Converting oligo(ethyleneglycol)s into non-toxic highly selective biocompatible antimicrobial poly(ethyleneglycol)s: synthesis, antimicrobial and antibiofilm activity

Designing nontoxic, non-hemolytic selective antimicrobials remains an important and challenging research problem. Herein, we report an affordable synthetic route to prepare a series of ten multifunctional polyethylene glycols (PEG) via a cascade reaction approach, involving aza-Michael polyaddition followed by post-polymerization modifications using triazolinedione based click reactions. All polymers are characterized by NMR, IR, SEC, DSC and TGA analysis. Antimicrobial and hemolytic studies reveal that structure plays a pivotal role to tune the antimicrobial efficacy and selectivity (HC/MIC) of the functional PEGs. The selectivity (HC/MIC) reported for the best prototype (InPEG700-C12-TAD) is 129, 33 and 39 against P. aeruginosa, E. coli and S. aureus respectively. Additionally, all the polymers are non-cytotoxic as revealed by MTT assay and exhibits excellent antibiofilm activity.