Poly-l-lysine coating
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Background: Poly-l-lysine (PLL) enhances nanoparticle (NP) uptake, but the molecular mechanism remains unresolved. We asked whether PLL may interact with negatively charged glycoconjugates on the cell surface and facilitate uptake of magnetic NPs (MNPs) by tumor cells. Methods: PLL-coated MNPs (PLL-MNPs) with positive and negative ζ-potential were prepared and characterized. Confocal and transmission electron microscopy was used to analyze cellular internalization of MNPs. A colorimetric iron assay was used to quantitate cell-associated MNPs (MNPcell). Results: Coadministration of PLL and dextran-coated MNPs in culture enhanced cellular internalization of MNPs, with increased vesicle size and numbers/cell. MNPcell was increased by eight- to 12-fold in response to PLL in a concentration-dependent manner in human glioma and HeLa cells. However, the application of a magnetic field attenuated PLL-induced increase in MNPcell. PLL-coating increased MNPcell regardless of ζ-potential of PLL-MNPs, whereas magnetic force did not enhance MNPcell. In contrast, epigallocatechin gallate and magnetic force synergistically enhanced PLL-MNP uptake. In addition, heparin, but not sialic acid, greatly reduced the enhancement effects of PLL; however, removal of heparan sulfate from heparan sulfate proteoglycans of the cell surface by heparinase III significantly reduced MNPcell. Conclusion: Our results suggest that PLL-heparan sulfate proteoglycan interaction may be the first step mediating PLL-MNP internalization by tumor cells. Given these results, PLL may facilitate NP interaction with tumor cells via a molecular mechanism shared by infection machinery of certain viruses.
- MeSH
- buněčná membrána metabolismus MeSH
- dextrany chemie metabolismus MeSH
- endoteliální buňky pupečníkové žíly (lidské) MeSH
- gliom farmakoterapie patologie MeSH
- HeLa buňky MeSH
- heparansulfát proteoglykany chemie metabolismus MeSH
- lidé MeSH
- magnetické nanočástice aplikace a dávkování chemie MeSH
- magnetické pole MeSH
- nádorové buněčné linie MeSH
- polylysin chemie metabolismus farmakokinetika MeSH
- polysacharid-lyasy metabolismus MeSH
- transmisní elektronová mikroskopie MeSH
- železo metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Coprecipitation of FeCl2 and FeCl3 with aqueous ammonia was used to prepare iron oxide nanoparticles dispersible in aqueous medium. Oxidation of the particles with sodium hypochlorite then yielded maghemite (γ-Fe2 O3 ) nanoparticles which were coated with two types of coating -d-mannose or poly(l-lysine) (PLL) as confirmed by FTIR analysis. The particles were <10 nm according to transmission electron microscopy. Their hydrodynamic particle size was ∼180 nm (by dynamic light scattering). The d-mannose-, PLL-coated, and neat γ-Fe2 O3 particles as well as commercial Resovist® were used to label rat macrophages. The viability and contrast properties of labeled macrophages were compared. PLL-coated γ-Fe2 O3 nanoparticles were found optimal. The labeled macrophages were injected to rats monitored in vivo by magnetic resonance imaging up to 48 h. Transport of macrophages labeled with PLL-γ-Fe2 O3 nanoparticles in rats was confirmed. Tracking of macrophages using the developed particles can be used for monitoring of inflammations and cell migration in cell therapy.
- MeSH
- buněčný tracking metody MeSH
- kontrastní látky * chemie farmakologie MeSH
- krysa rodu rattus MeSH
- magnetická rezonanční tomografie metody MeSH
- makrofágy radiografie MeSH
- nanočástice chemie MeSH
- polylysin * chemie farmakologie MeSH
- velikost částic MeSH
- železité sloučeniny * chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
New surface-modified iron oxide nanoparticles were developed by precipitation of Fe(II) and Fe(III) salts with ammonium hydroxide and oxidation of the resulting magnetite with sodium hypochlorite, followed by the addition of poly( L-lysine) (PLL) solution. PLL of several molecular weights ranging from 146 ( L-lysine) to 579 000 was tested as a coating to boost the intracellular uptake of the nanoparticles. The nanoparticles were characterized by TEM, dynamic light scattering, FTIR, and ultrasonic spectrometry. TEM revealed that the particles were ca. 6 nm in diameter, while FTIR showed that their surfaces were well-coated with PLL. The interaction of PLL-modified iron oxide nanoparticles with DMEM culture medium was verified by UV-vis spectroscopy. Rat bone marrow stromal cells (rMSCs) and human mesenchymal stem cells (hMSC) were labeled with PLL-modified iron oxide nanoparticles or with Endorem (control). Optical microscopy and TEM confirmed the presence of PLL-modified iron oxide nanoparticles inside the cells. Cellular uptake was very high (more than 92%) for PLL-modified nanoparticles that were coated with PLL (molecular weight 388 00) at a concentration of 0.02 mg PLL per milliliter of colloid. The cellular uptake of PLL-modified iron oxide was facilitated by its interaction with the negatively charged cell surface and subsequent endosomolytic uptake. The relaxivity of rMSCs labeled with PLL-modified iron oxide and the amount of iron in the cells were determined. PLL-modified iron oxide-labeled rMSCs were imaged in vitro and in vivo after intracerebral grafting into the contralateral hemisphere of the adult rat brain. The implanted cells were visible on magnetic resonance (MR) images as a hypointense area at the injection site and in the lesion. In comparison with Endorem, nanoparticles modified with PLL of an optimum molecular weight demonstrated a higher efficiency of intracellular uptake by MSC cells.
- MeSH
- adsorpce MeSH
- chemické jevy MeSH
- endocytóza účinky léků MeSH
- financování organizované MeSH
- fyzikální chemie MeSH
- krysa rodu rattus MeSH
- kultivační média MeSH
- kultivované buňky MeSH
- lidé MeSH
- lysin chemie MeSH
- magnetická rezonanční tomografie MeSH
- magnetismus MeSH
- mezenchymální kmenové buňky účinky léků ultrastruktura MeSH
- mikroskopie elektronová rastrovací MeSH
- molekulová hmotnost MeSH
- nanočástice MeSH
- oxid železnato-železitý MeSH
- oxidy chemie MeSH
- polylysin chemie MeSH
- proteiny MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- transmisní elektronová mikroskopie MeSH
- transplantace kmenových buněk MeSH
- ultrazvuk MeSH
- velikost částic MeSH
- železité sloučeniny chemie MeSH
- železo chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
The interaction between negatively charged lipid vesicles and positively charged DNA/polylysine complexes was studied. The interaction does not lead to release of DNA from the initial complexes. The particles formed are easy to prepare, they have slight negative charge, small dimensions and show good stability in physiological NaCl solution. Such properties might indicate that stabilization of the particles by lipid coating might be a potent strategy, alternative to PEGylation of DNA/polycation complexes.Interaction of DNA/polycation complex particles with lipid vesicles.
Magnetic nanoparticles offer multiple possibilities for biomedical applications. Besides their physico-chemical properties, nanoparticle-cellular interactions are determinant for biological safety. In this work, magnetic nanoparticles were synthesized by one-shot precipitation or two-step reaction and coated with biocompatible polymers, such as poly(l-lysine) and poly(N,N-dimethylacrylamide-co-acrylic acid), and carbohydrates, like l-ascorbic acid, d-galactose, d-mannose, and sucrose. The resulting magnetic nanoparticles were characterized by dynamic light scattering, FT-Raman spectroscopy, transmission electron microscopy, SQUID magnetometry, and Mössbauer spectroscopy. Ability of the nanoparticles to be used in theranostic applications was also evaluated, showing that coating with biocompatible polymers increased the heating efficiency. Nanoparticles synthesized by one-shot precipitation were 50% larger (∼13nm) than those obtained by a two-step reaction (∼8nm). Magnetic nanoparticles at concentrations up to 500μgmL-1 were non-cytotoxic to L929 fibroblasts. Particles synthesized by one-shot precipitation had little effect on viability, cell cycle and apoptosis of the three human colon cancer cell lines used: Caco-2, HT-29, and SW-480. At the same concentration (500μgmL-1), magnetic particles prepared by a two-step reaction reduced colon cancer cell viability by 20%, affecting cell cycle and inducing cell apoptosis. Uptake of surface-coated magnetic nanoparticles by colon cancer cells was dependent on particle synthesis, surface coating and incubation time.
- MeSH
- apoptóza účinky léků MeSH
- biokompatibilní potahované materiály chemie farmakokinetika farmakologie MeSH
- buněčný cyklus účinky léků MeSH
- buňky HT-29 MeSH
- Caco-2 buňky MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- magnetismus * MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory tračníku metabolismus patologie MeSH
- polymery chemie MeSH
- povrchové vlastnosti MeSH
- teranostická nanomedicína metody MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Cationic colloidal gold nanorods (GNRs) have a great potential as a theranostic tool for diverse medical applications. GNRs' properties such as cellular internalization and stability are determined by physicochemical characteristics of their surface coating. GNRs modified by (16-mercaptohexadecyl)trimethylammonium bromide (MTAB), MTABGNRs, show excellent cellular uptake. Despite their promise for biomedicine, however, relatively little is known about the cellular pathways that facilitate the uptake of GNRs, their subcellular fate and intracellular persistence. Here we studied the mechanism of cellular internalization and long-term fate of GNRs coated with MTAB, for which the synthesis was optimized to give higher yield, in various human cell types including normal diploid versus cancerous, and dividing versus nondividing (senescent) cells. The process of MTABGNRs internalization into their final destination in lysosomes proceeds in two steps: (1) fast passive adhesion to cell membrane mediated by sulfated proteoglycans occurring within minutes and (2) slower active transmembrane and intracellular transport of individual nanorods via clathrin-mediated endocytosis and of aggregated nanorods via macropinocytosis. The expression of sulfated proteoglycans was the major factor determining the extent of uptake by the respective cell types. Upon uptake into proliferating cells, MTABGNRs were diluted equally and relatively rapidly into daughter cells; however, in nondividing/senescent cells the loss of MTABGNRs was gradual and very modest, attributable mainly to exocytosis. Exocytosed MTABGNRs can again be internalized. These findings broaden our knowledge about cellular uptake of gold nanorods, a crucial prerequisite for future successful engineering of nanoparticles for biomedical applications such as photothermal cancer therapy or elimination of senescent cells as part of the emerging rejuvenation approach.
- MeSH
- buněčná membrána účinky léků metabolismus MeSH
- endocytóza účinky léků fyziologie MeSH
- exocytóza * účinky léků fyziologie MeSH
- konfokální mikroskopie MeSH
- kultivační média MeSH
- kvartérní amoniové sloučeniny chemická syntéza chemie MeSH
- lidé MeSH
- lyzozomy účinky léků MeSH
- mikroskopie elektronová rastrovací MeSH
- nádorové buněčné linie MeSH
- nanotrubičky analýza chemie MeSH
- polylysin chemie farmakokinetika MeSH
- proliferace buněk účinky léků MeSH
- proteoglykany chemie metabolismus MeSH
- průtoková cytometrie MeSH
- stabilita léku MeSH
- sulfhydrylové sloučeniny chemie MeSH
- techniky syntetické chemie MeSH
- zlato chemie farmakokinetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Novel porous boron-doped diamond (BDDporous)-based materials have attracted lots of research interest due to their enhanced detection ability and biocompatibility, favouring them for use in neuroscience. This study reports on morphological, spectral, and electrochemical characterisation of three BDDporous electrodes of different thickness given by a number of deposited layers (2, 3 and 5). These were prepared using microwave plasma-enhanced chemical vapour deposition on SiO2 nanofiber-based scaffolds. Further, the effect of number of layers and poly-l-lysine coating, commonly employed in neuron cultivation experiments, on sensing properties of the neurotransmitter dopamine in a pH 7.4 phosphate buffer media was investigated. The boron doping level of ∼2 × 1021 atoms cm-3 and increased content of non-diamond (sp2) carbon in electrodes with more layers was evaluated by Raman spectroscopy. Cyclic voltammetric experiments revealed reduced working potential windows (from 2.4 V to 2.2 V), higher double-layer capacitance values (from 405 μF cm-2 to 1060 μF cm-2), enhanced rates of electron transfer kinetics and larger effective surface areas (from 5.04 mm2 to 7.72 mm2), when the number of porous layers increases. For dopamine, a significant boost in analytical performance was recognized with increasing number of layers using square-wave voltammetry: the highest sensitivity of 574.1 μA μmol-1 L was achieved on a BDDporous electrode with five layers and dropped to 35.9 μA μmol-1 L when the number of layers decreased to two. Consequently, the lowest detection limit of 0.20 μmol L-1 was obtained on a BDDporous electrode with five layers. Moreover, on porous electrodes, enhanced selectivity for dopamine detection in the presence of ascorbic acid and uric acid was demonstrated. The application of poly-l-lysine coating on porous electrode surface resulted in a decrease in dopamine peak currents by 17% and 60% for modification times of 1 h and 15 h, respectively. Hence, both examined parameters, the number of deposited porous layers and the presence of poly-l-lysine coating, were proved to considerably affect the characteristics and performance of BDDporous electrodes.
This study aims to design an optimal polyelectrolyte multilayer film of poly-l-lysine (PLL) and hyaluronic acid (HA) as an anti-inflammatory cytokine release system in order to decrease the implant failure due to any immune reactions. The chemical modification of the HA with aldehyde moieties allows self-cross-linking of the film and an improvement in the mechanical properties of the film. The cross-linking of the film and the release of immunomodulatory cytokine (IL-4) stimulate the differentiation of primary human monocytes seeded on the films into pro-healing macrophages phenotype. This induces the production of anti-inflammatory cytokines (IL1-RA and CCL18) and the decrease of pro-inflammatory cytokines secreted (IL-12, TNF-α, and IL-1β). Moreover, we demonstrate that cross-linking PLL/HA film using HA-aldehyde is already effective by itself to limit inflammatory processes. Finally, this functionalized self-cross-linked PLL/HA-aldehyde films constitutes an innovative and efficient candidate for immunomodulation of any kind of implants of various architecture and properties.
- MeSH
- buněčná adheze účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- cytokiny aplikace a dávkování chemie MeSH
- imunomodulace účinky léků MeSH
- kultivované buňky MeSH
- kyselina hyaluronová chemie MeSH
- lidé MeSH
- makrofágy cytologie účinky léků metabolismus MeSH
- monocyty cytologie účinky léků metabolismus MeSH
- polyelektrolyty chemie MeSH
- povrchové vlastnosti MeSH
- reagencia zkříženě vázaná chemie MeSH
- zánět farmakoterapie imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
To assist in overcoming the inherent instability of nucleic acid-containing polyplexes in physiological solutions, we have here set out to develop removable nanocoatings for modifying the surface of siRNA-based nanoparticles. Here, N-(2-hydroxypropyl)methacrylamide (HPMA) based copolymers containing carbonylthiazolidine-2-thione (TT) reactive groups in their side chains bound via disulfide spacers to the polymeric backbone were synthesized, and these copolymers were used to coat the surface of polyplexes formed by the self-assembly of anti-Luciferase siRNA with the polycations polyethylene imine (PEI) and poly(HPMA)-grafted poly(l-lysine) (GPL). The coating process was monitored by analyzing changes in the weight-average molecular weight (M(w)), the hydrodynamic radius (R(h)), and the zeta-potential (ζ) of the polyplexes, using both static (SLS) and dynamic (DLS) light scattering methods. The outlined methods resulted in the attachment of, on average, 28 polymer molecules to the surface of the polyplexes, forming a ∼5-nm-thick hydrophilic stealth coating. Initial efforts to develop RGD-targeted coated polyplexes are also described. Atomic force microscopy (AFM) showed an angular polyplex structure and confirmed the narrow size distribution of the coated nanoparticles. The stability of the polymer-coated and uncoated polyplexes was evaluated by gel electrophoresis and by turbidity measurements, and it was found that modifying the surface of the siRNA-containing polyplexes substantially improved their stability in physiological solutions. Using polymer-coated GPL-based polyplexes containing anti-Luciferase siRNA, we finally also obtained some initial proof-of-principle for time- and concentration-dependent target-specific gene silencing, suggesting that these systems hold significant potential for further in vitro and in vivo evaluation.
