Semi-interpenetrating Polyurethane Network Foams Containing Highly Branched Poly(N-isopropyl acrylamide) with...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Microbiology

Background:

• Development of advanced materials for bacterial detection and adhesion is crucial.
• Poly(N-isopropylacrylamide) (PNIPAM) exhibits thermoresponsive properties useful in smart materials.
• Vancomycin functionalization can impart specific bacterial binding capabilities.

Purpose of the Study:

• To create vancomycin-functionalized, highly branched PNIPAM (HB-PNIPAM) incorporated into polyurethane foams.
• To investigate the thermal response and bacterial adhesion properties of these novel semi-interpenetrating networks.
• To develop a colorimetric and fluorescent sensor for detecting specific bacterial strains.

Main Methods:

• Synthesis of HB-PNIPAM functionalized with vancomycin.
• Incorporation of HB-PNIPAM into polyurethane foams to form semi-interpenetrating networks.
• Labeling PNIPAM with Nile red for solvatochromic dye properties.
• Characterization of thermal response, foam shrinkage, and bacterial adhesion selectivity.
• Fluorescence spectroscopy for bacterial presence detection.

Main Results:

• The polymer architecture influenced the thermal response of HB-PNIPAM.
• Temperature-dependent color changes were observed in the foam, indicating thermal responsiveness.
• HB-PNIPAM incorporation reduced foam shrinkage up to 20 °C.
• Foams demonstrated selective adhesion for Staphylococcus aureus over Pseudomonas aeruginosa.
• Increased fluorescence intensity (590-800 nm) indicated the presence of S. aureus.

Conclusions:

• Vancomycin-functionalized HB-PNIPAM/polyurethane foams act as effective bacterial adhesives.
• The developed material exhibits tunable thermal properties and selective adhesion for Gram-positive bacteria.
• The foams serve as a visual and fluorescent sensor for detecting Staphylococcus aureus.