Page 67 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

As in the case for PLGA, conventional fiber
collection (Figure 3.4a) a orded relatively dense,
layered materials with few macroporosity, the co-
deposition of ice particles resulted in a high porous
3-dimensional mesh (Figure 3.4b). Voids of several
hundred micrometers indicate the position of the ice
particles templates. This structure resembles closely
the o en cited morphology of collagen analog
extracellular matrix polymer sca olds as required
for tissue engineering e.g. of skin, bone and so tissues.2,13,36,42
Table 3.1 Final porosities of polymer
temperature (300K) or using a dry ice cooled collection drum (200-220K).
Drum temperature
300 K
200 – 220 K
Relative humidity
30 % 15 % 30 % 50 % 85 %
PLGA
79 % 75 % 95 % 95 % 95 %
Mesh porosity
PEU
64 % 66 % 90 % 91 % 88 %
ULTRA-POROUS 3D POLYMER MESHES BY LOW-TEMPERATURE ELECTROSPINNING
3.4.2 Mesh porosity and fiber spacing
The influence of co-deposited ice particles on the
polymer mesh morphology was quantified by
comparing the mean distances between polymer
fibers in the xy-plane (parallel to the collection drum
surface) and in the z-direction (perpendicular to the
collection drum surface). Figure 3.5 compares the
mean fiber distances and their standard deviation 3 and shows that the in-plane (xy-direction) distances
were not a ected by the co-deposition of ice particles
while the fiber spacing in the z-direction was strongly
increased, confirming the higher porosity as visible in
SEM images (Figure 3.2 to Figure 3.4). The significant
increase of the mesh porosity by low-temperature electrospinning is quantitatively shown in Table 3.1.
meshes collected at room
This observation did not depend on the type of polymer used and was consistent for both biomaterials, indicating a broader applicability of the
here investigated use of ice particles as removable pore templates.
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