Page 40 - Tailoring Electrospinning Techniques for Regenerative Medicine - Marc Simonet

CHAPTER 2
2.1 Abstract
Reproducibility is a well-known issue in research involving electrospun materials, and, therefore, it is one of the main obstacles preventing this processing technique to prevail into the industry. Controlling environmental parameters during the electrospinning process helps in drastically reducing variability of results and, at the same time, has a strong impact on fiber characteristics. Using poly(e- caprolactone) (PCL) as a model system, in this work we investigated the influence of relative humidity and environmental temperature on the resulting mesh morphology for di erent PCL solutions. PCL solutions were electrospun on a rotating mandrel, for di erent rotational speeds and over a broad range of environmental conditions (30% – 90% of
relative humidity and temperature of 20°C – 40°C) with di erent chloroform/tetrahydrofuran ratios in the solvent mixture. In this way we could assess the role of solvent water miscibility in determining surface features. While temperature changes have only a moderate e ect on the resulting fibers, relative humidity does not only change the surface morphology of electrospun fibers, but also the critical rotation speed of the collecting mandrel needed for obtaining alignment. Furthermore, we observed a self-assembled perpendicular monolayer-like fiber architectures when the electrospinning was performed above critical rotation speed required for aligned fibers.
38