(631q) Development and Characterization of Porous Chitosan/Xanthan Gum Scaffolds for Animal Cells Culture

Polymeric biodegradable materials are usually employed in the tissue engineering area as constituents of supports for cell adhesion, maintenance and growth. Properties such as biocompatibility, pore shapes and sizes, behavior in biological fluids, as well as the characteristics of the tissue to be regenerated itself, are important issues for the selection of the materials to be used in the production of this kind of supports. Systems based on the biocompatible biopolymers chitosan and xanthan may be a promising alternative for the preparation of scaffolds intended for use in skin healing. The purpose of this work was then to develop and evaluate the characteristics of chitosan and xanthan porous scaffolds obtained in the presence or not of the surfactants Tween 80 and Pluronic F68. The results show that the proportion of the polymers and the addition of the surfactants affect the scaffolds thickness, porosity, mechanical resistance and cytotoxicity, as well their ability to absorb distinct aqueous solutions and their stability regarding mass loss in the same solutions. Supports without surfactants showed thickness from 117 to 123 µm, high aqueous solutions absorption capacity (from 6 to 86 g^-1 of solution g^-1 of dry membrane), maximum mass loss of 23% when exposed to serum-supplemented RPMI culture medium for 144 h, tensile strength up to 25 MPa and volume expansion around 8 times when hydrated. The addition of surfactants resulted in thickness increase to up to 809 µm, decreasing, however, volume expansion after hydration in around 75%, tensile strenght to around 1 MPa and aqueous solutions absorption to 7 to 34 g^-1 of solution g^-1 of dry membrane. In vitro tests performed with L929 cells cultured in serum-supplemented RPMI showed that the supports prepared without surfactants and with Pluronic F68 are not cytotoxic, while samples obtained with Tween 80 induced high cell death, despite the fact that both surfactants should not affect cell behavior at the employed concentration.