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Updated: Oct 7, 2025
High-throughput Identification of Bacteria Repellent Polymers for Medical Devices
Published on: November 5, 2016
pH-Responsive Fluorescent Polymer-Drug System for Real-Time Detection and In Situ Eradication of Bacterial Biofilms
Xiaomei Dai1, Qingqing Xu1, Lele Yang1
1Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Key Laboratory of Chemo/Biosensing, Laboratory of Biosensing and Bioimaging (LOBAB), College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China.
Abstract:
Bacterial biofilms encased in extracellular polymeric substances to create protected microenvironments are typically challenging to disperse by common antibiotics and cannot be in situ visualized under current modalities. Herein, a pH-responsive branched polymer [poly(MBA-AEPZ)-AEPZ-NA] capable of overcoming antibiotic resistance and real-time visualizing biofilms for fluorescence imaging-guided infection control is reported. The positively charged polymer can effectively penetrate bacterial biofilms, neutralize the anionic character, and then disrupt the structural integrity, thus significantly promoting the transport of antibiotics into biofilms. The polymer shows a weak fluorescence emission intensity under physiological conditions (pH 7.4) but emits intense green-light emission within the localized biofilm microenvironment (pH 5.5) to real-time visualize bacterial biofilms. A therapeutic system made of the polymer and a model antibiotic can significantly reduce the dosages of the drug, thereby minimizing biofilm-induced drug resistance. Notably, a green fluorescent polymer responding to localized pH conditions is demonstrated in living zebrafish. This work confirmed that combinations of the pH-responsive branched polymer and antibiotics could be administered to overcome drug resistance and realize fluorescence imaging-guided treatment of bacterial biofilm infections.
Insights
A novel pH-responsive polymer effectively visualizes and disrupts bacterial biofilms, enhancing antibiotic penetration and overcoming drug resistance for improved infection control. This polymer enables real-time fluorescence imaging-guided treatment.
Area of Science:
- Biomaterials Science
- Infectious Disease Research
- Polymer Chemistry
Background:
- Bacterial biofilms, protected by extracellular polymeric substances, present significant challenges for conventional antibiotic treatments.
- Current imaging modalities struggle with in situ visualization of biofilms, hindering effective infection monitoring and control.
- Biofilm-associated antibiotic resistance limits therapeutic efficacy and necessitates novel treatment strategies.
Purpose of the Study:
- To develop a pH-responsive branched polymer capable of overcoming antibiotic resistance in bacterial biofilms.
- To enable real-time visualization of biofilms using fluorescence imaging for guided infection control.
- To create a therapeutic system combining the polymer with antibiotics for enhanced treatment efficacy.
Main Methods:
- Synthesis of a pH-responsive branched polymer [poly(MBA-AEPZ)-AEPZ-NA] with positive charge characteristics.
- Evaluation of the polymer's ability to penetrate biofilms, neutralize anionic components, and disrupt structural integrity.
- Assessment of enhanced antibiotic transport into biofilms facilitated by the polymer.
- Characterization of the polymer's fluorescence properties at physiological (pH 7.4) and biofilm microenvironment (pH 5.5) conditions.
- Demonstration of the polymer's in vivo performance in living zebrafish models.
Main Results:
- The positively charged polymer effectively penetrates and disrupts bacterial biofilms, promoting antibiotic delivery.
- The polymer exhibits pH-dependent fluorescence, emitting intense green light specifically within the acidic biofilm microenvironment (pH 5.5) for real-time visualization.
- A therapeutic system combining the polymer and antibiotics significantly reduced required drug dosages, mitigating biofilm-induced drug resistance.
- In vivo studies in zebrafish confirmed the polymer's green fluorescence and responsiveness to localized pH conditions.
Conclusions:
- The developed pH-responsive branched polymer offers a dual function of biofilm disruption and real-time fluorescence imaging.
- This polymer-antibiotic combination strategy effectively overcomes drug resistance and facilitates fluorescence imaging-guided treatment of bacterial biofilm infections.
- The findings present a promising approach for advanced diagnostics and therapeutics in managing persistent microbial infections.
