Ruthenium complexes/polypeptide self-assembled nanoparticles for identification of bacterial infection and targeted antibacterial research

Bacterial infection has been a threat to human health, and so early diagnosis and treatment of bacterial infection is an urgent problem that needs to be solved. In this work, a multifunctional theranostic selenium nanoplatform (Se@PEP-Ru NPs) with early imaging diagnosis and efficient treatment of bacterial infections was designed and constructed. First, the antibacterial peptide UBI29-41 (PEP) was linked to functionalized Selenium nanoparticles (NPs), which enhanced the stability of the antimicrobial peptide and also caused the nanocomposites to specifically target bacterial infection. Ruthenium complexes with good antibacterial activity and fluorescence properties were then coated on to their outer layers. It was worth mentioning that, when the resulting nanoprobe was injected into mice by intravenous injection it was found to be sensitive to sites of bacterial infection for selective fluorescence imaging and targeted therapy. Thus, it can be used to distinguish between bacterial infection, inflammation, and tumor-induced tissue infection with high specificity. In the further antibacterial activity experiments, Ruthenium complexes showed synergistic antimicrobial activity with Se NPs, which indicated that the antibacterial activity of Se@PEP-Ru NPs was the strongest that could promote wound healing. Thus, Se@PEP-Ru NPs appears to be a promising antimicrobial with good biocompatibility, excellent selectivity, and potent antimicrobial activity.