title: Developing a tissue-engineered neural-electrical relay using encapsulated neuronal constructs on conducting polymer fibers.
abstract: Neural-electrical interface platforms are being developed to extracellularly monitor neuronal population activity. Polyaniline-based electrically conducting polymer fibers are attractive substrates for sustained functional interfaces with neurons due to their flexibility, tailored geometry and controlled electro-conductive properties. In this study, we addressed the neurobiological considerations of utilizing small diameter (<400 microm) fibers consisting of a blend of electrically conductive polyaniline and polypropylene (PA-PP) as the backbone of encapsulated tissue-engineered neural-electrical relays. We devised new approaches to promote survival, adhesion and neurite outgrowth of primary dorsal root ganglion neurons on PA-PP fibers. We attained a greater than ten-fold increase in the density of viable neurons on fiber surfaces to approximately 700 neurons mm(-2) by manipulating surrounding surface charges to bias settling neuronal suspensions toward fibers coated with cell-adhesive ligands. This stark increase in neuronal density resulted in robust neuritic extension and network formation directly along the fibers. Additionally, we encapsulated these neuronal networks on PA-PP fibers using agarose to form a protective barrier while potentially facilitating network stability. Following encapsulation, the neuronal networks maintained integrity, high viability (>85%) and intimate adhesion to PA-PP fibers. These efforts accomplished key prerequisites for the establishment of functional electrical interfaces with neuronal populations using small diameter PA-PP fibers-specifically, improved neurocompatibility, high-density neuronal adhesion and neuritic network development directly on fiber surfaces.
authors.affiliation: Center for Brain Injury and Repair, Department of Neurosurgery, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. dkacy@mail.med.upenn.edu
authors.forename: D Kacy
authors.initials: DK
authors.lastname: Cullen
authors.forename: Ankur
authors.initials: A
authors.lastname: R Patel
authors.forename: John F
authors.initials: JF
authors.lastname: Doorish
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Smith
authors.forename: Bryan J
authors.initials: BJ
authors.lastname: Pfister
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials; D002448:Cell Adhesion / Q000502:physiology; D002470:Cell Survival; D003094:Collagen / Q000737:chemistry; D004553:Electric Conductivity; D004581:Electronics; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D020100:Hydrogels / Q000737:chemistry; D018613:Microscopy, Confocal; D008858:Microscopy, Phase-Contrast; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology; D016501:Neurites / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D011108:Polymers / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012685:Sepharose / Q000737:chemistry; D023822:Tissue Engineering
chemical_list: D000814:Aniline Compounds; D001672:Biocompatible Materials; D020100:Hydrogels; D011108:Polymers; D011126:Polypropylenes; C416807:polyaniline; D003094:Collagen; D012685:Sepharose