pH-Sensitive Zwitterionic Polymer as an Antimicrobial Agent with Effective Bacterial Targeting

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Antimicrobial Agents

Background:

• Increasing bacterial infections worldwide necessitate novel biocompatible antimicrobial agents.
• Existing treatments face challenges with resistance and side effects.
• Smart polymers offer targeted delivery and on-demand functionality.

Purpose of the Study:

• To develop a pH-sensitive polymer that transitions from biocompatible to antimicrobial.
• To investigate the antimicrobial efficacy of this polymer against common bacterial pathogens.
• To explore its potential as an on-demand therapeutic agent.

Main Methods:

• Synthesis of poly(2-(3-aminopropyl-N,N-dimethylammonium)ethyl methacrylate) (P(APDMAEMA)) via RAFT polymerization.
• Modification of P(APDMAEMA) with citraconic anhydride to yield P(CitAPDMAEMA).
• Evaluation of pH-dependent properties, biocompatibility, hemotoxicity, and antimicrobial activity against E. coli and S. aureus.

Main Results:

• P(CitAPDMAEMA) exhibits zwitterionic properties at physiological pH with good biocompatibility and low hemotoxicity.
• At acidic pH (infection sites), P(CitAPDMAEMA) hydrolyzes, becoming cationic.
• The cationic form demonstrates significant binding to bacteria and inhibits the growth of E. coli and S. aureus.

Conclusions:

• P(CitAPDMAEMA) functions as a smart, pH-responsive polymer.
• Its transition to a cationic state at acidic pH enables targeted antimicrobial activity.
• P(CitAPDMAEMA) shows potential as a novel on-demand antimicrobial agent for combating bacterial infections.