Water-soluble Fe3O4 Nanoparticles Research Articles

Calixarenes functionalised water-soluble iron oxide magnetite nanoparticles for enzyme immobilisation

ABSTRACT In this study, we first used water-soluble iron oxide nanoparticles for Candida rugosa lipase immobilisation. Moreover, two new complexation phenomena of the prepared water-soluble Fe3O4 nanoparticles with an enzyme might address interesting results in terms of enzyme activity and stability in typical enzymatic reactions. The catalytic activity on pH and temperature dependence, and reusability of the immobilised lipases ( p-SCX4-NP-E and p-SCX8-NP-E) were also investigated with the hydrolysis reaction of p-nitrophenyl palmitate (p-NPP). The results show that the highest catalytic affinities for p-SCX4-NP-E and p-SCX8-NP-E were obtained at pH 5.0 and pH 7.0, respectively.

PH and NIR-light-responsive magnetic iron oxide nanoparticles for mitochondria-mediated apoptotic cell death induced by chemo-photothermal therapy

Recently, various therapeutic strategies in anticancer drug development are focused to reduce adverse side effects and to enhance the therapeutic efficacy. Mostly, the iron oxide (Fe3O4) nanoparticles have widely been utilized as an efficient drug delivery system towing to their unique properties such as excellent magnetic behavior, considerably low toxicity, easy surface modification and high drug-loading efficacy. In the present study, we synthesized a multifunctional, DMSA coated, water soluble Fe3O4 nanoparticles (Fe3O4@DMSA/DOX) for an effective pH and NIR-light triggered delivery of anticancer drug (DOX) in cancer therapy. The combination of photothermal therapy combined with chemotherapy results demonstrated that the synthesized Fe3O4@DMSA/DOX is an excellent candidate for pH- and NIR-light induced phothothermal agent for an effective delivery of anticancer drug (DOX) into the target sub-cellular level into the human breast cancer (MDA-MB-231) cells. Furthermore, the Fe3O4@DMSA/DOX nanoparticles induced an excellent temperature elevation upon NIR light irradiation and controlled DOX release in vitro. The Fe3O4@DMSA/DOX nanoparticles exhibited synergistic effect when combining chemotherapy with photothermal therapy and showed an excellent cell toxicity to MDA-MB-231 cells. In addition, the combined chemo-photothermal therapy of Fe3O4@DMSA/DOX nanoparticles promoted an effective cell death by mitochondrial disruption mediated by ROS generation. Thus, the synthesized Fe3O4@DMSA/DOX nanoparticles could be utilized as potential anticancer agents for breast cancer treatment.

Water-soluble Fe3O4 nanoparticles with high solubility for removal of heavy-metal ions from waste water

In this contribution, we synthesized water-soluble Fe(3)O(4) nanoparticles (NPs) with sufficiently high solubility (28 mg mL(-1)) and stability (at least one month) through a hydrothermal approach, and found that they exhibited excellent removal ability for heavy-metal ions from waste water. For the first time, the water-soluble Fe(3)O(4) NPs were used as adsorbents for heavy-metals removal from wastewater. It is noteworthy that the adsorption ability of the water-soluble Fe(3)O(4) NPs for Pb(2+) and Cr(6+) is stronger than water-insoluble Fe(3)O(4) NPs. Furthermore, the water-soluble Fe(3)O(4) NPs exhibited relatively high saturation magnetization (83.4 emu g(-1)), which allowed their highly-efficient magnetic separation from wastewater. The most important thing is that the water-soluble magnetite as an adsorbent can directly dissolve in water without the help of mechanical stirring or any extraneous forces, which may solve a key problem for the practical application of magnetic powders in the field of sewage purification. Moreover, the water-soluble Fe(3)O(4) NPs show a highly-efficient adsorption capacity for 10 ppm of Pb(2+) ions solution which can reach 90% within 2 minutes.

Synthesis of PEO-based glucose-sensitive block copolymers and their application for preparation of superparamagnetic iron oxide nanoparticles

Amphiphilic block copolymers were synthesized by reversible addition fragmentation chain transfer (RAFT) radical block polymerization of N-vinylimidazole and 3-(methacrylamido)phenylboronic acid using poly (ethylene oxide) (PEO)-based xanthate type of RAFT agent and 2,2′-azobisisobutyronitrile (AIBN) in dimethylformaide (DMF) at 90∼110 °C for 24 h. Poly(ethylene oxide-b-3-(methacrylamido)phenylboronic acid) and poly(ethylene oxide-b-N-vinylimidazole-b-3-(methacrylamido)phenylboronic acid) were prepared successfully through the sequential monomer addition method. Both block copolymers were found to exhibit glucose-responsive behavior via the feasibility test for complex formation with Alizarin Red S (ARS). The ratio of molecular weight of the poly(N-vinyimidazole) to the poly(3-(methacrylamido)phenylboronic acid) appeared to play an important role in the pH- & glucose-responsive behavior. The resulting block copolymers were used successfully as polymeric stabilizers to prepare water-soluble Fe3O4 nanoparticles. All the materials were characterized by the combination of 1H nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and x-ray diffraction (XRD) analyses.

Facile Fabrication of Water-Soluble Magnetic Nanoparticles and Their Spherical Aggregates

In this paper, we report a facile synthetic approach for preparing water-soluble Fe3O4 nanoparticles with a surface-surrounded layer by the use of polyethylene glycol(5) nonylphenyl ether (NP5) and cyclodextrin (CD) in aqueous medium and also for building nanostructured spherical aggregates from individual magnetic nanoparticles, which were dependent on the concentration of CD and NP5, respectively. The morphology of Fe3O4 nanoparticles was studied by transmission electron microscopy. The mesoporous, spherical aggregates of Fe3O4 particles possessed a BET surface area of ca. 141.1 m2 g-1 without compromising that of the separated Fe3O4 nanoparticles with coating (164.6 m2 g-1) and still possessed magnetic properties. This method is very meaningful because it directly produces water-soluble magnetic nanoparticles, which is very important for applications of magnetic nanoparticles in biomedical fields and nanostructured spherical aggregates as magnetic carriers.

Controlled Synthesis of <I>Y</I>-Junction Polyaniline Nanorods and Nanotubes Using <I>In Situ</I> Self-Assembly of Magnetic Nanoparticles

Novel Y-junction polyaniline (PANI) nanorods and nanotubes (40-100 nm in diameter and a few micrometers in length) were selectively prepared, for the first time, using in situ self-assembly of water-soluble Fe3O4 nanoparticles coated with polyethylene glycol(5) nonylphenyl ether (NP5) and cyclodextrin (CD) as templates and pH control in an aqueous medium. The morphology of Fe3O4 nanoparticles and the PANI nanostructures (rods and tubes) was determined by TEM and the effects of reaction conditions on the morphology of PANI nanostructures were also studied. Characterization experiments including FTIR and X-ray diffraction were carried out to study the chemical and electronic structures of the PANI nanostructures.

Three-Layer Composite Magnetic Nanoparticle Probes for DNA

A method for synthesizing composite nanoparticles with a gold shell, an Fe3O4 inner shell, and a silica core has been developed. The approach utilizes positively charged amino-modified SiO2 particles as templates for the assembly of negatively charged 15 nm superparamagnetic water-soluble Fe3O4 nanoparticles. The SiO2-Fe3O4 particles electrostatically attract 1-3 nm Au nanoparticle seeds that act in a subsequent step as nucleation sites for the formation of a continuous gold shell around the SiO2-Fe3O4 particles upon HAuCl4 reduction. The three-layer magnetic nanoparticles, when functionalized with oligonucleotides, exhibit the surface chemistry, optical properties, and cooperative DNA binding properties of gold nanoparticle probes, but the magnetic properties of the Fe3O4 inner shell.

Controlled synthesis of polyaniline nanostructures with junctions using in situ self-assembly of magnetic nanoparticles

Novel Y-junction polyaniline (PANI) nanorods and nanotubes (40–100 nm in diameter and a few micrometers in length) were selectively prepared, for the first time, using in situ self-assembly of water-soluble Fe3O4 nanoparticles coated with polyethylene glycol(5) nonylphenyl ether (NP5) and cyclodextrin (CD) as templates and pH control in an aqueous medium. The morphology of the Fe3O4 nanoparticles and the PANI nanostructures (rods and tubes) was determined by TEM and the effects of reaction conditions such as the concentration of aniline and organic solvent on the morphology of the PANI nanostructures were also studied. Characterization experiments including FTIR, UV-vis spectrometry and X-ray diffraction were carried out to study the chemical and electronic structures of the PANI nanostructures.