On magnetophoretic separation of blood cells using Halbach array of magnets

Shiriny, Afshin; Bayareh, Morteza

doi:10.1007/s11012-020-01225-y

Cited by 37 publications

(28 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fluid medium surrounding the MNPs was set to standard values of water to give an indication of particle motion.

where

is the radius of the particle (in m),

and

are the permeability of the MNP and fluid, respectively (where

), and

is the magnetic field gradient (in Am −2 ) ( Shiriny and Bayareh, 2020 ).…”

Section: Methodsmentioning

confidence: 99%

Magnetic Nanoparticle-Mediated Orientation of Collagen Hydrogels for Engineering of Tendon-Mimetic Constructs

Wright

Righelli

Broomhall

et al. 2022

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

Despite the high incidence of tendon injuries worldwide, an optimal treatment strategy has yet to be defined. A key challenge for tendon repair is the alignment of the repaired matrix into orientations which provide maximal mechanical strength. Using oriented implants for tissue growth combined with either exogenous or endogenous stem cells may provide a solution. Previous research has shown how oriented fiber-like structures within 3D scaffolds can provide a framework for organized extracellular matrix deposition. In this article, we present our data on the remote magnetic alignment of collagen hydrogels which facilitates long-term collagen orientation. Magnetic nanoparticles (MNPs) at varying concentrations can be contained within collagen hydrogels. Our data show how, in response to the magnetic field lines, MNPs align and form string-like structures orientating at 90 degrees from the applied magnetic field from our device. This can be visualized by light and fluorescence microscopy, and it persists for 21 days post-application of the magnetic field. Confocal microscopy demonstrates the anisotropic macroscale structure of MNP-laden collagen gels subjected to a magnetic field, compared to gels without MNP dosing. Matrix fibrillation was compared between non- and biofunctionalized MNP hydrogels, and different gels dosed with varying MNP concentrations. Human adipose stem cells (hASCs) seeded within the magnetically aligned gels were observed to align in parallel to MNP and collagen orientation 7 days post-application of the magnetic field. hASCs seeded in isotropic gels were randomly organized. Tenocyte-likeness of the cells 7 days post-seeding in collagen I scaffolds was confirmed by the positive expression of tenomodulin and scleraxis proteins. To summarize, we have developed a convenient, non-invasive protocol to control the collagen I hydrogel architecture. Through the presence or absence of MNP dosing and a magnetic field, collagen can be remotely aligned or randomly organized, respectively, in situ. Tendon-like cells were observed to organize in parallel to unidirectionally aligned collagen fibers and polydirectionally in non-aligned collagen constructs. In this way, we were able to engineer the constructs emulating a physiologically and pathologically relevant tendon niche. This can be considered as an innovative approach particularly useful in tissue engineering or organ-on-a-chip applications for remotely controlling collagen matrix organization to recapitulate the native tendon.

show abstract

“…The fluid medium surrounding the MNPs was set to standard values of water to give an indication of particle motion.

where

is the radius of the particle (in m),

and

are the permeability of the MNP and fluid, respectively (where

), and

is the magnetic field gradient (in Am −2 ) ( Shiriny and Bayareh, 2020 ).…”

Section: Methodsmentioning

confidence: 99%

Magnetic Nanoparticle-Mediated Orientation of Collagen Hydrogels for Engineering of Tendon-Mimetic Constructs

Wright

Righelli

Broomhall

et al. 2022

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

show abstract

“…These cells are therefore submitted to positive and negative MAP forces, respectively, and can be separated in microfluidic devices under continuous flow. To compensate for the low value of magnetic contrast factor ∆χ, when cells are in their native state, high magnetic field gradients, as produced by integrated microstructures, are usually required [70][71][72][73]. Interestingly, Shamloo et al have proposed reinforcing the effect of high magnetic field gradients produced by a ferromagnetic track using a sheath flow directing cells toward it, where the gradient was maximum.…”

Section: Exploiting Cell Intrinsic Magnetic Propertiesmentioning

confidence: 99%

“…Cells will be more or less deflected from their laminar flow path according to their magnetic properties, which enables their sorting, and potentially transfer of target cells in another fluid [77]. The arrangement of several permanent magnets of different magnetization orientations expands the possibilities of this strategy, as in the Halbach configuration (Figure 11B) [71,165] strengthening the magnetic field on one side of the magnets. Alternatively, magnets arranged with opposing poles enable a large magnetic field gradient to be obtained.…”

Section: Permanent Magnetsmentioning

confidence: 99%

Basic Principles and Recent Advances in Magnetic Cell Separation

Frénéa‐Robin

Marchalot

2022

Magnetochemistry

View full text Add to dashboard Cite

Magnetic cell separation has become a key methodology for the isolation of target cell populations from biological suspensions, covering a wide spectrum of applications from diagnosis and therapy in biomedicine to environmental applications or fundamental research in biology. There now exists a great variety of commercially available separation instruments and reagents, which has permitted rapid dissemination of the technology. However, there is still an increasing demand for new tools and protocols which provide improved selectivity, yield and sensitivity of the separation process while reducing cost and providing a faster response. This review aims to introduce basic principles of magnetic cell separation for the neophyte, while giving an overview of recent research in the field, from the development of new cell labeling strategies to the design of integrated microfluidic cell sorters and of point-of-care platforms combining cell selection, capture, and downstream detection. Finally, we focus on clinical, industrial and environmental applications where magnetic cell separation strategies are amongst the most promising techniques to address the challenges of isolating rare cells.

show abstract

“…There are several reviews of magnetic particles [13,14] and descriptions of their performance in different magnetophoretic (flow) setups [6][7][8][9][10]. In order to generate a larger force at a distance in some cases a Halbach configuration is used for static [15] or flow-through separation [11,16,17]. In most of these a general formulation for magnetic force is reviewed, and in some an estimation of the force exerted by the used system is calculated.…”

Section: Introductionmentioning

confidence: 99%

Optimal Halbach Configuration for Flow-through Immunomagnetic CTC Enrichment

et al. 2021

View full text Add to dashboard Cite

Due to the low frequency of circulating tumor cells (CTC), the standard CellSearch method of enumeration and isolation using a single tube of blood is insufficient to measure treatment effects consistently, or to steer personalized therapy. Using diagnostic leukapheresis this sample size can be increased; however, this also calls for a suitable new method to process larger sample inputs. In order to achieve this, we have optimized the immunomagnetic enrichment process using a flow-through magnetophoretic system. An overview of the major forces involved in magnetophoretic separation is provided and the model used for optimizing the magnetic configuration in flow through immunomagnetic enrichment is presented. The optimal Halbach array element size was calculated and both optimal and non-optimal arrays were built and tested using anti-EpCAM ferrofluid in combination with cell lines of varying EpCAM antigen expression. Experimentally measured distributions of the magnetic moment of the cell lines used for comparison were combined with predicted recoveries and fit to the experimental data. Resulting predictions agree with measured data within measurement uncertainty. The presented method can be used not only to optimize magnetophoretic separation using a variety of flow configurations but could also be adapted to optimize other (static) magnetic separation techniques.

show abstract

On magnetophoretic separation of blood cells using Halbach array of magnets

Cited by 37 publications

References 63 publications

Magnetic Nanoparticle-Mediated Orientation of Collagen Hydrogels for Engineering of Tendon-Mimetic Constructs

Magnetic Nanoparticle-Mediated Orientation of Collagen Hydrogels for Engineering of Tendon-Mimetic Constructs

Basic Principles and Recent Advances in Magnetic Cell Separation

Optimal Halbach Configuration for Flow-through Immunomagnetic CTC Enrichment

Contact Info

Product

Resources

About