title: Nerve growth factor-immobilized electrically conducting fibrous scaffolds for potential use in neural engineering applications.
abstract: Engineered scaffolds simultaneously exhibiting multiple cues are highly desirable for neural tissue regeneration. To this end, we developed a neural tissue engineering scaffold that displays submicrometer-scale features, electrical conductivity, and neurotrophic activity. Specifically, electrospun poly(lactic acid-co-glycolic acid) (PLGA) nanofibers were layered with a nanometer thick coating of electrically conducting polypyrrole (PPy) presenting carboxylic groups. Then, nerve growth factor (NGF) was chemically immobilized onto the surface of the fibers. These NGF-immobilized PPy-coated PLGA (NGF-PPyPLGA) fibers supported PC12 neurite formation ( 28.0±3.0%  of the cells) and neurite outgrowth (14.2   μm median length), which were comparable to that observed with NGF (50 ng/mL) in culture medium (  29.0±1.3%, 14.4  μm). Electrical stimulation of PC12 cells on NGF-immobilized PPyPLGA fiber scaffolds was found to further improve neurite development and neurite length by 18% and 17%, respectively, compared to unstimulated cells on the NGF-immobilized fibers. Hence, submicrometer-scale fibrous scaffolds that incorporate neurotrophic and electroconducting activities may serve as promising neural tissue engineering scaffolds such as nerve guidance conduits.
authors.affiliation: BioengineeringDepartment, University of California, Berkeley, CA 94720 USA. jaeylee@berkeley.edu
authors.forename: Jae Y
authors.initials: JY
authors.lastname: Lee
authors.forename: Chris A
authors.initials: CA
authors.lastname: Bashur
authors.forename: Craig A
authors.initials: CA
authors.lastname: Milroy
authors.forename: Leandro
authors.initials: L
authors.lastname: Forciniti
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Goldstein
authors.forename: Christine E
authors.initials: CE
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D004553:Electric Conductivity; D004558:Electric Stimulation; D055767:Immobilized Proteins / Q000737:chemistry / Q000494:pharmacology*; D008856:Microscopy, Fluorescence; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D020932:Nerve Growth Factor / Q000737:chemistry / Q000494:pharmacology*; D009416:Nerve Regeneration / Q000502:physiology*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D011108:Polymers; D011758:Pyrroles; D051381:Rats; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D055767:Immobilized Proteins; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D020932:Nerve Growth Factor