Résumé
Ultrafine poly (D, L-lactide) (PLA) fibers with diameter less than 200 nm produced by electrospinning were studied to obtain tissue restoration resembling extracellular matrix. Scanning electron microscopy was used to observe the fiber morphology. Results showed that the solvent was the critical factor to determine the formation of the electrospun PLA fibers. Compared with acetone, N,N-dimethylformamide (DMF) was a better solvent for PLA to electrospin. Entrance of an organic salt, triethylbenzylammonium chlorate, led to a great increase of the conductivity of PLA/DMF solutions, so that the average fiber diameter of the electrospun PLA fibers decreased dramatically from 500 nm to 100-200 nm. The addition of surfactant, Span-80, did not improve the fiber morphology but formed beaded fiber web.