title: Novel enzymatically cross-linked hyaluronan hydrogels support the formation of 3D neuronal networks.
abstract: Hyaluronan (HA) is an essential component of the central nervous system's extracellular matrix and its high molecular weight (MW) form has anti-inflammatory and anti-fibrotic properties relevant for regenerative medicine. Here, we introduce a new hydrogel based on high MW HA which is cross-linked using the transglutaminase (TG) activity of the activated blood coagulation factor XIII (FXIIIa). These HA-TG gels have significant advantages for neural tissue engineering compared to previous HA gels. Due to their chemical inertness in the absence of FXIIIa, the material can be stored long-term, is stable in solution, and shows no cytotoxicity. The gelation is completely cell-friendly due to the specificity of the enzyme and the gelation rate can be tuned from seconds to hours at physiological pH and independently of stiffness. The gels are injectable, and attach covalently to fibrinogen and fibrin, two common bioactive components in in vitro tissue engineering, as well as proteins present in vivo, allowing the gels to covalently bind to brain or spinal cord defects. These optimal chemical and bioactive properties of HA-TG gels enabled the formation of 3D neuronal cultures of unprecedented performance, showing fast neurite outgrowth, axonal and dendritic speciation, strong synaptic connectivity in 3D networks, and rapidly-occurring and long-lasting coordinated electrical activity.
authors.affiliation: Department of Health Sciences and Technology, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Broguiere
authors.affiliation: Department of Health Sciences and Technology, ETH Zürich, Otto-Stern-Weg 7, 8093 Zürich, Switzerland.
authors.forename: Luca
authors.initials: L
authors.lastname: Isenmann
authors.affiliation: Department of Health Sciences and Technology, 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: D001369:Axons / Q000648:ultrastructure; D001672:Biocompatible Materials / Q000138:chemical synthesis; D001779:Blood Coagulation Factors / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004553:Electric Conductivity; D005337:Fibrin / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D009415:Nerve Net / Q000166:cytology* / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology* / Q000648:ultrastructure; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*; D011503:Transglutaminases / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D001779:Blood Coagulation Factors; D003432:Cross-Linking Reagents; D020100:Hydrogels; D005337:Fibrin; D005340:Fibrinogen; D006820:Hyaluronic Acid; D011503:Transglutaminases
keywords: Hyaluronan; Hydrogel; Neuron; Tissue engineering; Transglutaminase