A novel fluffy conductive polypyrrole nano-layer coated PLLA fibrous scaffold for nerve tissue engineering

In this study, a novel three-dimensional fluffy PPy conductive fibrous scaffold (3D-cFSs) was fabricated by electrospinning technique combined with situ surface polymerization. Chemical compositions, morphology were characterized by fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The results showed that the average diameter of PPy coated PLLA fibers in the 3D-cFSs was 2.086 microm, the thickness of PPy nano-layer was -45 nm. These PPy coated PLLA fibers were in discrete state, the size of interconnected pores in the 3D-cFSs was from 50 microm to 100 microm, this unique structure ensured that cells can entry into internal of 3D-cFSs smoothly without any other extra help to achieve three-dimensional cell culture (3D-culture). Rat pheochromocytoma 12 (PC12) cells (as model cell) were cultured in the 3D-cFSs to evaluate its potential application for nerve tissue engineering. The interaction between cell and scaffold was test by detecting the cell proliferation, viability, and morphology. After 3 days culture, the number of PC12 in 3D-cFSs were much higher than that on the conductive fibrous meshes (cFMs) and well developed cell-fibers constructs were observed from fluorescence image and SEM of PC12 in the central of 3D-cFSs. These results showed that the 3D-cFSs provided cell 3D-culture, and improved cell growth. Therefore, we suggest that the 3D-cFSs maybe a suitable scaffold for the nerve tissue engineering as cells substrate to apply electrical stimulation.