Biosourced polymeric cryogels for future biomedical applications with remarkable antimicrobial activities and tribological properties

Cryogels, known as a subclass of hydrogels, are promising biomaterials to use in various biotechnological fields. In recent years, applications of antimicrobial hydrogels with improved antimicrobial activities, high biocompatibility, and physicochemical stability have attracted attention as an alternative to using antimicrobial drugs against microbial interactions that may threaten human health, which may even result in death. In this paper, we investigated in detail the biological activities and tribological performances of the previously characterized 2hydroxyethyl methacrylate (HEMA)-based amphiphilic cryogels (PHEMA-PLinaOH) (HC series) that contain hydroxylated polymeric linoleic acid (PLinaOH) as biosource. The biocompatibilities of these cryogels were examined against human embriyonic kidney (HEK293) cell line with MTT assay and acridine orange/ethidium bromide (AO/EB) dual staining. The antimicrobial activities of the materials were extensively investigated against Staphylococcus aureus ATCC 29213 and Pseudomonas aeruginosa PA01 besides four different strains of the yeast Saccharomyces cerevisiae BY4741 by using biofilms eradication, antibiofilm activity and colony forming unit assays. Additionally, the possible morphological changes in microbial cells were evaluated by taking FESEM images. The tribological performances of the cryogels were evaluated in terms of their applicability for future biomedical applications such as artificial articular cartilage or tissue scaffold. Our results showed that while the cryogels did not show significant inhibition on HEK293 cell viability and intensive live cell population was observed after AO/EB staining, they exerted remarkable antimicrobial activities against all studied bacterial and fungal strains. The morphological deformations including the decrease in EPS density and formation of holes were recorded for bacteria and yeast cells with FESEM images, respectively. Finally, it was determined that the increase in the fatty acid ratio contributes positively to tribological properties of the cryogels. All the results indicate that these polymeric cryogels might be considered potential biomaterials for future tissue-engineering studies.