Attachment of ampicillin to expanded poly(tetrafluoroethylene): surface reactions leading to inhibition of microbial growth.
The broad spectrum antibiotic, ampicillin (AM), was reacted to expanded poly (tetrafluoroethylene) (ePTFE) surfaces and resulted in the formation of antimicrobial surfaces effective against gram-positive, Staphylococcus aureus, Bacillus thuringiensis, and Enterococcus faecalis, and gram-negative, Escherichia coli, Pseudomonas putida, and Salmonella enterica bacteria. These ePTFE surface modifications were accomplished by utilization of microwave maleic anhydride (MA) plasma reactions leading to the formation of acid groups, followed by amidation reactions of heterofunctional NH 2/COOH-terminated polyethylene glycol (PEG). The final step, the attachment of AM to the PEG spacer, was achieved by amidation reactions between COOH-terminated PEG and NH 2 groups of AM. This approach protects the COOH-AM functionality and diminishes the possibility of hydrolysis of the antimicrobial active portion of AM. These studies also show that approximately 90% of AM molecules are still covalently attached to PEG-MA-ePTFE surfaces after exposure to the bacteria solutions. Even after a 24 h period, the AM volume concentration changes only from 2.25 to 2.04 microg/m3, and depending upon the bacteria type, the bacteria suspensions containing AM-PEG-MA-ePTFE specimens retain 85-99% of their initial optical density.
Aumsuwan
Nattharika
N
Department of Chemistry and Biochemistry, School of Polymers and High Performance Materials, Shelby F Thames Polymer Science Research Center, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
Danyus
Ryan C
RC
Heinhorst
Sabine
S
Urban
Marek W
MW
D000667:Ampicillin / Q000737:chemistry* / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D006090:Gram-Negative Bacteria; D006094:Gram-Positive Bacteria; D011092:Polyethylene Glycols; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D013499:Surface Properties; D013535:Suspensions
D000900:Anti-Bacterial Agents; D013535:Suspensions; D011092:Polyethylene Glycols; D000667:Ampicillin; D011138:Polytetrafluoroethylene