Supramolecular self-assembly of poly(ethylene glycol)-b-poly(L-lysine) and EDTA into nanofibers and their synergistic inhibition of Escherichia coli proliferation

Supramolecular assembly of amphiphilic polymer poly(ethylene glycol)-b-poly(L-lysine) (PEG-b-PLL) and ethylenediaminetetraacetic acid (EDTA) were used to efficiently inhibit E. coli proliferation. PEG-b-PLL is a moderate antibacterial polymer itself with a minimum inhibitory concentration (MIC) of 43.8 μg/mL, and it inhibits bacteria by the electrostatic interactions and hydrophobic interactions with bacteria membrane. EDTA induces the lipopolysaccharide release and enhanced membrane permeability of E. coli, and affects the divalent ion equilibrium on the bacteria membrane. The self-assembly of PEG-b-PLL and EDTA into spindly nanofibers, showing synergistic inhibition of E. coli (MIC: 10.9 μg/mL). Our strategy provides a new way of designing supramolecular antibacterials with synergistic antibacterial effects by virtue of different inhibition mechanisms.