Electrospun silk fibroin tubular matrixes for small vessel bypass grafting

Electrospinning (ES) silk fibroin (SF) offers attractive opportunities for producing matrixes (ES–SF mats) with great potential for tissue regeneration. Scanning electron microscopy (SEM) analyses showed that uniform ES–SF mats containing nanometric fibres were obtained by electrospinning a 7.5% w/v SF solution in formic acid, with an electric field of 2.4 kV cm-1 and a spinneret collector distance of 10 cm. The structure of ES–SF mats before and after immersion in methanol (5, 10 and 15 min) was investigated by Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) analyses. Crystallinity was enhanced by dipping time as shown by trends of FT-IR crystallinity index and DSC melting/decomposition temperature. Electrospun silk fibroin mats were seeded with L929 murine fibroblasts, incubated for 1, 3 and 7 days at 37uC and, at each time point, SEM investigations and Alamar blue test were performed. The SEM images showed good cell adhesion after 1 day and cell confluence at the 7th day. Alamar blue test showed very low differences between cell viability on ES-SF mats and control.