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

      Swift, Thomas; Hoskins, Richard; Hicks, J.; Dyson, Edward N.; Daignault, M.; Buckle, Dorothy; Douglas, C.W.I.; MacNeil, S.; Rimmer, Stephen (2021-05-17)
      Highly branched poly(N-isopropylacrylamide) (HB-PNIPAM), functionalized with vancomycin at the chain ends, acted as a bacterial adhesive and was incorporated into polyurethane foams to form semi-interpenetrating networks. The poly(N-isopropylacrylamide) was labelled with a solvatochromic dye, Nile red. It was found that the thermal response of the polymer was dependent on architecture and temperature dependent color changes were observed within the foam. The foams had open pore structures and the presence of the HB-PNIPAM substantially reduced the shrinkage of the foam as the temperature was increased upto 20 °C. The foams were selectively adhesive for Staphylococcus aureus (Gram-positive bacteria) compared to Pseudomonas aeruginosa (Gram-negative bacteria) and the presence of S. aureus was indicated by increased fluorescence intensity (590 to 800 nm).