Diagnostic devices and a variety of biomedical implants are used in direct contact with biological fluids that creates a number of problems. One of the most significant is the process of biofouling, i.e. the unwanted adsorption of proteins, occurring on the surfaces exposed to solutions containing biological material. Therefore, the development of the “antifouling” coatings protecting against non-specific protein adsorption, bacteria and fungi colonization are an important area of research within a broader field of biointerface science. Immobilization of neutral hydrophilic polymers (e.g. poly(ethylene glycol) (PEG)) at surfaces is one of the accepted methods to reduce non-specific adsorption of proteins. On the other hand, silver and/or copper containing materials and coatings with antimicrobial activity find applications: in medicine to reduce infections in hospitals, in burn treatment as well as to prevent bacteria and fungi colonization on prostheses, catheters, vascular grafts, dental materials. One goal of the work was to explore the method of direct immobilization of PEG layer to reduce/eliminate non-specific adsorption of proteins at surface of polyelectrolyte multilayer thin films. Synthesized copolymers of poly(glutamic acid) or poly(L-lysine) with grafted PEG chains with various grafting ratio and various chain lengths,were used for that modification by formation of the external layer of films. The biofouling process was investigated by studying the adsorption of different proteins, e.g. HSA,using Quartz Crystal Microbalance and fluorescent methods. Apart from polyelectrolytes negatively charged silver or copper nanoparticles were used for the multilayers construction, which led to the formation of nanocomposite films. It was found that nanocomposite films have antimicrobial properties, which makes them very interesting for a number of practical application e.g. prevention of microbial colonization on treated surfaces.
Acknowledgements: The work was financed by NCN project UMO 2012/07/N/ST5/00173.
