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Alkyltriphenylphosphonium-Functionalized Hyperbranched Polyethyleneimine Nanoparticles for Safe and Efficient
Katerina N Panagiotaki1, Kyriaki-Marina Lyra1, Aggeliki Papavasiliou1
1Institute of Nanoscience and Nanotechnology, National Centre of Scientific Research ''Demokritos", 15310 Aghia Paraskevi, Attiki, Greece.
International Journal of Molecular Sciences
|June 13, 2025
Summary
Novel polymeric antibacterial agents functionalized with amphiphilic groups show potent activity against E. coli and S. aureus. Structure-activity relationships reveal low-molecular-weight polymers with longer alkyl chains are most effective, with minimal mammalian cell toxicity.
Area of Science:
- Polymer Chemistry
- Materials Science
- Microbiology
Background:
- Polymeric antibacterial agents offer enhanced efficacy and reduced resistance compared to traditional antibiotics.
- Their antimicrobial activity is linked to functional groups, electrostatic interactions, and cell membrane disruption.
- Hyperbranched polyethyleneimines (PEIs) are a promising class of polymers for developing new antibacterial materials.
Purpose of the Study:
- To synthesize and characterize novel polymeric nanoparticles based on functionalized polyethyleneimines.
- To evaluate the antimicrobial efficacy of these nanoparticles against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria.
- To investigate the influence of polymer molecular weight, alkyl chain length, and functional group density on antibacterial activity.
Main Methods:
- Synthesis of hyperbranched polyethyleneimines (PEIs) functionalized with amphiphilic alkyltriphenylphosphonium groups.
- Chemical and physicochemical characterization of the synthesized nanoparticles.
- Determination of minimum inhibitory concentrations (MICs) against E. coli and S. aureus.
- Scanning Electron Microscopy (SEM) to visualize bacterial cell morphology changes.
Main Results:
- All synthesized compounds demonstrated antibacterial properties against both E. coli and S. aureus.
- Lower molecular weight PEI derivatives and longer alkyl chains exhibited superior efficacy, particularly against S. aureus (MIC < 0.25 μg/mL).
- SEM analysis confirmed bacterial membrane disruption and intracellular leakage, indicating cell death.
Conclusions:
- Functionalized PEI nanoparticles show significant potential as effective antibacterial agents.
- A clear structure-property relationship exists, where lower molecular weight and longer alkyl chains enhance antimicrobial activity.
- These findings support the development of novel potent antibacterial polymers through rational design.
