Tuning the properties of electrospun polylactide mats by ethanol treatment

In the present work, we analyzed the changes in structure and mechanical properties of electrospun PLA mats induced by ethanol treatment. The amorphous PLA mats gained elasticity when immersed into ethanol (the elongation at break increased from epsilon similar to 50% in air to epsilon similar to 280% in ethanol) and partly retained it after drying (epsilon similar to 110%). At the nanoscale, the ethanol treatment caused crimping of the fibers without crystallinity increase. Stretching of the electrospun mats in ethanol caused high alignment of the fibers (geometrical orientation factor f = 0.92) without the need for a special collector electrode such as a pair of blades, which yielded mats with geometrical orientation factor f = 0.71. The aligned mats prepared by stretching in ethanol caused contact guidance of HaCaT human keratinocytes and did not taint viability and proliferation rate of cells in comparison with the non-aligned ones. Our research demonstrates the tuning of electrospun mats properties by post-treatment without any modification of the chemical structure. (C) 2019 The Author(s). Published by Elsevier Ltd.