@article {17039, title = {Buildup of Biomimetic and Multiple Stimuli Responsive Thin Coatings of Polysaccharides and Recombinant Biopolymers}, journal = {II Meeting of the Institute for Biotechnology and Bioengineering}, year = {2010}, month = {2010-11-15 00:00:00}, address = {Braga (Portugal)}, abstract = {

The modification of surfaces has been used in cutting-edge applications to produce smart or stimuli-responsive and patterned surfaces that may be used to develop several biomedical technologies. In this work, smart thin coatings using chitosan and recombinant elastin-like polymers (ELP) containing the cell attachment sequence RGD were fabricated in a sequential fashion through layer-by-layer adsorption. The adsorption of each layer was followed in situ using a quartz-crystal microbalance with dissipation monitoring and showed that both polymers can be successfully combined to conceive multilayer coatings.

Because ELPs are a class of biomaterials exhibiting smart properties in solution, the smart properties of the coatings were tested for their wettability by contact angle measurements (CAs) as a function of several stimuli, namely temperature, pH and ionic strength. Wettability transitions were observed from a moderate hydrophobic surface (CAs approximately from 62{\textordmasculine} to 71{\textordmasculine}) to an extremely wettable one (CA considered to be 0{\textordmasculine}) as the temperature, pH and ionic strength were raised above 50 {\textordmasculine}C, 11, and 1.25M, respectively. Atomic force microscopy was performed to assess the coating topography, showing the formation of larger and compact micelle-like structures upon the aggregation of ELPs at the surface, increasing its water affinity.

Cell adhesion tests were conducted using a SaOS-2 cell line. Enhanced cell adhesion was observed in the coatings, as compared to a coating with a chitosan-ending film and a scrambled RDG biopolymer. The developed films have great potential as biomimetic coatings of biomaterials for different tissue engineering applications, controlled delivery systems and tunable cell adhesion.

}, keywords = {Biomaterials, Multilayers, Recombinant polymers, Smart coatings, Surface modificacion}, author = {Costa, R. R. and Cust{\'o}dio, C. A. and Arias, F. J. and Rodr{\'\i}guez-Cabello, J. C. and Mano, J. F.} }