Magnetophoretic Velocity Determined by Space- and Time-Resolved Extinction Profiles

Mykhaylyk, Olga; Lerche, D.; Vlaskou, Dialechti; Schoemig, Veronika; Detloff, Torsten; Krause, Daniel; Wolff, Markus; Joas, T; Berensmeier, Sonja; Plank, Christian

doi:10.1109/lmag.2015.2474306

Cited by 13 publications

(9 citation statements)

References 8 publications

(8 reference statements)

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“…These observations of increasing sedimentation velocity in an external magnetic field are in good agreement with the literature. 53,54 Since the sedimentation velocity does not only change with the salt concentration, but also is significantly enhanced by the externally applied magnetic field (∼53 kA m −1 ), we attempt to quantify the underlying mechanisms by further calculations (Supporting Information). Such a magnetic field leads to magnetic coupling parameters λ which are larger than unity for aggregated iron oxide nanoparticles with a diameter of more than 25 nm (Figure S14).…”

Section: Resultsmentioning

confidence: 99%

Magnetically Induced Aggregation of Iron Oxide Nanoparticles for Carrier Flotation Strategies

Schwaminger

Schwarzenberger

Gatzemeier

et al. 2021

ACS Appl. Mater. Interfaces

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On the nanoscale, iron oxides can be used for multiple applications ranging from medical treatment to biotechnology. We aimed to utilize the specific properties of these nanoparticles for new process concepts in flotation. Magnetic nanoparticles were synthesized by alkaline coprecipitation, leading to a primary particle size of 9 nm, and coated with oleate. The nanomaterial was characterized for its superparamagnetism and its colloidal stability at different ionic strengths, with and without an external magnetic field. The nanomaterial was used for model experiments on magnetic carrier flotation of microplastic particles, based on magnetically induced heteroagglomeration. We were able to demonstrate the magnetically induced aggregation of the nanoparticles which allows for new flotation strategies. Since the nanomaterial has zero remanent magnetization, the agglomeration is reversible which facilitates the process control. Magnetic carrier flotation based on iron oxide nanoparticles can pave the way to promising new recycling processes for microplastic wastes.

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Section: Resultsmentioning

confidence: 99%

Magnetically Induced Aggregation of Iron Oxide Nanoparticles for Carrier Flotation Strategies

Schwaminger

Schwarzenberger

Gatzemeier

et al. 2021

ACS Appl. Mater. Interfaces

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“…Briefly, Adenoviral particles were labeled with a iodine-127 as decribed were and assembled with PEI-Mag2 nanoparticles at different MNP-to-VP ratios in PBS for 30 min or further 1-to-1 diluted with Fetal Calf Serum, incubated for the next 30 and then exposed at the Magnetic Plate for 30 min, non-sedimented radioactivity was measured in a supernatant. To evaluate the rate of the magnetic vectors migration in applied gradient magnetic fields (magnetophoretic velocity) we have registered clarification kinetics of the suspensions by measuring space and time resolved extinction profiles using a customized (LUMiReader ® ) device equipped with a set of permanent magnets as described recently by Mykhaylyk et al [ 30 ]. Concentration changes were detected by multiple extinction profiles taken at time intervals of 1 s with a spatial resolution of 30 μm at an analytical optical wavelength of 410 nm with Neodymium-Iron-Boron-Magnets positioned underneath the cuvette.…”

Section: Methodsmentioning

confidence: 99%

Magnetofection Enhances Adenoviral Vector-based Gene Delivery in Skeletal Muscle Cells

Pereyra

Mykhaylyk

Lockhart

et al. 2016

J Nanomed Nanotechnol

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The goal of magnetic field-assisted gene transfer is to enhance internalization of exogenous nucleic acids by association with magnetic nanoparticles (MNPs). This technique named magnetofection is particularly useful in difficult-to-transfect cells. It is well known that human, mouse, and rat skeletal muscle cells suffer a maturation-dependent loss of susceptibility to Recombinant Adenoviral vector (RAd) uptake. In postnatal, fully differentiated myofibers, the expression of the primary Coxsackie and Adenoviral membrane receptor (CAR) is severely downregulated representing a main hurdle for the use of these vectors in gene transfer/therapy. Here we demonstrate that assembling of Recombinant Adenoviral vectors with suitable iron oxide MNPs into magneto-adenovectors (RAd-MNP) and further exposure to a gradient magnetic field enables to efficiently overcome transduction resistance in skeletal muscle cells. Expression of Green Fluorescent Protein and Insulin-like Growth Factor 1 was significantly enhanced after magnetofection with RAd-MNPs complexes in C2C12 myotubes in vitro and mouse skeletal muscle in vivo when compared to transduction with naked virus. These results provide evidence that magnetofection, mainly due to its membrane-receptor independent mechanism, constitutes a simple and effective alternative to current methods for gene transfer into traditionally hard-to-transfect biological models.

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“…This measuring technique allows the user to record concentration changes across the entire sample height due to the migration of particles or droplets driven by earth gravity or centrifugal fields, respectively, as well as, e.g. magnetic fields (Mykhaylyk et al, 2015). Fig.…”

Section: In-situ Visualization Of Particle Migration-step-technology ®mentioning

confidence: 99%

“…The first example of a "sedimentation-based technique" to analyze magnetic particles (Mykhaylyk et al, 2015) revolves around the analysis of magnetic lipoplexes formulated by different MNPs combined with liposomal enhancers for gene delivery to human corneal endothelium (Czugala et al, 2016). Complexes were assembled at a pDNA concentration of 10 μg/mL by 3 different MNPs but different Fe-to-pDNA w/w ratios (Tab.…”

Section: Characterization Of Magnetic Particlesmentioning

confidence: 99%

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Comprehensive Characterization of Nano- and Microparticles by In-Situ Visualization of Particle Movement Using Advanced Sedimentation Techniques

Lerche¹

2019

KONA

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The state of a suspension is crucial with regard to processing pathways, functionality and performance of the end product. In the past decade, substantial progress has been made in designing highly specialized and functionalized particles. In current particle technology, besides classic particle properties such as particle size distribution, shape and density, surface properties play an essential role for processing, product specification and use. For example, in medical therapy, analytical diagnostic applications, as well as in separation processing and harvesting of high-valued materials, magnetic micro-and nanoparticles play an increasing role. In addition to traditional parameters such as size, the particle magnetization has to be quantified here. Sedimentation techniques have been used for hundreds of years to determine the geometrical characteristics of dispersed particles. Numerous national and international standards regarding these techniques have been published. Mainly due to the fast growing market share of laser scattering techniques over the past two decades, most customers these days are not aware of some advantageous features of particle characterization via a firstprinciple fractionating approach such as sedimentation. This is unfortunate as sedimentation techniques have made huge technological leaps forward regarding electronics, sensors and computing abilities. This paper aims to give a short review about different cumulative and incremental sedimentation approaches to measure the particle size distribution. It focuses mainly on the in-situ visualization (STEP-Technology ® ) of particle migration in gravitational and centrifugal fields. It describes the basics of the new multi-sample measuring approaches to quantify the separation kinetics by spatial and time-resolved particle concentration over the entire sample height. Based on these data, the sedimentation velocity and particle size distribution are elucidated and estimates of accuracy, precision and experimental uncertainties are discussed. Multi-wavelength approaches, correction of higher concentration, and the influence of rheological behavior of continuous phase will also be discussed. Applications beyond the traditional scope of sedimentation analysis are presented. This concerns the in-situ determination of hydrodynamic particle density and of magnetophoretic velocity distributions for magnetic particulate objects.

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Magnetophoretic Velocity Determined by Space- and Time-Resolved Extinction Profiles

Cited by 13 publications

References 8 publications

Magnetically Induced Aggregation of Iron Oxide Nanoparticles for Carrier Flotation Strategies

Magnetically Induced Aggregation of Iron Oxide Nanoparticles for Carrier Flotation Strategies

Magnetofection Enhances Adenoviral Vector-based Gene Delivery in Skeletal Muscle Cells

Comprehensive Characterization of Nano- and Microparticles by In-Situ Visualization of Particle Movement Using Advanced Sedimentation Techniques

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