Stimuli-Responsive Thin Coatings Using Elastin-Like Polymers for Biomedical Applications

Smart thin coatings using a accombinant elastin-like polymer (ELP) containing the cell attachment sequence arginine-glycine-(aspartic acid) (RGD) are fabricated for the first time through simple deposition of the ELP dissolved in aqueous-based solutions. The biopolymer is produced and characterized Ming electrophoresis and mass spectroscopy. The temperature and pH responsiveness are asessed by aggregate size measurements and differential scanning calorimetry. The deposition of the studied ELP onto chitosan is followed in situ with a quartz-crystal microbalance with dissipation monitoring (QCM-D). Contact angle measurements are performed at room temperature and at 50 degrees C, showing reversible changes from a moderate hydrophobic behavior to an extremely wettable surface. AFM analysis performed at room temperature reveals a smooth surface and no organized structure. At 50 degrees C, the surface presents spherical nanometer-sized structures of collapsed blo-polyrirlier chai.09. Such results suggest that the ELP chains, when collapsed aggregate into micellle-like structures at the surface of the substrate, increasing as water affinity. Cell adhesion tests on the developed coatings are. conducted using a SaOS2 cell line. Enhanced cell adhesion could be observed in the H-RGD6-costed surfaces, as compared with the original chitosan monolayer,. 0 intermediate behavior is found in chitosan coated with the corresponding ELP without the RGD sequence. Therefore, the developed films have great potential as biomimetic coatings of biomaterials for different biomedical applications, including tissue engineering and controlled delivery of. active agents. Their thermo-responsive behavior can also be exploited for tunable cell adhesion and controlled protein adsorption.