Hybrid anti-biofouling coatings for medical applications

This work presents the preparation of hybrid films based on urethane linkage and poly(dimethylsiloxane) segments for application as anti-biofouling coating for medical applications. The synthesis of such material is based on the green chemistry of carbon dioxide fixation and sol-gel approach. Polyurethanes and elastomers based on silicone chemistry, besides the interesting physical properties such as flexibility and thermal stability, they present compatibility with blood and low toxicity and have been used as cardiac valves most notably as intraaortic balloons, catheters and as a pacemaker component. A hybrid material is prepared by the combination of organic and inorganic components and constitutes an alternative for functional materials production. The functional materials can be obtained by the functionalization of surfaces or designing properties to serve specific applications needing. In the last years, the use of medical implants has increased. Is common the colonization of these devices by microorganisms which form a biofilm. Infections caused by gram-negative bacteria and fungi tend to be more serious. Fungal infections are most commonly caused by the pathogenic Candida. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. The urethane PDMS segmented hybrid materials, here labelled as PDMSUr, had the adhesion of gram negative bacteria (E.coli) tested as well as the biofilm formation of Candida albicans. Metallic or glass substrata were coated by the PDMSUr and put in contact with E.coli and Candida during 4 hours. The coatings presented bacteriostatic behaviour avoiding the adhesion of bacteria and they were able to inhibit the biofilm formation of C. albicans in preliminary test. Also, the hybrid PDMSUr coating did not presented toxicity to fibroblast cells. Therefore, the PDMSUr coatings developed in this work are good candidates for anti-biofouling applications.