ORIGINAL ARTICLE In Vitro Mechanical Property Evaluation of Chitosan-Based Hydrogels Intended for Vascular Graft Development Audrey Aussel 1,2,3 & Alexandra Montembault 4 & Sébastien Malaise 4 & Marie Pierre Foulc 5 & William Faure 5 & Sandro Cornet 6 & Rachida Aid 7,8 & Marc Chaouat 7 & Thierry Delair 4 & Didier Letourneur 7,8 & Laurent David 4 & Laurence Bordenave 1,2,3,6 Received: 22 April 2017 /Accepted: 20 July 2017 # Springer Science+Business Media, LLC 2017 Abstract Vascular grafts made of synthetic polymers perform poorly in cardiac and peripheral bypass applications. In these applications, chitosan-based materials can be produced and shaped to provide a novel scaffold for vascular tissue engi- neering. The goal of this study was to evaluate in vitro the mechanical properties of a novel chitosan formulation to as- sess its potential for this scaffold. Two chitosan-based hydro- gel tubes were produced by modulating chitosan concentra- tion. Based on the standard ISO 7198:1998, the hydrogel tubes were characterized in vitro in terms of suture retention strength, tensile strength, compliance, and burst pressure. By increasing chitosan concentration, suture retention value in- creased to reach 1.1 N; average burst strength and elastic moduli also increased significantly. The compliance seemed to exhibit a low value for chitosan tubes of high concentration. By modulating chitosan concentration, we produced scaffolds with suitable mechanical properties to be im- planted in vivo and withstand physiological blood pressures. Keywords Chitosan . Hydrogels . Mechanical properties . In vitro . Vascular graft development Introduction Arterial substitutes are still needed nowadays as the incidence of cardiovascular disease rises with an aging population and increasing obesity. While autologous vessels are preferred for bypass surgery, they may not be available for different rea- sons. Thus, due to the poor performance of vascular grafts made of synthetic polymers in small-diameter vascular substi- tute applications, there is a strong clinical and societal demand for novel biomaterials to produce small caliber vessels with better patency [1, 2]. The emergence of tissue engineering opens new possibilities in reconstructive vascular grafting [3] and scaffolds made of different materials have been inves- tigated in blood vessel tissue engineering. Among scaffolds, natural and biodegradable polymers such as chitosan may lead to better outcomes than synthetic polymers. Chitosans consti- tute a family of biocompatible polysaccharides that can be found in biomass in the cell wall of fungi. Chitosans are pro- duced from the N-deacetylation of chitin, an abundant poly- saccharide present in crab shells, shrimp shells, or squid pens. Their extraction process has been significantly improved in the last decade. Today, products with low levels of endotoxins and high molar mass are commercially available for medical devices [4]. Chitosans are soluble in acidic aqueous media and can be processed into a wide range of physical forms (hydrogels, lyophilizates, fibers, etc.) containing only chitosan and water [4]. Chitosan hydrogels are investigated for a wide range of bio- medical applications, among which tissue engineering [5, 6] Associate Editor Adrian Chester oversaw the review of this article Audrey Aussel and Alexandra Montembault equally co-first authors * Laurence Bordenave laurence.bordenave@chu-bordeaux.fr 1 University Bordeaux, 33000 Bordeaux, France 2 INSERM, Bioingénierie tissulaire, U1026, 33000 Bordeaux, France 3 CHU de Bordeaux, 33000 Bordeaux, France 4 University Lyon, Université Lyon 1, Ingénierie des Matériaux Polymères (IMP), CNRS UMR 5223, 69622 Villeurbanne Cedex, France 5 Rescoll, 8 Allée Geoffroy Saint-Hilaire, 33600 Pessac, France 6 CHU de Bordeaux, CIC 1401, 33000 Bordeaux, France 7 INSERM, U1148, Laboratoire de recherche vasculaire translationnelle, 75000 Paris, France 8 University Paris Diderot, Sorbonne Paris Cité, 75000 Paris, France J. of Cardiovasc. Trans. Res. DOI 10.1007/s12265-017-9763-z