title: Chitosan-silica hybrid porous membranes.
abstract: Chitosan-silica porous hybrids were prepared by a novel strategy in order to improve the mechanical properties of chitosan (CHT) in the hydrogel state. The inorganic silica phase was introduced by sol-gel reactions in acidic medium inside the pores of already prepared porous scaffolds. In order to make the scaffolds insoluble in acidic media chitosan was cross-linked by genipin (GEN) with an optimum GEN concentration of 3.2 wt.%. Sol-gel reactions took place with Tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) acting as silica precursors. GPTMS served also as a coupling agent between the free amino groups of chitosan and the silica network. The morphology study of the composite revealed that the silica phase appears as a layer covering the chitosan membrane pore walls. The mechanical properties of the hybrids were characterized by means of compressive stress-strain measurements. By immersion in water the hybrids exhibit an increase in elastic modulus up to two orders of magnitude.
authors: Physics Department, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece; Centro de Biomateriales e Ingeniería Tisular, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain. Electronic address: pandis@mail.ntua.gr.
authors: Christos
authors: C
authors: Pandis
authors: 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.
authors: Sara
authors: S
authors: Madeira
authors: 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.
authors: Joana
authors: J
authors: Matos
authors: Physics Department, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece.
authors: Apostolos
authors: A
authors: Kyritsis
authors: 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.
authors: João F
authors: JF
authors: Mano
authors: Centro de Biomateriales e Ingeniería Tisular, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; Ciber en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Spain.
authors: José Luis Gómez
authors: JL
authors: Ribelles
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D019245:Compressive Strength; D003432:Cross-Linking Reagents; D055119:Elastic Modulus; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D039823:Iridoids; D008422:Materials Testing; D008567:Membranes, Artificial; D044367:Phase Transition; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D039823:Iridoids; D008567:Membranes, Artificial; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D012822:Silicon Dioxide; D048271:Chitosan; C007834:genipin
keywords: Chitosan; Genipin; Hybrid; Mechanical properties; Scaffolds; Silica