Journal Article 9000-70-8 Gelatin Hydrogels Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't 3D printing 7782-42-5 9004-61-9 9007-49-2 DNA Graphite Hyaluronic Acid Nanotubes, Carbon Oxides Polyethylene Terephthalates Published Erratum Research Support, U.S. Gov't, Non-P.H.S. biomaterials carbon nanotubes conductive inks copper nanowire aerosponges copper nanowire hydrogels flexible electronics graphene microgels multilayer constructs porous metals tissue engineering tunable stiffness