Master of Science Thesis

Title:Adsorption of Bovine Albumin and Hyaluronic Acid onto Titanium Ceramics. Analisys by QCM-D and AFM.
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The use of coatings on surfaces has been a strategy used to improve the performance of medical devices. Titanium ceramic coatings are considered biocompatible with good mechanical and tribological properties. When the coating surface is in contact with body fluids adsorption of macromolecules takes place and can modify the behavior of the surface.
In this work the adsorption, at 25 ºC, of bovine serum albumin (BSA) and sodium hyaluronate (NaHA) were studied in three titanium ceramic coatings deposited by physical vapor deposition (PVD): titanium nitride (TiN), titanium niobium nitride (TiNbN) and titanium carbonitride (TiCN).
The techniques used in the adsorption study were the quartz crystal microbalance with dissipation analysis (QCM-D) and the atomic force microscopy (AFM).
The results for the adsorption of BSA suggest that there is no significant difference between the adsorption in the three ceramic materials. We also found that the BSA adsorbs onto titanium nitrides surface in a monolayer because the thickness of the film, determined by QCM-D and AFM, is compatible with the molecular dimension of the protein.
With the study of the adsorption of NaHA onto the titanium nitrides and onto the monolayer of BSA we conclude that, at neutral pH, the interaction between the NaHA and BSA is weak.
The adhesion forces between the pairs: TiN-BSA, TiNbN-BSA, BSA(TiN)-BSA e BSA(TiNbN)-BSA, were determined in water medium by AFM. Experimental results were higher than the van der Waals forces estimated by Hamaker method.

Albumin, Hyaluronic Acid, Adsorption, Quartz Crystal Microbalance, Atomic Force Microscopy, Titanium Nitrides