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Postdoctoral position proposal
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Modelling of the dynamics of a soft capsule/vector in blood
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Background0 0.2and/or
fluid-structure
interactions,
0.4 0.6 0.8 1interests:
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0micro-fluid
0.2 0.4 0.6 0.8 1 mechanics,
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mathematical/numerical modelling, biophysics/biomechanics, soft matter, cancer therapy
12 months
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(a) λ = 0.1 Duration:(b)
λ = 0.2
(c) λ = 0.5
(d) Location:
λ = 0.87 Marseille, France
Lab: M2P2 - CNRS UMR7340, Ecole Centrale Marseille & Aix-Marseille University
Contact: M. Jaeger ([email protected]), M. Leonetti ([email protected])
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Fig. 15. final caption
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Cancer therapy is frequently based on drug delivery with often disastrous side effects. Using
erimental and
simulated shapes for several values of deflation, confinement
nanovectors with encapsulated active principles allows to target the treatment and use smaller
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flow velocity.
Predicted
final
shapes
well
the images
re- the expected
quantities
of drugs.
These
vectorsmatch
are oftenvery
thought
by with
biomimetic
analogy with
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r
properties: biocompatibility,
biodegradability,
to the immune system and flow
ing from experiments
in a quite large
range of ∆,invisibility
λ and Ca.
resistance. Examples of vectors are liposomes, vesicles, capsules and polymersomes.
(a) λ = 0.1
1
experimental and
and flow velocity.
sulting from exper
Figure: Left – non axisymmetric shape of a vesicle in a Poseuille flow. Center – comparison
between the numerical (red line) and experimental shapes of an axisymmetric vesicle in
motion in a capillary. Right – pulling of a tether from a vesicle by hydrodynamic flow and
subsequent
pearling instability
along the tether.
16. Comparison
of simulations
and experimental
results obtained in [6]. Vesicles
flowing from left to right. For the three vesicles we have: ∆ = 0.45, λ = 0.8,
We propose to modellize the dynamics of a soft particle made of a thin membrane under flow.
= 10 ; ∆ = 1.7,
λ = 0.67, Ca = 30; ∆ = 2, λ = 0.4, Ca = 60
The difficulty and the richness of the problem come from the coupling between the shape and
the flow what needs a deep knowledge of the mechanics of the membrane and an accurate
implementation of membrane force. Indeed, following the kind of soft particle/vector, the
response
the membrane is governed by elasticity, bending rigidity, membrane viscosity
Sedimentation
in of
a capillary
or/and membrane incompressibility. The first case to study is the dynamics of a polymersome
under linear flow, a case highly studied for drug delivery. Its membrane is a 2D viscous
incompressible fluid with a bending rigidity. The difference with a vesicle, the prototype
of Comparison
Fig. 16.
his section we
present
some
results
on
the
tether
deformation
for
vesicle
soft particles as elastic capsule comes from the higher dissipation in the membrane compared
are flowing from le
to the bulk For
one. The
points
of departurevesicles
are firstlyunder
the large
litterature
on vesicle dynamics
fined in a capillary.
freely
suspended
flow
membrane
10 ; ∆ = 1.7,
(shape
instabilities, migration
in quadratic
flow, microcirculation...)
and and
secondlyCa
our=3D
es are observed
experimentally
in shear,
acoustic-driven
, elongational
code which is dedicated to vesicles under flow. It is based on the boundary integral method
ling flows. Invalid
thefor
case
of an
initial
prolate,
after the
the shape
Stokes
flow.
Various
relevant just
configurations
willrelease,
be investigated:
shape instabilities
ves rapidly,under
leading
the
of abetween
protrusion
at the rear
of the
linearto
flow,
lift formation
force, interactions
two polymersomes,
margination...
cle. This protrusion thus elongates, and a thin tether connecting a qua-
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Sedimentatio
The results will be compare with experiments done in our team and performed by
collaborators (IPBS, IRMCP, LAAS, LAI).
In this section we
in a cap
tubes are observed
settling flows. In t
evolves rapidly, le
vesicle. This protr
The knowledge of the GPU22
numerical optimization and/or the method of the Fast Multipole
confined
Method can be appreciated for other studies in the future but is absolutely not a prerequisite.