An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

• . Consequently, multi-domain nanoparticles exhibit a lower hysteresis loss than single-domain nanoparticles [4]. For both theoretical and experimental researches in this field, choosing the right parameters of superparamagnetic nanoparticle systems to control magnetic hyperthermia is an important task [3][8][9

• superparamagnetic behaviour [15]. The typical time between two flips is called relaxation time, and the reversal process is called relaxation process. In nanofluids, the superparamagnetic nanoparticles have two associated relaxation processes: the Néel relaxation process and Brownian relaxation process. The former

• nanoparticle causes changes in the orientation of its magnetization [16]. At the limit between hysteretic and superparamagnetic regime, under biomedical conditions of amplitude and frequency of the external magnetic field, susceptibility losses in magnetic colloids can be described by linear response theory

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• blocking temperature (TB) of the sample. The result of the ZFC and FC measurements confirmed the superparamagnetic behavior of the nanocrystals [36]. Below the blocking temperature, the material is ferromagnetic, and above TB, it is superparamagnetic [33]. The values for the TB are given in Table 2. TB

Synthesis, characterization and in vitro biocompatibility study of Au/TMC/Fe₃O₄ nanocomposites as a promising, nontoxic system for biomedical applications

• Hanieh Shirazi,
• Maryam Daneshpour,
• Soheila Kashanian and
• Kobra Omidfar

Beilstein J. Nanotechnol. 2015, 6, 1677–1689, doi:10.3762/bjnano.6.170

• behavior as compared to TMC. The zero remanence and coercivity values indicated the superparamagnetic nature of these nanoparticles. In accordance with the direct relation between crystallinity and magnetization of magnetic nanoparticles, these results confirm the crystallinity of the nanoparticle systems

Structural and magnetic properties of iron nanowires and iron nanoparticles fabricated through a reduction reaction

• Marcin Krajewski,
• Wei Syuan Lin,
• Hong Ming Lin,
• Katarzyna Brzozka,
• Sabina Lewinska,
• Natalia Nedelko,
• Anna Slawska-Waniewska,
• Jolanta Borysiuk and
• Dariusz Wasik

Beilstein J. Nanotechnol. 2015, 6, 1652–1660, doi:10.3762/bjnano.6.167

• different applications. For instance, in the case of drug delivery systems nanostructures need to exhibit rather superparamagnetic behaviour with low coercivity. On the other hand, in the case of magnetic recording media there are needed materials with a high value of coercivity. Thus, it is very important

Thermal treatment of magnetite nanoparticles

• Beata Kalska-Szostko,
• Urszula Wykowska,
• Dariusz Satula and
• Per Nordblad

Beilstein J. Nanotechnol. 2015, 6, 1385–1396, doi:10.3762/bjnano.6.143

• one of the most investigated materials due to its unusual magnetic properties. In addition, it is recognized as an inert compound that is almost entirely nontoxic to living organisms [1]. Apart from that, iron and its oxides on the nanometer scale can possess superparamagnetic properties, allowing for

• ) [42]. The measured RT Mössbauer spectra show that the particles are not in a superparamagnetic state, which means that all particles fall in size below superparamagnetic blocking temperature (TB) but the reminiscence of superparamagnetic doublet is detected in the center of the spectra [43]. For the

• sensitive to the oxidation process in comparison to other particles. A possible explanation of the observed scenario is that the nanoparticles have different inherent structures that significantly influence the superparamagnetic blocking temperature. One argument is that the MNP-1 particles, which can be

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• using different contrast agents (CAs). The ideal CA should be stable, tissue specific, less toxic with longer shelf life and a reasonable clearing period. The most common MRI CAs are paramagnetic chelated lanthanide complexes (positive contrast, T1-enhanced) and superparamagnetic iron oxide NPs

• process was done at about 42 °C temperature under an applied AC magnetic field (250 kHz, 376 Oe). The results suggested that tumour cell death was low for DOX-loaded YVO4-MSN as compare to superparamagnetic ion oxide nanoparticles (SPIONs)-loaded DOX@YVO4-MSN in an oscillating AC magnetic field. 2.2

• oxide or lanthanide complexes as magnetic and ruthenium or lanthanide complexes as fluorescent probe Superparamagnetic iron oxide NPs have been widely studied as MRI contrast agents for biological systems. These are less toxic compared to their chelated lanthanide counterparts. Again, because of the

Hematopoietic and mesenchymal stem cells: polymeric nanoparticle uptake and lineage differentiation

• Ivonne Brüstle,
• Thomas Simmet,
• Gerd Ulrich Nienhaus,
• Katharina Landfester and
• Volker Mailänder

Beilstein J. Nanotechnol. 2015, 6, 383–395, doi:10.3762/bjnano.6.38

• hMSCs have been used in many studies, only a limited number of studies with these cells have been undertaken [1]. Cells labeled with superparamagnetic nanoparticles can be tracked after transplantation using MRI methods [23]. This approach allows for a deeper knowledge about the biological distribution

Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

• Nils Bohmer and
• Andreas Jordan

Beilstein J. Nanotechnol. 2015, 6, 167–176, doi:10.3762/bjnano.6.16

• line. Cells were transfected with specific siRNAs against Caveolin-1, Dynamin 2, Flotillin-1, Clathrin, PIP5Kα and CDC42. Knockdown of Caveolin-1 reduces endocytosis of superparamagnetic iron oxide nanoparticles (SPIONs) and silica-coated iron oxide nanoparticles (SCIONs) between 23 and 41%, depending

• nanoparticle species, which are taken up specifically by target cells and exploit their maximum potential. In this study differently modified silica coated superparamagnetic iron oxide nanoparticles (SPIONs) and silica coated iron oxide nanoparticles (SCIONs), which were all comparable in their primary size

• and surface charge, were tested in HeLa cells as a model cell line. To elucidate, which molecular pathways are involved in their endocytosis, well-known endocytotic mechanisms [26][27][28] were inhibited by specific knockdown of key proteins via siRNA (Figure 1). Experimental Superparamagnetic iron

Multifunctional layered magnetic composites

• Maria Siglreitmeier,
• Baohu Wu,
• Tina Kollmann,
• Martin Neubauer,
• Gergely Nagy,
• Dietmar Schwahn,
• Vitaliy Pipich,
• Damien Faivre,
• Dirk Zahn,
• Andreas Fery and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2015, 6, 134–148, doi:10.3762/bjnano.6.13

• . Successful and homogeneous gelatin infiltration in between the chitin layers can be shown. The hybrid material is characterized by TEM and shows a layered structure filled with MNPs with a size of around 10 nm. Magnetic analysis of the material demonstrates superparamagnetic behavior as characteristic for

• characteristic for superparamagnetic material [39] with a particle size less than 20 nm. Due to magnetic anisotropy the hysteresis curve at T = 2 K shows ferrimagnetic hysteresis. The saturation magnetization for all analyzed samples is around 26 emu/g at 298 K and 36 emu/g at 2 K which are similar values

• ferrogel loaded chitin scaffolds. From the obtained force versus deformation curves we can already see significant qualitative differences. Figure 12 shows a comparison of pure and nanoparticle-filled gelatin. With the addition of the superparamagnetic particles the slope of the force curves increases, i.e

The distribution and degradation of radiolabeled superparamagnetic iron oxide nanoparticles and quantum dots in mice

• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Markus Heine,
• Christian Waurisch,
• Gordon M. Stachowski,
• Stephen G. Hickey,
• Alexander Eychmüller,
• Jörg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 111–123, doi:10.3762/bjnano.6.11

• , Germany Institute of Physical Chemistry and Electrochemistry, Technical University of Dresden, Bergstr. 66b, 01069 Dresden, Germany 10.3762/bjnano.6.11 Abstract 51Cr-labeled, superparamagnetic, iron oxide nanoparticles (51Cr-SPIOs) and 65Zn-labeled CdSe/CdS/ZnS-quantum dots (65Zn-Qdots) were prepared

• kinetics, targeting efficacy and the acute as well as the chronic toxicity of both nanoparticle systems is needed. We are interested in techniques that allow the quantification of nanoparticles in vivo and have already developed a post-synthetic method to radiolabel the cores of superparamagnetic iron

The fate of a designed protein corona on nanoparticles in vitro and in vivo

• Denise Bargheer,
• Julius Nielsen,
• Gabriella Gébel,
• Markus Heine,
• Sunhild C. Salmen,
• Roland Stauber,
• Horst Weller,
• Joerg Heeren and
• Peter Nielsen

Beilstein J. Nanotechnol. 2015, 6, 36–46, doi:10.3762/bjnano.6.5

• Chemistry, University Hamburg, Grindelallee 117, 20146 Hamburg, Germany Molecular and Cellular Oncology, ENT/University Medical Center Mainz, Langenbeckstr. 1, 55101 Mainz, Germany 10.3762/bjnano.6.5 Abstract A variety of monodisperse superparamagnetic iron oxide particles (SPIOs) was designed in which the

• diagnostic using functionalized SPIOs in magnetic resonance imaging. Experimental Synthesis of nanoparticle The superparamagnetic iron oxide nanoparticle was synthesized according to reported procedures with slight modifications [24]. In brief, a mixture of 0.178 g FeOOH (2.0 mmol), 2.26 g oleic acid (8.0

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• used superparamagnetic iron oxide nanoparticles. Keywords: amino groups; apoptosis; carboxyl groups; cell proliferation; leukemia cell lines; macrophages; mTOR; polystyrene nanoparticles; Review Applications of polystyrene Polystyrene, one of the most extensively used types of plastic [1], is an

• recognition and internalization of particulate matter including nanoparticles. As a consequence, macrophages accumulate with time a main portion of nanoparticles incorporated by the body [25]. Thus, the clinically approved superparamagnetic iron oxide (SPIO) MRI contrast agent ResovistTM is taken up after

Nanoparticle interactions with live cells: Quantitative fluorescence microscopy of nanoparticle size effects

• Li Shang,
• Karin Nienhaus,
• Xiue Jiang,
• Linxiao Yang,
• Katharina Landfester,
• Volker Mailänder,
• Thomas Simmet and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2014, 5, 2388–2397, doi:10.3762/bjnano.5.248

• . Based on studies of the uptake of carboxydextran-coated superparamagnetic iron oxide NPs of 20 and 60 nm by human macrophages, Lunov et al. [49] developed a mathematical model that predicts the wrapping times of different NPs. In addition, the relation between membrane elasticity, cytoskeletal forces

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• magnetic nanoparticles in the late 1970’s for the first time [83]. Nowadays, superparamagnetic iron oxide nanoparticle-based MRI contrast agents are used in clinical applications [84]. Further, iron oxide based nanoparticles are in focus of research for their application as MRI contrast agents, including

Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• Technische Universität Darmstadt, Technical Chemistry, D-64287 Darmstadt, Germany Merck KGaA, D-64287 Darmstadt, Germany 10.3762/bjnano.5.235 Abstract Human serum albumin nanoparticles have been utilized as drug delivery systems for a variety of medical applications. Since ultra-small superparamagnetic

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

• for the above mentioned purposes [9]. Monosized iron oxide nanoparticles, sometimes called ultra-small superparamagnetic iron oxide nanoparticles, play the dominant role. Quantum dots, gold and, recently, also upconversion nanoparticles are used less frequently. The main advantages of iron oxides

• report is to describe the labeling of human fibroblast-like cells with new surface-modified superparamagnetic maghemite nanoparticles both before and after their surface coating with D-mannose or poly(N,N-dimethylacrylamide) and to determine the survival of the cells. Possible cytotoxic effects of the

• ][25]. In particular, PDMAAm-coated γ-Fe2O3 nanoparticles exhibited a long-term colloidal stability even after more than six months of storage. All types of γ-Fe2O3 nanoparticles displayed superparamagnetic behavior [29], which is characterized by a strong response to a magnetic field and zero remanent

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

• Sains Malaysia, 11800 Pulau Pinang, Malaysia 10.3762/bjnano.5.160 Abstract We report a sonochemical method of functionalizing superparamagnetic iron oxide nanoparticles (SPION) with (3-aminopropyl)triethoxysilane (APTES). Mechanical stirring, localized hot spots and other unique conditions generated by

• reaction time was greatly minimized. More importantly, the product displayed superparamagnetic behaviour at room temperature with a more than 20% higher saturation magnetization. Keywords: (3-aminopropyl)triethoxysilane (APTES); functionalization; nanoparticles; silanization; sonochemical

• ; superparamagnetic iron oxide nanoparticles (SPION); Findings Superparamagnetic iron oxide nanoparticles (SPION) have a wide range of applications in biomedical research and development. The main drawbacks of SPION are a high surface energy, van der Waals forces of attraction and dipole to dipole interactions that

The cell-type specific uptake of polymer-coated or micelle-embedded QDs and SPIOs does not provoke an acute pro-inflammatory response in the liver

• Markus Heine,
• Alexander Bartelt,
• Oliver T. Bruns,
• Denise Bargheer,
• Artur Giemsa,
• Barbara Freund,
• Ludger Scheja,
• Christian Waurisch,
• Alexander Eychmüller,
• Rudolph Reimer,
• Horst Weller,
• Peter Nielsen and
• Joerg Heeren

Beilstein J. Nanotechnol. 2014, 5, 1432–1440, doi:10.3762/bjnano.5.155

• .5.155 Abstract Semiconductor quantum dots (QD) and superparamagnetic iron oxide nanocrystals (SPIO) have exceptional physical properties that are well suited for biomedical applications in vitro and in vivo. For future applications, the direct injection of nanocrystals for imaging and therapy represents

• : hepatocytes; inflammation; Kupffer cells; liver sinusoidal endothelial cells; nanoparticle toxicity; nanoparticle uptake; quantum dots; superparamagnetic iron-oxide nanocrystals; Introduction The superior optical properties of QDs compared to organic dyes render them promising candidates for the demands of

• employing various cell culture systems described toxic effects of QDs [3][4]. Iron-containing superparamagnetic iron oxide nanocrystals (SPIOs) used for magnetic resonance imaging (MRI) have a relative good reputation given that iron is an essential trace element and it can be assumed that iron from

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

• chemotherapeutic agent due to its poor water-solubility and chemical instability and, as a consequence, no effective administration means have been designed. In this work, camptothecin has been successfully loaded into iron oxide superparamagnetic nanoparticles with an average size of 14 nm. It was found that

• ; cancer therapy; iron oxide superparamagnetic nanoparticles; polyethylene glycol; Introduction Camptothecin (CPT) is a quinoline based alkaloid, which exhibits a potent cytotoxic activity against a broad spectrum of tumours [1][2][3]. While most antineoplastic agents inhibit cancer cell proliferation by

• by means of nano-formulations cover a wide range of organic nanomaterials [11][12][13][14][15][16][17][18][19]. Noticeably, a cyclodextrin-containing polymer–CPT nano-formulation is currently undergoing phase II clinical trials [20]. Superparamagnetic iron oxide nanoparticles (SPION) are particularly

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

• in nano-neurotechnology. D-Mannose-coated superparamagnetic nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) salts followed by oxidation with sodium hypochlorite and addition of D-mannose. Effects of D-mannose-coated superparamagnetic maghemite (γ-Fe2O3) nanoparticles on key

• showed both negative and positive effects [1]. One of the concerns is that nanoparticles can potentially harm the function of or have toxic effects on human nerve cells owing to their ability to pass through biological membranes [2]. Superparamagnetic iron oxide nanoparticles are considered as promising

• acidification of synaptic vesicles in nerve terminals by using pH-sensitive fluorescent dye acridine orange. Results D-Mannose-coated superparamagnetic γ-Fe2O3 nanoparticles: Synthesis and characterization In this paper, superparamagnetic iron oxide nanoparticles were synthesized by the well-known precipitation

Oriented attachment explains cobalt ferrite nanoparticle growth in bioinspired syntheses

• Annalena Wolff,
• Walid Hetaba,
• Marco Wißbrock,
• Stefan Löffler,
• Nadine Mill,
• Katrin Eckstädt,
• Axel Dreyer,
• Inga Ennen,
• Norbert Sewald,
• Peter Schattschneider and
• Andreas Hütten

Beilstein J. Nanotechnol. 2014, 5, 210–218, doi:10.3762/bjnano.5.23

• -attraction and repulsive forces due to c25-mms6 or hydration layers, are most likely the dominating factors in this process since the small substructures possess diameters below the superparamagnetic limit [9][11]. During the assembly, crystallites grow and form the subunits referred to as primary building

Nanoglasses: a new kind of noncrystalline materials

• Herbert Gleiter

Beilstein J. Nanotechnol. 2013, 4, 517–533, doi:10.3762/bjnano.4.61

• crystallites were revealed in the low temperature Mössbauer spectra [17]. These crystallites are superparamagnetic at ambient temperature. Plastic deformation of nanoglasses Experimental observations: By using microcompression experiments [43], the deformation behaviors of the following two kinds of glasses

Hydrogen-plasma-induced magnetocrystalline anisotropy ordering in self-assembled magnetic nanoparticle monolayers

• Alexander Weddemann,
• Judith Meyer,
• Anna Regtmeier,
• Irina Janzen,
• Dieter Akemeier and
• Andreas Hütten

Beilstein J. Nanotechnol. 2013, 4, 164–172, doi:10.3762/bjnano.4.16

• magnetic properties [3][4] or specific biological surface coatings [5][6] have been established. Such nanocrystals have a nonzero magnetization at zero field because of finite-size effects. Nevertheless, due to their superparamagnetic nature, the effective magnetic moment of an ensemble of noninteracting

• σII = 1.14 nm. According to Hütten et al. [3], the smaller species are superparamagnetic while the larger contain a certain degree of ferromagnetic components. Sample preparation Both samples were prepared in a procedure introduced by Puntes et al. [14] under airless conditions. For the synthesis of

• temperatures of about 300 and 500 °C, respectively. Numerical model In order to obtain a qualitative understanding of the microscopic origin of the experimental findings, simulations of two-dimensional particle arrays are carried out. Since particles of the given size are superparamagnetic, they are

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• important limitation for a significant increase of the areal storage density in magnetic recording is the superparamagnetic effect. Below a critical grain size of the used CoCrPt exchange-decoupled granular films the information cannot be stored for a reasonable time (typically ten years) due to thermal

• magnetic grains with parallel magnetization either pointing up- or downwards. Increasing areal densities of recording bits, while maintaining the signal-to-noise ratio, demands a reduction of the grain size [1]. As a result of the miniaturization, however, the grain size approaches the superparamagnetic

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• release of this agent on contact with hydrocarbons is used as an indication of the presence of oil on recovery of the nanoparticles [10]. In contaminant removal, nanocomposites composed of collagen and superparamagnetic iron-oxide nanoparticles (SPIONs) have been investigated. The collagen selectively