title: Elastic chitosan/chondroitin sulfate multilayer membranes.
abstract: Freestanding multilayered films were obtained using layer-by-layer (LbL) technology from the assembly of natural polyelectrolytes, namely chitosan (CHT) and chondroitin sulfate (CS). The morphology and the transparency of the membranes were evaluated. The influence of genipin (1 and 2 mg ml(-1)), a naturally-derived crosslinker agent, was also investigated in the control of the mechanical properties of the CHT/CS membranes. The water uptake ability can be tailored by changing the crosslinker concentration that also controls the Young's modulus and ultimate tensile strength. The maximum extension tends to decrease upon crosslinking with the highest genipin concentration, compromising the elastic properties of CHT/CS membranes: nevertheless, when using a lower genipin concentration, the ultimate tensile stress is similar to the non-crosslinked one, but exhibits a significantly higher modulus. Moreover, the crosslinked multilayer membranes exhibited shape memory properties, through a simple hydration action. The in vitro biological assays showed better L929 cell adhesion and proliferation when using the crosslinked membranes and confirmed the non-cytotoxicity of the developed CHT/CS membranes. Within this research work, we were able to construct freestanding biomimetic multilayer structures with tailored swelling, mechanical and biological properties that could find applicability in a variety of biomedical applications.
authors.affiliation: 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal. ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal. Present address: Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: M P
authors.initials: MP
authors.lastname: Sousa
authors.forename: F
authors.initials: F
authors.lastname: Cleymand
authors.forename: J F
authors.initials: JF
authors.lastname: Mano
mesh_terms: D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D002470:Cell Survival; D048271:Chitosan / Q000737:chemistry*; D002809:Chondroitin Sulfates / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D055119:Elastic Modulus; D039823:Iridoids / Q000737:chemistry; D008567:Membranes, Artificial; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D039823:Iridoids; D008567:Membranes, Artificial; C480355:chitosan sulfate; D002809:Chondroitin Sulfates; D048271:Chitosan; C007834:genipin