A NO photoreleasing supramolecular hydrogel with bactericidal action

Area of Science:

• Biomaterials Science
• Supramolecular Chemistry
• Photochemistry

Background:

• Developing advanced hydrogels for biomedical applications is crucial.
• Nitric oxide (NO) has diverse biological functions, including antimicrobial properties.
• Controlled release of NO requires stable and biocompatible delivery systems.

Purpose of the Study:

• To engineer a novel, stable hydrogel via spontaneous self-assembly.
• To incorporate a nitric oxide (NO) photodonor into the hydrogel matrix.
• To evaluate the hydrogel's capacity for light-controlled NO release and its bactericidal efficacy.

Main Methods:

• Spontaneous self-assembly of poly-β-cyclodextrin polymer, hydrophobically modified dextran, and an adamantyl-appended NO photodonor.
• Characterization of hydrogel stability and NO photodonor leaching under physiological conditions.
• Assessment of NO release upon visible light excitation and its transfer to myoglobin.
• Evaluation of light-dependent bactericidal activity against Escherichia coli suspensions.

Main Results:

• A stable, solvent-free hydrogel was formed through a "lock-and-key" supramolecular assembly.
• The NO photodonor remained immobilized within the hydrogel, preventing leaching.
• Visible light successfully triggered remote-controlled NO release.
• The hydrogel exhibited effective, light-dependent bactericidal activity against Escherichia coli.

Conclusions:

• The engineered hydrogel provides a stable platform for NO photodonor immobilization and controlled release.
• This system offers a promising light-activated antimicrobial strategy.
• The solvent-free, self-assembly approach simplifies hydrogel fabrication for potential therapeutic applications.