Related Experiment Video
Updated: Jun 28, 2025
The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms
Published on: July 2, 2013
Gram-negative bacteria recognition and photodynamic elimination by Zn-DPA based sensitizers
Zuokai Wang1, Shuang Zeng2, Yifu Hao2
1State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials, Dalian University of Technology, Dalian, 116024, PR China.
Abstract:
The abuse and overuse of antibiotics let drug-resistant bacteria emerges. Antibacterial photodynamic therapy (APDT) has shown outstanding merits to eliminate the drug-resistant bacteria via cytotoxic reactive oxygen species produced by irradiating photosensitizer. However, most of photosensitizers are not effective for Gram-negative bacteria elimination. Herein conjugates of NBS, a photosensitizer, linked with one (NBS-DPA-Zn) or two (NBS-2DPA-Zn) equivalents of zinc-dipicolylamine (Zn-DPA) have been designed to achieve the functional recognition of different bacteria. Due to the cationic character of NBS and metal transfer channel effect of Zn-DPA, NBS-DPA-Zn exhibited the first regent to distinguish P. aeruginosa from other Gram-negative bacteria. Whereas NBS-2DPA-Zn showed broad-spectrum antibacterial effect because the two arm of double Zn-DPA enhanced interactions with anionic membranes of bacteria, led the bacteria aggregation and thus provided the efficacy of APDT to bacteria and corresponding biofilm. In combination with a hydrogel of Pluronic, NBS-2DPA-Zn@gel shows promising clinical application in mixed bacterial diabetic mouse model infection. This might propose a new method that can realize functional identification and elimination of bacteria through intelligent regulation of Zn-DPA, and shows excellent potential for antibacterial application.
Insights
New photosensitizers can distinguish and eliminate drug-resistant Gram-negative bacteria. NBS-DPA-Zn differentiates bacteria, while NBS-2DPA-Zn offers broad-spectrum antibacterial photodynamic therapy (APDT) and biofilm eradication.
Area of Science:
- Biochemistry
- Materials Science
- Microbiology
Background:
- Antibiotic resistance is a growing global health threat, necessitating novel antibacterial strategies.
- Antibacterial photodynamic therapy (APDT) utilizes photosensitizers to generate reactive oxygen species for bacterial elimination.
- Existing APDT photosensitizers often show limited efficacy against Gram-negative bacteria.
Purpose of the Study:
- To design and synthesize novel photosensitizer conjugates for targeted Gram-negative bacteria elimination.
- To investigate the differential bacterial recognition and antibacterial activity of NBS-DPA-Zn and NBS-2DPA-Zn conjugates.
- To evaluate the potential of NBS-2DPA-Zn in a hydrogel formulation for treating mixed bacterial infections.
Main Methods:
- Synthesis of NBS-DPA-Zn and NBS-2DPA-Zn conjugates by linking NBS photosensitizer with zinc-dipicolylamine (Zn-DPA).
- Evaluation of bacterial recognition capabilities based on cationic character and Zn-DPA interactions.
- Assessment of APDT efficacy against Gram-negative bacteria and biofilms, including in a diabetic mouse model with Pluronic hydrogel formulation.
Main Results:
- NBS-DPA-Zn demonstrated specific recognition of *P. aeruginosa* among Gram-negative bacteria.
- NBS-2DPA-Zn exhibited broad-spectrum antibacterial activity against Gram-negative bacteria and eradicated biofilms.
- NBS-2DPA-Zn formulated in Pluronic hydrogel showed promising results in a mixed bacterial diabetic mouse model.
Conclusions:
- The designed NBS-DPA-Zn and NBS-2DPA-Zn conjugates offer a novel approach for functional bacterial identification and elimination.
- Intelligent regulation of Zn-DPA moieties allows for tailored antibacterial strategies against specific or multiple bacterial pathogens.
- These findings highlight the potential of advanced photosensitizer conjugates for combating drug-resistant bacterial infections and biofilms.
