Enantiopure polythiophene nanoparticles. Chirality dependence of cellular uptake, intracellular distribution and antimicrobial activity.

The use of intrinsic chiral molecules opens the door to bio-imaging specific tools and to the development of target-therapy. In this work the synthesis and characterization of polythiophenes with alkyl side chains containing one or chiral carbon is reported. Enantiopure chiral nanoparticles ( or NPs) were prepared from the polymers by a reprecipitation method. UV-vis, photoluminescence and circular dichroism spectroscopy of the NPs are described. analysis and metabolic assays show that both and NPs are efficiently taken-up by fibroblast cells without signs of toxicity. SDS-PAGE experiments show that formation of hard protein 'corona' enhances the chirality difference between nanoparticles. Co-localization experiments demonstrate that the cells are able to discriminate between the enantiomeric and nanoparticles. Finally, experiments carried out on Gram negative and Gram positive bacteria show that the enantiomeric NPs display different antibacterial activity.