Page 89 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

TAILORING THE VOID SPACE AND MECHANICAL PROPERTIES IN ELECTROSPUN SCAFFOLDS
Figure 4.6 Influence of fiber sti ness and spinning time on sca old thickness. Data for PCL (60 min LTE,40 min LTE,20 min LTE, and ☐ 4 60 min conv.) and PLA ( 60 min LTE, 40 min LTE, 20 min LTE, and △ 60 min conv.). The symbols marked with a* are the sca old shown
in Figure 4.2. The length of the target drum was kept constant (50 mm). Trend lines are given for the di erent spinning times of LTE and conv.
spun sca olds.
It is also evident that there is a large and steady increase in mesh thickness when using LTE spinning. Increasing the spinning time from 40 to 60 minutes resulted in an increase in sca old thickness of 2.5 to 4 mm for PLA. For conventional electrospun sca olds of a constant fiber sti ness (i.e. fiber diameter = 9 μm), only a small increase in sca old thickness from 0.2 mm to 0.25 mm respectively was observed for the same change in t (datapoints not shown).
Clearly, our data imply that control over the final sca old thickness and void space can indeed be
realized in LTE-spun sca olds by selecting materials of a suitable elastic modulus and/or adjusting the fiber diameter to obtain the desired fiber sti ness. Additionally, fiber sti ness may be changed while maintaining the fiber diameter by spinning polymer blends, coaxial spinning or post processing by e.g. crosslinking.
4.4.4 Mechanical properties
Low-temperature electrospinning, similar to any process that increases the sca old void space and
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