Biodegradable nanostructures with selective lysis of microbial membranes

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Antimicrobial Agents

Background:

• Macromolecular antimicrobial agents, including cationic polymers and peptides, are crucial for combating multi-drug-resistant microbes.
• Existing polymers are often non-biodegradable and mimic peptide structures to interact with microbial membranes.
• Disruption of microbial cell membranes by these agents is a key mechanism of action.

Purpose of the Study:

• To report the development of the first biodegradable and in vivo applicable antimicrobial polymer nanoparticles.
• To synthesize these nanoparticles using metal-free organocatalytic ring-opening polymerization of functional cyclic carbonate.
• To evaluate their efficacy against Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA), and fungi.

Main Methods:

• Synthesis of biodegradable polymer nanoparticles via metal-free organocatalytic ring-opening polymerization.
• Assessment of nanoparticle disruption of microbial walls/membranes.
• Evaluation of antimicrobial activity against Gram-positive bacteria, MRSA, and fungi.
• In vitro assessment of haemolysis to determine toxicity.

Main Results:

• Demonstrated selective and efficient disruption of microbial walls/membranes by the synthesized nanoparticles.
• Inhibited the growth of Gram-positive bacteria, MRSA, and fungi.
• Showed no significant haemolysis across a wide range of concentrations, indicating low toxicity.
• Established the potential for large-scale, low-cost synthesis.

Conclusions:

• The developed biodegradable polymer nanoparticles represent a novel class of antimicrobial agents.
• These nanoparticles are effective against key pathogens like MRSA and fungi with minimal host toxicity.
• They hold significant promise for treating infectious diseases, particularly those caused by drug-resistant microbes.