title: A versatile bioink for three-dimensional printing of cellular scaffolds based on thermally and photo-triggered tandem gelation.
abstract: Layer-by-layer bioprinting is a logical choice for the fabrication of stratified tissues like articular cartilage. Printing of viable organ replacements, however, is dependent on bioinks with appropriate rheological and cytocompatible properties. In cartilage engineering, photocrosslinkable glycosaminoglycan-based hydrogels are chondrogenic, but alone have generally poor printing properties. By blending the thermoresponsive polymer poly(N-isopropylacrylamide) grafted hyaluronan (HA-pNIPAAM) with methacrylated hyaluronan (HAMA), high-resolution scaffolds with good viability were printed. HA-pNIPAAM provided fast gelation and immediate post-printing structural fidelity, while HAMA ensured long-term mechanical stability upon photocrosslinking. The bioink was evaluated for rheological properties, swelling behavior, printability and biocompatibility of encapsulated bovine chondrocytes. Elution of HA-pNIPAAM from the scaffold was necessary to obtain good viability. HA-pNIPAAM can therefore be used to support extrusion of a range of biopolymers which undergo tandem gelation, thereby facilitating the printing of cell-laden, stratified cartilage constructs with zonally varying composition and stiffness.
authors.affiliation: Cartilage Engineering+Regeneration Laboratory, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland.
authors.forename: Matti
authors.initials: M
authors.lastname: Kesti
authors.affiliation: Cartilage Engineering+Regeneration Laboratory, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Müller
authors.affiliation: Biomaterials Department, INNOVENT e.V. Jena, Prüssingstrasse 27 B, 07745 Jena, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Becher
authors.affiliation: Biomaterials Department, INNOVENT e.V. Jena, Prüssingstrasse 27 B, 07745 Jena, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schnabelrauch
authors.affiliation: AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos Platz, Switzerland.
authors.forename: Matteo
authors.initials: M
authors.lastname: D'Este
authors.affiliation: AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos Platz, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Eglin
authors.affiliation: Cartilage Engineering+Regeneration Laboratory, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland. Electronic address: marcy.zenobi@hest.ethz.ch.
authors.forename: Marcy
authors.initials: M
authors.lastname: Zenobi-Wong
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000818:Animals; D002356:Cartilage / Q000737:chemistry*; D002417:Cattle; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods; D066330:Printing, Three-Dimensional; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; C052970:poly-N-isopropylacrylamide; D006820:Hyaluronic Acid
keywords: Bioprinting; Cartilage engineering; HA-pNIPAAM; Thermoresponsive polymer