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The aim of this study was to develop multifunctional magnetic poly(ε‐caprolactone) (PCL) mats with antibacterial properties for bone tissue engineering and osteosarcoma prevention. To provide good dispersion of magnetic iron oxide nanoparticles (IONs), they were first grafted with PCL using a novel three‐step approach. Then, a series of PCL‐based mats containing a fixed amount of ION@PCL particles and an increasing content of ascorbic acid (AA) was prepared by electrospinning. AA is known for increasing osteoblast activity and suppressing osteosarcoma cells. Composites were characterized in terms of morphology, mechanical properties, hydrolytic stability, antibacterial performance, and biocompatibility. AA affected both the fiber diameter and the mechanical properties of the nanocomposites. All produced mats were nontoxic to rat bone marrow‐derived mesenchymal cells; however, a composite with 5 wt.% of AA suppressed the initial proliferation of SAOS‐2 osteoblast‐like cells. Moreover, AA improved antibacterial properties against Staphylococcus aureus and Escherichia coli compared to PCL. Overall, these magnetic composites, reported for the very first time, can be used as scaffolds for both tissue regeneration and osteosarcoma prevention. [ABSTRACT FROM AUTHOR]

In this study, spherical or hexagonal NaYF4:Yb,Er nanoparticles (UCNPs) with sizes of 25 nm (S-UCNPs) and 120 nm (L-UCNPs) were synthesized by high-temperature coprecipitation and subsequently modified with three kinds of polymers. These included poly(ethylene glycol) (PEG) and poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide) [P(DMA-AEA)] terminated with an alendronate anchoring group, and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). The internalization of nanoparticles by rat mesenchymal stem cells (rMSCs) and C6 cancer cells (rat glial tumor cell line) was visualized by electron microscopy and the cytotoxicity of the UCNPs and their leaches was measured by the real-time proliferation assay. The comet assay was used to determine the oxidative damage of the UCNPs. An in vivo study on mice determined the elimination route and potential accumulation of UCNPs in the body. The results showed that the L- and S-UCNPs were internalized into cells in the lumen of endosomes. The proliferation assay revealed that the L-UCNPs were less toxic than S-UCNPs. The viability of rMSCs incubated with particles decreased in the order S-UCNP@Ale-(PDMA-AEA) > S-UCNP@Ale-PEG > S-UCNPs > S-UCNP@PMVEMA. Similar results were obtained in C6 cells. The oxidative damage measured by the comet assay showed that neat L-UCNPs caused more oxidative damage to rMSCs than all coated UCNPs while no difference was observed in C6 cells. An in vivo study indicated that L-UCNPs were eliminated from the body via the hepatobiliary route; L-UCNP@Ale-PEG particles were almost eliminated from the liver 96 h after intravenous application. Pilot fluorescence imaging confirmed the limited in vivo detection capabilities of the nanoparticles. [ABSTRACT FROM AUTHOR]

In the fight against antibiotic resistance, which is rising to dangerously high levels worldwide, new strategies based on antibiotic-conjugated biocompatible polymers bound to magnetic nanoparticles that allow the drug to be manipulated and delivered to a specific target are being proposed. Here, we report the direct surface engineering of nontoxic iron oxide nanoparticles (IONs) using biocompatible dextran (Dex) covalently linked to β-cyclodextrin (β-CD) with the ability to form non-covalent complexes with silver-sulfamethazine (SMT-Ag). To achieve a good interaction of β-CD-modified dextran with the surface of the nanoparticles, it was functionalized with diphosphonic acid (DPA) that provides strong binding to Fe atoms. The synthesized polymers and nanoparticles were characterized by various methods, such as nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and ultraviolet–visible (UV–Vis) spectroscopies, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), atomic absorption spectroscopy (AAS), dynamic light scattering (DLS), etc. The resulting magnetic ION@DPA-Dex-β-CD-SMT-Ag nanoparticles were colloidally stable in water and contained 24 μg of antibiotic per mg of the particles. When tested for in vitro antimicrobial activity on Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and fungi (yeast Candida albicans and mold Aspergillus niger), the particles showed promising potential. [ABSTRACT FROM AUTHOR]

Upconverting nanoparticles are interesting materials that have the potential for use in many applications ranging from solar energy harvesting to biosensing, light-triggered drug delivery, and photodynamic therapy (PDT). One of the main requirements for the particles is their surface modification, in our case using poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and temoporfin (THPC) photosensitizer to ensure the colloidal and chemical stability of the particles in aqueous media and the formation of singlet oxygen after NIR irradiation, respectively. Codoping of Fe2+, Yb3+, and Er3+ ions in the NaYF4 host induced upconversion emission of particles in the red region, which is dominant for achieving direct excitation of THPC. Novel monodisperse PMVEMA-coated upconversion NaYF4:Yb3+,Er3+,Fe2+ nanoparticles (UCNPs) with chemically bonded THPC were found to efficiently transfer energy and generate singlet oxygen. The cytotoxicity of the UCNPs was determined in the human pancreatic adenocarcinoma cell lines Capan-2, PANC-01, and PA-TU-8902. In vitro data demonstrated enhanced uptake of UCNP@PMVEMA-THPC particles by rat INS-1E insulinoma cells, followed by significant cell destruction after excitation with a 980 nm laser. Intratumoral administration of these nanoconjugates into a mouse model of human pancreatic adenocarcinoma caused extensive necrosis at the tumor site, followed by tumor suppression after NIR-induced PDT. In vitro and in vivo results thus suggest that this nanoconjugate is a promising candidate for NIR-induced PDT of cancer. [ABSTRACT FROM AUTHOR]

The biocompatibility of NPs to blood cells is a key issue when these NPs are planned for intravenous application because of potential contact with blood cells and proteins. In this work, γ-Fe2O3 NPs (~ 9 nm) and their poly(N,N-dimethylacrylamide) (PDMA) and SiO2-coated derivatives (γ-Fe2O3@PDMA and γ-Fe2O3@SiO2, respectively) were investigated. It was detected that both PDMA and SiO2 coatings decreased NPs' aggregation in the buffer solutions, as well as in cell culture medium. Neither neat γ-Fe2O3 NPs nor their coated derivatives possessed hemolytic activity toward red blood cells. There was no significant loss of body weight observed after the intravenous injection to laboratory mice. The immune response to the injected NPs was assessed by the ELISA measuring. No antibodies of the IgM class were detected, which suggests lack of acute inflammation. On the 35th day of the experiment, there was a rise in the content of the anti-OVA IgG noticed in all three types of the NPs; however, this rise was lower compared to that induced by the positive control. The injected NPs were found to be spread and settled in the pouch cavity, and none of the tested NPs caused vascular damage or distinct signs of inflammation. Summarizing, γ-Fe2O3 NPs coated with the PDMA or SiO2 manifested good compatibility with blood cells in in vitro and in vivo investigations. [ABSTRACT FROM AUTHOR]

In this report, we synthesized hexagonal NaYF4:Yb,Er upconverting nanoparticles (UCNPs) of 171 nm in size with a narrow particle size distribution. To address their colloidal stabi-lity in aqueous media and to incorporate a photosensitizer that can produce reactive singlet oxygen (1O2) to kill tumor cells, UCNPs were conjugated with 6-bromohexanoic acid-functionalized Rose Bengal (RB) and coated with PEG-alendronate (PEG-Ale). The particles were thoroughly characterized by transmission electron microscopy, dynamic light scattering, ATR FTIR, X-ray photoelectron spectroscopy, thermogravimetric analysis, and spectrofluorometry, and 1O2 formation was detected using a 9,10-diphenylanthracene spectrophotometric probe. Cytotoxicity determination on rat mesenchymal stem cells by using the MTT assay showed that neutralization of the large positive surface charge of neat UCNPs with PEG-Ale and the bound RB sensitizer significantly reduced the concentration-dependent cytotoxicity. The presented strategy shows great potential for the use of these particles as a novel agent for the photodynamic therapy of tumors. [ABSTRACT FROM AUTHOR]

Upconverting nanoparticles (UCNPs) are of particular interest in nanomedicine for in vivo deep-tissue optical cancer bioimaging due to their efficient cellular uptake dependent on polymer coating. In this study, particles, ca. 25 nm in diameter, were prepared by a high-temperature coprecipitation of lanthanide chlorides. To ensure optimal dispersion of UCNPs in aqueous milieu, they were coated with three different polymers containing reactive groups, i.e., poly(ethylene glycol)-alendronate (PEG-Ale), poly(N,N-dimethylacrylamide-co-2-aminoethylacrylamide)-alendronate (PDMA-Ale), and poly(methyl vinyl ether-co-maleic acid) (PMVEMA). All the particles were characterized by TEM, DLS, FTIR, and spectrofluorometer to determine the morphology, hydrodynamic size and ξ-potential, composition, and upconversion luminescence. The degradability/dissolution of UCNPs in water, PBS, DMEM, or artificial lysosomal fluid (ALF) was evaluated using an ion-selective electrochemical method and UV-Vis spectroscopy. The dissolution that was more pronounced in PBS at elevated temperatures was decelerated by polymer coatings. The dissolution in DMEM was relatively small, but much more pronounced in ALF. PMVEMA with multiple anchoring groups provided better protection against particle dissolution in PBS than PEG-Ale and PDMA-Ale polymers containing only one reactive group. However, the cytotoxicity of the particles depended not only on their ability to rapidly degrade, but also on the type of coating. According to MTT, neat UCNPs and UCNP@PMVEMA were toxic for both rat cells (C6) and rat mesenchymal stem cells (rMSCs), which was in contrast to the UCNP@Ale-PDMA particles that were biocompatible. On the other hand, both the cytotoxicity and uptake of the UCNP@Ale-PEG particles by C6 and rMSCs were low, according to MTT assay and ICP-MS, respectively. This was confirmed by a confocal microscopy, where the neat UCNPs were preferentially internalized by both cell types, followed by the UCNP@PMVEMA, UCNP@Ale-PDMA, and UCNP@Ale-PEG particles. This study provides guidance for the selection of a suitable nanoparticle coating with respect to future biomedical applications where specific behaviors (extracellular deposition vs. cell internalization) are expected. [ABSTRACT FROM AUTHOR]

Overproduction of reactive oxygen species (ROS) is an unwanted phenomenon, leading to cellular damages. The aim of this study was to investigate the ability of neat and surface-modified iron oxide nanoparticles (IONs) to eliminate ROS produced by immune cells. The employed coating included heparin (ION@Hep) or heparin and chitosan grafted with phenolic compounds famous for antioxidant properties, i.e., gallic acid (ION@Ch-G) or phloroglucinol (ION@CH-P). A total peroxyl radical-trapping potential assay showed that both types of the phenolic compounds-modified IONs exhibited superior radical scavenging activity over the neat and ION@Hep particles at 100 μg/mL. Up to ~ 75 μg/mL, the particles were non-toxic towards RAW 264.7 macrophages. Capability of the particles to limit ROS production was investigated in vitro on polymorphonuclear (PMN) cells isolated from human whole blood and expressed as an ability to reduce the oxidative burst in the stimulated cells, as well as a potential to increase the viability of bacteria cultivated with the PMN cells. The highest viability of bacteria was observed for the neat and ION@Ch-G, while the ION@Ch-G particles also the most effectively inhibited the oxidative burst. The results indicated that ROS scavenging depend on the presence of polymer and selection of phenols, enriching the IONs. [ABSTRACT FROM AUTHOR]

High-quality upconverting NaYF4:Yb3+,Er3+ nanoparticles (UCNPs; 26 nm in diameter) based on lanthanides were synthesized by a high-temperature coprecipitation method. The particles were modified by bisphosphonate-terminated poly(ethylene glycol) (PEG) and Rose Bengal (RB) photosensitizer. The particles were thoroughly characterized using transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, FTIR, and X-ray photoelectron and upconversion luminescence spectroscopy in terms of morphology, hydrodynamic size, composition, and energy transfer to the photosensitizer. Moreover, the singlet oxygen generation from RB-containing UCNPs was investigated using 9,10-diphenylanthracene probe under 980 nm excitation. The cytotoxicity of UCNPs before and after conjugation with RB was evaluated on highly sensitive rat mesenchymal stem cells (rMSCs) and significant differences were found. Correspondingly, consi-derable variations in viability were revealed between the irradiated and non-irradiated rat glioma cell line (C6) exposed to RB-conjugated UCNPs. While the viability of rMSCs was not affected by the presence of UCNPs themselves, the cancer C6 cells were killed after the irradiation at 980 nm due to the reactive oxygen species (ROS) production, thus suggesting the potential of RB-conjugated PEG-modified UCNPs for applications in photodynamic therapy of cancer. [ABSTRACT FROM AUTHOR]

Coating of nanoparticles with gallates renders them antioxidant and enhances cellular internalization. In this study, (amino)silica magnetic particles modified with tannic acid (TA) and optionally with chitosan (CS) were developed, and their physicochemical properties and antioxidant activity were evaluated. The results demonstrated that the TA-modified aminosilica-coated particles, as well as the silica-coated particles with a double TA layer, exhibited high antioxidant activity, whereas the silica-coated particles with no or only a single TA layer were well-internalized by LN-229 cells. In addition, a magnet placed under the culture plates greatly increased the cellular uptake of all TA-coated magnetic nanoparticles. The coating thus had a considerable impact on nanoparticle–cell interactions and particle internalization. The TA-coated magnetic nanoparticles have great potential as intracellular carriers with preserved antioxidant activity. [ABSTRACT FROM AUTHOR]

Block copolymer comprising of hydrophilic poly[N-(2-hydroxypropyl)methacrylamide] (PHP) and reactive poly[N-(2-hydrazinyl-2-oxoethyl)methacrylamide] (PMAH) was synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization and conjugated with doxorubicin (Dox) and/or RGDS targeting peptide via one-step reaction using N-γ-maleimidobutyryl-oxysuccinimide ester. The resulting copolymer served as a coating of magnetic γ-Fe2O3 nanoparticles that were tested in cell proliferation and in vivo experiments on a mice model with inoculated rat C6 glioblastoma tumor. The nanoparticles conjugated with RGDS peptide and doxorubicin easily engulfed both C6 tumor cell line, primary glioblastoma (GB) cells, and human mesenchymal stem cells (hMSC) used as a control; the particles decreased the GB cell growth by 45% compared to control cells without any treatment. Moreover, the γ-Fe2O3@P(HP-MAH)-RGDS-Dox nanoparticles injected into C6 glioblastoma cell-derived tumors grown in the posterior flank of mice decreased the tumor size and more apoptotic cells were spread compared to that treated with free Dox. [ABSTRACT FROM AUTHOR]

Upconverting luminescent lanthanide-doped nanoparticles (UCNP) belong to promising new materials that absorb infrared light able to penetrate in the deep tissue level, while emitting photons in the visible or ultraviolet region, which makes them favorable for bioimaging and cell labeling. Here, we have prepared upconverting NaYF4:Yb,Er@NaYF4:Nd core–shell nanoparticles, which were coated with copolymers of N,N-dimethylacrylamide (DMA) and 2-(acryloylamino)-2-methylpropane-1-sulfonic acid (AMPS) or tert-butyl [2-(acryloylamino)ethyl]carbamate (AEC-Boc) with negative or positive charges, respectively. The copolymers were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization, reaching Mn ~ 11 kDa and containing ~ 5 mol% of reactive groups. All copolymers contained bisphosphonate end-groups to be firmly anchored on the surface of NaYF4:Yb,Er@NaYF4:Nd core–shell nanoparticles. To compare properties of polymer coatings, poly(ethylene glycol)-coated and neat UCNP were used as a control. UCNP with various charges were then studied as labels of carcinoma cells, including human hepatocellular carcinoma HepG2, human cervical cancer HeLa, and rat insulinoma INS-1E cells. All the particles proved to be biocompatible (nontoxic); depending on their ξ-potential, the ability to penetrate the cells differed. This ability together with the upconversion luminescence are basic prerequisites for application of particles in photodynamic therapy (PDT) of various tumors, where emission of nanoparticles in visible light range at ~ 650 nm excites photosensitizer. [ABSTRACT FROM AUTHOR]

Upconverting nanoparticles (UCNPs) are being extensively investigated for applications in bioimaging because of their ability to emit ultraviolet, visible, and near-infrared light. NaYF4 is one of the most suitable host matrices for producing high-intensity upconversion fluorescence; however, UCNPs based on NaYF4 are not chemically stable in aqueous media. To prevent dissolution, their surfaces should be modified. We studied the formation of protective phosphonate coatings made of ethylenediamine(tetramethylenephosphonic acid), alendronic acid, and poly(ethylene glycol)-neridronate on cubic NaYF4 nanoparticles and hexagonal Yb3+,Er3+-doped upconverting NaYF4 nanoparticles (β-UCNPs). The effects of synthesis temperature and ultrasonic agitation on the quality of the coatings were studied. The formation of the coatings was investigated by transmission electron microscopy, zeta-potential measurements, and infrared spectroscopy. The quality of the phosphonate coatings was examined with respect to preventing the dissolution of the NPs in phosphate-buffered saline (PBS). The dissolution tests were carried out under physiological conditions (37 °C and pH 7.4) for 3 days and were followed by measurements of the dissolved fluoride with an ion-selective electrode. We found that the protection of the phosphonate coatings can be significantly increased by synthesizing them at 80 °C. At the same time, the coatings obtained at this temperature suppressed the surface quenching of the upconversion fluorescence in β-UCNPs. [ABSTRACT FROM AUTHOR]

Magnetic hypercrosslinked poly(styrene-co-divinylbenzene) microspheres (mgt.HPS1-NH2 and mgt.HPS2-NH2) containing different contents of amino groups were prepared and characterized in this study. The microspheres were used for the capture of uncompacted and compacted bacterial and calf thymus DNAs in the presence of different PEG 6000 and NaCl concentrations. Magnetic macroporous poly(glycidyl methacrylate-co-[2-(methacryloyloxy)ethoxy]acetic acid-co-ethylene dimethacrylate) microspheres containing amino and carboxyl groups [mgt.P(GMA-MOEAA-EDMA)-NH2] and magnetic non-porous carboxyl group-functionalized poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) [mgt.P(HEMA-GMA)-COOH] microspheres were used as a control. The size changes of uncompacted and compacted bacterial and calf thymus DNAs were measured in the range of concentrations 0–16% PEG 6000 and 0.5–2.0 M NaCl by dynamic light scattering (DLS). The highest capture of compacted bacterial and calf thymus DNAs was achieved with mgt.HPS1-NH2, mgt.HPS2-NH2 microspheres using 8% PEG 6000 and 2.0 M NaCl and with mgt.P(GMA-MOEAA-EDMA)-NH2 microspheres using 8% and 16% PEG 6000 and 2.0 M NaCl. Developed microspheres were used for DNA isolation from real vegetable (broccoli flowering head) samples. DNA was in quality suitable for PCR. [ABSTRACT FROM AUTHOR]

We firstly identified 48 kDa molecular form of the unconventional myosin 1c (p48/Myo1C), and isolated it from blood serum of multiple sclerosis patients. The amount of p48/Myo1C in human blood serum correlated with some autoimmune, hemato‐oncological and neurodegenerative diseases and thus may serve as a potential molecular biomarker. The biological functions of this protein in human blood remain unknown. Previously, we used the monodisperse magnetic poly (glycidyl methacrylate)(mag‐PGMA–NH2) microspheres with immobilized 48/Myo1C and western‐blot analysis, which allowed us to identify IgM and IgG immunoglobulins presenting an affinity to this protein. Here, we used mass spectrometry followed by the western blotting in order to identify other blood serum proteins with affinity to 48/Myo1C. The obtained data demonstrate that 48/Myo1C binds to component 3 of the complement and the antithrombin‐III proteins. A combination of magnetic microparticle‐based affinity chromatography with MALDI–TOF mass spectrometry and an in silico analysis provided an opportunity to identify the partners of interaction of 48/Myo1C with other proteins, in particular those participating in complement and coagulation cascades. [ABSTRACT FROM AUTHOR]

Development of therapeutic systems to treat glioblastoma, the most common and aggressive brain tumor, belongs to priority tasks in cancer research. We have synthesized colloidally stable magnetic nanoparticles (Dh=336 nm) coated with doxorubicin (Dox) conjugated copolymers of N,N‐dimethylacrylamide and either N‐acryloylglycine methyl ester or N‐acryloylmethyl 6‐aminohexanoate. The terminal carboxyl groups of the copolymers were reacted with alendronate by carbodiimide formation. Methyl ester groups were then transferred to hydrazides for binding Dox by a hydrolytically labile hydrazone bond. The polymers were subsequently bound on the magnetic nanoparticles through bisphosphonate terminal groups. Finally, the anticancer effect of the Dox‐conjugated particles was investigated using the U‐87 glioblastoma cell line in terms of particle internalization and cell viability, which decreased to almost zero at a concentration of 100 μg of particles per ml. These results confirmed that poly(N,N‐dimethylacrylamide)‐coated magnetic nanoparticles can serve as a solid support for Dox delivery to glioblastoma cells. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIOn) are widely used as a contrast agent for cell labeling. Macrophages are the first line of defense of organisms in contact with nanoparticles after their administration. In this study we investigated the effect of silica-coated nanoparticles (γ-Fe2O3–SiO2) with or without modification by an ascorbic acid (γ-Fe2O3–SiO2-ASA), which is meant to act as an antioxidative agent on rat peritoneal macrophages. Both types of nanoparticles were phagocytosed by macrophages in large amounts as confirmed by transmission electron microscopy and Prusian blue staining, however they did not substantially affect the viability of exposed cells in monitored intervals. We further explored cytotoxic effects related to oxidative stress, which is frequently documented in cells exposed to nanoparticles. Our analysis of double strand breaks (DSBs) marker γH2AX showed an increased number of DSBs in cells treated with nanoparticles. Nanoparticle exposure further revealed only slight changes in the expression of genes involved in oxidative stress response. Lipid peroxidation, another marker of oxidative stress, was not significantly affirmed after nanoparticle exposure. Our data indicate that the effect of both types of nanoparticles on cell viability, or biomolecules such as DNA or lipids, was similar; however the presence of ascorbic acid, either bound to the nanoparticles or added to the cultivation medium, worsened the negative effect of nanoparticles in various tests performed. The attachment of ascorbic acid on the surface of nanoparticles did not have a protective effect against induced cytotoxicity, as expected. [ABSTRACT FROM AUTHOR]

The cytopoxic effect of RL2 lactaptin (the recombinant analog of proteolytic fragment of human kappa‐casein) toward tumor cells in vitro and in vivo presents it as a novel promising antitumor drug. The binding of any drug with serum proteins can affect their activity, distribution, rate of excretion and toxicity in the human body. Here, we studied the ability of RL2 to bind to various blood serum proteins. Using magnetic microparticles bearing by RL2 as an affinity matrix, in combination with mass spectrometry and western blot analysis, we found a number of blood serum proteins possessing affinity for RL2. Among them IgA, IgM and IgG subclasses of immunoglobulins, apolipoprotein A1 and various cortactin isoforms were identified. This data suggests that in the bloodstream RL2 lactaptin takes part in complicate protein–protein interactions, which can affect its activity. [ABSTRACT FROM AUTHOR]

Biocompatible poly(4‐styrenesulfonic acid‐co‐maleic acid)‐stabilized GdF3 : Eu3+(Tb3+) nanoparticles were obtained by a one‐step coprecipitation method in ethylene glycol or water. The particles are very small (3 nm), have a narrow size distribution, and were detectable by fluorescence, magnetic resonance, and X‐ray contrast imaging. These properties allow multimodal imaging, which has prospective applications in the simultaneous and detailed detection of diseased tissues. [ABSTRACT FROM AUTHOR]

The efficiency of solid phase extraction (SPE) of DNA on polymer particles is limited by the features of the applied solid support, such as size, hydrophilicity, and functionality and their application in SPE also requires additional steps and compounds to finally obtain sufficient amount of high-quality DNA. The present study describes a preparation of sub-micrometer monodisperse poly(methacrylic acid-co-ethylene dimethacrylate) (PME) particles by precipitation polymerization. The effect of the ethylene dimethacrylate (EDMA) crosslinker concentration on morphology and particle size, which varied from 730 to 900 nm, was investigated. The particles with 5 and 15 wt% EDMA were selected for a study of SPE of plasmid DNA under various adsorption and elution conditions, followed by the enzymatic restriction of isolated DNA to verify a quality the nucleic acid. The particles with 15 wt% EDMA were suitable for the SPE because they retained better colloidal stability during the adsorption without additional induction of DNA conformational change. The quality of isolated DNA was finally verified by enzymatic restriction by restriction endonuclease EcoRI. Moreover, the developed method using PME particles was successfully utilized for DNA isolation from Escherichia coli lysate. [ABSTRACT FROM AUTHOR]

Isolation of deoxyribonucleic acid is an important step in the molecular diagnostics of microorganisms. A high quality of isolated deoxyribonucleic acid is necessary for deoxyribonucleic acid amplification by the polymerase chain reaction. The conventional deoxyribonucleic acid isolation using phenol–chloroform extraction and deoxyribonucleic acid precipitation in ethanol is time-consuming and requires the use of toxic phenol. Magnetic separation techniques using magnetic solid particles are one of modern methods to speed up the nucleic acids isolation. The aim of this work was to use two different types of magnetic particles for solid-phase deoxyribonucleic acid extraction. The amounts of deoxyribonucleic acid in separation mixtures were measured using ultraviolet spectrophotometry. The first experimental conditions were tested on chicken erythrocytes deoxyribonucleic acid. Phosphate buffer (pH 7, 7.6 and 8) was used for the adsorption of deoxyribonucleic acid on magnetic particles. Tested values of pH have no effects on deoxyribonucleic acid adsorption. It was shown that approximately almost one half of deoxyribonucleic acid was adsorbed to the particles. A number of different elution conditions (temperature, time and pH value of elution buffer) were investigated to determine their effect on elution efficiency. It was shown that only a small fraction of the bound DNA was released at 22 °C, while the release was more effective as the temperature was increased also the amount of elution deoxyribonucleic acid was more effective when time was increased. The higher amounts of deoxyribonucleic acid were eluted with TE buffer pH 9.0. Second, bacterial deoxyribonucleic acid was tested. This deoxyribonucleic acid eluted from the particles was in polymerase chain reaction ready quality. [ABSTRACT FROM AUTHOR]

Innovative nanotechnology aims to develop particles that are small, monodisperse, smart, and do not cause unintentional side effects. Uniform magnetic Fe3O4 nanoparticles (12 nm in size) were prepared by thermal decomposition of iron(III) oleate. To make them colloidally stable and dispersible in water and cell culture medium, they were modified with phosphonic acid- (PA) and hydroxamic acid (HA)-terminated poly(ethylene glycol) yielding PA-PEG@Fe3O4 and HA-PEG@Fe3O4 nanoparticles; conventional γ-Fe2O3 particles were prepared as a control. Advanced techniques were used to evaluate the properties and safety of the particles. Completeness of the nanoparticle coating was tested by real-time polymerase chain reaction. Interaction of the particles with primary human peripheral blood cells, cellular uptake, cytotoxicity, and immunotoxicity were also investigated. Amount of internalized iron in peripheral blood mononuclear cells was 72, 38, and 25 pg Fe/cell for HA-PEG@Fe3O4, γ-Fe2O3, and PA-PEG@Fe3O4, respectively. Nanoparticles were localized within the cytoplasm and in the extracellular space. No cytotoxic effect of both PEGylated nanoparticles was observed (0.12–75 μg/cm2) after 24 and 72-h incubation. Moreover, no suppressive effect was found on the proliferative activity of T-lymphocytes and T-dependent B-cell response, phagocytic activity of monocytes and granulocytes, and respiratory burst of phagocytes. Similarly, no cytotoxic effect of γ-Fe2O3 particles was observed. However, they suppressed the proliferative activity of T-lymphocytes (75 μg/cm2, 72 h) and also decreased the phagocytic activity of monocytes (15 μg/cm2, 24 h; 3–75 μg/cm2, 72 h). We thus show that newly developed particles have great potential especially in cancer diagnostics and therapy. [ABSTRACT FROM AUTHOR]

A method for the microextraction of DNA from raw vegetables and highly processed foods of plant origin suitable for PCR analysis was developed. It is based on non-selective binding of DNA in the presence of PEG 6,000/NaCl to hydrophilic magnetic nonporous poly(2-hydroxyethyl methacrylate- co-glycidyl methacrylate) - P(HEMA- co-GMA) microspheres covered by carboxyl groups. The quantitative polymerase chain reaction (qPCR) by in-house designed primers targeting a highly repetitive rDNA locus allowed for detection of plant DNAs in a wide range of concentrations (0.1 pg/μL to 10 ng/μL). The described procedure is fast and simple. We further demonstrate that relatively mild acidic treatment of vegetable at elevated temperatures resulted in a dramatic reduction of PCR efficiency indicating extensive degradation of DNA during pickling. The described method is suitable for the analysis of highly degraded DNA from pickled food products. Practical applications DNA-based methods, such as the polymerase chain reaction (PCR), represent an important genetic approach for identification of plant species composition of foods. DNA from processed foods varies in both quality and quantity between the protocols used. Plant samples are generally characterised by a complex composition containing various inhibitors of PCR. Current methods have been tailored for specific samples while no universal protocol is available. Development of a simple universal procedure leading to PCR-ready DNA would be beneficial. Isolation strategies based on solid phase systems have become popular for PCR-ready DNA isolations from complex matrices. Here we applied magnetic hydrophilic P(HEMA- co-GMA) microspheres to extract DNA from raw vegetables and highly processed foods of plant origin. Proposed small scale PCR-ready DNA extraction protocol was comparable with a silica-based DNeasy Plant Mini Kit (Qiagen) and classical CTAB extraction methods in quality and amplificability of DNA while it is less costly and time consuming. [ABSTRACT FROM AUTHOR]

The aim of the present study is to develop new magnetic polymer microspheres with functional groups available for easy protein and antibody binding. Monodisperse macroporous poly(2-hydroxyethyl methacrylate) (PHEMA-COOH) microspheres ∼4 μm in diameter and containing ∼1 mmol COOH/g were synthesized by multistep swelling polymerization of 2-hydroxyethyl methacrylate (HEMA), ethylene dimethacrylate (EDMA), and 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA), which was followed by MCMEMA hydrolysis. The microspheres were rendered magnetic by precipitation of iron oxide inside the pores, which made them easily separable in a magnetic field. Properties of the resulting magnetic poly(2-hydroxyethyl methacrylate) (mgt.PHEMA) particles with COOH functionality were examined by scanning and transmission electron microscopy (SEM and TEM), static volumetric adsorption of helium and nitrogen, mercury porosimetry, Fourier transform infrared (FTIR) and atomic absorption spectroscopy (AAS), and elemental analysis. Mgt.PHEMA microspheres were coupled with p46/Myo1C protein purified from blood serum of multiple sclerosis (MS) patients, which enabled easy isolation of monospecific anti-p46/Myo1C immunoglobulin G (IgG) antibodies from crude antibody preparations of mouse blood serum. High efficiency of this approach was confirmed by SDS/PAGE, Western blot, and dot blot analyses. The newly developed mgt.PHEMA microspheres conjugated with a potential disease biomarker, p46/Myo1C protein, are thus a promising tool for affinity purification of antibodies, which can improve diagnosis and treatment of MS patients. [ABSTRACT FROM AUTHOR]

ABSTRACT Nonspecific interaction is a key parameter affecting the efficiency of proteins, nucleic acids or cell separation. Currently, many approaches to introduce antifouling properties to materials have been developed. Among these, surface modification with polymer brushes plays a prominent role. The aim of this study was to synthesize new magnetic microspheres grafted with poly( N,N-dimethylacrylamide) (PDMA) that resist nonspecific protein adsorption. Monodisperse macroporous poly(2-hydroxyethyl methacrylate) (PHEMA) microspheres, 4 μm in size, were synthesized by a multiple swelling polymerization method. To render the microspheres magnetic, iron oxide was precipitated inside the microsphere pores. Functional carboxyl groups, introduced by the hydrolysis of the 2-(methacryloyl)oxyethyl acetate (HEMA-Ac) comonomer, were used to react with propargylamine, followed by coupling of a chain transfer agent via an azide-alkyne click reaction. PDMA was grafted from the PHEMA microspheres using reversible addition-fragmentation chain transfer polymerization (RAFT), resulting in surfaces with more than 81 wt % PDMA attached. The successful modification of the microspheres was confirmed by XPS. The magnetic microspheres grafted with PDMA showed excellent antifouling properties as tested in bovine serum protein solutions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1036-1043 [ABSTRACT FROM AUTHOR]

ABSTRACT The minimization of nonspecific protein adsorption is a crucial step in the development of bioseparation processes, immunoassays, and affinity diagnostics. Among the numerous biomaterials, polyzwitterions are known to effectively suppress protein and cell adhesion. This article describes the formation of monodisperse polymer microspheres coated with polysulfobetaine with the aim to limit nonspecific adsorption of bovine serum albumin (BSA) as a model protein. In this process, 2-μm poly(glycidyl methacrylate) (PGMA) microspheres were prepared by dispersion polymerization. To render the microspheres hydrophilic and biocompatible, [3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide (MPDSAH) was grafted from the surface by reversible addition-fragmentation chain transfer (RAFT) polymerization. Elemental analysis of the modified microspheres revealed up to 20 wt % of poly{[3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonimum hydroxide} (PMPDSAH). The microspheres were characterized in terms of particle size, morphology, and zeta potential. The amount of BSA nonspecifically adsorbed on the PMPDSAH-modified microspheres decreased to half of that captured on the unmodified PGMA microspheres. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2273-2284 [ABSTRACT FROM AUTHOR]

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-Fe2O3) 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-Fe2O3 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-Fe2O3 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-Fe2O3 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. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1141-1148, 2015. [ABSTRACT FROM AUTHOR]

Monodisperse superparamagnetic iron oxide nanoparticles of controlled size were synthesized by thermal decomposition of organic iron compounds in different high-boiling solvents in the presence of oleic acid and/or oleylamine. The compounds included Fe(III) oleate and mandelate, formed from FeCl and the respective acids. The size of the nanoparticles was easily tuned to 8-27 nm by varying the experimental conditions. The nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and magnetization measurements. The hydrophobic coating of the particles was analyzed by thermogravimetric analysis (TGA) and atomic absorption spectroscopy (AAS). To make the particles biocompatible and water dispersible, nontoxic hydrophilic poly(ethylene glycol) derivatives were synthesized and used for phase transfer of hydrophobic particles into water using a ligand-exchange procedure. [ABSTRACT FROM AUTHOR]

Superporous poly(2-hydroxyethyl methacrylate) is successfully used as a scaffold material for tissue engineering; however, it lacks functional groups that support cell adhesion. The objective of this study was to investigate the cell-adhesive properties of biomimetic ligands, such as laminin-derived Ac-CGGASIKVAVS-OH (SIKVAV) peptide and fibronectin subunits (Fn), as well as small molecules exemplified by 2-mercaptoethanol (ME) and cysteine (Cys), immobilized on a copolymer of 2-hydroxyethyl methacrylate (HEMA) with 2-aminoethyl methacrylate (AEMA) by a maleimide-thiol coupling reaction. The maleimide group was introduced to the P(HEMA-AEMA) hydrogels by the reaction of their amino groups with N-γ-maleimidobutyryl-oxysuccinimide ester (GMBS). Mesenchymal stem cells (MSCs) were used to investigate the cell adhesive properties of the modified hydrogels. A significantly larger area of cell growth as well as a higher cell density were found on Fn- and SIKVAV-modified hydrogels when compared to the ME- and Cys-modified supports or neat P(HEMA-AEMA). Moreover, Fn-modification strongly stimulated cell proliferation. The ability of MSCs to differentiate into adipocytes and osteoblasts was maintained on both Fn- and SIKVAV-modifications, but it was reduced on ME-modified hydrogels and neat P(HEMA-AEMA). The results show that the immobilization of SIKVAV and Fn-subunits onto superporous P(HEMA-AEMA) hydrogels via a GMBS coupling reaction improves cell adhesive properties. The high proliferative activity observed on Fn-modified hydrogels suggests that the immobilized Fn-subunits maintain their bioactivity and thus represent a promising tool for application in tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2315-2323, 2014. [ABSTRACT FROM AUTHOR]

PLGA (poly d, l-lactic- co-glycolic acid) nanoparticles (NPs) encapsulating magnetite nanoparticles (MNPs) along with a model drug human serum albumin (HSA) were prepared by double emulsion solvent evaporation method. This Part I will focus on size and size distribution of prepared NPs, whereas encapsulation efficiency will be discussed in Part II. It was found that mean hydrodynamic particle size was influenced by five important process variables. To explore their effects, a five-factorial, three-level experimental design and statistical analysis were carried out using STATISTICA® software. Effect of process variables on the mean size of nanoparticles was investigated and finally conditions to minimize size of NPs were proposed. GAMS™/MINOS software was used for optimization. The mean hydrodynamic size of nanoparticles ranged from 115 to 329 nm depending on the process conditions. Smallest possible mean particle size can be achieved by using low polymer concentration and high dispersion energy (enough sonication time) along with small aqueous/organic volume ratio. [ABSTRACT FROM AUTHOR]