Water-Stable Silver-Based Metal-Organic Frameworks of Quaternized Carboxylates and Their Antimicrobial Activity.

Three-dimensional (3D) and two-dimensional (2D) Ag-based zwitterionic metal-organic frameworks (MOFs) [Ag 2 (Cedcp)] n ( 1 , 3D, H 3 CedcpBr denotes N -(carboxyethyl)-(3,5-dicarboxyl)-pyridinium bromide) and {[Ag 4 (Cmdcp) 2 (H 2 O) 4 ]·4H 2 O} n ( 2 , 2D, H 3 CmdcpBr denotes N -(carboxymethyl)-(3,5-dicarboxyl)-pyridinium bromide) have been prepared and investigated for antimicrobial activity via minimal inhibition concentration (MIC) test and killing kinetic assay. Both MOFs 1 and 2 show good water stability and solubility ascribed to their characteristic aromatic rings and positively charged pyridinium of the ligands, as well as the presence of Ag + on their surface, leading to strong antimicrobial activity and a wide antimicrobial spectrum toward Gram-negative and positive bacteria. The results indicated that MOF 2 possesses a faster antibacterial activity (60 min) than MOF 1 (120 min). Scanning electron microscopy analysis further suggests that the Ag-based MOFs are capable of rupturing the bacterial membrane, leading to cell death. Moreover, both MOFs exhibit little hemolytic activity against mouse erythrocytes and show good biocompatibility in vitro , rendering MOFs 1 and 2 potential therapeutic agents for diseases caused by bacteria.