Synthesis of Cationic Biphen[4, 5]arenes as Biofilm Disruptors

Abstract: Since bacteria in biofilms are inherently resistant to antibiotics and biofilm-associated infections pose serious threat to global public health, new therapeutic agents and schemes are urgently needed to meet clinical requirements. Here two quaternary ammonium-functionalized biphen[n]arenes (WBPn, n = 4, 5) were designed and synthesized with excellent anti-biofilm potency. Not only could they inhibit assembly of biofilm, but also eradicate intractable mature biofilm formed by Gram-positive S. aureus and Gram-negative E. coli bacterial strains. Moreover, they could strongly complex a conventional antibiotic, cefazolin sodium (CFZ) with complex stability constants of (7.41 ± 0.29) × 104 M-1 for CFZ/WBP4 and (4.98 ± 0.49) × 103 M-1 for CFZ/WBP5. Combination of CFZ by WBP4 and WBP5 synergistically enhanced biofilm eradication performance in vitro and statistically improved healing efficacy on E. coli-infected mice models, providing novel supramolecular strategy for combating biofilm-associated infections.