title: An ice-templated, linearly aligned chitosan-alginate scaffold for neural tissue engineering.
abstract: Several strategies have been investigated to enhance axonal regeneration after spinal cord injury, however, the resulting growth can be random and disorganized. Bioengineered scaffolds provide a physical substrate for guidance of regenerating axons towards their targets, and can be produced by freeze casting. This technique involves the controlled directional solidification of an aqueous solution or suspension, resulting in a linearly aligned porous structure caused by ice templating. In this study, freeze casting was used to fabricate porous chitosan-alginate (C/A) scaffolds with longitudinally oriented channels. Chick dorsal root ganglia explants adhered to and extended neurites through the scaffold in parallel alignment with the channel direction. Surface adsorption of a polycation and laminin promoted significantly longer neurite growth than the uncoated scaffold (poly-L-ornithine + Laminin = 793.2 ± 187.2 μm; poly-L-lysine + Laminin = 768.7 ± 241.2 μm; uncoated scaffold = 22.52 ± 50.14 μm) (P < 0.001). The elastic modulus of the hydrated scaffold was determined to be 5.08 ± 0.61 kPa, comparable to reported spinal cord values. The present data suggested that this C/A scaffold is a promising candidate for use as a nerve guidance scaffold, because of its ability to support neuronal attachment and the linearly aligned growth of DRG neurites.
authors.affiliation: Department of Biomedical Engineering, Science, and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia.
authors.forename: Nicola L
authors.initials: NL
authors.lastname: Francis
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Hunger
authors.forename: Amalie E
authors.initials: AE
authors.lastname: Donius
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Riblett
authors.forename: Antonios
authors.initials: A
authors.lastname: Zavaliangos
authors.forename: Ulrike G K
authors.initials: UG
authors.lastname: Wegst
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Wheatley
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002642:Chick Embryo; D048271:Chitosan / Q000494:pharmacology*; D005615:Freezing; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects; D020723:Glucuronic Acid / Q000494:pharmacology; D006603:Hexuronic Acids / Q000494:pharmacology; D007053:Ice; D008422:Materials Testing; D055595:Mechanical Phenomena / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D009420:Nervous System / Q000187:drug effects*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D055114:X-Ray Microtomography
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D007053:Ice; D020723:Glucuronic Acid; D048271:Chitosan
keywords: alginate; axon regeneration; chitosan; freeze casting; scaffold