Self-Assembling Quaternary Ammonium Sulfonamide Antimicrobials

A series of novel sulfonamide based quaternary ammonium (QUAT’s) antimicrobials containing a variety of chemical anchors R-SO2-NH-(CH2)3-N(CH3)2-(CH2)3-Y (where R = alkyl or aryl and Y = organosilane (Si(OMe)3), organophosphorus (P(O)(OR1)) and benzophenone (-OC6H4-C(O)-C6H5)) were used to immobilize them on different substrates. Sulfonamide organosilane QUAT’s were immobilized on to textiles substrates, whereas benzophenone QUAT’s were used to exclusively coat plastic surfaces (polyethylene (PE), and polyvinylchloride (PVC)), and organophosphorus QUAT’s were prepared for testing on metal surfaces (stainless steel). The covalently attached antimicrobial coatings were found to kill gram +ve and -ve bacteria on contact, hindering their attachment and colonization without any leachate. The partially water soluble sulfonamide QUAT’s presented are readily prepared, easy to apply and are relatively inexpensive. Textile samples were prepared by immersion in a MeOH:H2O (30:70) solution of organosilane QUAT’s followed by curing/drying at room temperature for 2 – 24 hours. Plastic samples were prepared by electrospraying an EtOH:H2O (10:90) solution containing benzophenone QUAT’s followed by UV curing using for 2 – 5 minutes. All samples showed a 100% reduction (107– 106 cells) of viable Arthrobacter, S. aureus, and E.coli after 3 hours of contact time and maintained their activity over 24 hours versus the control (untreated) samples.