Bio-based thermostable, biodegradable and biocompatible hyperbranched polyurethane/Ag nanocomposites with antimicrobial activity

The enhanced thermal and antimicrobial activity of silver nanoparticles prompts their uses in many medical devices. Mesua ferrea L. seed oil based antimicrobial biocompatible hyperbranched and linear polyurethane/Ag nanocomposites have been prepared in dimethylformamide without using any extra reducing agent. Formation of the stable and well-dispersed Ag nanoparticles was confirmed by ultra violet, X-ray diffractometeric, transmission electron microscopic and Fourier transform infra-red spectroscopic analyses. The enhancement of properties like thermal stability by (46-53)°C and 42 °C, tensile strength to ∼170% and ∼180% for hyperbranched and linear polyurethanes respectively was observed by the formation of nanocomposites. The cytocompatibility test based on the inhibition of RBC hemolysis showed that the materials lack cytotoxicity. The nanocomposites showed biodegradability as conferred from the bacterial degradation. Dose dependent excellent antibacterial activity of the nanocomposites against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria and antifouling activity against Candida albicans was observed.