Biological properties of printable polyaniline and polyaniline-silver colloidal dispersions stabilized by gelatin

•The gelatin-stabilized polyaniline colloids with or without silver have been prepared.•Polyaniline colloids having spindle-like morphology and the particle size smaller than 200 nm.•The similar oxidation of aniline with silver nitrate leads to hybrid composite with more complex morphology.•Synthetized colloids were deposited using spiral bar coating and flexography printing technique.•The prepared layers possess high antibacterial activity.

The oxidation of aniline with ammonium peroxydisulfate in the presence of gelatin yields spindle-like colloidal polyaniline particles having the particle size smaller than 200 nm. The similar oxidation of aniline with silver nitrate leads to hybrid composite polyaniline-silver nanoparticles with more complex morphology. The composites were characterized by transmission electron microscopy, dynamic light scattering and UV-vis spectroscopy. The cytoxicity of colloids has also been investigated. To test biointerface properties, the synthetized colloids were deposited to poly(ethylene terephthalate) foil using spiral bar coating and flexography printing technique. Prepared layers were tested for eukaryotic cell adhesion and proliferation, and antibacterial activity. The prepared surfaces do not only allow for eukaryotic cell adhesion and proliferation but also they possess significant antibacterial properties against Escherichia coli and Staphylococcus aureus, even without silver nanoparticles. This newly prepared surface has therefore high practical potential in variety of application in regenerative medicine or biosensing.