Upper Critical Solution Temperature Polyvalent Scaffolds Aggregate and Exterminate Bacteria

Specific recognition and strong affinities of bacteria receptors with the host cell glycoconjugates pave the way to control the bacteria aggregation and kill bacteria. Herein, using aggregation-induced emission (AIE) molecules decorated upper critical solution temperature (UCST) polyvalent scaffold (PATC-GlcN), an approach toward visualizing bacteria aggregation and controlling bacteria-polyvalent scaffolds affinities under temperature stimulus is described. Polyvalent scaffolds with diblocks, one UCST block PATC of polyacrylamides showing a sharp UCST transition and typical AIE behavior, the second bacteria recognition block GlcN of hydrophilic glucosamine modified polyacrylamide, are prepared through a reversible addition and fragmentation chain transfer polymerization. Aggregated chain conformation of polyvalent scaffolds at temperature below UCST induces the aggregation of E. coli ATCC8739, because of the high density of glucosamine moieties, whereas beyond UCST, the hydrophilic state of the scaffolds dissociates the bacteria aggregation. The sweet-talking of bacteria toward the polyvalent scaffolds can be visualized by the fluorescent imaging technique, simultaneously. Due to the specific recognition of polyvalent scaffolds with bacteria, the photothermal agent IR780 loaded PATC-GlcN shows the targeted killing ability toward E. coli ATCC8739 in vitro and in vivo under NIR radiation.

Automated summary

In this study, a method based on reversible addition and fragmentation chain transfer polymerization was described, which allows for the visualization of bacteria aggregation and control of bacteria-polyvalent scaffolds affinities under temperature stimulus through the decoration of aggregation-induced emission (AIE) molecules. The polyvalent scaffolds, composed of UCST block PATC and hydrophilic glucosamine modified polyacrylamide block GlcN, were found to induce the aggregation of E. coli ATCC8739 below UCST temperature, while beyond UCST temperature, the hydrophilic state of the scaffolds dissociated the bacteria aggregation. The specific recognition of the polyvalent scaffolds with bacteria enabled the targeted killing of E. coli ATCC8739 using the photothermal agent IR780 loaded PATC-GlcN under NIR radiation.