Hi Mohammad,

Since fibers are drawn during electrospinning you will get molecular alignment in each fiber, which will relax when heated above your thermal transition temperature (which you can check for with DSC). Additionally, upon hydration, plasticization can greatly decrease your glass transition temperature and may bring it near or below 37 C.  As such I recommend running DSC of fibers as-spun and of fibers after hydration for 24 h, and see where your transition temperatures are.

If this is the cause of your shrinkage, you could attempt to prevent it by performing a thermal treatment on the fiber mat to removal residual stress in the fibers. Our group has done this previously to prevent significant fiber mat shrinkage and fiber realignment (see publication below). Basically what you can try is infiltrating your fiber mat with pluronic 127, heat to remove residual stress without shrinking the fibers, then remove the pluronic and wash the fiber mat. Details of how to do this can be found in the publication below.  Hope this helps and good luck! 

Article Shape-memory-actuated change in scaffold fiber alignment dir...

Hi Mohammad

Cells are strong enough to compact an electrospun mesh. But my guess is, that your PLGA crystallizes and hence the scaffold shrinks. Electrospun PLGA  can crystallize/shrink at RT, the higher the temp. the faster.

A simple test to check if it crystallizes: Place your PLGA scaffold in a 80°C oven over night (best vacuum oven) and compare the scaffold dimensions before and after. 

If you have access to a DSC you can test this with a few mg rather then a piece of scaffold and compare melting enthalpy.

Which PLGA grade are you using?

Cheers Marc

hey Marc

75/25

do you know a way that we can able to stopped shrinkage?

What about PLGA 50:50  free carboxylic end? Does it also shrink at high temperature?

Hi Mohammad,

Since fibers are drawn during electrospinning you will get molecular alignment in each fiber, which will relax when heated above your thermal transition temperature (which you can check for with DSC). Additionally, upon hydration, plasticization can greatly decrease your glass transition temperature and may bring it near or below 37 C.  As such I recommend running DSC of fibers as-spun and of fibers after hydration for 24 h, and see where your transition temperatures are.

If this is the cause of your shrinkage, you could attempt to prevent it by performing a thermal treatment on the fiber mat to removal residual stress in the fibers. Our group has done this previously to prevent significant fiber mat shrinkage and fiber realignment (see publication below). Basically what you can try is infiltrating your fiber mat with pluronic 127, heat to remove residual stress without shrinking the fibers, then remove the pluronic and wash the fiber mat. Details of how to do this can be found in the publication below.  Hope this helps and good luck! 

Article Shape-memory-actuated change in scaffold fiber alignment dir...

hello Richard

tanks for your great answer. can i have your paper?

thank you

You're welcome, I hope this helps! A pdf of the article can be found here:

http://mather.syr.edu/Mather/2013/FangHendersonMather_ActaBiomaterialia_2013.pdf