasmic remnants and damaged wrinkled cells in ME-180 cells were visualized using scanning electron microscopic and fluorescent microscopic techniques. Data concluded that chitosan enveloped FA nanoparticles could be exploited as an excellent therapeutic drug against cancer cells proliferation.

  5. Magnetite nanoparticles induced adaptive mechanisms counteract cell death in human pulmonary fibroblasts.

    PubMed

    Radu, Mihaela; Dinu, Diana; Sima, Cornelia; Burlacu, Radu; Hermenean, Anca; Ardelean, Aurel; Dinischiotu, Anca

    2015-10-01

    Magnetite nanoparticles (MNP) have attracted great interest for biomedical applications due to their unique chemical and physical properties, but the MNP impact on human health is not fully known. Consequently, our study proposes to highlight the biochemical mechanisms that underline the toxic effects of MNP on a human lung fibroblast cell line (MRC-5). The cytotoxicity generated by MNP in MRC-5 cells was dose and time-dependent. MNP-treated MRC-5 cells accumulated large amount of iron and reactive oxygen species (ROS) and exhibited elevated antioxidant scavenger enzymes. Reduced glutathione (GSH) depletion and enhanced lipid peroxidation (LPO) processes were also observed. The cellular capacity to counteract the oxidative damage was sustained by high levels of heat shock protein 60 (Hsp60), a protein that confers resistance against ROS attack and inhibition of cell death. While significant augmentations in nitric oxide (NO) and prostaglandine E2 (PGE2) levels were detected after 72 h of MNP-exposure only, caspase-1 was activated earlier starting with 24h post-treatment. Taken together, our results suggest that MRC-5 cells have the capacity to develop cell protection mechanisms against MNP. Detailed knowledge of the mechanisms induced by MNP in cell culture could be essential for their prospective use in various in vivo biochemical applications. PMID:26065626

  6. Trisomy 12 chronic lymphocytic leukemia cells exhibit upregulation of integrin signaling that is modulated by NOTCH1 mutations

    PubMed Central

    Riches, John C.; O’Donovan, Conor J.; Kingdon, Sarah J.; McClanahan, Fabienne; Clear, Andrew J.; Neuberg, Donna S.; Werner, Lillian; Croce, Carlo M.; Ramsay, Alan G.; Rassenti, Laura Z.; Kipps, Thomas J.; Gribben, John G.

    2014-01-01

    The leukocyte adhesion cascade is important in chronic lymphocytic leukemia (CLL), as it controls migration of malignant cells into the pro-survival lymph node microenvironment. Circulating trisomy 12 CLL cells have increased expression of the integrins CD11a and CD49d, as well as CD38, but the tissue expression of these and other molecules, and the functional and clinical sequelae of these changes have not been described. Here, we demonstrate that circulating trisomy 12 CLL cells also have increased expression of the integrins CD11b, CD18, CD29, and ITGB7, and the adhesion molecule CD323. Notably, there was reduced expression of CD11a, CD11b, and CD18 in trisomy 12 cases with NOTCH1 mutations compared with wild type. Trisomy 12 cells also exhibit upregulation of intracellular integrin signaling molecules CALDAG-GEFI, RAP1B, and Ras-related protein ligand, resulting in enhanced very late antigen-4 [VLA-4] directed adhesion and motility. CD38 expression in CLL has prognostic significance, but the increased CD38 expression in trisomy 12 CLL cells must be taken into account in this subgroup, and the threshold of CD38 positivity should be raised to 40% for this marker to retain its prognostic value. In conclusion, trisomy 12 CLL cells exhibit functional upregulation of integrin signaling, with β2-integrin expression being modulated by NOTCH1 mutation status. PMID:24829201

  7. Carbon nanoparticles for gene transfection in eukaryotic cell lines.

    PubMed

    Zanin, H; Hollanda, L M; Ceragioli, H J; Ferreira, M S; Machado, D; Lancellotti, M; Catharino, R R; Baranauskas, V; Lobo, A O

    2014-06-01

    For the first time, oxygen terminated cellulose carbon nanoparticles (CCN) was synthesised and applied in gene transfection of pIRES plasmid. The CCN was prepared from catalytic of polyaniline by chemical vapour deposition techniques. This plasmid contains one gene that encodes the green fluorescent protein (GFP) in eukaryotic cells, making them fluorescent. This new nanomaterial and pIRES plasmid formed π-stacking when dispersed in water by magnetic stirring. The frequencies shift in zeta potential confirmed the plasmid strongly connects to the nanomaterial. In vitro tests found that this conjugation was phagocytised by NG97, NIH-3T3 and A549 cell lines making them fluorescent, which was visualised by fluorescent microscopy. Before the transfection test, we studied CCN in cell viability. Both MTT and Neutral Red uptake tests were carried out using NG97, NIH-3T3 and A549 cell lines. Further, we use metabolomics to verify if small amounts of nanomaterial would be enough to cause some cellular damage in NG97 cells. We showed two mechanisms of action by CCN-DNA complex, producing an exogenous protein by the transfected cell and metabolomic changes that contributed by better understanding of glioblastoma, being the major finding of this work. Our results suggested that this nanomaterial has great potential as a gene carrier agent in non-viral based therapy, with low cytotoxicity, good transfection efficiency, and low cell damage in small amounts of nanomaterials in metabolomic tests.

  8. Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

    PubMed Central

    Shang, Li; Nienhaus, Karin; Jiang, Xiue; Yang, Linxiao; Landfester, Katharina; Mailänder, Volker; Simmet, Thomas

    2014-01-01

    Summary Engineered nanomaterials are known to enter human cells, often via active endocytosis. Mechanistic details of the interactions between nanoparticles (NPs) with cells are still not well enough understood. NP size is a key parameter that controls the endocytic mechanism and affects the cellular uptake yield. Therefore, we have systematically analyzed the cellular uptake of fluorescent NPs in the size range of 3.3–100 nm (diameter) by live cells. By using spinning disk confocal microscopy in combination with quantitative image analysis, we studied the time courses of NP association with the cell membrane and subsequent internalization. NPs with diameters of less than 10 nm were observed to accumulate at the plasma membrane before being internalized by the cells. In contrast, larger NPs (100 nm) were directly internalized without prior accumulation at the plasma membrane, regardless of their surface charges. We attribute this distinct size dependence to the requirement of a sufficiently strong local interaction of the NPs with the endocytic machinery in order to trigger the subsequent internalization. PMID:25551067

  9. Embryonic Stem Cells Exhibit mRNA Isoform Specific Translational Regulation.

    PubMed

    Wong, Queenie Wing-Lei; Vaz, Candida; Lee, Qian Yi; Zhao, Tian Yun; Luo, Raymond; Archer, Stuart K; Preiss, Thomas; Tanavde, Vivek; Vardy, Leah A

    2016-01-01

    The presence of multiple variants for many mRNAs is a major contributor to protein diversity. The processing of these variants is tightly controlled in a cell-type specific manner and has a significant impact on gene expression control. Here we investigate the differential translation rates of individual mRNA variants in embryonic stem cells (ESCs) and in ESC derived Neural Precursor Cells (NPCs) using polysome profiling coupled to RNA sequencing. We show that there are a significant number of detectable mRNA variants in ESCs and NPCs and that many of them show variant specific translation rates. This is correlated with differences in the UTRs of the variants with the 5'UTR playing a predominant role. We suggest that mRNA variants that contain alternate UTRs are under different post-transcriptional controls. This is likely due to the presence or absence of miRNA and protein binding sites that regulate translation rate. This highlights the importance of addressing translation rate when using mRNA levels as a read out of protein abundance. Additional analysis shows that many annotated non-coding mRNAs are present on the polysome fractions in ESCs and NPCs. We believe that the use of polysome fractionation coupled to RNA sequencing is a useful method for analysis of the translation state of many different RNAs in the cell.

  10. Mycobacterium tuberculosis strains exhibit differential and strain-specific molecular signatures in pulmonary epithelial cells.

    PubMed

    Mvubu, Nontobeko Eunice; Pillay, Balakrishna; Gamieldien, Junaid; Bishai, William; Pillay, Manormoney

    2016-12-01

    Although pulmonary epithelial cells are integral to innate and adaptive immune responses during Mycobacterium tuberculosis infection, global transcriptomic changes in these cells remain largely unknown. Changes in gene expression induced in pulmonary epithelial cells infected with M. tuberculosis F15/LAM4/KZN, F11, F28, Beijing and Unique genotypes were investigated by RNA sequencing (RNA-Seq). The Illumina HiSeq 2000 platform generated 50 bp reads that were mapped to the human genome (Hg19) using Tophat (2.0.10). Differential gene expression induced by the different strains in infected relative to the uninfected cells was quantified and compared using Cufflinks (2.1.0) and MeV (4.0.9), respectively. Gene expression varied among the strains with the total number of genes as follows: F15/LAM4/KZN (1187), Beijing (1252), F11 (1639), F28 (870), Unique (886) and H37Rv (1179). A subset of 292 genes was commonly induced by all strains, where 52 genes were down-regulated while 240 genes were up-regulated. Differentially expressed genes were compared among the strains and the number of induced strain-specific gene signatures were as follows: F15/LAM4/KZN (138), Beijing (52), F11 (255), F28 (55), Unique (186) and H37Rv (125). Strain-specific molecular gene signatures associated with functional pathways were observed only for the Unique and H37Rv strains while certain biological functions may be associated with other strain signatures. This study demonstrated that strains of M. tuberculosis induce differential gene expression and strain-specific molecular signatures in pulmonary epithelial cells. Specific signatures induced by clinical strains of M. tuberculosis can be further explored for novel host-associated biomarkers and adjunctive immunotherapies. PMID:27497873

  11. Mycobacterium tuberculosis strains exhibit differential and strain-specific molecular signatures in pulmonary epithelial cells.

    PubMed

    Mvubu, Nontobeko Eunice; Pillay, Balakrishna; Gamieldien, Junaid; Bishai, William; Pillay, Manormoney

    2016-12-01

    Although pulmonary epithelial cells are integral to innate and adaptive immune responses during Mycobacterium tuberculosis infection, global transcriptomic changes in these cells remain largely unknown. Changes in gene expression induced in pulmonary epithelial cells infected with M. tuberculosis F15/LAM4/KZN, F11, F28, Beijing and Unique genotypes were investigated by RNA sequencing (RNA-Seq). The Illumina HiSeq 2000 platform generated 50 bp reads that were mapped to the human genome (Hg19) using Tophat (2.0.10). Differential gene expression induced by the different strains in infected relative to the uninfected cells was quantified and compared using Cufflinks (2.1.0) and MeV (4.0.9), respectively. Gene expression varied among the strains with the total number of genes as follows: F15/LAM4/KZN (1187), Beijing (1252), F11 (1639), F28 (870), Unique (886) and H37Rv (1179). A subset of 292 genes was commonly induced by all strains, where 52 genes were down-regulated while 240 genes were up-regulated. Differentially expressed genes were compared among the strains and the number of induced strain-specific gene signatures were as follows: F15/LAM4/KZN (138), Beijing (52), F11 (255), F28 (55), Unique (186) and H37Rv (125). Strain-specific molecular gene signatures associated with functional pathways were observed only for the Unique and H37Rv strains while certain biological functions may be associated with other strain signatures. This study demonstrated that strains of M. tuberculosis induce differential gene expression and strain-specific molecular signatures in pulmonary epithelial cells. Specific signatures induced by clinical strains of M. tuberculosis can be further explored for novel host-associated biomarkers and adjunctive immunotherapies.

  12. Ex vivo expanded human circulating Vδ1 γδT cells exhibit favorable therapeutic potential for colon cancer

    PubMed Central

    Wu, Dang; Wu, Pin; Wu, Xianguo; Ye, Jun; Wang, Zhen; Zhao, Shuai; Ni, Chao; Hu, Guoming; Xu, Jinghong; Han, Yuehua; Zhang, Ting; Qiu, Fuming; Yan, Jun; Huang, Jian

    2015-01-01

    Gamma delta T (γδT) cells are innate-like lymphocytes with strong, MHC-unrestricted cytotoxicity against cancer cells and show a promising prospect in adoptive cellular immunotherapy for various malignancies. However, the clinical outcome of commonly used Vγ9Vδ2 γδT (Vδ2 T) cells in adoptive immunotherapy for most solid tumors is limited. Here, we demonstrate that freshly isolated Vδ1 γδT (Vδ1 T) cells from human peripheral blood (PB) exhibit more potent cytotoxicity against adherent and sphere-forming human colon cancer cells than Vδ2 T cells in vitro. We also develop an optimized protocol to preferentially expand Vδ1 T cells isolated from PB of both healthy donors and colon cancer patients by in vitro short-term culture with phytohemagglutinin (PHA) and interleukin-7 (IL-7). Expanded Vδ1 T cells highly expressed cytotoxicity-related molecules, chemokine receptors and cytokines with enhanced cytolytic effect against adherent and sphere-forming colon cancer cells in a cell-to-cell contact dependent manner. In addition, PHA and IL-7 expanded Vδ1 T cells showed proliferation and survival advantage partly through an IL-2 signaling pathway. Furthermore, ex vivo expanded Vδ1 T cells also restrained the tumor growth and prolonged the tumor-burdened survival of human colon carcinoma xenografted mice. Our findings suggest that human PB Vδ1 T cells expanded by PHA and IL-7 are a promising candidate for anticancer adoptive immunotherapy for human solid tumors such as colon cancer. PMID:25949914

  13. Cytotoxicity of various types of gold-mesoporous silica nanoparticles in human breast cancer cells

    PubMed Central

    Liu, Guomu; Li, Qiongshu; Ni, Weihua; Zhang, Nannan; Zheng, Xiao; Wang, Yingshuai; Shao, Dan; Tai, Guixiang

    2015-01-01

    Recently, gold nanoparticles (AuNPs) have shown promising biological applications due to their unique electronic and optical properties. However, the potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. Mesoporous silica is very suitable for the use as a coating material for AuNPs and might not only reduce the cytotoxicity of cetyltrimethylammonium bromide-coated AuNPs but might also facilitate the loading and delivery of drugs. Herein, three types of rod-like gold-mesoporous silica nanoparticles (termed bare AuNPs, core–shell Au@mSiO2NPs, and Janus Au@mSiO2NPs) were specially designed, and the effects of these AuNPs on cellular uptake, toxic behavior, and mechanism were then systematically studied. Our results indicate that bare AuNPs exerted higher toxicity than the Au@mSiO2NPs and that Janus Au@mSiO2NPs exhibited the lowest toxicity in human breast cancer MCF-7 cells, consistent with the endocytosis capacity of the nanoparticles, which followed the order, bare AuNPs > core–shell Au@mSiO2NPs > Janus Au@mSiO2NPs. More importantly, the AuNPs-induced apoptosis of MCF-7 cells exhibited features that were characteristic of intracellular reactive oxygen species (ROS) generation, activation of c-Jun-N-terminal kinase (JNK) phosphorylation, an enhanced Bax-to-Bcl-2 ratio, and loss of the mitochondrial membrane potential. Simultaneously, cytochrome c was released from mitochondria, and the caspase-3/9 cascade was activated. Moreover, both ROS scavenger (N-acetylcysteine) and JNK inhibitor (SP600125) partly blocked the induction of apoptosis in all AuNPs-treated cells. Taken together, these findings suggest that all AuNPs induce apoptosis through the ROS-/JNK-mediated mitochondrial pathway. Thus, Janus Au@mSiO2NPs exhibit the potential for applications in biomedicine, thus aiding the clinical translation of AuNPs. PMID:26491285

  14. Cytotoxicity of various types of gold-mesoporous silica nanoparticles in human breast cancer cells.

    PubMed

    Liu, Guomu; Li, Qiongshu; Ni, Weihua; Zhang, Nannan; Zheng, Xiao; Wang, Yingshuai; Shao, Dan; Tai, Guixiang

    2015-01-01

    Recently, gold nanoparticles (AuNPs) have shown promising biological applications due to their unique electronic and optical properties. However, the potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. Mesoporous silica is very suitable for the use as a coating material for AuNPs and might not only reduce the cytotoxicity of cetyltrimethylammonium bromide-coated AuNPs but might also facilitate the loading and delivery of drugs. Herein, three types of rod-like gold-mesoporous silica nanoparticles (termed bare AuNPs, core-shell Au@mSiO2NPs, and Janus Au@mSiO2NPs) were specially designed, and the effects of these AuNPs on cellular uptake, toxic behavior, and mechanism were then systematically studied. Our results indicate that bare AuNPs exerted higher toxicity than the Au@mSiO2NPs and that Janus Au@mSiO2NPs exhibited the lowest toxicity in human breast cancer MCF-7 cells, consistent with the endocytosis capacity of the nanoparticles, which followed the order, bare AuNPs > core-shell Au@mSiO2NPs > Janus Au@mSiO2NPs. More importantly, the AuNPs-induced apoptosis of MCF-7 cells exhibited features that were characteristic of intracellular reactive oxygen species (ROS) generation, activation of c-Jun-N-terminal kinase (JNK) phosphorylation, an enhanced Bax-to-Bcl-2 ratio, and loss of the mitochondrial membrane potential. Simultaneously, cytochrome c was released from mitochondria, and the caspase-3/9 cascade was activated. Moreover, both ROS scavenger (N-acetylcysteine) and JNK inhibitor (SP600125) partly blocked the induction of apoptosis in all AuNPs-treated cells. Taken together, these findings suggest that all AuNPs induce apoptosis through the ROS-/JNK-mediated mitochondrial pathway. Thus, Janus Au@mSiO2NPs exhibit the potential for applications in biomedicine, thus aiding the clinical translation of AuNPs.

  15. Cytotoxicity of various types of gold-mesoporous silica nanoparticles in human breast cancer cells.

    PubMed

    Liu, Guomu; Li, Qiongshu; Ni, Weihua; Zhang, Nannan; Zheng, Xiao; Wang, Yingshuai; Shao, Dan; Tai, Guixiang

    2015-01-01

    Recently, gold nanoparticles (AuNPs) have shown promising biological applications due to their unique electronic and optical properties. However, the potential toxicity of AuNPs remains a major hurdle that impedes their use in clinical settings. Mesoporous silica is very suitable for the use as a coating material for AuNPs and might not only reduce the cytotoxicity of cetyltrimethylammonium bromide-coated AuNPs but might also facilitate the loading and delivery of drugs. Herein, three types of rod-like gold-mesoporous silica nanoparticles (termed bare AuNPs, core-shell Au@mSiO2NPs, and Janus Au@mSiO2NPs) were specially designed, and the effects of these AuNPs on cellular uptake, toxic behavior, and mechanism were then systematically studied. Our results indicate that bare AuNPs exerted higher toxicity than the Au@mSiO2NPs and that Janus Au@mSiO2NPs exhibited the lowest toxicity in human breast cancer MCF-7 cells, consistent with the endocytosis capacity of the nanoparticles, which followed the order, bare AuNPs > core-shell Au@mSiO2NPs > Janus Au@mSiO2NPs. More importantly, the AuNPs-induced apoptosis of MCF-7 cells exhibited features that were characteristic of intracellular reactive oxygen species (ROS) generation, activation of c-Jun-N-terminal kinase (JNK) phosphorylation, an enhanced Bax-to-Bcl-2 ratio, and loss of the mitochondrial membrane potential. Simultaneously, cytochrome c was released from mitochondria, and the caspase-3/9 cascade was activated. Moreover, both ROS scavenger (N-acetylcysteine) and JNK inhibitor (SP600125) partly blocked the induction of apoptosis in all AuNPs-treated cells. Taken together, these findings suggest that all AuNPs induce apoptosis through the ROS-/JNK-mediated mitochondrial pathway. Thus, Janus Au@mSiO2NPs exhibit the potential for applications in biomedicine, thus aiding the clinical translation of AuNPs. PMID:26491285

  16. Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer

    PubMed Central

    Li, Chao; Ruan, Jing; Yang, Meng; Pan, Fei; Gao, Guo; Qu, Su; Shen, You-Lan; Dang, Yong-Jun; Wang, Kan; Jin, Wei-Lin; Cui, Da-Xiang

    2015-01-01

    Objective Human induced pluripotent stem (iPS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human iPS cells labeled with fluorescent magnetic nanoparticles (FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Methods Human iPS cells were prepared and cultured for 72 h. The culture medium was collected, and then was co-incubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human iPS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. Results iPS cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iPS cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. Conclusion FMNP-labeled human iPS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer. PMID:26487961

  17. Augmented cellular uptake of nanoparticles using tea catechins: effect of surface modification on nanoparticle-cell interaction

    NASA Astrophysics Data System (ADS)

    Lu, Yi-Ching; Luo, Pei-Chun; Huang, Chun-Wan; Leu, Yann-Lii; Wang, Tzu-Hao; Wei, Kuo-Chen; Wang, Hsin-Ell; Ma, Yunn-Hwa

    2014-08-01

    Nanoparticles may serve as carriers in targeted therapeutics; interaction of the nanoparticles with a biological system may determine their targeting effects and therapeutic efficacy. Epigallocatechin-3-gallate (EGCG), a major component of tea catechins, has been conjugated with nanoparticles and tested as an anticancer agent. We investigated whether EGCG may enhance nanoparticle uptake by tumor cells. Cellular uptake of a dextran-coated magnetic nanoparticle (MNP) was determined by confocal microscopy, flow cytometry or a potassium thiocyanate colorimetric method. We demonstrated that EGCG greatly enhanced interaction and/or internalization of MNPs (with or without polyethylene glycol) by glioma cells, but not vascular endothelial cells. The enhancing effects are both time- and concentration-dependent. Such effects may be induced by a simple mix of MNPs with EGCG at a concentration as low as 1-3 μM, which increased MNP uptake 2- to 7-fold. In addition, application of magnetic force further potentiated MNP uptake, suggesting a synergetic effect of EGCG and magnetic force. Because the effects of EGCG were preserved at 4 °C, but not when EGCG was removed from the culture medium prior to addition of MNPs, a direct interaction of EGCG and MNPs was implicated. Use of an MNP-EGCG composite produced by adsorption of EGCG and magnetic separation also led to an enhanced uptake. The results reveal a novel interaction of a food component and nanocarrier system, which may be potentially amenable to magnetofection, cell labeling/tracing, and targeted therapeutics.

  18. Augmented cellular uptake of nanoparticles using tea catechins: effect of surface modification on nanoparticle-cell interaction.

    PubMed

    Lu, Yi-Ching; Luo, Pei-Chun; Huang, Chun-Wan; Leu, Yann-Lii; Wang, Tzu-Hao; Wei, Kuo-Chen; Wang, Hsin-Ell; Ma, Yunn-Hwa

    2014-09-01

    Nanoparticles may serve as carriers in targeted therapeutics; interaction of the nanoparticles with a biological system may determine their targeting effects and therapeutic efficacy. Epigallocatechin-3-gallate (EGCG), a major component of tea catechins, has been conjugated with nanoparticles and tested as an anticancer agent. We investigated whether EGCG may enhance nanoparticle uptake by tumor cells. Cellular uptake of a dextran-coated magnetic nanoparticle (MNP) was determined by confocal microscopy, flow cytometry or a potassium thiocyanate colorimetric method. We demonstrated that EGCG greatly enhanced interaction and/or internalization of MNPs (with or without polyethylene glycol) by glioma cells, but not vascular endothelial cells. The enhancing effects are both time- and concentration-dependent. Such effects may be induced by a simple mix of MNPs with EGCG at a concentration as low as 1-3 μM, which increased MNP uptake 2- to 7-fold. In addition, application of magnetic force further potentiated MNP uptake, suggesting a synergetic effect of EGCG and magnetic force. Because the effects of EGCG were preserved at 4 °C, but not when EGCG was removed from the culture medium prior to addition of MNPs, a direct interaction of EGCG and MNPs was implicated. Use of an MNP-EGCG composite produced by adsorption of EGCG and magnetic separation also led to an enhanced uptake. The results reveal a novel interaction of a food component and nanocarrier system, which may be potentially amenable to magnetofection, cell labeling/tracing, and targeted therapeutics.

  19. Relating Intercellular Variability in Nanoparticle Uptake with Biological Consequence: A Quantitative X-ray Fluorescence Study for Radiosensitization of Cells.

    PubMed

    Turnbull, Tyron; Douglass, Michael; Paterson, David; Bezak, Eva; Thierry, Benjamin; Kempson, Ivan

    2015-11-01

    Internalized gold nanoparticles were quantified in large numbers of individual prostate cancer cells using large area synchrotron X-ray fluorescence microscopy. Cells were also irradiated with a 6 MV linear accelerator to assess the biological consequence of radiosensitization with gold nanoparticles. A large degree of heterogeneity in nanoparticle uptake between cells resulted in influenced biological effect.

  20. Comparison of intracellular accumulation and cytotoxicity of free mTHPC and mTHPC-loaded PLGA nanoparticles in human colon carcinoma cells

    NASA Astrophysics Data System (ADS)

    Löw, Karin; Knobloch, Thomas; Wagner, Sylvia; Wiehe, Arno; Engel, Andrea; Langer, Klaus; von Briesen, Hagen

    2011-06-01

    The second generation photosensitizer mTHPC was approved by the European Medicines Agency (EMA) for the palliative treatment of advanced head and neck cancer in October 2001. It is known that mTHPC possesses a significant phototoxicity against a variety of human cancer cells in vitro but also exhibits dark toxicity and can cause adverse effects (especially skin photosensitization). Due to its poor water solubility, the administration of hydrophobic photosensitizer still presents several difficulties. To overcome the administration problems, the use of nanoparticles as drug carrier systems is much investigated. Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) have been extensively studied as delivery systems into tumours due to their biocompatibility and biodegradability. The goal of this study was the comparison of free mTHPC and mTHPC-loaded PLGA nanoparticles concerning cytotoxicity and intracellular accumulation in human colon carcinoma cells (HT29). The nanoparticles delivered the photosensitizer to the colon carcinoma cells and enabled drug release without losing its activity. The cytotoxicity assays showed a time- and concentration-dependent decrease in cell proliferation and viability after illumination. However, first and foremost mTHPC lost its dark toxic effects using the PLGA nanoparticles as a drug carrier system. Therefore, PLGA nanoparticles are a promising drug carrier system for the hydrophobic photosensitizer mTHPC.

  1. Photocurrent enhancements of organic solar cells by altering dewetting of plasmonic Ag nanoparticles

    PubMed Central

    Fleetham, Tyler; Choi, Jea-Young; Choi, Hyung Woo; Alford, Terry; Jeong, Doo Seok; Lee, Taek Sung; Lee, Wook Seong; Lee, Kyeong-Seok; Li, Jian; Kim, Inho

    2015-01-01

    Incorporation of metal nanoparticles into active layers of organic solar cells is one of the promising light trapping approaches. The size of metal nanoparticles is one of key factors to strong light trapping, and the size of thermally evaporated metal nanoparticles can be tuned by either post heat treatment or surface modification of substrates. We deposited Ag nanoparticles on ITO by varying nominal thicknesses, and post annealing was carried out to increase their size in radius. PEDOT:PSS was employed onto the ITO substrates as a buffer layer to alter the dewetting behavior of Ag nanoparticles. The size of Ag nanoparticles on PEDOT:PSS were dramatically increased by more than three times compared to those on the ITO substrates. Organic solar cells were fabricated on the ITO and PEDOT:PSS coated ITO substrates with incorporation of those Ag nanoparticles, and their performances were compared. The photocurrents of the cells with the active layers on PEDOT:PSS with an optimal choice of the Ag nanoparticles were greatly enhanced whereas the Ag nanoparticles on the ITO substrates did not lead to the photocurrent enhancements. The origin of the photocurrent enhancements with introducing the Ag nanoparticles on PEDOT:PSS are discussed. PMID:26388104

  2. Field emission scanning electron microscopy (FE-SEM) as an approach for nanoparticle detection inside cells.

    PubMed

    Havrdova, M; Polakova, K; Skopalik, J; Vujtek, M; Mokdad, A; Homolkova, M; Tucek, J; Nebesarova, J; Zboril, R

    2014-12-01

    When developing new nanoparticles for bio-applications, it is important to fully characterize the nanoparticle's behavior in biological systems. The most common techniques employed for mapping nanoparticles inside cells include transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These techniques entail passing an electron beam through a thin specimen. STEM or TEM imaging is often used for the detection of nanoparticles inside cellular organelles. However, lengthy sample preparation is required (i.e., fixation, dehydration, drying, resin embedding, and cutting). In the present work, a new matrix (FTO glass) for biological samples was used and characterized by field emission scanning electron microscopy (FE-SEM) to generate images comparable to those obtained by TEM. Using FE-SEM, nanoparticle images were acquired inside endo/lysosomes without disruption of the cellular shape. Furthermore, the initial steps of nanoparticle incorporation into the cells were captured. In addition, the conductive FTO glass endowed the sample with high stability under the required accelerating voltage. Owing to these features of the sample, further analyses could be performed (material contrast and energy-dispersive X-ray spectroscopy (EDS)), which confirmed the presence of nanoparticles inside the cells. The results showed that FE-SEM can enable detailed characterization of nanoparticles in endosomes without the need for contrast staining or metal coating of the sample. Images showing the intracellular distribution of nanoparticles together with cellular morphology can give important information on the biocompatibility and demonstrate the potential of nanoparticle utilization in medicine. PMID:25173605

  3. Field emission scanning electron microscopy (FE-SEM) as an approach for nanoparticle detection inside cells.

    PubMed

    Havrdova, M; Polakova, K; Skopalik, J; Vujtek, M; Mokdad, A; Homolkova, M; Tucek, J; Nebesarova, J; Zboril, R

    2014-12-01

    When developing new nanoparticles for bio-applications, it is important to fully characterize the nanoparticle's behavior in biological systems. The most common techniques employed for mapping nanoparticles inside cells include transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These techniques entail passing an electron beam through a thin specimen. STEM or TEM imaging is often used for the detection of nanoparticles inside cellular organelles. However, lengthy sample preparation is required (i.e., fixation, dehydration, drying, resin embedding, and cutting). In the present work, a new matrix (FTO glass) for biological samples was used and characterized by field emission scanning electron microscopy (FE-SEM) to generate images comparable to those obtained by TEM. Using FE-SEM, nanoparticle images were acquired inside endo/lysosomes without disruption of the cellular shape. Furthermore, the initial steps of nanoparticle incorporation into the cells were captured. In addition, the conductive FTO glass endowed the sample with high stability under the required accelerating voltage. Owing to these features of the sample, further analyses could be performed (material contrast and energy-dispersive X-ray spectroscopy (EDS)), which confirmed the presence of nanoparticles inside the cells. The results showed that FE-SEM can enable detailed characterization of nanoparticles in endosomes without the need for contrast staining or metal coating of the sample. Images showing the intracellular distribution of nanoparticles together with cellular morphology can give important information on the biocompatibility and demonstrate the potential of nanoparticle utilization in medicine.

  4. Enhanced antiproliferative activity of carboplatin-loaded chitosan-alginate nanoparticles in a retinoblastoma cell line.

    PubMed

    Parveen, Suphiya; Mitra, Moutushy; Krishnakumar, S; Sahoo, Sanjeeb K

    2010-08-01

    In the present study the potential of carboplatin-loaded chitosan-alginate nanoparticles (CANPs) for the treatment of retinoblastoma was investigated. The carboplatin-loaded CANPs were approximately 300 nm in size, exhibited a high zeta potential of approximately 36 mV and drug encapsulation of approximately 20 wt.%. The CANPs were further characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry and transmission electron microscopy. In vitro release studies revealed fast release of approximately 25% of the drug during the first 24h, followed by sustained release. CANPs demonstrated greater and sustained antiproliferative activity of the drug in a dose- and time-dependent manner (carboplatin IC(50)=0.56 microg ml(-1), carboplatin-loaded CANPs IC(50)=0.004 microg ml(-1)), as well as an enhanced apoptotic effect as compared with the drug in solution in a retinoblastoma cell line (Y79). The higher cytotoxic effect of CANPs may be due to their greater cellular uptake as compared with native carboplatin. It was also demonstrated that clathrin-mediated endocytosis plays a key role in the internalization of CANPs in the Y79 cell line. In conclusion, biodegradable chitosan nanoparticles could be used as an effective ocular drug delivery system for sustained intracellular delivery of carboplatin for the treatment of retinoblastoma. PMID:20149903

  5. Signet ring cell tumor of the minor salivary gland exhibiting benign behavior.

    PubMed

    Foschini, Maria P; Baldovini, Chiara; Pennesi, Maria G; Cocchi, Roberto; Simpson, Roderick H W

    2012-02-01

    Signet ring cell (SRC) carcinomas are usually aggressive malignancies, arising most frequently in the stomach and gastrointestinal tract, but also, although less often, in other organs such as the breast, bladder, and lungs. They are particularly unusual in the salivary glands, and the aim of the present study is to report a case of a tumor of the minor salivary glands of the lower lip composed largely of SRCs but which displayed benign clinical behavior.

  6. Müller cell GFAP expression exhibits gradient from focus of photoreceptor light damage.

    PubMed

    Burns, M S; Robles, M

    1990-05-01

    High intensity (ca. 150 foot-candles), cumulative fluorescent light exposure regimes of 40 or 60 minutes to pigmented Long Evans rats were sufficient to elicit glial fibrillary acidic protein immunoreactivity (GFAP-IR) in Müller cells, when the animals are sacrificed 7 days post-exposure. Exposure to only 20 minutes of cumulative light or sacrifice immediately after exposure was not sufficient to initiate GFAP-IR in Müller cells. A gradient of GFAP-IR was observed extending from an approximately circular focus superior to the optic disc to the peripheral retina, whether or not there was morphological damage to the photoreceptors observable at the light microscopic level. Photoreceptor lesions produced by laser photocoagulation elicited the same gradient of GFAP-IR, and showed that GFAP-IR was not a reflection of a central to peripheral gradient of light received by the retina. Excessive light exposure initiated a signal which induced GFAP expression in Müller cells. This signal appeared to require a dark period and may be a diffusible factor that moves through extracellular pathways. PMID:2200639

  7. Viola tricolor Induces Apoptosis in Cancer Cells and Exhibits Antiangiogenic Activity on Chicken Chorioallantoic Membrane

    PubMed Central

    Sadeghnia, Hamid Reza; Ghorbani Hesari, Taghi; Mortazavian, Seyed Mohsen; Mousavi, Seyed Hadi; Tayarani-Najaran, Zahra

    2014-01-01

    In the present study, the cytotoxic and apoptogenic properties of hydroalcoholic extract and ethyl acetate (EtOAc), n-butanol, and water fractions (0–800 μg/mL) of Viola tricolor were investigated in Neuro2a mouse neuroblastoma and MCF-7 human breast cancer cells. In addition, antiangiogenic effect of EtOAc fraction was evaluated on chicken chorioallantoic membrane (CAM). The quality of EtOAc fraction was also characterized using high performance liquid chromatography (HPLC) fingerprint. Cytotoxicity assay revealed that EtOAc fraction was the most potent among all fractions with maximal effect on MCF-7 and minimal toxicity against normal murine fibroblast L929 cells. Apoptosis induction by EtOAc fraction was confirmed by increased sub-G1 peak of propidium iodide (PI) stained cells. This fraction triggered the apoptotic pathway by increased Bax/Bcl-2 ratio and cleaved caspase-3 level. Moreover, treatment with EtOAc fraction significantly decreased the diameter of vessels on CAM, while the number of newly formed blood vessels was not suppressed significantly. Analysis of quality of EtOAc fraction using HPLC fingerprint showed six major peaks with different retention times. The results of the present study suggest that V. tricolor has potential anticancer property by inducing apoptosis and inhibiting angiogenesis. PMID:25243166

  8. Viola tricolor induces apoptosis in cancer cells and exhibits antiangiogenic activity on chicken chorioallantoic membrane.

    PubMed

    Sadeghnia, Hamid Reza; Ghorbani Hesari, Taghi; Mortazavian, Seyed Mohsen; Mousavi, Seyed Hadi; Tayarani-Najaran, Zahra; Ghorbani, Ahmad

    2014-01-01

    In the present study, the cytotoxic and apoptogenic properties of hydroalcoholic extract and ethyl acetate (EtOAc), n-butanol, and water fractions (0-800 μg/mL) of Viola tricolor were investigated in Neuro2a mouse neuroblastoma and MCF-7 human breast cancer cells. In addition, antiangiogenic effect of EtOAc fraction was evaluated on chicken chorioallantoic membrane (CAM). The quality of EtOAc fraction was also characterized using high performance liquid chromatography (HPLC) fingerprint. Cytotoxicity assay revealed that EtOAc fraction was the most potent among all fractions with maximal effect on MCF-7 and minimal toxicity against normal murine fibroblast L929 cells. Apoptosis induction by EtOAc fraction was confirmed by increased sub-G1 peak of propidium iodide (PI) stained cells. This fraction triggered the apoptotic pathway by increased Bax/Bcl-2 ratio and cleaved caspase-3 level. Moreover, treatment with EtOAc fraction significantly decreased the diameter of vessels on CAM, while the number of newly formed blood vessels was not suppressed significantly. Analysis of quality of EtOAc fraction using HPLC fingerprint showed six major peaks with different retention times. The results of the present study suggest that V. tricolor has potential anticancer property by inducing apoptosis and inhibiting angiogenesis.

  9. VMP1-deficient Chlamydomonas exhibits severely aberrant cell morphology and disrupted cytokinesis

    PubMed Central

    2014-01-01

    Background The versatile Vacuole Membrane Protein 1 (VMP1) has been previously investigated in six species. It has been shown to be essential in macroautophagy, where it takes part in autophagy initiation. In addition, VMP1 has been implicated in organellar biogenesis; endo-, exo- and phagocytosis, and protein secretion; apoptosis; and cell adhesion. These roles underly its proven involvement in pancreatitis, diabetes and cancer in humans. Results In this study we analyzed a VMP1 homologue from the green alga Chlamydomonas reinhardtii. CrVMP1 knockdown lines showed severe phenotypes, mainly affecting cell division as well as the morphology of cells and organelles. We also provide several pieces of evidence for its involvement in macroautophagy. Conclusion Our study adds a novel role to VMP1's repertoire, namely the regulation of cytokinesis. Though the directness of the observed effects and the mechanisms underlying them remain to be defined, the protein's involvement in macroautophagy in Chlamydomonas, as found by us, suggests that CrVMP1 shares molecular characteristics with its animal and protist counterparts. PMID:24885763

  10. Toxicity of silver nanoparticles in mouse embryonic stem cells and chemical based reprogramming of somatic cells to sphere cells

    NASA Astrophysics Data System (ADS)

    Rajanahalli Krishnamurthy, Pavan

    Abstract 1: Silver nanoparticles (Ag Np's) have an interesting surface chemistry and unique plasmonic properties. They are used in a wide variety of applications ranging from consumer products like socks, medical dressing, computer chips and it is also shown to have antimicrobial, anti bacterial activity and wound healing. Ag Np toxicity studies have been limited to date which needs to be critically addressed due to its wide applications. Mouse embryonic stem (MES) cells represent a unique cell population with the ability to undergo both self renewal and differentiation. They exhibit very stringent and tightly regulated mechanisms to circumvent DNA damage and stress response. We used 10 nm coated (polysaccharide) and uncoated Ag Np's to test its toxic effects on MES cells. MES cells and embryoid bodies (EB's) were treated with two concentrations of Ag Np's: 5 microg/ml and 50 ug/ml and exposed for 24, 48 and 72 hours. Increased cell death, ROS production and loss of mitochondrial membrane potential and alkaline phosphatase (AP) occur in a time and a concentration dependant manner. Due to increased cell death, there is a progressive increase in Annexin V (apoptosis) and Propidium Iodide (PI) staining (necrosis). Oct4 and Nanog undergo ubiquitination and dephosphorylation post-translational modifications in MES cells thereby altering gene expression of pluripotency factors and differentiation of EB's into all the three embryonic germ layers with specific growth factors were also inhibited after Ag Np exposure. Flow cytometry analysis revealed Ag Np's treated cells had altered cell cycle phases correlating with altered self renewal capacity. Our results suggest that Ag Np's effect MES cell self renewal, pluripotency and differentiation and serves as a perfect model system for studying toxicity induced by engineered Ag Np's. Abstract 2: The reprogramming of fibroblasts to pluripotent stem cells and the direct conversion of fibroblasts to functional neurons has been

  11. Interaction of multi-functional silver nanoparticles with living cells

    NASA Astrophysics Data System (ADS)

    Sur, Ilknur; Cam, Dilek; Kahraman, Mehmet; Baysal, Asli; Culha, Mustafa

    2010-04-01

    Silver nanoparticles (AgNPs) are widely used in household products and in medicine due to their antibacterial and to wound healing properties. In recent years, there is also an effort for their use in biomedical imaging and photothermal therapy. The primary reason behind the effort for their utility in biomedicine and therapy is their unique plasmonic properties and easy surface chemistry for a variety of functionalizations. In this study, AgNPs modified with glucose, lactose, oligonucleotides and combinations of these ligands are investigated for their cytotoxicity and cellular uptake in living non-cancer (L929) and cancer (A549) cells. It is found that the chemical nature of the ligand strongly influences the toxicity and cellular uptake into the model cells. While the lactose-and glucose-modified AgNPs enter the L929 cells at about the same rate, a significant increase in the rate of lactose-modified AgNPs into the A549 cells is observed. The binding of oligonucleotides along with the carbohydrate on the AgNP surfaces influences the differential uptake rate pattern into the cells. The cytotoxicity study with the modified AgNPs reveals that only naked AgNPs influence the viability of the A549 cells. The findings of this study may provide the key to developing effective applications in medicine such as cancer therapy.

  12. Functionalization of whole‐cell bacterial reporters with magnetic nanoparticles

    PubMed Central

    Zhang, Dayi; Fakhrullin, Rawil F.; Özmen, Mustafa; Wang, Hui; Wang, Jian; Paunov, Vesselin N.; Li, Guanghe; Huang, Wei E.

    2011-01-01

    Summary We developed a biocompatible and highly efficient approach for functionalization of bacterial cell wall with magnetic nanoparticles (MNPs). Three Acinetobacter baylyi ADP1 chromosomally based bioreporters, which were genetically engineered to express bioluminescence in response to salicylate, toluene/xylene and alkanes, were functionalized with 18 ± 3 nm iron oxide MNPs to acquire magnetic function. The efficiency of MNPs functionalization of Acinetobacter bioreporters was 99.96 ± 0.01%. The MNPs‐functionalized bioreporters (MFBs) can be remotely controlled and collected by an external magnetic field. The MFBs were all viable and functional as good as the native cells in terms of sensitivity, specificity and quantitative response. More importantly, we demonstrated that salicylate sensing MFBs can be applied to sediments and garden soils, and semi‐quantitatively detect salicylate in those samples by discriminably recovering MFBs with a permanent magnet. The magnetically functionalized cells are especially useful to complex environments in which the indigenous cells, particles and impurities may interfere with direct measurement of bioreporter cells and conventional filtration is not applicable to distinguish and harvest bioreporters. The approach described here provides a powerful tool to remotely control and selectively manipulate MNPs‐functionalized cells in water and soils. It would have a potential in the application of environmental microbiology, such as bioremediation enhancement and environment monitoring and assessment. PMID:21255376

  13. Engineered Upconversion Nanoparticles for Resolving Protein Interactions inside Living Cells.

    PubMed

    Drees, Christoph; Raj, Athira Naduviledathu; Kurre, Rainer; Busch, Karin B; Haase, Markus; Piehler, Jacob

    2016-09-12

    Upconversion nanoparticles (UCNPs) convert near-infrared into visible light at much lower excitation densities than those used in classic two-photon absorption microscopy. Here, we engineered <50 nm UCNPs for application as efficient lanthanide resonance energy transfer (LRET) donors inside living cells. By optimizing the dopant concentrations and the core-shell structure for higher excitation densities, we observed enhanced UCNP emission as well as strongly increased sensitized acceptor fluorescence. For the application of these UCNPs in complex biological environments, we developed a biocompatible surface coating functionalized with a nanobody recognizing green fluorescent protein (GFP). Thus, rapid and specific targeting to GFP-tagged fusion proteins in the mitochondrial outer membrane and detection of protein interactions by LRET in living cells was achieved. PMID:27510808

  14. Engineered Upconversion Nanoparticles for Resolving Protein Interactions inside Living Cells.

    PubMed

    Drees, Christoph; Raj, Athira Naduviledathu; Kurre, Rainer; Busch, Karin B; Haase, Markus; Piehler, Jacob

    2016-09-12

    Upconversion nanoparticles (UCNPs) convert near-infrared into visible light at much lower excitation densities than those used in classic two-photon absorption microscopy. Here, we engineered <50 nm UCNPs for application as efficient lanthanide resonance energy transfer (LRET) donors inside living cells. By optimizing the dopant concentrations and the core-shell structure for higher excitation densities, we observed enhanced UCNP emission as well as strongly increased sensitized acceptor fluorescence. For the application of these UCNPs in complex biological environments, we developed a biocompatible surface coating functionalized with a nanobody recognizing green fluorescent protein (GFP). Thus, rapid and specific targeting to GFP-tagged fusion proteins in the mitochondrial outer membrane and detection of protein interactions by LRET in living cells was achieved.

  15. Anticancer studies of the synthesized gold nanoparticles against MCF 7 breast cancer cell lines

    NASA Astrophysics Data System (ADS)

    Kamala Priya, M. R.; Iyer, Priya R.

    2015-04-01

    It has been previously stated that gold nanoparticles have been successfully synthesized using various green extracts of plants. The synthesized gold nanoparticles were characterized under scanning electron microscopy and EDX to identify the size of the nanoparticles. It was found that the nanoparticles were around 30 nm in size, which is a commendable nano dimension achieved through a plant mediated synthesis. The nanoparticles were further studied for their various applications. In the current study, we have made attempts to exploit the anticancer ability of the gold nano particles. The nanoparticles were studied against MCF 7 breast cancer cell lines. The results obtained from the studies of anticancer activity showed that gold nanoparticles gave an equivalent good results, in par with the standard drugs against cancer. The AuNP's proved to be efficient even from the minimum concentrations of 2 μg/ml, and as the concentration increased the anticancer efficacy as well increased.

  16. Anticancer studies of the synthesized gold nanoparticles against MCF 7 breast cancer cell lines

    NASA Astrophysics Data System (ADS)

    Kamala Priya, M. R.; Iyer, Priya R.

    2014-09-01

    It has been previously stated that gold nanoparticles have been successfully synthesized using various green extracts of plants. The synthesized gold nanoparticles were characterized under scanning electron microscopy and EDX to identify the size of the nanoparticles. It was found that the nanoparticles were around 30 nm in size, which is a commendable nano dimension achieved through a plant mediated synthesis. The nanoparticles were further studied for their various applications. In the current study, we have made attempts to exploit the anticancer ability of the gold nano particles. The nanoparticles were studied against MCF 7 breast cancer cell lines. The results obtained from the studies of anticancer activity showed that gold nanoparticles gave an equivalent good results, in par with the standard drugs against cancer. The AuNP's proved to be efficient even from the minimum concentrations of 2 μg/ml, and as the concentration increased the anticancer efficacy as well increased.

  17. Mesenchymal stromal cells derived from acute myeloid leukemia bone marrow exhibit aberrant cytogenetics and cytokine elaboration.

    PubMed

    Huang, J C; Basu, S K; Zhao, X; Chien, S; Fang, M; Oehler, V G; Appelbaum, F R; Becker, P S

    2015-01-01

    Bone marrow-derived mesenchymal stromal cells (BM-MSCs) play a fundamental role in the BM microenvironment (BME) and abnormalities of these cells may contribute to acute myeloid leukemia (AML) pathogenesis. The aim of the study was to characterize the cytokine and gene expression profile, immunophenotype and cytogenetics of BM-MSCs from AML patients compared to normal BM-MSCs from healthy donors. AML BM-MSCs showed decreased monocyte chemoattractant protein-1 levels compared to normal BM-MSCs. AML BM-MSCs expressed similar β1 integrin, CD44, CD73, CD90 and E-cadherin compared to normal BM-MSCs. Cytogenetic analysis revealed chromosomal aberrations in AML BM-MSCs, some overlapping with and others distinct from their corresponding AML blasts. No significant difference in gene expression was detected between AML BM-MSCs compared to normal BM-MSCs; however, comparing the differences between AML and MSCs from AML patients with the differences between normal hematopoietic cells and normal MSCs by Ingenuity pathway analysis showed key distinctions of the AML setting: (1) upstream gene regulation by transforming growth factor beta 1, tumor necrosis factor, tissue transglutaminase 2, CCAAT/enhancer binding protein alpha and SWItch/Sucrose NonFermentable related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4; (2) integrin and interleukin 8 signaling as overrepresented canonical pathways; and (3) upregulation of transcription factors FBJ murine osteosarcoma viral oncogene homolog and v-myb avian myeloblastosis viral oncogene homolog. Thus, phenotypic abnormalities of AML BM-MSCs highlight a dysfunctional BME that may impact AML survival and proliferation. PMID:25860293

  18. Preparation and characterization of realgar nanoparticles and their inhibitory effect on rat glioma cells

    PubMed Central

    An, Yan-li; Nie, Fang; Wang, Zi-yu; Zhang, Dong-sheng

    2011-01-01

    Aim Our objective was to prepare a new nano-sized realgar particle and characterize its anti-tumor effect on tumor cells. Methods Nanoparticles were prepared by coprecipitation and were detected by transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometry (EDS), and dynamic light scattering. An anti-proliferative effect of realgar nanoparticles on rat glioma (C6) cells was determined by the MTT assay. Cell cycle and apoptosis rates were observed by flow cytometry. Apoptosis-related gene expression was detected by immunofluorescence staining. Results Realgar nanoparticles were successfully prepared. The particles were spherical, with an average diameter of approximately 80 nm, and contained arsenic and sulfur elements. Realgar nanoparticles inhibited C6 cell proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment of C6 cells with realgar nanoparticles significantly increased the proportions of cells in S and G2/M phases, decreased the proportion of cells in G0/G1 phase, downregulated Bcl-2 expression, and substantially upregulated Bax expression. Conclusion Realgar nanoparticles significantly inhibited C6 glioma cell proliferation and promoted cell apoptosis by inducing the upregulation of Bax and downregulation of Bcl-2 expression. Realgar nanoparticles are a promising in vitro anti-cancer strategy and may be applicable for human cancer therapy studies. PMID:22238507

  19. Dual targeted polymeric nanoparticles based on tumor endothelium and tumor cells for enhanced antitumor drug delivery.

    PubMed

    Gupta, Madhu; Chashoo, Gousia; Sharma, Parduman Raj; Saxena, Ajit Kumar; Gupta, Prem Narayan; Agrawal, Govind Prasad; Vyas, Suresh Prasad

    2014-03-01

    Some specific types of tumor cells and tumor endothelial cells represented CD13 proteins and act as receptors for Asn-Gly-Arg (NGR) motifs containing peptide. These CD13 receptors can be specifically recognized and bind through the specific sequence of cyclic NGR (cNGR) peptide and presented more affinity and specificity toward them. The cNGR peptide was conjugated to the poly(ethylene glycol) (PEG) terminal end in the poly(lactic-co-glycolic) acid PLGA-PEG block copolymer. Then, the ligand conjugated nanoparticles (cNGR-DNB-NPs) encapsulating docetaxel (DTX) were synthesized from preformed block copolymer by the emulsion/solvent evaporation method and characterized for different parameters. The various studies such as in vitro cytotoxicity, cell apoptosis, and cell cycle analysis presented the enhanced therapeutic potential of cNGR-DNB-NPs. The higher cellular uptake was also found in cNGR peptide anchored NPs into HUVEC and HT-1080 cells. However, free cNGR could inhibit receptor mediated intracellular uptake of NPs into both types of cells at 37 and 4 °C temperatures, revealing the involvement of receptor-mediated endocytosis. The in vivo biodistribution and antitumor efficacy studies indicated that targeted NPs have a higher therapeutic efficacy through targeting the tumor-specific site. Therefore, the study exhibited that cNGR-functionalized PEG-PLGA-NPs could be a promising approach for therapeutic applications to efficient antitumor drug delivery.

  20. A novel innexin2 forming membrane hemichannel exhibits immune responses and cell apoptosis in Scylla paramamosain.

    PubMed

    Wang, Shu-Ping; Chen, Fang-Yi; Dong, Li-Xia; Zhang, Ya-Qun; Chen, Hui-Yun; Qiao, Kun; Wang, Ke-Jian

    2015-11-01

    Innexins are a class of transmembrane proteins that are important for embryonic development, morphogenesis and electrical synapse formation. In the present study, a novel innexin2 gene from Scylla paramamosain was named Sp-inx2 and characterized. The complete cDNA and genomic DNA sequences of Sp-inx2 were revealed. Sp-inx2 mRNA transcripts were distributed in various tissues of S. paramamosain and were most abundant in the hemocytes. The Sp-inx2 was significantly upregulated in hemocyte, gill and hepatopancreas tissues with the challenge of either Vibrio alginolyticus, Vibrio parahaemolyticus or lipopolysaccharides (LPSs) when analyzed at 3 and 6 h using quantitative real-time PCR, suggesting that it could activate an immune response against the challenge of LPSs or Vibrio species. Using the chemical inhibitors carbenoxolone and probenecid, the absorption of the fluorescent dye Lucifer yellow decreased in the primary cultured hemocytes of crabs, thus confirming that hemichannels composed of Sp-inx2 existed in the crab hemocytes. With LPS stimulation, the level of mRNA transcripts and protein expression of Sp-inx2 in the same cultured hemocytes gradually increased from 6 to 48 h, while the activity of hemichannels was down-regulated at 6 and 12 h, demonstrating that LPSs could modulate the absorption activity of hemichannels in addition to its upregulation of Sp-inx2 gene expression. Furthermore, the dye uptake rate in HeLa cells in which Sp-inx2 was ectopically expressed increased dramatically but the increase was significantly down-regulated with the addition of 50 μg mL(-1) LPS, suggesting that the LPS stimulation could effectively reduce the activity of hemichannels. Interestingly, with the ectopic expression of Sp-inx2 in HeLa and EPC cells, apoptosis spontaneously occurred in both cultured cell lines when detected using TUNEL assay. In summary, a new Sp-inx2 gene was first characterized in a marine animal S. paramamosain and it had a function associated with

  1. Use of titanium dioxide nanoparticles biosynthesized by Bacillus mycoides in quantum dot sensitized solar cells

    PubMed Central

    2014-01-01

    Background One of the major challenges of nanotechnology during the last decade has been the development of new procedures to synthesize nanoparticles. In this context, biosynthetic methods have taken hold since they are simple, safe and eco-friendly. Results In this study, we report the biosynthesis of TiO2 nanoparticles by an environmental isolate of Bacillus mycoides, a poorly described Gram-positive bacterium able to form colonies with novel morphologies. This isolate was able to produce TiO2 nanoparticles at 37°C in the presence of titanyl hydroxide. Biosynthesized nanoparticles have anatase polymorphic structure, spherical morphology, polydisperse size (40–60 nm) and an organic shell as determined by UV–vis spectroscopy, TEM, DLS and FTIR, respectively. Also, conversely to chemically produced nanoparticles, biosynthesized TiO2 do not display phototoxicity. In order to design less expensive and greener solar cells, biosynthesized nanoparticles were evaluated in Quantum Dot Sensitized Solar Cells (QDSSCs) and compared with chemically produced TiO2 nanoparticles. Solar cell parameters such as short circuit current density (ISC) and open circuit voltage (VOC) revealed that biosynthesized TiO2 nanoparticles can mobilize electrons in QDSSCs similarly than chemically produced TiO2. Conclusions Our results indicate that bacterial extracellular production of TiO2 nanoparticles at low temperatures represents a novel alternative for the construction of green solar cells. PMID:25027643

  2. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles

    PubMed Central

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-01-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c+, CD141+ and CD16+ myeloid DCs and CD123+ plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141+ DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  3. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles.

    PubMed

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-06-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c(+) , CD141(+) and CD16(+) myeloid DCs and CD123(+) plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141(+) DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  4. Chitosan-coated triangular silver nanoparticles as a novel class of biocompatible, highly effective photothermal transducers for in vitro cancer cell therapy.

    PubMed

    Boca, Sanda C; Potara, Monica; Gabudean, Ana-Maria; Juhem, Aurelie; Baldeck, Patrice L; Astilean, Simion

    2011-12-01

    One of the relevant directions that nanotechnology is taking nowadays is connected with nanomedicine and specifically related to the use of light and nanoparticles in early diagnosis and effective therapeutics of cancer. Noble-metal nanoparticles can act under laser irradiation as effective photothermal transducers for triggering localized hyperthermia of tumors. In this work we report the performance of newly synthesized chitosan-coated silver nanotriangles (Chit-AgNTs) with strong resonances in near-infrared (NIR) to operate as photothermal agents against a line of human non-small lung cancer cells (NCI-H460). The hyperthermia experiments were conducted by excitation of nanoparticles-loaded cells at 800 nm wavelength from a Ti:Sapphire laser. We found that the rate of cell mortality in the presence of Chit-AgNTs is higher than in the presence of thiolated poly(ethylene) glycol capped gold nanorods (PEG-AuNRs) - a common hyperthermia agent used as reference-, while no destructive effects were noticed on the control sample (cells without nanoparticles) under identical irradiation conditions. Additionally, we conducted cytotoxicity assays and found Chit-AgNTs to be efficiently uptaken by the cells while exhibiting good biocompatibility for healthy human embryonic cells (HEK), which is essential for any in vivo applications. Our results reveal a novel class of biocompatible plasmonic nanoparticles with high potential to be implemented as effective phototherapeutic agents in the battle against cancer.

  5. Specific biomolecule corona is associated with ring-shaped organization of silver nanoparticles in cells

    NASA Astrophysics Data System (ADS)

    Drescher, Daniela; Guttmann, Peter; Büchner, Tina; Werner, Stephan; Laube, Gregor; Hornemann, Andrea; Tarek, Basel; Schneider, Gerd; Kneipp, Janina

    2013-09-01

    We correlate the localization of silver nanoparticles inside cells with respect to the cellular architecture with the molecular information in the vicinity of the particle surface by combining nanoscale 3D cryo-soft X-ray tomography (cryo-SXT) with surface-enhanced Raman scattering (SERS). The interaction of the silver nanoparticle surface with small molecules and biopolymers was monitored by SERS in vitro over time in living cells. The spectra indicate a stable, time-independent surface composition of silver nanoparticles, despite the changing environment in the endosomal structure. Cryo-SXT reveals a characteristic ring-shaped organization of the silver nanoparticles in endosomes of different cell types. The ring-like structures inside the endosomes suggest a strong association among silver particles and with membrane structures. The comparison of the data with those obtained with gold nanoparticles suggests that the interactions between the nanoparticles and with the endosomal component are influenced by the molecular composition of the corona.We correlate the localization of silver nanoparticles inside cells with respect to the cellular architecture with the molecular information in the vicinity of the particle surface by combining nanoscale 3D cryo-soft X-ray tomography (cryo-SXT) with surface-enhanced Raman scattering (SERS). The interaction of the silver nanoparticle surface with small molecules and biopolymers was monitored by SERS in vitro over time in living cells. The spectra indicate a stable, time-independent surface composition of silver nanoparticles, despite the changing environment in the endosomal structure. Cryo-SXT reveals a characteristic ring-shaped organization of the silver nanoparticles in endosomes of different cell types. The ring-like structures inside the endosomes suggest a strong association among silver particles and with membrane structures. The comparison of the data with those obtained with gold nanoparticles suggests that the

  6. Single-phased luminescent mesoporous nanoparticles for simultaneous cell imaging and anticancer drug delivery.

    PubMed

    Di, Weihua; Ren, Xinguang; Zhao, Haifeng; Shirahata, Naoto; Sakka, Yoshio; Qin, Weiping

    2011-10-01

    Multifunctional materials for biological use have mostly been designed with composite or hybrid nanostructures in which two or more components are incorporated. The present work reports on a multifunctional biomaterial based on single-phased luminescent mesoporous lanthanide oxide nanoparticles that combine simultaneous drug delivery and cell imaging. A simple strategy based on solid-state-chemistry thermal decomposition process was employed to fabricate the spherical mesoporous Gd(2)O(3):Eu nanoparticles with homogeneous size distribution. The porous nanoparticles developed by this strategy possess well-defined mesopores, large pore size and volume, and high specific surface area. The mesoporous features of nanoparticles impart the material with capabilities of loading and releasing the drug with a relatively high loading efficiency and a sustained release behavior of drugs. The DOX-loaded porous Gd(2)O(3) nanoparticles are able to kill the cancer cells efficiently upon incubation with the human cervical carcinoma (HeLa) cells, indicating the potential for treatment of cancer cells. Meanwhile, the intrinsic luminescence of Gd(2)O(3):Eu nanoparticles gives the function of optical imaging. Therefore, the drug release activity and effect of drugs on the cells can be effectively monitored via luminescence of nanoparticles themselves, realizing multifunctionality of simultaneous cell imaging and anticancer drug delivery in a single-phased nanoparticle.

  7. ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation.

    PubMed

    Hsueh, Yi-Huang; Ke, Wan-Ju; Hsieh, Chien-Te; Lin, Kuen-Song; Tzou, Dong-Ying; Chiang, Chao-Lung

    2015-01-01

    Zinc oxide nanoparticles (ZnO NPs) are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm), with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5-10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles.

  8. ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation.

    PubMed

    Hsueh, Yi-Huang; Ke, Wan-Ju; Hsieh, Chien-Te; Lin, Kuen-Song; Tzou, Dong-Ying; Chiang, Chao-Lung

    2015-01-01

    Zinc oxide nanoparticles (ZnO NPs) are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm), with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5-10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles. PMID:26039692

  9. ZnO Nanoparticles Affect Bacillus subtilis Cell Growth and Biofilm Formation

    PubMed Central

    Hsueh, Yi-Huang; Ke, Wan-Ju; Hsieh, Chien-Te; Lin, Kuen-Song; Tzou, Dong-Ying; Chiang, Chao-Lung

    2015-01-01

    Zinc oxide nanoparticles (ZnO NPs) are an important antimicrobial additive in many industrial applications. However, mass-produced ZnO NPs are ultimately disposed of in the environment, which can threaten soil-dwelling microorganisms that play important roles in biodegradation, nutrient recycling, plant protection, and ecological balance. This study sought to understand how ZnO NPs affect Bacillus subtilis, a plant-beneficial bacterium ubiquitously found in soil. The impact of ZnO NPs on B. subtilis growth, FtsZ ring formation, cytosolic protein activity, and biofilm formation were assessed, and our results show that B. subtilis growth is inhibited by high concentrations of ZnO NPs (≥ 50 ppm), with cells exhibiting a prolonged lag phase and delayed medial FtsZ ring formation. RedoxSensor and Phag-GFP fluorescence data further show that at ZnO-NP concentrations above 50 ppm, B. subtilis reductase activity, membrane stability, and protein expression all decrease. SDS-PAGE Stains-All staining results and FT-IR data further demonstrate that ZnO NPs negatively affect exopolysaccharide production. Moreover, it was found that B. subtilis biofilm surface structures became smooth under ZnO-NP concentrations of only 5–10 ppm, with concentrations ≤ 25 ppm significantly reducing biofilm formation activity. XANES and EXAFS spectra analysis further confirmed the presence of ZnO in co-cultured B. subtilis cells, which suggests penetration of cell membranes by either ZnO NPs or toxic Zn+ ions from ionized ZnO NPs, the latter of which may be deionized to ZnO within bacterial cells. Together, these results demonstrate that ZnO NPs can affect B. subtilis viability through the inhibition of cell growth, cytosolic protein expression, and biofilm formation, and suggest that future ZnO-NP waste management strategies would do well to mitigate the potential environmental impact engendered by the disposal of these nanoparticles. PMID:26039692

  10. Active targeting of cancer cells using folic acid-conjugated platinum nanoparticles

    NASA Astrophysics Data System (ADS)

    Teow, Yiwei; Valiyaveettil, Suresh

    2010-12-01

    Interaction of nanoparticles with human cells is an interesting topic for understanding toxicity and developing potential drug candidates. Water soluble platinum nanoparticles were synthesized viareduction of hexachloroplatinic acid using sodium borohydride in the presence of capping agents. The bioactivity of folic acid and poly(vinyl pyrrolidone) capped platinum nanoparticles (Pt-nps) has been investigated using commercially available cell lines. In the cell viability experiments, PVP-capped nanoparticles were found to be less toxic (>80% viability), whereas, folic acid-capped platinum nanoparticles showed a reduced viability down to 24% after 72 h of exposure at a concentration of 100 μg ml-1 for MCF7 breast cancer cells. Such toxicity, combined with the possibility to incorporate functional organic molecules as capping agents, can be used for developing new drug candidates.

  11. Active targeting of cancer cells using folic acid-conjugated platinum nanoparticles.

    PubMed

    Teow, Yiwei; Valiyaveettil, Suresh

    2010-12-01

    Interaction of nanoparticles with human cells is an interesting topic for understanding toxicity and developing potential drug candidates. Water soluble platinum nanoparticles were synthesized via reduction of hexachloroplatinic acid using sodium borohydride in the presence of capping agents. The bioactivity of folic acid and poly(vinyl pyrrolidone) capped platinum nanoparticles (Pt-nps) has been investigated using commercially available cell lines. In the cell viability experiments, PVP-capped nanoparticles were found to be less toxic (>80% viability), whereas, folic acid-capped platinum nanoparticles showed a reduced viability down to 24% after 72 h of exposure at a concentration of 100 μg ml(-1) for MCF7 breast cancer cells. Such toxicity, combined with the possibility to incorporate functional organic molecules as capping agents, can be used for developing new drug candidates.

  12. Orthopaedic applications of nanoparticle-based stem cell therapies

    PubMed Central

    2012-01-01

    Stem cells have tremendous applications in the field of regenerative medicine and tissue engineering. These are pioneering fields that aim to create new treatments for disease that currently have limited therapies or cures. A particularly popular avenue of research has been the regeneration of bone and cartilage to combat various orthopaedic diseases. Magnetic nanoparticles (MNPs) have been applied to aid the development and translation of these therapies from research to the clinic. This review highlights contemporary research for the applications of iron-oxide-based MNPs for the therapeutic implementation of stem cells in orthopaedics. These MNPs comprise of an iron oxide core, coated with a choice of biological polymers that can facilitate the uptake of MNPs by cells through improving endocytic activity. The combined use of these oxides and the biological polymer coatings meet biological requirements, effectively encouraging the use of MNPs in regenerative medicine. The association of MNPs with stem cells can be achieved via the process of endocytosis resulting in the internalisation of these particles or the attachment to cell surface receptors. This allows for the investigation of migratory patterns through various tracking studies, the targeting of particle-labelled cells to desired locations via the application of an external magnetic field and, finally, for activation stem cells to initiate various cellular responses to induce the differentiation. Characterisation of cell localisation and associated tissue regeneration can therefore be enhanced, particularly for in vivo applications. MNPs have been shown to have the potential to stimulate differentiation of stem cells for orthopaedic applications, without limiting proliferation. However, careful consideration of the use of active agents associated with the MNP is suggested, for differentiation towards specific lineages. This review aims to broaden the knowledge of current applications, paving the way to

  13. Manganese-impregnated mesoporous silica nanoparticles for signal enhancement in MRI cell labelling studies

    NASA Astrophysics Data System (ADS)

    Guillet-Nicolas, Rémy; Laprise-Pelletier, Myriam; Nair, Mahesh M.; Chevallier, Pascale; Lagueux, Jean; Gossuin, Yves; Laurent, Sophie; Kleitz, Freddy; Fortin, Marc-André

    2013-11-01

    Mesoporous silica nanoparticles (MSNs) are used in drug delivery and cell tracking applications. As Mn2+ is already implemented as a ``positive'' cell contrast agent in preclinical imaging procedures (in the form of MnCl2 for neurological studies), the introduction of Mn in the porous network of MSNs would allow labelling cells and tracking them using MRI. These particles are in general internalized in endosomes, an acidic environment with high saline concentration. In addition, the available MSN porosity could also serve as a carrier to deliver medical/therapeutic substances through the labelled cells. In the present study, manganese oxide was introduced in the porous network of MCM-48 silica nanoparticles (Mn-M48SNs). The particles exhibit a narrow size distribution (~140 nm diam.) and high porosity (~60% vol.), which was validated after insertion of Mn. The resulting Mn-M48SNs were characterized by TEM, N2 physisorption, and XRD. Evidence was found with H2-TPR, and XPS characterization, that Mn(ii) is the main oxidation state of the paramagnetic species after suspension in water, most probably in the form of Mn-OOH. The colloidal stability as a function of time was confirmed by DLS in water, acetate buffer and cell culture medium. In NMR data, no significant evidence of Mn2+ leaching was found in Mn-M48SNs in acidic water (pH 6), up to 96 hours after suspension. High longitudinal relaxivity values of r1 = 8.4 mM-1 s-1 were measured at 60 MHz and 37 °C, with the lowest relaxometric ratios (r2/r1 = 2) reported to date for a Mn-MSN system. Leukaemia cells (P388) were labelled with Mn-M48SNs and nanoparticle cell internalization was confirmed by TEM. Finally, MRI contrast enhancement provided by cell labelling with escalated incubation concentrations of Mn-M48SNs was quantified at 1 T. This study confirmed the possibility of efficiently confining Mn into M48SNs using incipient wetness, while maintaining an open porosity and relatively high pore volume. Because

  14. Engineered metal nanoparticles in the sub-nanomolar levels kill cancer cells

    PubMed Central

    Vodyanoy, Vitaly; Daniels, Yasmine; Pustovyy, Oleg; MacCrehan, William A; Muramoto, Shin; Stan, Gheorghe

    2016-01-01

    Background Small metal nanoparticles obtained from animal blood were observed to be toxic to cultured cancer cells, whereas noncancerous cells were much less affected. In this work, engineered zinc and copper metal nanoparticles were produced from bulk metal rods by an underwater high-voltage discharge method. The metal nanoparticles were characterized by atomic force microscopy and X-ray photoelectron spectroscopy. The metal nanoparticles, with estimated diameters of 1 nm–2 nm, were determined to be more than 85% nonoxidized. A cell viability assay and high-resolution light microscopy showed that exposure of RG2, cultured rat brain glioma cancer cells, to the zinc and copper nanoparticles resulted in cell morphological changes, including decreased cell adherence, shrinking/rounding, nuclear condensation, and budding from cell bodies. The metal-induced cell injuries were similar to the effects of staurosporine, an active apoptotic reagent. The viability experiments conducted for zinc and copper yielded values of dissociation constants of 0.22±0.08 nmol/L (standard error [SE]) and 0.12±0.02 nmol/L (SE), respectively. The noncancerous astrocytes were not affected at the same conditions. Because metal nanoparticles were lethal to the cancer cells at sub-nanomolar concentrations, they are potentially important as nanomedicine. Purpose Lethal concentrations of synthetic metal nanoparticles reported in the literature are a few orders of magnitude higher than the natural, blood-isolated metal nanoparticles; therefore, in this work, engineered metal nanoparticles were examined to mimic the properties of endogenous metal nanoparticles. Materials and methods RG2, rat brain glioma cells CTX TNA2 brain rat astrocytes, obtained from the American Type Culture Collection, high-voltage discharge, atomic force microscope, X-ray photoelectron spectroscopy, high-resolution light microscopy, zeta potential measurements, and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium

  15. Effect of surface charge of magnetite nanoparticles on their internalization into breast cancer and umbilical vein endothelial cells.

    PubMed

    Osaka, Tetsuya; Nakanishi, Takuya; Shanmugam, Sangaraju; Takahama, Shintaro; Zhang, Hong

    2009-07-01

    Internalization of magnetite nanoparticles with diameter of approximately 40 nm into normal and cancer cells was examined by microscopic observation and flow cytometry. Magnetite nanoparticles were synthesized by hydrolysis in an aqueous solution containing ferrous chloride with organic amines as a base. It was demonstrated that the difference in surface charge of magnetite nanoparticles brought about the difference in uptake efficiency. The nanoparticles with positive charge showed higher internalization into human breast cancer cells than the nanoparticles with negative charge, while the degree of internalization of the positively- and negatively-charged nanoparticles into human umbilical vein endothelial cells (HUVEC) was almost the same.

  16. Superparamagnetic iron oxide nanoparticles regulate smooth muscle cell phenotype

    PubMed Central

    Angelopoulos, Ioannis; Southern, Paul; Pankhurst, Quentin A.

    2016-01-01

    Abstract Superparamagnetic iron oxide nanoparticles (SPION) are used for an increasing range of biomedical applications, from imaging to mechanical actuation of cells and tissue. The aim of this study was to investigate the loading of smooth muscle cells (SMC) with SPION and to explore what effect this has on the phenotype of the cells. Adherent human SMC were loaded with ∼17 pg of unconjugated, negatively charged, 50 nm SPION. Clusters of the internalized SPION particles were held in discrete cytoplasmic vesicles. Internalized SPION did not cause any change in cell morphology, proliferation, metabolic activity, or staining pattern of actin and calponin, two of the muscle contractile proteins involved in force generation. However, internalized SPION inhibited the increased gene expression of actin and calponin normally observed when cells are incubated under differentiation conditions. The observed change in the control of gene expression of muscle contractile apparatus by SPION has not previously been described. This finding could offer novel approaches for regulating the phenotype of SMC and warrants further investigation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2412–2419, 2016. PMID:27176658

  17. Magnetic Carbon nanoparticles enabled efficient photothermal alteration of mammalian cells

    NASA Astrophysics Data System (ADS)

    Cardenas, Nelson; Thomas, Patrick; Yu, Lingfeng; Mohanty, Samarendra

    2011-03-01

    While cw near-infrared (NIR) laser beams have been finding widespread application in photothermal therapy of cancer and pulsed NIR laser microbeams are recently being used for optoporation of exogeneous impermeable materials into cells. Since, carbon nanomaterials are very good in photothermal conversion, we utilized carbon nanoparticles (CNP) doped with Fe, so that they can be localized in a defined area by two fold selectivity, (i) external magnetic field for retention of the CNP in targeted area and (ii) surface functionalization for binding the targeted cells. Here, we report efficient photothermal therapy as well as poration of cells using magnetic CNPs with very low power continuous wave laser beam. Localization of CNPs on cell membrane under application of magnetic field was confirmed by scanning electron microscopy. At different power levels, cells could be damaged or microinjected with fluorescence protein-encoding plasmids or impermeable dyes. Monte Carlo simulation showed that the dose of NIR laser beam is sufficient to elicit response for magnetic CNP based photothermal treatment at significant depth. The results of our study suggest that magnetic CNP based photothermal alteration is a viable approach to remotely guide treatments offering high efficiency with significantly reduced cytotoxicity.

  18. Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

    PubMed Central

    2014-01-01

    The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate. The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles. PMID:25242904

  19. Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line

    NASA Astrophysics Data System (ADS)

    Han, Jae Woong; Gurunathan, Sangiliyandi; Jeong, Jae-Kyo; Choi, Yun-Jung; Kwon, Deug-Nam; Park, Jin-Ki; Kim, Jin-Hoi

    2014-09-01

    The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate . The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.

  20. Nickel oxide nanoparticle-based method for simultaneous harvesting and disruption of microalgal cells.

    PubMed

    Huang, Wen-Can; Kim, Jong-Duk

    2016-10-01

    Microalgae biodiesel is considered one of the most promising renewable fuels. However, the high cost of the downstream process is a major barrier to large-scale microalgal lipid production. In this study, a novel approach based on nickel oxide nanoparticles (NiO NPs) was developed and its effectiveness for simultaneous harvesting and cell disruption in microalgal lipid production was determined. NiO NPs exhibited a microalgal harvesting efficiency of 98.75% in 1min at pH 7. Moreover, after treating with NiO NPs for 96h, the lipid extraction efficiency of microalgae (with 80% water content) reached 91.08% and was 208.37% compared to that without NiO treatment. This approach is simple and does not necessitate drying; furthermore, no equipment with high energy consumption was required.

  1. Nickel oxide nanoparticle-based method for simultaneous harvesting and disruption of microalgal cells.

    PubMed

    Huang, Wen-Can; Kim, Jong-Duk

    2016-10-01

    Microalgae biodiesel is considered one of the most promising renewable fuels. However, the high cost of the downstream process is a major barrier to large-scale microalgal lipid production. In this study, a novel approach based on nickel oxide nanoparticles (NiO NPs) was developed and its effectiveness for simultaneous harvesting and cell disruption in microalgal lipid production was determined. NiO NPs exhibited a microalgal harvesting efficiency of 98.75% in 1min at pH 7. Moreover, after treating with NiO NPs for 96h, the lipid extraction efficiency of microalgae (with 80% water content) reached 91.08% and was 208.37% compared to that without NiO treatment. This approach is simple and does not necessitate drying; furthermore, no equipment with high energy consumption was required. PMID:27481468

  2. Local Genome Topology Can Exhibit an Incompletely Rewired 3D-Folding State during Somatic Cell Reprogramming.

    PubMed

    Beagan, Jonathan A; Gilgenast, Thomas G; Kim, Jesi; Plona, Zachary; Norton, Heidi K; Hu, Gui; Hsu, Sarah C; Shields, Emily J; Lyu, Xiaowen; Apostolou, Effie; Hochedlinger, Konrad; Corces, Victor G; Dekker, Job; Phillips-Cremins, Jennifer E

    2016-05-01

    Pluripotent genomes are folded in a topological hierarchy that reorganizes during differentiation. The extent to which chromatin architecture is reconfigured during somatic cell reprogramming is poorly understood. Here we integrate fine-resolution architecture maps with epigenetic marks and gene expression in embryonic stem cells (ESCs), neural progenitor cells (NPCs), and NPC-derived induced pluripotent stem cells (iPSCs). We find that most pluripotency genes reconnect to target enhancers during reprogramming. Unexpectedly, some NPC interactions around pluripotency genes persist in our iPSC clone. Pluripotency genes engaged in both "fully-reprogrammed" and "persistent-NPC" interactions exhibit over/undershooting of target expression levels in iPSCs. Additionally, we identify a subset of "poorly reprogrammed" interactions that do not reconnect in iPSCs and display only partially recovered, ESC-specific CTCF occupancy. 2i/LIF can abrogate persistent-NPC interactions, recover poorly reprogrammed interactions, reinstate CTCF occupancy, and restore expression levels. Our results demonstrate that iPSC genomes can exhibit imperfectly rewired 3D-folding linked to inaccurately reprogrammed gene expression. PMID:27152443

  3. B cells from aged mice exhibit reduced apoptosis upon B-cell antigen receptor stimulation and differential ability to up-regulate survival signals.

    PubMed

    Montes, C L; Maletto, B A; Acosta Rodriguez, E V; Gruppi, A; Pistoresi-Palencia, M C

    2006-01-01

    During ageing, autoimmune disorders and the higher susceptibility to infectious have been associated with alterations in the humoral immune response. We report that splenic B lymphocytes from aged mice exhibit lower level of apoptosis induced by B-cell antigen receptor (BCR) ligation in vitro. Respect to B cells from young mice the anti-mu stimulated aged B cells show similar Bcl-2 and Bcl-xL expression but differential kinetic of A1 degradation and a higher level of cFLIP and FAIM. Even though B cells from aged mice show minor Fas expression they exhibit the same susceptibility to anti-Fas induced apoptosis. Aged B cells also present upon BCR stimulation, a higher proliferative response and similar level of activation markers expression than B cells from young mice. These data agree with the observation that aged mice exhibit an increment of T2 and mature B cell subset which rapidly enters cell cycle upon BCR engagement. The diminished apoptosis after activation in aged mice could compromise homeostatic mechanism allowing the persistence of self and non-self antigen specific B cells.

  4. Array-based sensing with nanoparticles: “Chemical noses” for sensing biomolecules and cell surfaces

    PubMed Central

    Miranda, Oscar R.; Creran, Brian; Rotello, Vincent M.

    2010-01-01

    Nanoparticle-based arrays have been used to distinguish a wide range of biomolecular targets through pattern recognition. In this report, we highlight new “chemical nose” methodologies that use nanoparticle systems to provide high sensitivity sensing of biomolecular targets, including fluorescent polymer/gold nanoparticle complexes that can discriminate between different bioanalytes including proteins, bacteria, and mammalian cells as well as dye-based micellar systems for the detection of clinically important metallo- and non-metallo proteins. PMID:20801707

  5. Preparation, characterization and toxicological investigation of copper loaded chitosan nanoparticles in human embryonic kidney HEK-293 cells.