Fabrication of extracellular matrix-coated conductive polypyrrole-poly(l-lactide) fiber-films and their synergistic effect with (nerve growth factor)/(epidermal growth factor) on neurites growth

Aligned porous ECM-linked PPy-PLLA fibers-films were fabricated via oxidation polymerization of pyrrole and L929 cell culture/lysing, and syngistic effect of NGF, EGF, extracellular matrix and electro-stimuli on the outgrowth & orientation of axons was investigated. [Display omitted] Non-nerve cell-derived extracellular matrix (ECM) was coated on the aligned porous polypyrrole-poly(l-lactide) (PPy-PLLA) fiber-films with the conductivity of ∼12 mS/m via L929 cells culture and lysing, resulting in ∼10% increase of PC12 cells attachment and ∼26 μm increase of neurites length. The neurite length of ∼149 μm in EGF/NGF group (optimal concentration radio of 12.5/50 (ng/mL)) on aligned and ECM-conjugated fiber-films was significantly larger than ∼94 μm in only NGF group (50 ng/mL), confirming the synergy of EGF, NGF and aligned ECM-conjuaged PPy-PLLA fibers. When differentiated PC12 cells were exerted electrical stimulation (ES) of 100 mV/cm for 4 h/day in 2 day through ECM-PPy-PLLA fiber-films, their neurite length reached to ∼251 μm, significantly larger than ∼149 μm of group without ES, due to the higer expression of related neural proteins in ES group. A simple mechanism was proposed to analyze synergistical effect of ECM, EGF, NGF on axons adhesion and elongation along the aligned ECM-coated fibers under ES condition.