The increased mortality caused by pathogenic bacterial infection calls for early infection diagnosis and effective antibiotic alternatives. In this work, we developed a fluorescent nano-probe named ZnO@PEP-MPA by conjugating BSA-stabilized ZnO quantum dot (ZnO@BSA) with UBI29-41, an anti-bacteria peptide fragment, and MPA, a near infrared (NIR) dye. The nanoprobe ZnO@PEP-MPA exhibited low cytotoxicity and could discriminate the bacterial infection from sterile inflammation or cancer in vivo with high specificity and low detection limitation. Based on the platform of ZnO@PEP-MPA, a theranostic nanocomposite, Van@ZnO-PEP-MPA was firstly established by further decorating ZnO@PEP-MPA with Vancomycin, a kind of glycopeptide antibiotic, which demonstrated enhanced antibacterial activity and desirable biocompatibility both in vitro and in vivo. Furthermore, another antibiotic methicillin was immobilized onto ZnO@PEP-MPA, forming Met@ZnO-PEP-MPA and demonstrated significant improved capability to combat with the anti-methicillin-resistant-bacteria in comparison with free methicillin as a result of the increased cell membrane permeation mediated by ZnO@BSA-PEP-MPA. Therefore, ZnO-PEP-MPA reported in this work holds promising potential to realize efficient non-invasive diagnosis of bacterial infections, providing important guiding information for treatment, and can be employed as drug carriers for effective bacterial-targeting therapy, favorable to hurdle multi-drug resistance after being loaded with antibiotics.
Keywords: Anti-multidrug resistance; Bacteria-targeting; Diagnosis; In vivo; Therapy; ZnO quantum dots.
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