Lysine-doped polypyrrole/spider silk protein/poly(L-lactic) acid containing nerve growth factor composite fibers for neural application

摘要

Lysine-doped polypyrrole (PPy)/regenerated spider silk protein (RSSP)/poly(L-lactic) acid (PLLA)erve growth factor (NGF) (L-PRPN) composite scaffold was fabricated by co-axial electrospraying and electrospinning. This L-PRPN composite scaffold had a structure of microfibers with a core-shell structure as the stems and nanofibers as branches. Assessment in vitro demonstrated that the L-PRPN composite microano-fibrous scaffold could maintain integrated structure for at least 4 months and the pH value of PBS at about 7.28. It had good biocompatibility and cell adhesion and relatively stable conductivity. PC 12 cells cultured on this scaffold, anisotropic cell-neurite-cell-neurite or neurite-neurite sheets were formed after being cultured for 6 days. Evaluations in vivo also showed that L-PRPN composite fibrous conduit was effective at bridging 2.0 cm sciatic nerve gap in adult rat within 10 months. This conduit and electrical stimulation (ES) through it promoted Schwann cell migration and axonal regrowth. (C) 2015 Elsevier B.V. All rights reserved.