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The margination propensity of spherical particles for vascular targeting in the microcirculation.

Gentile F, Curcio A, Indolfi C, Ferrari M, Decuzzi P - J Nanobiotechnology (2008)

Bottom Line: In horizontal capillaries, margination is mainly due to the gravitational force for particles with d > 200 nm and V approximately s increases with d4; whereas for smaller particles V approximately s increases with d3.In vertical capillaries, since the particles are heavier than the fluid they would tend to marginate towards the walls in downward flows and towards the center in upward flows, with V approximately s increasing with d9/2.However, the margination in vertical capillaries is predicted to be much smaller than in horizontal capillaries.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center of Bio-/Nanotechnology and -/Engineering for Medicine University of Magna Graecia at Catanzaro, Viale Europa - Loc, Germaneto, 88100, Catanzaro, Italy. Paolo.Decuzzi@uth.tmc.edu.

ABSTRACT
The propensity of circulating particles to drift laterally towards the vessel walls (margination) in the microcirculation has been experimentally studied using a parallel plate flow chamber. Fluorescent polystyrene particles, with a relative density to water of just 50 g/cm3comparable with that of liposomal or polymeric nanoparticles used in drug delivery and bio-imaging, have been used with a diameter spanning over three order of magnitudes from 50 nm up to 10 mum. The number n approximately s of particles marginating per unit surface have been measured through confocal fluorescent microscopy for a horizontal chamber, and the corresponding total volume V approximately s of particles has been calculated. Scaling laws have been derived as a function of the particle diameter d. In horizontal capillaries, margination is mainly due to the gravitational force for particles with d > 200 nm and V approximately s increases with d4; whereas for smaller particles V approximately s increases with d3. In vertical capillaries, since the particles are heavier than the fluid they would tend to marginate towards the walls in downward flows and towards the center in upward flows, with V approximately s increasing with d9/2. However, the margination in vertical capillaries is predicted to be much smaller than in horizontal capillaries. These results suggest that, for particles circulating in an external field of volume forces (gravitation or magnetic), the strategy of using larger particles designed to marginate and adhere firmly to the vascular walls under flow could be more effective than that of using particles sufficiently small (d < 200 nm) to hopefully cross a discontinuous endothelium.

No MeSH data available.


Related in: MedlinePlus

The volume of particles marginating per unit surface  as a function of the particle total number ntot (fixed diameter d = 500 nm).
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Figure 5: The volume of particles marginating per unit surface as a function of the particle total number ntot (fixed diameter d = 500 nm).

Mentions: which gives almost the same scaling as predicted in (5), assuming a fixed total volume of injected particles. In Fig. 5, the variation of the volume as a function of the total number of particles injected ntot in the flow chamber is plotted for a fixed particle size (d = 500 nm), showing a linear increase of following the experimental relationship


The margination propensity of spherical particles for vascular targeting in the microcirculation.

Gentile F, Curcio A, Indolfi C, Ferrari M, Decuzzi P - J Nanobiotechnology (2008)

The volume of particles marginating per unit surface  as a function of the particle total number ntot (fixed diameter d = 500 nm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2563017&req=5

Figure 5: The volume of particles marginating per unit surface as a function of the particle total number ntot (fixed diameter d = 500 nm).
Mentions: which gives almost the same scaling as predicted in (5), assuming a fixed total volume of injected particles. In Fig. 5, the variation of the volume as a function of the total number of particles injected ntot in the flow chamber is plotted for a fixed particle size (d = 500 nm), showing a linear increase of following the experimental relationship

Bottom Line: In horizontal capillaries, margination is mainly due to the gravitational force for particles with d > 200 nm and V approximately s increases with d4; whereas for smaller particles V approximately s increases with d3.In vertical capillaries, since the particles are heavier than the fluid they would tend to marginate towards the walls in downward flows and towards the center in upward flows, with V approximately s increasing with d9/2.However, the margination in vertical capillaries is predicted to be much smaller than in horizontal capillaries.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center of Bio-/Nanotechnology and -/Engineering for Medicine University of Magna Graecia at Catanzaro, Viale Europa - Loc, Germaneto, 88100, Catanzaro, Italy. Paolo.Decuzzi@uth.tmc.edu.

ABSTRACT
The propensity of circulating particles to drift laterally towards the vessel walls (margination) in the microcirculation has been experimentally studied using a parallel plate flow chamber. Fluorescent polystyrene particles, with a relative density to water of just 50 g/cm3comparable with that of liposomal or polymeric nanoparticles used in drug delivery and bio-imaging, have been used with a diameter spanning over three order of magnitudes from 50 nm up to 10 mum. The number n approximately s of particles marginating per unit surface have been measured through confocal fluorescent microscopy for a horizontal chamber, and the corresponding total volume V approximately s of particles has been calculated. Scaling laws have been derived as a function of the particle diameter d. In horizontal capillaries, margination is mainly due to the gravitational force for particles with d > 200 nm and V approximately s increases with d4; whereas for smaller particles V approximately s increases with d3. In vertical capillaries, since the particles are heavier than the fluid they would tend to marginate towards the walls in downward flows and towards the center in upward flows, with V approximately s increasing with d9/2. However, the margination in vertical capillaries is predicted to be much smaller than in horizontal capillaries. These results suggest that, for particles circulating in an external field of volume forces (gravitation or magnetic), the strategy of using larger particles designed to marginate and adhere firmly to the vascular walls under flow could be more effective than that of using particles sufficiently small (d < 200 nm) to hopefully cross a discontinuous endothelium.

No MeSH data available.


Related in: MedlinePlus