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Exploiting Size-Dependent Drag and Magnetic Forces for Size-Specific Separation of Magnetic Nanoparticles.

Rogers HB, Anani T, Choi YS, Beyers RJ, David AE - Int J Mol Sci (2015)

Bottom Line: Magnetic field-flow fractionation, however, was found to be an effective method for the separation of polydisperse suspensions of iron oxide nanoparticles with diameters greater than 20 nm.Both transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis were used to confirm the size of the MNPs.Further development of this work could lead to MNPs with the narrow size distributions necessary for their in vitro and in vivo optimization.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Auburn University, 212 Ross Hall, Auburn, AL 36849, USA. hunterrogers2014@u.northwestern.edu.

ABSTRACT
Realizing the full potential of magnetic nanoparticles (MNPs) in nanomedicine requires the optimization of their physical and chemical properties. Elucidation of the effects of these properties on clinical diagnostic or therapeutic properties, however, requires the synthesis or purification of homogenous samples, which has proved to be difficult. While initial simulations indicated that size-selective separation could be achieved by flowing magnetic nanoparticles through a magnetic field, subsequent in vitro experiments were unable to reproduce the predicted results. Magnetic field-flow fractionation, however, was found to be an effective method for the separation of polydisperse suspensions of iron oxide nanoparticles with diameters greater than 20 nm. While similar methods have been used to separate magnetic nanoparticles before, no previous work has been done with magnetic nanoparticles between 20 and 200 nm. Both transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis were used to confirm the size of the MNPs. Further development of this work could lead to MNPs with the narrow size distributions necessary for their in vitro and in vivo optimization.

No MeSH data available.


Related in: MedlinePlus

Transverse relaxivity R2 values for the MNP-95, MNP-151, and MNP-O distributions with respect to iron concentration. R2 values determined using linear trend line.
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ijms-16-20001-f006: Transverse relaxivity R2 values for the MNP-95, MNP-151, and MNP-O distributions with respect to iron concentration. R2 values determined using linear trend line.

Mentions: Preliminary data, shown in Figure 6, indicates that as the average hydrodynamic diameter of the MNPs increased, the transverse proton relaxation time also increased. Considering the inverse relaxation times at the highest concentration used, the R2 values increased from 11.2 to 51.05 s−1 as the MNP size increased from 95 to 151 nm. This size-dependent behavior is similar to that previously reported for magnetic particles of hydrodynamic sizes less than 100 nm [34]. Additionally, it is interesting to note that the R2 values of the MNP-O samples, which contain particles of the same size as both MNP-95 and MNP-151, as well as sizes between the two distributions, were consistently between the R2 values of MNP-95 and MNP-151. For example, the R2 value for the MNP-O sample with an iron concentration of 0.009 mg/mL was determined to be 14.3 s−1 compared to the values of MNP-95 and MNP-151 at the same concentration of 5.2 and 27.87 s−1, respectively.


Exploiting Size-Dependent Drag and Magnetic Forces for Size-Specific Separation of Magnetic Nanoparticles.

Rogers HB, Anani T, Choi YS, Beyers RJ, David AE - Int J Mol Sci (2015)

Transverse relaxivity R2 values for the MNP-95, MNP-151, and MNP-O distributions with respect to iron concentration. R2 values determined using linear trend line.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581337&req=5

ijms-16-20001-f006: Transverse relaxivity R2 values for the MNP-95, MNP-151, and MNP-O distributions with respect to iron concentration. R2 values determined using linear trend line.
Mentions: Preliminary data, shown in Figure 6, indicates that as the average hydrodynamic diameter of the MNPs increased, the transverse proton relaxation time also increased. Considering the inverse relaxation times at the highest concentration used, the R2 values increased from 11.2 to 51.05 s−1 as the MNP size increased from 95 to 151 nm. This size-dependent behavior is similar to that previously reported for magnetic particles of hydrodynamic sizes less than 100 nm [34]. Additionally, it is interesting to note that the R2 values of the MNP-O samples, which contain particles of the same size as both MNP-95 and MNP-151, as well as sizes between the two distributions, were consistently between the R2 values of MNP-95 and MNP-151. For example, the R2 value for the MNP-O sample with an iron concentration of 0.009 mg/mL was determined to be 14.3 s−1 compared to the values of MNP-95 and MNP-151 at the same concentration of 5.2 and 27.87 s−1, respectively.

Bottom Line: Magnetic field-flow fractionation, however, was found to be an effective method for the separation of polydisperse suspensions of iron oxide nanoparticles with diameters greater than 20 nm.Both transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis were used to confirm the size of the MNPs.Further development of this work could lead to MNPs with the narrow size distributions necessary for their in vitro and in vivo optimization.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Auburn University, 212 Ross Hall, Auburn, AL 36849, USA. hunterrogers2014@u.northwestern.edu.

ABSTRACT
Realizing the full potential of magnetic nanoparticles (MNPs) in nanomedicine requires the optimization of their physical and chemical properties. Elucidation of the effects of these properties on clinical diagnostic or therapeutic properties, however, requires the synthesis or purification of homogenous samples, which has proved to be difficult. While initial simulations indicated that size-selective separation could be achieved by flowing magnetic nanoparticles through a magnetic field, subsequent in vitro experiments were unable to reproduce the predicted results. Magnetic field-flow fractionation, however, was found to be an effective method for the separation of polydisperse suspensions of iron oxide nanoparticles with diameters greater than 20 nm. While similar methods have been used to separate magnetic nanoparticles before, no previous work has been done with magnetic nanoparticles between 20 and 200 nm. Both transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis were used to confirm the size of the MNPs. Further development of this work could lead to MNPs with the narrow size distributions necessary for their in vitro and in vivo optimization.

No MeSH data available.


Related in: MedlinePlus