title: 3D printing of layered brain-like structures using peptide modified gellan gum substrates.
abstract: The brain is an enormously complex organ structured into various regions of layered tissue. Researchers have attempted to study the brain by modeling the architecture using two dimensional (2D) in vitro cell culturing methods. While those platforms attempt to mimic the in vivo environment, they do not truly resemble the three dimensional (3D) microstructure of neuronal tissues. Development of an accurate in vitro model of the brain remains a significant obstacle to our understanding of the functioning of the brain at the tissue or organ level. To address these obstacles, we demonstrate a new method to bioprint 3D brain-like structures consisting of discrete layers of primary neural cells encapsulated in hydrogels. Brain-like structures were constructed using a bio-ink consisting of a novel peptide-modified biopolymer, gellan gum-RGD (RGD-GG), combined with primary cortical neurons. The ink was optimized for a modified reactive printing process and developed for use in traditional cell culturing facilities without the need for extensive bioprinting equipment. Furthermore the peptide modification of the gellan gum hydrogel was found to have a profound positive effect on primary cell proliferation and network formation. The neural cell viability combined with the support of neural network formation demonstrated the cell supportive nature of the matrix. The facile ability to form discrete cell-containing layers validates the application of this novel printing technique to form complex, layered and viable 3D cell structures. These brain-like structures offer the opportunity to reproduce more accurate 3D in vitro microstructures with applications ranging from cell behavior studies to improving our understanding of brain injuries and neurodegenerative diseases.
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Lozano
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Leo
authors.initials: L
authors.lastname: Stevens
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Brianna C
authors.initials: BC
authors.lastname: Thompson
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Gilmore
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Gorkin
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Elise M
authors.initials: EM
authors.lastname: Stewart
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia; Soft Materials Group, School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Marc
authors.initials: M
authors.lastname: in het Panhuis
authors.affiliation: Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA.
authors.forename: Mario
authors.initials: M
authors.lastname: Romero-Ortega
authors.affiliation: Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, University of Wollongong, Wollongong, NSW 2522, Australia. Electronic address: gwallace@uow.edu.au.
authors.forename: Gordon G
authors.initials: GG
authors.lastname: Wallace
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000378:metabolism; D005614:Freeze Fracturing; D005782:Gels; D008807:Mice, Inbred BALB C; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000494:pharmacology*; D016062:Porosity; D066330:Printing, Three-Dimensional; D012710:Serum Albumin, Bovine / Q000378:metabolism
chemical_list: D005782:Gels; D009842:Oligopeptides; D011135:Polysaccharides, Bacterial; C039217:fluorescein isothiocyanate bovine serum albumin; D012710:Serum Albumin, Bovine; C048288:gellan gum; C047981:arginyl-glycyl-aspartic acid; D016650:Fluorescein-5-isothiocyanate
keywords: 3D printing; Brain-like structure; Diffusion; GG modification; Gellan gum (GG)