Self-Assembly and Disassembly of Glycol Chitosan/Photosensitizer Nano-Micelles for Antibacterial Photodynamic Therapy

Abstract

Creating an efficient antimicrobial photodynamic therapy (PDT) method while reducing the difficulty of preparation and operation is much anticipated but challenging. In this research, we facilely developed glycol chitosan (GC)/protoporphyrin IX (PpIX) nano-micelles for effective photodynamic inactivation of Gram-positive bacteria. The mixture of glycol chitosan (GC) and protoporphyrin IX (PpIX) self-assembled into positively charged GC/PpIX nano-micelles through hydrophobic interaction and electrostatic interaction. GC/PpIX nano-micelles significantly improved singlet oxygen generation, and notably enhanced the antibacterial PDT effect toward Gram-positive bacteria in a preincubation-free manner without developing drug resistance. Upon binding to the bacterial cells through electrostatic interaction, GC/PpIX nano-micelles were disassembled, leaving GC on the bacterial surface, inducing bacterial cell aggregation and acting like a glue to coat the bacterial surface and release PpIX into the cells, generating singlet oxygen under light irradiation to impair DNA. Collectively, the easy construction of GC/PpIX nano-micelles offers a modality for effective antibacterial PDT with simple operation and without drug resistance development, benefiting the treatment of Gram-positive bacterial infections in clinic.

The Use of Photoactive Polymeric Nanoparticles and Nanofibers to Generate a Photodynamic-Mediated Antimicrobial Effect, with a Special Emphasis on Chronic Wounds

“…-Microbial cell death involved damage to the DNA. [112] Lipase-sensitive methoxy PEG-block-PCL micelles Hypocrellin -Lipase was secreted upon interaction with the bacterial cell membrane and mediated the release of the PS.…”

A Cascade BIME-Triggered Near-IR Cyanine Nanoplatform for Enhanced Antibacterial Photodynamic Therapy

“…The abuse of conventional antibiotics has led to a significant increase of multidrug-resistant (MDR) bacteria and antibiotic-resistant infections, which severely threaten human health. , Hence, it is urgent to develop a new antibacterial strategy to prevent the generation of MDR bacteria. − Antibacterial photodynamic therapy (aPDT) has been identified as an advantageous strategy to effectively treat microbial infection, which has hardly trended toward the emergence of undesirable drug-resistant strains. − Nevertheless, the therapeutic efficacy of photodynamic therapy (PDT) is seriously compromised by several obstacles of conventional photosensitizers including poor water solubility, an aggregation-caused quenching effect in biological media, and poor bacteria affinity. − Aimed at solving these problems, amphiphilic copolymers, host–guest complexes, and mesoporous silica nanoparticles have been developed as nanocarriers to improve the solubility and suppress the aggregation of photosensitizers. − Apart from crossing the inherent barriers of photosensitizers by using the above approaches, it is an alternative strategy for exploiting and integrating the antibacterial microenvironment to further improve the aPDT efficiency. , …”

Efficient Synergistic Antibacterial Activity of α-MSH Using Chitosan-Based Versatile Nanoconjugates

“… 22 , 27 There are many inorganic and organic nanocarriers known so far that have potential antibacterial properties. 28 Interestingly, chitosan-based biopolymers have emerged as an attractive potent antibacterial agent against various bacteria like E. coli and S. aureus . 29 Modified chitosan with certain metal ions and antibiotics have been proven to be efficient against fungus Cryptococcus neoformans ( C. neoformans ), Candida albicans ( C. albicans ), and Gram-negative Pseudomonas aeruginosa ( P. aeruginosa ) and MDR S. aureus .…”

“…A nanocarrier that is easy to synthesize, efficient in bioconjugation, and has drug-loading ability with versatile implications is a promising candidate in the aspect of translational research and development for bench-to-bedside applications. , There are many inorganic and organic nanocarriers known so far that have potential antibacterial properties . Interestingly, chitosan-based biopolymers have emerged as an attractive potent antibacterial agent against various bacteria like E.…”