Soft Materials that Intercept, Respond to, and Sequester Bacterial Siderophores

Area of Science:

• Materials Science
• Biochemistry
• Microbiology

Background:

• Bacteria utilize iron-chelating molecules called siderophores to scavenge iron and maintain homeostasis.
• Controlling bacterial iron acquisition is a potential strategy for managing bacterial populations.

Purpose of the Study:

• To design and characterize novel Fe-containing soft materials that interact with bacterial siderophores.
• To explore the potential of these materials in controlling bacterial iron homeostasis and for microbiological research.

Main Methods:

• Fabrication of metal-organic network coatings by crosslinking tannic acid with iron(III).
• Testing material stability and erosion in response to siderophores (enterobactin, deferoxamine B) and bacterial cultures (Escherichia coli).
• Investigating stimuli-responsive drug release and the development of Fe-containing polymer hydrogels for siderophore sequestration.

Main Results:

• Metal-organic network coatings erode upon exposure to biologically relevant concentrations of enterobactin and deferoxamine B, with disassembly rates dependent on siderophore concentration and affinity.
• Coatings disassemble in the presence of wild-type E. coli cultures, primarily due to enterobactin secretion.
• Demonstrated stimuli-responsive release of the antibiotic ciprofloxacin and development of hydrogels that sequester enterobactin.

Conclusions:

• Developed Fe-containing soft materials that interface with bacterial iron homeostasis mechanisms.
• These materials can dynamically respond to or report on iron-scavenging bacteria.
• The study provides new tools for microbiological research and novel strategies for controlling bacterial communities.