Poly(ethyleneimines) in dermal applications: biocompatibility and antimicrobial effects.

Area of Science:

• Polymer chemistry
• Antimicrobial agents
• Biocompatibility testing

Background:

• Cationic polyamines, including poly(ethyleneimines) (PEIs), possess inherent antimicrobial properties due to their ability to disrupt microbial cell membranes.
• PEIs are being explored for various applications, necessitating a thorough understanding of their safety and efficacy profiles.

Purpose of the Study:

• To evaluate the biocompatibility and antibacterial activity of linear (lPEI) and branched (bPEI) poly(ethyleneimines) with varying molar masses.
• To determine the structure-activity and structure-toxicity relationships of PEIs for potential antimicrobial applications.

Main Methods:

• Assessment of antibacterial activity against Staphylococcus aureus and Escherichia coli using minimal inhibitory concentration (MIC) assays.
• In vitro evaluation of cytotoxicity and genotoxicity across a range of PEI molar masses (0.8-750 kDa).

Main Results:

• Both lPEI and bPEI demonstrated significant antibacterial activity, with a greater effect on Gram-positive bacteria.
• lPEIs exhibited higher efficacy than bPEIs, though molar mass differences within 5-25 kDa were not significant for antibacterial activity.
• Cytotoxicity was dependent on molecular weight, with lower molar masses (0.8 and 5 kDa) showing better biocompatibility.
• A low genotoxic potential was confirmed for both lPEI and bPEIs.

Conclusions:

• Specific PEI formulations, namely 2.5 kDa-lPEI and 0.8 kDa-bPEI, are recommended for dermal antimicrobial applications.
• These PEIs offer a favorable balance of high biocompatibility and effective antibacterial efficacy.
• Further investigation into treatment effectiveness and safety is warranted for broader PEI applications.