Influence of crystallinity and fiber orientation on hydrophobicity and biological response of poly(L-lactide) electrospun mats

Poly(L-lactide) electrospun mats have been produced with random and aligned fiber orientation and degrees of crystallinity from 0 up to nearly 50%. These two factors, fiber alignment and degree of crystallinity, strongly affect the hydrophobicity of the samples, this being larger for the aligned fiber mats and for the fibers with a higher degree of crystallinity. Whereas, the first effect can be associated with a decrease in the degree of porosity, the second should be related to an increase in fiber stiffness as the observed fiber roughness variations do not show strong differences between the samples. Proliferation of human chondrocytes cultured in a monolayer on these substrates is similar in both aligned and non-aligned amorphous mats. Crystallization of the aligned mats, on the other hand, nearly suppresses proliferation and the cells produce higher amounts of aggrecan, characteristic of the extracellular matrix of hyaline cartilage.