Reversibly Charge-Switching Polyzwitterionic/Polycationic Coatings for Biomedical Applications: Optimizing the...

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials Engineering

Background:

• Charge-switching polymers offer potential for biofilm reduction on medical devices.
• Current materials lack sufficient stability for practical applications.
• Hydrolytic instability limits the lifetime and efficacy of existing charge-switching coatings.

Purpose of the Study:

• To develop a polynorbornene-based polycarboxybetaine with enhanced hydrolytic stability.
• To create stable, charge-switching polymer networks for potential use in medical devices.
• To overcome the limitations of existing ester-based systems.

Main Methods:

• Synthesis and molecular characterization of a novel polynorbornene-based polycarboxybetaine.
• Fabrication of surface-attached polymer networks via spin-coating and UV cross-linking.
• Evaluation of charge-switching behavior using zeta-potential measurements and assessment of storage stability under various conditions.

Main Results:

• A polynorbornene-based polycarboxybetaine with optimized molecular structure was synthesized.
• Uniform polymer coatings exhibiting tunable charge states were successfully prepared.
• The coatings demonstrated significant storage stability in dry and aqueous conditions (pH 4.5, 7.4) for 28 days.
• Hydrolytic degradation was observed at pH 8, but overall stability surpassed ester-based counterparts.

Conclusions:

• The developed polynorbornene-based polycarboxybetaine offers superior hydrolytic stability compared to ester-based systems.
• These materials show promise for creating durable, biofilm-reducing coatings for medical applications.
• Further research into optimizing stability at higher pH could expand their utility.