β-Carboline-Norfloxacin Nanoconjugates as Antibacterial Nanophotocages for the Delivery of Norfloxacin and Singlet Oxygen

Herein, we demonstrate the design and synthesis of a single-component prodrug [β-carboline-benzothiazole-norfloxacin (CB-NFX)] for the cocktail release of therapeutics that enables spatiotemporal control over bacterial growth. With the help of in silico studies, the prodrug was designed based on the β-carboline photoremovable protecting group, caging the acid functionality of norfloxacin (NFX) antibiotic. We have formulated nanoparticles of CB-NFX to obtain nanophotocage CB-NFX NPs. These nanoparticles adhere to the bacterial cell wall, followed by the release of NFX and singlet oxygen (1O2) upon visible-light irradiation. The combined effect of the therapeutics shows excellent spatiotemporal control in bacterial inhibition. This concept can be applied to develop other advanced antibacterial biomaterials for combination therapy (drug and 1O2) and find wide applications in antibacterial research.