title: An innovative co-axial system to electrospin in situ crosslinked gelatin nanofibers.
abstract: Crosslinking of gelatin nanofibers maintaining a fibrous morphology after exposure to an aqueous solution is still a challenge. In this work, we developed an innovative method based on the use of an ad hoc designed co-axial needle to fabricate gelatin mats crosslinked with a very small amount of genipin and still able to retain their morphology when immersed in aqueous solution. Genipin-containing gelatin nanofibers are obtained by allowing mixing of the two solutions just within the needle. Genipin content of the electrospun mats can be modulated by varying feeding rates of the inner and outer solutions and their relative concentration. A subsequent thermal treatment of the mats, performed at 55 °C or 37 °C for 1 or 3 days and followed by rapid rinsing in ethanol and then in PB, allows one to obtain highly crosslinked gelatin nanofibers that perfectly maintain their morphology after immersion in an aqueous solution, display improved mechanical properties and enhanced stability. This new approach allows us to achieve gelatin mat stabilization using a very small amount of genipin with respect to other methods and to avoid post-treatment of the mats with the crosslinking agent, with a consequent significant reduction of the final cost of the materials. Moreover, in vitro tests demonstrate that the crosslinked mats support normal human primary chondrocyte culture, promoting their differentiation.
authors.affiliation: Department of Chemistry 'G. Ciamician' and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna, Via Selmi 2, 40126 Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Gualandi
authors.forename: Paola
authors.initials: P
authors.lastname: Torricelli
authors.forename: Silvia
authors.initials: S
authors.lastname: Panzavolta
authors.forename: Stefania
authors.initials: S
authors.lastname: Pagani
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Focarete
authors.forename: Adriana
authors.initials: A
authors.lastname: Bigi
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002454:Cell Differentiation; D002470:Cell Survival; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000201:enzymology; D003432:Cross-Linking Reagents; D005780:Gelatin / Q000737:chemistry*; D006801:Humans; D039823:Iridoids; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D039823:Iridoids; D005780:Gelatin; C007834:genipin; D007770:L-Lactate Dehydrogenase