title: Three-dimensional printing of high-content graphene scaffolds for electronic and biomedical applications.
abstract: The exceptional properties of graphene enable applications in electronics, optoelectronics, energy storage, and structural composites. Here we demonstrate a 3D printable graphene (3DG) composite consisting of majority graphene and minority polylactide-co-glycolide, a biocompatible elastomer, 3D-printed from a liquid ink. This ink can be utilized under ambient conditions via extrusion-based 3D printing to create graphene structures with features as small as 100 μm composed of as few as two layers (<300 μm thick object) or many hundreds of layers (>10 cm thick object). The resulting 3DG material is mechanically robust and flexible while retaining electrical conductivities greater than 800 S/m, an order of magnitude increase over previously reported 3D-printed carbon materials. In vitro experiments in simple growth medium, in the absence of neurogenic stimuli, reveal that 3DG supports human mesenchymal stem cell (hMSC) adhesion, viability, proliferation, and neurogenic differentiation with significant upregulation of glial and neuronal genes. This coincides with hMSCs adopting highly elongated morphologies with features similar to axons and presynaptic terminals. In vivo experiments indicate that 3DG has promising biocompatibility over the course of at least 30 days. Surgical tests using a human cadaver nerve model also illustrate that 3DG has exceptional handling characteristics and can be intraoperatively manipulated and applied to fine surgical procedures. With this unique set of properties, combined with ease of fabrication, 3DG could be applied toward the design and fabrication of a wide range of functional electronic, biological, and bioelectronic medical and nonmedical devices.
authors: †Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States.|§Simpson Querrey Institute for BioNanotechnology, Northwestern University, 303 East Superior Street, Chicago, Illinois 60611, United States.
authors: Adam E
authors: AE
authors: Jakus
authors: †Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States.
authors: Ethan B
authors: EB
authors: Secor
authors: ‡Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.|§Simpson Querrey Institute for BioNanotechnology, Northwestern University, 303 East Superior Street, Chicago, Illinois 60611, United States.
authors: Alexandra L
authors: AL
authors: Rutz
authors: ⊥Department of Surgery, Northwestern University, 251 East Huron Street, Galter 3-150, Illinois 60611, United States.
authors: Sumanas W
authors: SW
authors: Jordan
authors: †Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States.|∥Department of Chemistry, Northwestern University, 2220 Campus Drive, Evanston Illinois 60208, United States.
authors: Mark C
authors: MC
authors: Hersam
authors: †Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, United States.|§Simpson Querrey Institute for BioNanotechnology, Northwestern University, 303 East Superior Street, Chicago, Illinois 60611, United States.|⊥Department of Surgery, Northwestern University, 251 East Huron Street, Galter 3-150, Illinois 60611, United States.
authors: Ramille N
authors: RN
authors: Shah
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004553:Electric Conductivity; D005260:Female; D006108:Graphite / Q000737:chemistry* / Q000494:pharmacology*; D006801:Humans; D007281:Ink; D055595:Mechanical Phenomena; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D055495:Neurogenesis / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D011098:Polyglactin 910 / Q000737:chemistry; D066330:Printing, Three-Dimensional; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011098:Polyglactin 910; D006108:Graphite
keywords: 3D printing; graphene; neurogenesis; tissue engineering