Related Experiment Video
Updated: Aug 1, 2025
10:43
High-throughput Identification of Bacteria Repellent Polymers for Medical Devices
Published on: November 5, 2016
9.1K
pH Window for High Selectivity of Ionizable Antimicrobial Polymers toward Bacteria
Yuanyuan Geng1,2, Yueling Yuan1,2, Yan Bao3
1Guangzhou First People's Hospital, School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China.
ACS Applied Materials & Interfaces
|April 28, 2023
Summary
Researchers discovered a pH window for ionizable polymers, like PC6A, to selectively kill drug-resistant bacteria with low toxicity. This strategy enhances antimicrobial polymer design for effective treatment.
Area of Science:
- Polymer Chemistry
- Biomaterials Science
- Antimicrobial Research
Background:
- Antimicrobial polymers show promise against drug-resistant bacteria but often lack selectivity, causing toxicity to host cells.
- Designing polymers that target bacteria while sparing normal tissues is a significant challenge in antimicrobial development.
Purpose of the Study:
- To identify a pH-dependent strategy for developing highly selective antimicrobial polymers.
- To evaluate the selectivity, efficacy, and mechanism of action of a novel ionizable polymer (PC6A) against bacteria.
Main Methods:
- Synthesized and characterized ionizable polymer PC6A.
- Assessed polymer selectivity through hemolytic activity and antimicrobial assays across a pH range.
- Investigated the bactericidal mechanism and potential for resistance development.
- Evaluated synergistic effects with conventional antibiotics.
Main Results:
- Ionizable polymer PC6A exhibited maximum selectivity (131.6) at pH 7.4, with low hemolytic activity and potent antimicrobial effects.
- Low or high protonation degrees (PD) resulted in significantly lower selectivity (≤35.6).
- The primary bactericidal mechanism involved membrane lysis, and no drug resistance was observed after 32 passages.
- PC6A showed synergistic effects with antibiotics at pH 7.4.
Conclusions:
- A specific pH window, particularly pH 7.4, is crucial for achieving high selectivity in ionizable antimicrobial polymers.
- PC6A offers a promising strategy for developing safe and effective antimicrobial agents against drug-resistant bacteria.
- The findings provide a new approach for designing next-generation antimicrobial polymers with enhanced bacterial selectivity and reduced host toxicity.
Related Concept Videos
01:28Antimicrobial Effectiveness
99
The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally...
99
01:17Ion Exchange
630
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
630
00:57Antibiotic Selection
54.9K
Overview
54.9K
01:22Bacterial Cell Wall
119
The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and protecting against osmotic stress. This rigid yet flexible structure primarily comprises peptidoglycan, a polymer that forms a mesh-like matrix conferring mechanical strength and flexibility.Peptidoglycan Composition and StructurePeptidoglycan, the core of the bacterial cell wall, comprises alternating units of N-acetylglucosamine (NAG) and...
119
01:17Pore Transport and Ion-Pair Transport
537
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
537
01:27Chemical Agents for Microbial Control
144
Chemicals play important roles in controlling microbial growth by targeting microbial structures and functions as sanitizers, antiseptics, disinfectants, and sterilants.Alcohols are commonly used sanitizers, effectively disrupting lipid membranes, which compromises cell integrity. They are also used as antiseptics and disinfectants due to their rapid action and versatility.Phenols and their derivatives phenolics , known for denaturing proteins and disrupting cell membranes, are particularly...
144