title: Neurite extension and in vitro myelination within three-dimensional modified fibrin matrices.
abstract: The deposition of fibrin clots in vivo occurs after injury in the peripheral nervous system and their removal correlates with nerve regeneration. Fibrin clots provide a provisional matrix for invading cells, induce wound healing, and become proteolytically removed by regenerating tissue. Here, neurite extension and in vitro myelination were studied within three-dimensional fibrin matrices that were covalently modified with the sixth Ig-like domain of cell adhesion molecules L1 containing N-terminal transglutaminase substrate sequences (TG-L1Ig6) for covalent incorporation into fibrin matrices. TG-L1Ig6 is a specific receptor for alphavbeta3-integrin involved in neurite extension of PC12 cells and dorsal root ganglion neurons (DRGs). Neurite extension of PC12 cells depended on interactions between cell surface alphavbeta3 and RGD-sites provided by TG-L1Ig6. In addition, matrix properties such as fibrin crosslink density and matrix degradation by serine proteases were crucial. No involvement of matrix metalloproteinases was found. DRG neurite extension in native fibrin matrices was retarded as compared to neurite extension within L1Ig6-modified and laminin-1-containing matrices. Moreover, myelinated structures were almost exclusively found in TG-L1Ig6-modified and laminin-1-containing matrices. These results indicate that potential use of three-dimensional matrices in a biomaterials-based healing device to induce and/or help in vivo nerve regeneration requires specific structural and biological signals.
authors.affiliation: Institute for Biomedical Engineering and Department of Materials ETH and University of Zurich, Zurich, Switzerland.
authors.forename: Régis
authors.initials: R
authors.lastname: Pittier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Sauthier
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
authors.forename: Heike
authors.initials: H
authors.lastname: Hall
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001391:Azo Compounds; D002642:Chick Embryo; D046508:Culture Techniques / Q000379:methods; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects; D005109:Extracellular Matrix / Q000502:physiology*; D005176:Factor XIII / Q000494:pharmacology; D005337:Fibrin / Q000502:physiology*; D019922:GAP-43 Protein / Q000378:metabolism; D005727:Ganglia, Spinal / Q000166:cytology / Q000196:embryology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007211:Indoles / Q000378:metabolism; D016023:Integrins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D007797:Laminin / Q000494:pharmacology; D008954:Models, Biological; D004676:Myelin Basic Protein / Q000378:metabolism; D009186:Myelin Sheath / Q000378:metabolism*; D009281:Naphthalenes; D039842:Neural Cell Adhesion Molecule L1 / Q000494:pharmacology; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000906:Antibodies; D001391:Azo Compounds; D019922:GAP-43 Protein; D005904:Glial Fibrillary Acidic Protein; D007211:Indoles; D016023:Integrins; D007797:Laminin; D004676:Myelin Basic Protein; D009281:Naphthalenes; D039842:Neural Cell Adhesion Molecule L1; D011480:Protease Inhibitors; D011994:Recombinant Proteins; C121346:laminin 1; C007293:DAPI; D005337:Fibrin; D005176:Factor XIII; C016118:Sudan Black B