title: A rapid, quantitative method for assessing axonal extension on biomaterial platforms.
abstract: Measuring outgrowth of neuronal explants is critical in evaluating the ability of a biomaterial to act as a permissive substrate for neuronal adhesion and growth. Previous methods lack the ability to quantify robust outgrowth, or lack the capacity to quantify growth on opaque substrates because they exploit the transparent nature of culture dishes to segregate neuronal processes from an image background based on color intensity. In this study, we sought to investigate the ability of opaque silica sol-gel materials to facilitate axonal outgrowth; therefore, a method was developed for quantifying outgrowth of neurites from dorsal root ganglion explants on these unique surfaces. Dorsal root ganglia were isolated from stage-nine chick embryos and cultured for 48 h on sol-gel materials presenting agarose and chitosan polysaccharides individually or in combination. Explants were then imaged, and basic image analysis software was used by three independent observers to obtain axonal length and axonal area measurements. Robust axon length and axonal spread measurements for ganglia cultured on agarose-chitosan sol-gel matrices yield an estimate of strong neural compatibility for these substrates over silica matrices presenting no polysaccharides, or silica matrices presenting chitosan or agarose individually. We suggest that this simple protocol for quantifying material biocompatibility offers an analysis strategy that can be used universally to the same end.
authors.affiliation: Regeneration and Repair Laboratory, Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, USA.
authors.forename: Jared M
authors.initials: JM
authors.lastname: Cregg
authors.forename: Sherri L
authors.initials: SL
authors.lastname: Wiseman
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Pietrzak-Goetze
authors.forename: Martyn R
authors.initials: MR
authors.lastname: Smith
authors.forename: David B
authors.initials: DB
authors.lastname: Jaroch
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Clupper
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Gilbert
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000187:drug effects / Q000196:embryology / Q000502:physiology; D008422:Materials Testing / Q000379:methods; D009416:Nerve Regeneration / Q000502:physiology; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D012685:Sepharose / Q000737:chemistry / Q000494:pharmacology; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D012685:Sepharose; D048271:Chitosan