Novel Self-assembled Organic Nanoprobe for Molecular Imaging and Treatment of Gram-positive Bacterial Infection.

Increasing bacterial infections as well as a rise in bacterial resistance call for the development of novel and safe antimicrobial agents without inducing bacterial resistance. Nanoparticles (NPs) present some advantages in treating bacterial infections and provide an alternative strategy to discover new antibiotics. Here, we report the development of novel self-assembled fluorescent organic nanoparticles () with excellent antibacterial efficacy and good biocompatibility. Self-assembly of 1-(12-(pyridin-1-ium-1-yl)dodecyl)-4-(1,4,5-triphenyl-1H-imidazol-2-yl)pyridin-1-ium in aqueous solution was investigated using dynamic light scattering (DLS) and transmission electron microscopy (TEM). The bacteria were imaged under a laser scanning confocal microscope. We evaluated the antibacterial efficacy of using sugar plate test. The antimicrobial mechanism was explored by SEM. The biocompatibility of the nanoparticles was examined using cytotoxicity test, hemolysis assay, and histological staining. We further tested the antibacterial efficacy of using the -infected rats. In aqueous solution, could self-assemble into nanoparticles () with characteristic aggregation-induced emission (AIE). could simultaneously image gram-positive bacteria without the washing process. antimicrobial activity suggested that had excellent antibacterial activity against (MIC = 2.0 µg mL). Furthermore, exhibited intrinsic biocompatibility with mammalian cells, in particular, red blood cells. studies further demonstrated that had excellent antibacterial efficacy and significantly reduced bacterial load in the infectious sites. The integrated design of bacterial imaging and antibacterial functions in the self-assembled small molecules provides a promising strategy for the development of novel antimicrobial nanomaterials.