Smart Biointerface with Photoswitched Functions between Bactericidal Activity and Bacteria-Releasing Ability

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Biomedical Engineering

Background:

• Smart biointerfaces that control cell interactions are crucial for research and applications.
• Existing smart surfaces offer single-function switchability (e.g., cell attachment/detachment).
• Multifunctional switchable surfaces represent an advanced frontier in smart materials.

Purpose of the Study:

• To develop a smart supramolecular surface with reversible dual functions: bactericidal activity and bacteria release.
• To utilize UV-visible light as an external stimulus for switching surface functions.
• To demonstrate a novel platform for creating advanced, responsive biomaterials.

Main Methods:

• Fabrication of a surface functionalized with azobenzene (Azo) groups.
• Conjugation of a biocidal β-cyclodextrin derivative with quaternary ammonium salt groups (CD-QAS).
• Utilizing UV-visible light to trigger reversible Azo/CD-QAS complex formation and dissociation for kill-and-release cycles.

Main Results:

• The azobenzene-functionalized surface effectively killed over 90% of attached bacteria via CD-QAS.
• UV light induced cis-isomerization of Azo groups, dissociating the complex and releasing dead bacteria.
• Visible light allowed regeneration of the surface for repeated kill-and-release cycles.

Conclusions:

• Supramolecular chemistry enables the creation of smart, multifunctional surfaces with light-switchable properties.
• This kill-and-release platform demonstrates significant potential for biomedical devices and materials.
• The developed surface offers a reusable and responsive solution for controlling bacterial interactions.