Maghemite nanoparticle based silicone composite for application in arterial embolization hyperthermia is developed. It possesses embolization ability, high heating efficiency in alternating magnetic fields and radiopaque property. The initial components of the composite are selected so that the material stays liquid for 20min, providing the opportunity for transcatheter transportation and filling of the tumour vascular system. After this induction period the viscosity increases rapidly and soft embolus is formed which is able to occlude the tumour blood vessels. The composite is thermally stable up to 225°C, displays rubber-elastic properties and has a thermal expansion coefficient higher than that of blood. Maghemite nanoparticles uniformly distributed in the composite provide its rapid heating (tens of °Cmin(-1)) due to Neel magnetization relaxation. Required X-ray contrast of composite is achieved by addition of potassium iodide.

• MeSH
• indukovaná hypertermie * MeSH
• jodid draselný chemie   MeSH
• lidé MeSH
• magnetické pole * MeSH
• nanokompozity chemie   MeSH
• pružnost MeSH
• silikony chemie   MeSH
• terapeutická embolizace * MeSH
• železité sloučeniny chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Maghemite (gamma-Fe2O3) nanoparticles were obtained by the coprecipitation of Fe(II) and Fe (III) salts with ammonium hydroxide followed by oxidation with sodium hypochlorite. Solution radical polymerization of N,N-dimethylacrylamide(DMAAm) in the presence of maghemite nanoparticles yielded poly(N,N-dimethylacrylamide)(PDMAAm)-coated maghemite nanoparticles. The presence of PDMAAm on the maghemite particle surface was confirmed by elemental analysis and ATR FTIR spectroscopy. Other methods of nanoparticle characterization involved scanning and transmission electron microscopy, atomic adsorption spectroscopy (AAS), and dynamic light scattering (DLS). The conversion of DMAAm during polymerization and the molecular weight of PDMAAmbound to maghemite were determined by using gas and size-exclusion chromatography, respectively. The effect of ionic 4,4'-azobis(4-cyanovaleric acid) (ACVA) initiator on nanoparticle morphology was elucidated. The nanoparticles exhibited long-term colloidal stability in water or physiological buffer. Rat and human bone marrow mesenchymal stem cells (MSCs) were labeled with uncoated and PDMAAm-coated maghemite nanoparticles and with Endorem as a control. Uptake of the nanoparticles was evaluated by Prussian Blue staining, transmission electron microscopy, T(2)-MR relaxometry, and iron content analysis. Significant differences in labeling efficiency were found for human and rat cells. PDMAAm-modified nanoparticles demonstrated a higher efficiency of intracellular uptake into human cells in comparison with that of dextran-modified (Endorem) and unmodified nanoparticles. In gelatin, even a small number of labeled cells changed the contrast in MR images. PDMAAmcoatednanoparticles provided the highest T(2) relaxivity of all the investigated particles. In vivo MR imaging ofPDMAAm-modified iron oxide-labeled rMSCs implanted in a rat brain confirmed their better resolution compared with Endorem-labeled cells.

• MeSH
• akrylamidy chemie   MeSH
• barvení a značení metody   MeSH
• financování organizované MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie MeSH
• mezenchymální kmenové buňky cytologie   metabolismus   ultrastruktura   MeSH
• nanočástice chemie   MeSH
• radiační rozptyl MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• transmisní elektronová mikroskopie MeSH
• viabilita buněk MeSH
• želatina metabolismus   MeSH
• železité sloučeniny chemická syntéza   chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH

AIM: The aim of this study was to test an oral contrast solution with maghemite for the magnetic resonance imaging of small bowel diseases. PATIENTS AND METHODS: The study sample included 3 cohorts: 17 healthy volunteers (group A), 22 patients with small bowel disease (group C). Both groups underwent MR enterography and 24 patients with small bowel disease (group B) underwent magnetic resonance cholecystopancreaticography. Various concentrations in 1000 ml vs 500 ml of experimental solution were tested. All cohorts completed questionnaires evaluating the solution characteristics and side-efects during and after drinking. RESULTS: A maghemite concentration of 800 mg /4 g bentonite in 1000 ml solution was sufficient for proper intraluminal lay-out. An experimental solution of 500 ml was sufficient for magnetic resonance cholecystopancreaticography and 1000 ml for MR enterography. There were no statistically significant differences between groups for taste, taste characteristic or appearance of the experimental solution. Side-effects experienced during drinking were: nausea (29.4%) and eructation (29.4%) in group A, in group B (42%) and diarrhoea (27.3%) in group C. Side-effects 2 h after drinking occured in group A (nausea 17.6%) and in group C (diarrhoea 47%). The best tolerance of experimental solution was found in group B with a higher median patient age than groups A and C. The experimental solution was evaluated more favorably in the older subjects (age over 50 years). CONCLUSION: The experimental oral solution with maghemite was well tolerated in all 3 groups. Our study supports its use in magnetic resonance practice.

• MeSH
• Crohnova nemoc diagnóza   MeSH
• dospělí MeSH
• kontrastní látky * škodlivé účinky   MeSH
• lidé středního věku MeSH
• lidé MeSH
• magnetická rezonanční cholangiopankreatografie MeSH
• magnetická rezonanční tomografie * MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nanočástice * MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• tenké střevo patologie   MeSH
• železité sloučeniny škodlivé účinky   diagnostické užití   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sodium hyaluronate (HA) was associated with dopamine (DPA) and introduced as a coating for maghemite (γ-Fe(2)O(3)) nanoparticles obtained by the coprecipitation of iron(II) and iron(III) chlorides and oxidation with sodium hypochlorite. The effects of the DPA anchorage of HA on the γ-Fe(2)O(3) surface on the physicochemical properties of the resulting colloids were investigated. Nanoparticles coated at three different DPA-HA/γ-Fe(2)O(3) and DPA/HA ratios were chosen for experiments with rat bone marrow mesenchymal stem cells and human chondrocytes. The nanoparticles were internalized into rat bone marrow mesenchymal stem cells via endocytosis as confirmed by Prussian Blue staining. The efficiency of mesenchymal stem cell labeling was analyzed. From among the investigated samples, efficient cell labeling was achieved by using DPA-HA-γ-Fe(2)O(3) nanoparticles with DPA-HA/γ-Fe(2)O(3) = 0.45 (weight/ weight) and DPA/HA = 0.038 (weight/weight) ratios. The particles were used as a contrast agent in magnetic resonance imaging for the labeling and visualization of cells.

• MeSH
• biokompatibilní potahované materiály chemie   MeSH
• buněčná diferenciace MeSH
• chondrocyty cytologie   MeSH
• dopamin chemie   MeSH
• endocytóza MeSH
• ferrokyanidy MeSH
• kontrastní látky diagnostické užití   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• kyselina hyaluronová chemie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• magnetické nanočástice chemie   diagnostické užití   ultrastruktura   MeSH
• mezenchymální kmenové buňky cytologie   účinky léků   MeSH
• nanomedicína MeSH
• transmisní elektronová mikroskopie MeSH
• velikost částic MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nanoparticles of various compositions are increasingly being used in many areas of medicine. The aim of this study was to develop nanoparticles, which would possess both magnetic and conductive properties and, thus improve their suitability for a wider range of biomedical applications. Namely, it would enable both the particle manipulation and imaging using their magnetic properties and simultaneous stimulation of electro-sensitive cell types using their magnetic properties, which can be used in tissue therapy, engineering and as biosensors. Maghemite (γ-Fe2O3) particles were prepared by the co-precipitation of Fe(2+) and Fe(3+) salts with ammonium hydroxide, followed by the controlled oxidation with NaOCl. The polyaniline (PANI) shell on the γ-Fe2O3 nanoparticles was obtained by the polymerization of aniline hydrochloride with ammonium peroxydisulfate in an aqueous solution of poly(N-vinylpyrrolidone) at two reaction temperatures (0 and 25 °C). The resulting γ-Fe2O3&PANI particles were characterized by both the light and transmission electron microscopies, dynamic light scattering, magnetic measurements, UV-vis and energy dispersive X-ray (EDAX) spectroscopy. The size of the starting γ-Fe2O3 particles was 11 nm, that increased to 25 nm after the modification with PANI. The incubation of both the γ-Fe2O3 and γ-Fe2O3&PANI nanoparticles with the human neuroblastoma derived SH-SY5Y cells for 8 days showed neither significant decrease in the cell viability, nor detectable changes in the cell morphology. This indicates, that the particles have no detectable cytotoxicity in cell culture and represent a promising tool for further use in biomedical applications.

• MeSH
• aniliny chemie   MeSH
• chemické jevy MeSH
• lidé MeSH
• magnetismus * MeSH
• nádorové buněčné linie MeSH
• nanoslupky chemie   otrava   ultrastruktura   MeSH
• oxidace-redukce MeSH
• polyvinyly chemie   MeSH
• proliferace buněk účinky léků   MeSH
• pyrrolidiny chemie   MeSH
• radiační rozptyl MeSH
• spektrofotometrie MeSH
• spektrometrie rentgenová emisní MeSH
• světlo MeSH
• transmisní elektronová mikroskopie MeSH
• viabilita buněk účinky léků   MeSH
• železité sloučeniny chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nanoparticles are commonly used in diagnostics and therapy. They are also increasingly being implemented in cancer immunotherapy because of their ability to deliver drugs and modulate the immune system. However, the effect of nanoparticles on immune cells involved in the anti-tumor immune response is not well understood. The study reported here showed that nickel-doped maghemite nanoparticles (FN NP) are differentially cytotoxic to cultured mouse and human cancer cell lines, causing their death without negatively impacting the subsequent anticancer immune response. It also found that FN NP induced cell death in the mouse colorectal cancer cell line CT26 and human prostate cancer cell line PC-3, but not in the human prostate cancer cell line LNCaP. The induced cancer cell death did not affect the phenotype and responsivity of the isolated mouse peritoneal macrophages, or ex vivo-generated mouse bone marrow-derived, or human monocyte-derived dendritic cells. Additionally, the induced cancer cell death did not prevent the ex vivo-generated mouse or human dendritic cells from stimulating lymphocytes and enriching cell cultures with cancer cell-reactive T-cells. In conclusion, this study shows that FN NP could be a valuable platform for targeting cancer cells without causing immunosuppressive effects on the subsequent anticancer immune response.

• MeSH
• buňky PC-3 MeSH
• dendritické buňky * imunologie   MeSH
• imunoterapie * metody   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prostaty imunologie   terapie   MeSH
• nádory imunologie   terapie   MeSH
• nikl * chemie   imunologie   MeSH
• železité sloučeniny chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The preparation and thorough characterization of a hybrid magnetic carrier system for the possible transport of activated platinum-based anticancer drugs, as demonstrated for cisplatin (cis-[Pt(NH3)2Cl2], CDDP), are described. The final functionalized mag/Au-LA-CDDP* system consists of maghemite/gold nanoparticles (mag/Au) coated by lipoic acid (HLA; LA stands for deprotonated form of lipoic acid) and functionalized by activated cisplatin in the form of cis-[Pt(NH3)2(H2O)2]2+ (CDDP*). The relevant techniques (XPS, EDS, ICP-MS) proved the incorporation of the platinum-containing species on the surface of the studied hybrid system. HRTEM, TEM and SEM images showed the nanoparticles as spherical with an average size of 12 nm, while their superparamagnetic feature was proven by 57Fe Mössbauer spectroscopy. In the case of mag/Au, mag/Au-HLA and mag/Au-LA-CDDP*, weaker magnetic interactions among the Fe3+ centers of maghemite, as compared to maghemite nanoparticles (mag), were detected, which can be associated with the non-covalent coating of the maghemite surface by gold. The pH and time-dependent stability of the mag/Au-LA-CDDP* system in different media, represented by acetate (pH 5.0), phosphate (pH 7.0) and carbonate (pH 9.0) buffers and connected with the release of the platinum-containing species, showed the ability of CDDP* to be released from the functionalized nanosystem.

• MeSH
• biologický transport MeSH
• diferenční termická analýza MeSH
• fotoelektronová spektroskopie MeSH
• koncentrace vodíkových iontů MeSH
• kovové nanočástice chemie   ultrastruktura   MeSH
• magnetické jevy * MeSH
• nanotechnologie metody   MeSH
• nosiče léků chemie   MeSH
• platina terapeutické užití   MeSH
• spektrofotometrie atomová MeSH
• spektrofotometrie infračervená MeSH
• spektrometrie rentgenová emisní MeSH
• spektroskopie Mossbauerova MeSH
• termogravimetrie MeSH
• železité sloučeniny chemie   MeSH
• zlato chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nearly monodispersed superparamagnetic maghemite nanoparticles (15-20nm) were prepared by a one-step thermal decomposition of iron(II) acetate in air at 400 degrees C. The presented synthetic route is simple, cost effective and allows to prepare the high-quality superparamagnetic particles in a large scale. The as-prepared particles were exploited for the development of magnetic nanocomposites with the possible applicability in medicine and biochemistry. For the purposes of the MRI diagnostics, the maghemite particles were simply dispersed in the bentonite matrix. The resulting nanocomposite represents very effective and cheap oral negative contrast agent for MRI of the gastrointestinal tract and reveals excellent contrast properties, fully comparable with those obtained for commercial contrast material. The results of the clinical research of this maghemite-bentonite contrast agent for imaging of the small bowel are discussed. For biochemical applications, the primary functionalization of the prepared maghemite nanoparticles with chitosan was performed. In this way, a highly efficient magnetic carrier for protein immobilization was obtained as demonstrated by conjugating thermostable raffinose-modified trypsin (RMT) using glutaraldehyde. The covalent conjugation resulted in a further increase in trypsin thermostability (T(50)=61 degrees C) and elimination of its autolysis. Consequently, the immobilization of RMT allowed fast in-solution digestion of proteins and their identification by MALDI-TOF mass spectrometry.

• MeSH
• difrakce rentgenového záření MeSH
• enzymy imobilizované MeSH
• financování organizované MeSH
• gastrointestinální trakt patologie   MeSH
• kontrastní látky MeSH
• magnetická rezonanční tomografie MeSH
• mikroskopie elektronová rastrovací MeSH
• transmisní elektronová mikroskopie MeSH
• trypsin MeSH
• železité sloučeniny MeSH

Two experiments were carried out to study the competition for adsorption between trace elements (TEs) and nutrients following the application of nano-maghemite (NM) (iron nano-oxide; Fe2O3) to a soil solution (the 0.01molL(-1) CaCl2 extract of a TEs-contaminated soil). In the first, the nutrients K, N, and P were added to create a set of combinations: potential availability of TEs during their interaction with NM and nutrients were studied. In the second, response surface methodology was used to develop predictive models by central composite design (CCD) for competition between TEs and the nutrients K and N for adsorption onto NM. The addition of NM to the soil solution reduced specifically the concentrations of available As and Cd, but the TE-adsorption capacity of NM decreased as the P concentration increased. The CCD provided more concise and valuable information, appropriate to estimate the behavior of NM sequestering TEs: according to the suggested models, K(+) and NH4(+) were important factors for Ca, Fe, Mg, Mn, Na, and Zn adsorption (Radj(2)=95%, except for Zn with Radj(2)=87%). The obtained information and models can be used to predict the effectiveness of NM for the stabilization of TEs, crucial during the phytoremediation of contaminated soils.

• MeSH
• adsorpce MeSH
• látky znečišťující půdu chemie   MeSH
• nanostruktury * MeSH
• stopové prvky chemie   MeSH
• železité sloučeniny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AIM: To determine cytotoxicity and effect of silica-coated magnetic nanoparticles (MNPs) on immune response, in particular lymphocyte proliferative activity, phagocytic activity, and leukocyte respiratory burst and in vitro production of interleukin-6 (IL-6) and 8 (IL-8), interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and granulocyte macrophage colony stimulating factor (GM-CSF). METHODS: Maghemite was prepared by coprecipitation of iron salts with ammonia, oxidation with NaOCl and modified by tetramethyl orthosilicate and aminosilanes. Particles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). Cytotoxicity and lymphocyte proliferative activity were assessed using [3H]-thymidine incorporation into DNA of proliferating human peripheral blood cells. Phagocytic activity and leukocyte respiratory burst were measured by flow cytometry; cytokine levels in cell supernatants were determined by ELISA. RESULTS: γ-Fe2O3&SiO2-NH2 MNPs were 13 nm in size. According to TEM, they were localized in the cell cytoplasm and extracellular space. Neither cytotoxic effect nor significant differences in T-lymphocyte and T-dependent B-cell proliferative response were found at particle concentrations 0.12-75 μg/cm2 after 24, 48, and 72 h incubation. Significantly increased production of IL-6 and 8, and GM-CSF cytokines was observed in the cells treated with 3, 15, and 75 µg of particles/cm2 for 48 h and stimulated with pokeweed mitogen (PHA). No significant changes in TNF-α and IFN-γ production were observed. MNPs did not affect phagocytic activity of monocytes and granulocytes when added to cells for 24 and 48 h. Phagocytic respiratory burst was significantly enhanced in the cultures exposed to 75 µg MNPs/cm2 for 48 h. CONCLUSIONS: The cytotoxicity and in vitro immunotoxicity were found to be minimal in the newly developed porous core-shell γ-Fe2O3&SiO2-NH2 magnetic nanoparticles.

• MeSH
• fagocyty fyziologie   MeSH
• faktor stimulující granulocyto-makrofágové kolonie metabolismus   MeSH
• interleukin-6 metabolismus   MeSH
• interleukin-8 metabolismus   MeSH
• leukocyty fyziologie   MeSH
• lidé MeSH
• lymfocyty fyziologie   MeSH
• nanoslupky chemie   ultrastruktura   MeSH
• oxid křemičitý chemie   MeSH
• průtoková cytometrie MeSH
• respirační vzplanutí fyziologie   MeSH
• TNF-alfa metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• železité sloučeniny chemie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH