Self-adaptive antibacterial surfaces with bacterium-triggered antifouling-bactericidal switching properties

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Infectious Disease Research

Background:

• Catheter-induced infections pose significant clinical challenges, increasing morbidity, mortality, and healthcare costs.
• There is a critical need for advanced catheter materials with effective antibacterial properties to mitigate these risks.

Purpose of the Study:

• To develop a self-adaptive antibacterial surface for polyurethane (PU) catheters with switchable antifouling and bactericidal properties.
• To investigate the bacterium-triggered mechanism for transitioning between antifouling and bactericidal states.

Main Methods:

• Surface-initiated atom-transfer radical polymerization (SI-ATRP) was used to create a hierarchical polymer coating (PU-PQ-PEG) on PU.
• The coating featured a lower bactericidal layer (poly[2-(dimethyl decyl ammonium)ethyl methacrylate] - PQDMAEMA) and an upper antifouling layer (polyethylene glycol - PEG), both containing Schiff base structures.
• In vitro studies included protein/bacterial adhesion tests, a circulating model simulating hydrodynamic conditions, and in vivo animal experiments.

Main Results:

• The PU-PQ-PEG surface exhibited excellent antifouling and biocompatibility under normal conditions.
• Upon bacterial colonization and metabolism, the Schiff base structures degraded, triggering a switch to bactericidal activity.
• The self-adaptive antibacterial performance was confirmed under both static and hydrodynamic conditions, as well as in vivo.

Conclusions:

• The developed PU-PQ-PEG surface demonstrates a promising self-adaptive strategy for combating catheter-induced infections.
• This approach offers a dual mode of action, providing biocompatibility and transitioning to potent antibacterial activity when needed.
• The material shows potential for creating safer, more effective catheter materials with improved hemocompatibility.