The synthesis of polymeric dual-functional antimicrobial surface based on poly(2-methyl-2-oxazoline)

Abstract

There is a high interest in the development of antimicrobial coatings to fi ght bacterial infections.
We present the development of dual-functional antimicrobial surface, in which a biopassive platform was
functionalized with bioactive compounds on the surface, using a graft copolymer system poly(L-lysine)-graftpoly(
2-methyl-2-oxazoline)-quarternery ammonium compound (PLL-g-PMOXA-QAC). Alkyne functionality
was introduced to the PMOXA chain at α-terminus by initiating the living cationic polymerization of 2-methyl-
2-oxazoline with a propargylic-initiator. The reaction was terminated with carboxy derivative-terminator that
allows grafting of the polymeric chain from the β-terminus to poly(L-lysine) (PLL) backbone, resulting in graft
copolymer alkynyl PLL-g-PMOXA. The conjugation between alkynyl PLL-g-PMOXA and QAC was then
performed using click reaction. The chemical structures of the polymers were characterized by MALDI-TOF
spectrometry and NMR spectroscopy. The results demonstrate that we have successfully synthesized PLL-g-
PMOXA-QAC copolymer with grafting density (number of lysine/number of PMOXA) of 0.33. The resulting
PLL-g-PMOXA-QAC copolymer was then immobilized onto carboxylated tissue cultured polystyrene (TCPS)
surface and exposed to bacteria solution to test its dual-functional properties. Preliminary live-and-dead
bacteria study indicates dual-functionality of the PLL-g-PMOXA-QAC-coated surface.