title: Neurotrophin releasing single and multiple lumen nerve conduits.
abstract: Tissue engineering strategies for nerve repair employ polymer conduits termed guidance channels and bridges to promote regeneration for peripheral nerve injury and spinal cord injury, respectively. An approach for fabrication of nerve conduits with single and multiple lumens capable of controlled release of neurotrophic factors was developed. These conduits were fabricated from a mixture of poly(lactide-co-glycolide) (PLG) microspheres and porogen (NaCl) that was loaded into a mold and processed by gas foaming. The porosity and mechanical properties of the constructs were regulated by the ratio of porogen to polymer microsphere. The neurotrophin, nerve growth factor (NGF), was incorporated into the conduit by either mixing the protein with microspheres or encapsulating the protein within microspheres prior to gas foaming. A sustained release was observed for at least 42 days, with the release rate controlled by method of incorporation and polymer molecular weight. Released NGF retained its bioactivity, as demonstrated by its ability to stimulate neurite outgrowth from primary dorsal root ganglion (DRG). In vivo results indicate that conduits retain their original architecture, and allow for cellular infiltration into the channels. Polymer conduits with controllable lumen diameters and protein release may enhance nerve regeneration by guiding and stimulating neurite outgrowth.
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Rd E156, Evanston, IL 60208-3120, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Laura
authors.initials: L
authors.lastname: De Laporte
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Rives
authors.forename: Jae-Hyung
authors.initials: JH
authors.lastname: Jang
authors.forename: Wei-Chun
authors.initials: WC
authors.lastname: Lin
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Shull
authors.forename: Lonnie D
authors.initials: LD
authors.lastname: Shea
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D002642:Chick Embryo; D003692:Delayed-Action Preparations; D004355:Drug Stability; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology; D019344:Lactic Acid; D008297:Male; D008422:Materials Testing; D051379:Mice; D008815:Mice, Inbred Strains; D008863:Microspheres; D020932:Nerve Growth Factor / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D009416:Nerve Regeneration / Q000187:drug effects* / Q000502:physiology; D016501:Neurites / Q000502:physiology; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D016062:Porosity; D023822:Tissue Engineering
chemical_list: D003692:Delayed-Action Preparations; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D020932:Nerve Growth Factor