Nanoclay-induced bacterial flocculation for infection confinement

Area of Science:

• Materials Science
• Nanotechnology
• Microbiology
• Immunology

Background:

• Anionic nanoclays interact with biological systems.
• Human antimicrobial peptide LL-37 exhibits membrane-lysing properties.
• Bacterial lipopolysaccharide (LPS) triggers inflammatory responses.

Purpose of the Study:

• To investigate the effects of anionic nanoclays on bacteria-mimicking membranes and Gram-negative bacteria.
• To evaluate the combined effects of nanoclays and antimicrobial peptide LL-37 on bacterial aggregation and lysis.
• To assess the potential of these systems in suppressing LPS-induced inflammation.

Main Methods:

• Ellipsometry, dynamic light scattering, and ζ-potential measurements.
• Confocal microscopy with Live/Dead staining.
• Investigation of interactions with model lipid membranes, LPS, and Escherichia coli.

Main Results:

• Nanoclays alone did not bind to or destabilize anionic membranes but induced aggregation of live E. coli.
• LL-37 alone caused membrane lysis but not aggregation.
• Combined nanoclays and LL-37 induced potent bacterial aggregation and membrane lysis, suppressing LPS-induced NF-κB activation.

Conclusions:

• Anionic nanoclays can be loaded with LL-37 to create potent antimicrobial agents.
• These combined systems demonstrate effective bacterial aggregation and lysis, with broad tolerance for nanoclay properties.
• The systems show promise for infection confinement by suppressing inflammatory pathways.