title: Cell attachment and biocompatibility of polytetrafluoroethylene (PTFE) treated with glow-discharge plasma of mixed ammonia and oxygen.
abstract: The plasma generated from a gas mixture of NH3 plus O2 (NH3 + O2) has been used to impart unique chemical and biological characteristics to polytetrafluoroethylene (PTFE). PTFE treated with NH3 + O2 plasma was physiochemically distinct from surfaces treated with plasma of either NH3 or O2 alone, as determined by electron spectroscopy for chemical analysis (ESCA). The contact angle analysis revealed that the PTFE surfaces became less hydrophobic after plasma treatments. ESCA results indicate the presence of oxygen-containing groups and nitrogen-containing groups at the plasma-treated surfaces. PTFE treated with NH3 + O2 plasma resisted the attachment of platelets and leukocytes in a manner similar to untreated PTFE; however, the attachment of bovine aorta endothelial cells was substantially increased. Once attached, these cells grew to confluency. The increased endothelial cell attachment was higher than that observed following plasma treatment with each gas used separately, which could be attributed to the considerable amount of CF(OR)2-CF2 formed on the NH3 + O2 plasma-treated PTFE surface. At 14 days after subcutaneous implantation in rats, the PTFE wafers treated with NH3 + O2 plasma demonstrated less encapsulation and lower levels of inflammatory cells compared to controls. Collectively, the results suggest that NH3 + O2 plasma treatment imparts a unique character to PTFE and could be useful in certain in vivo applications.
authors.affiliation: BioSurface Engineering Technologies, Inc., 387 Technology Drive, College Park, MD 20742, USA. mchen@biosetinc.com
authors.forename: Meng
authors.initials: M
authors.lastname: Chen
authors.forename: Paul O
authors.initials: PO
authors.lastname: Zamora
authors.forename: Prantika
authors.initials: P
authors.lastname: Som
authors.forename: Louis A
authors.initials: LA
authors.lastname: Peña
authors.forename: Shigemasa
authors.initials: S
authors.lastname: Osaki
mesh_terms: D020341:Absorbable Implants; D000327:Adsorption; D000641:Ammonia / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001792:Blood Platelets / Q000166:cytology*; D001798:Blood Proteins / Q000737:chemistry; D002417:Cattle; D002448:Cell Adhesion; D002455:Cell Division; D002460:Cell Line; D042783:Endothelial Cells / Q000166:cytology*; D006801:Humans; D007962:Leukocytes / Q000166:cytology*; D010100:Oxygen / Q000737:chemistry*; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D051381:Rats; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D001798:Blood Proteins; D000641:Ammonia; D011138:Polytetrafluoroethylene; D010100:Oxygen