Antibacterial properties of elastomers modified with chitosan

Bacterial infections pose a serious threat to human health. For many years, there has been a search for materials that would inhibit their development. It was decided to take a closer look at various elastomeric materials with the addition of chitosan. Mixtures based on silicone, silicone with a platinum catalyst, acrylonitrile-butadiene rubber, natural rubber, and ethylene-propylene-diene rubber were developed and tested for antibacterial and physico-mechanical properties. The dispersion of chitosan in the elastomer was also investigated using a scanning electron microscope. Of the tested mixtures, three were selected, characterised by the best antibacterial and physico-mechanical properties and a very good dispersion of chitosan in the matrix. The mixtures were based on silicone, silicone with a platinum catalyst and natural rubber. Tests were performed to measure the release of compounds into water for these mixtures. Furthermore, cytotoxicity with L929 cells and cytocompatibility in direct contact with MG63 cells were investigated for silicone samples. The results showed that these materials were not toxic to mammalian cells and supported their growth. The best bactericidal properties against E. coli and S. aureus strains compared to the other tested materials (>99.0-99.9% of killed bacteria) were shown by samples made of silicone and silicone with a platinum catalyst and added chitosan. At the same time, the best physico-mechanical properties were found for the samples with chitosan based on silicone with added platinum and natural rubber. Developed materials appeared to be good candidates for manufacturing medical equipment on which the adhesion and growth of bacteria should be prevented.