title: A three-dimensional neural spheroid model for capillary-like network formation.
abstract: In vitro three-dimensional neural spheroid models have an in vivo-like cell density, and have the potential to reduce animal usage and increase experimental throughput. The aim of this study was to establish a spheroid model to study the formation of capillary-like networks in a three-dimensional environment that incorporates both neuronal and glial cell types, and does not require exogenous vasculogenic growth factors.
  
  
  
  We created self-assembled, scaffold-free cellular spheroids using primary-derived postnatal rodent cortex as a cell source. The interactions between relevant neural cell types, basement membrane proteins, and endothelial cells were characterized by immunohistochemistry. Transmission electron microscopy was used to determine if endothelial network structures had lumens.
  
  
  
  Endothelial cells within cortical spheroids assembled into capillary-like networks with lumens. Networks were surrounded by basement membrane proteins, including laminin, fibronectin and collagen IV, as well as key neurovascular cell types.
  
  
  
  Existing in vitro models of the cortical neurovascular environment study monolayers of endothelial cells, either on transwell inserts or coating cellular spheroids. These models are not well suited to study vasculogenesis, a process hallmarked by endothelial cell cord formation and subsequent lumenization.
  
  
  
  The neural spheroid is a new model to study the formation of endothelial cell capillary-like structures in vitro within a high cell density three-dimensional environment that contains both neuronal and glial populations. This model can be applied to investigate vascular assembly in healthy or disease states, such as stroke, traumatic brain injury, or neurodegenerative disorders.
authors.affiliation: Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: mollyboutin@gmail.com.
authors.forename: Molly E
authors.initials: ME
authors.lastname: Boutin
authors.affiliation: Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: Liana_Kramer@brown.edu.
authors.forename: Liana L
authors.initials: LL
authors.lastname: Kramer
authors.affiliation: Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: Liane_Livi@brown.edu.
authors.forename: Liane L
authors.initials: LL
authors.lastname: Livi
authors.affiliation: Department of Neuroscience, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: tylerclarkbrown@gmail.com.
authors.forename: Tyler
authors.initials: T
authors.lastname: Brown
authors.affiliation: Department of Neuroscience, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: Christopher_Moore@brown.edu.
authors.forename: Christopher
authors.initials: C
authors.lastname: Moore
authors.affiliation: Center for Biomedical Engineering, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Department of Molecular Pharmacology, Physiology, and Biotechnology, 175 Meeting Street, Brown University, Providence, RI, 02912, United States; Brown Institute for Brain Science, 175 Meeting Street, Brown University, Providence, RI, 02912, United States. Electronic address: Diane_Hoffman-Kim@brown.edu.
authors.forename: Diane
authors.initials: D
authors.lastname: Hoffman-Kim
mesh_terms: D000818:Animals; D002196:Capillaries / Q000502:physiology* / Q000648:ultrastructure; D018929:Cell Culture Techniques / Q000379:methods; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology; D042783:Endothelial Cells / Q000502:physiology* / Q000648:ultrastructure; D051379:Mice; D018919:Neovascularization, Physiologic; D009457:Neuroglia / Q000166:cytology / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D018874:Spheroids, Cellular / Q000502:physiology* / Q000648:ultrastructure
keywords: Brain; Capillary-like network; Cellular self-assembly; Cortex; Endothelial cells; Neurovascular unit; Spheroid; Vasculogenesis; in vitro