Influence of surface-modified maghemite nanoparticles on in vitro survival of human stem cells

• Michal Babič,
• Daniel Horák,
• Lyubov L. Lukash,
• Tetiana A. Ruban,
• Yurii N. Kolomiets,
• Svitlana P. Shpylova and
• Oksana A. Grypych

Beilstein J. Nanotechnol. 2014, 5, 1732–1737, doi:10.3762/bjnano.5.183

• (magnetite Fe3O4 or maghemite γ-Fe2O3) are their simple preparation and their magnetic properties, which are necessary for detection. Moreover, it is convenient that iron oxides are readily metabolized in the body. From this point of view, quantum dots are disqualified due to their toxicity. Like in every

A sonochemical approach to the direct surface functionalization of superparamagnetic iron oxide nanoparticles with (3-aminopropyl)triethoxysilane

• Bashiru Kayode Sodipo and
• Azlan Abdul Aziz

Beilstein J. Nanotechnol. 2014, 5, 1472–1476, doi:10.3762/bjnano.5.160

• silanol groups to form siloxane (Si–O–Si) bonds. The successful grafting of the APTES molecules on the SPION is verified through FTIR analysis (Figure 1). In both spectra, the peaks of the magnetite (Fe–O–Fe) band split into two. The energy absorbed at 628 and 573 cm−1 corresponds to the first band. The

• second band is observed at 441 cm−1 which is assigned to the Fe–O bond of bulk magnetite at 375 cm−1. The formation of SPION–APTES is observed in Figure 1b by the 1109 and 1044 cm−1 peaks, which can be assigned to the Si–O–Si bond. The IR absorption lines due to the adsorption of water molecules to the

• standard of either magnetite or maghemite (cubic phase) XRD spectrum. However, the assignment to one of these phases on the basis of the XRD is difficult owing to their related structures. The absence of peaks at 110 and 104 corresponding to goethite and hematite in the spectrum indicate that the co

PEGylated versus non-PEGylated magnetic nanoparticles as camptothecin delivery system

• Paula M. Castillo,
• Mario de la Mata,
• Maria F. Casula,
• José A. Sánchez-Alcázar and
• Ana P. Zaderenko

Beilstein J. Nanotechnol. 2014, 5, 1312–1319, doi:10.3762/bjnano.5.144

• coating further reduces SPION cytotoxicity [36]. Moreover, PEGylated CPT has demonstrated its capability to lock the CPT E ring in its desired active lactone configuration [37]. Herein, we report a simple method to synthesise PEG-coated ultrasmall magnetite (USM) nanoparticles, and we examine the ability

• (Figure 2c). Further insights into the crystalline structure were obtained from X-ray diffraction (XRD) patterns. Figure 3 reports the XRD pattern of our USM nanoparticles compared to a reference of a commercial magnetite standard. Although it is not possible to unambiguously ascribe the obtained pattern

• for USM nanoparticles to magnetite rather than to the isostructural spinel ferric iron oxide (maghemite), the XRD sample of the USM nanoparticles is consistent with the formation of magnetite. The peak broadening of the XRD pattern of the USM sample is in agreement with its nanocrystalline form. In

Antimicrobial nanospheres thin coatings prepared by advanced pulsed laser technique

• Alina Maria Holban,
• Valentina Grumezescu,
• Alexandru Mihai Grumezescu,
• Bogdan Ştefan Vasile,
• Roxana Truşcă,
• Rodica Cristescu,
• Gabriel Socol and
• Florin Iordache

Beilstein J. Nanotechnol. 2014, 5, 872–880, doi:10.3762/bjnano.5.99

• -chitosan-magnetite-eugenol (PLA-CS-Fe3O4@EUG) nanospheres by matrix assisted pulsed laser evaporation (MAPLE). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) investigation proved that the homogenous Fe3O4@EUG nanoparticles have an average diameter of about 7 nm, while the PLA

• ) bacteria strains. Moreover, the obtained nano-coatings showed a good biocompatibility and facilitated the normal development of human endothelial cells. These nanosystems may be used as efficient alternatives in treating and preventing bacterial infections. Keywords: antimicrobial; chitosan; magnetite

• nanoparticles; nanospheres; P. aeruginosa; polylactic acid; S. aureus; Introduction Driven by more and more microbial antibiotic resistance, alternative therapeutic approaches are emerging [1][2][3][4]. Polar and nonpolar, functionalized and non-functionalized magnetite nanostructures have proven successfully

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• of iron salts, namely FeCl2 and FeCl3, by rapid increase of pH by ammonia. Similarly as described in [12], this was followed by the oxidation of the resulting magnetite (Fe3O4) with sodium hypochlorite producing maghemite (γ-Fe2O3), which is chemically more stable than Fe3O4. This is in contrast to

• magnetite, which undergoes spontaneous oxidation by air. Proof of the maghemite by Mössbauer spectroscopy and powder X-ray diffraction, as well as its magnetic properties were described in our previous reports [15][16]. The neat γ-Fe2O3 nanoparticles were used in control experiments with cells or were used

• solution (350 mL) under a nitrogen atmosphere. The resulting coagualate of magnetite was left to grow for 45 min under nitrogen atmosphere, then magnetically separated and repeatedly (7–10×) washed (peptized) with Q-water to remove all impurities (including NH4Cl) remaining after the synthesis. Finally

Thermal stability and reduction of iron oxide nanowires at moderate temperatures

• Annalisa Paolone,
• Marco Angelucci,
• Stefania Panero,
• Maria Grazia Betti and
• Carlo Mariani

Beilstein J. Nanotechnol. 2014, 5, 323–328, doi:10.3762/bjnano.5.36

• infrared spectrum of the sample heated at 470 K (sample 3) is very similar to that of sample 2, while after the thermal treatment at 560 K (sample 4), the minimum around 700 cm−1 becomes deeper and the transmittance below 600 cm−1 decreases, which strongly resembles the infrared spectrum of magnetite

• treatment at T2 = 560 K. Moreover, at T2 a significant part of the sample is transformed into magnetite. We remark that the IR spectra are measured in transmission mode, so that they probe the whole thickness of the NW powders and are not limited to their surface. This issue is important to compare the IR

Magnetic interactions between nanoparticles

• Steen Mørup,
• Mikkel Fougt Hansen and
• Cathrine Frandsen

Beilstein J. Nanotechnol. 2010, 1, 182–190, doi:10.3762/bjnano.1.22

• direction in a double chain of 24 ~70 nm magnetite (Fe3O4) particles in magnetotactic bacteria [33], and it has resolved magnetic flux closure in small rings of 5–7 Co particles with a diameter of about 25 nm [32]. Influence of exchange coupling between nanoparticles on magnetic relaxation In a perfect

Magnetic nanoparticles for biomedical NMR-based diagnostics

• Huilin Shao,
• Tae-Jong Yoon,
• Monty Liong,
• Ralph Weissleder and
• Hakho Lee

Beilstein J. Nanotechnol. 2010, 1, 142–154, doi:10.3762/bjnano.1.17

• ][37][38][39][40][41][42]. CLIO nanoparticles contain a superparamagnetic iron oxide core (3–5 nm monocrystalline iron oxide) composed of ferrimagnetic magnetite (Fe3O4) and/or maghemite (γ-Fe2O3). The metallic core is subsequently coated with biocompatible dextran, before being cross-linked with

Uniform excitations in magnetic nanoparticles

• Steen Mørup,
• Cathrine Frandsen and
• Mikkel Fougt Hansen

Beilstein J. Nanotechnol. 2010, 1, 48–54, doi:10.3762/bjnano.1.6

• Equation 1, and the latter approximation is valid at low temperatures. The linear temperature dependence of the magnetization in nanoparticles was first observed by Mössbauer spectroscopy studies of magnetite (Fe3O4) nanoparticles [3], but it has later been studied in nanoparticles of several other

• the relaxation is fast compared to the timescale of Mössbauer spectroscopy, and the observed magnetic hyperfine field is then given by where B0 is the saturation hyperfine field. Figure 3 shows the temperature dependence of the magnetic hyperfine field of three samples of magnetite (Fe3O4

• dependence of the magnetization. TB is the superparamagnetic blocking temperature and TC is the Curie temperature. The reduced average magnetic hyperfine field as a function of temperature for particles of magnetite with sizes of 6 nm, 10 nm and 12 nm. The solid lines are the best linear fits to the