title: Synthesis and characterization of nitric oxide-releasing sol-gel microarrays.
abstract: Diazeniumdiolate-modified sol-gel microarrays capable of releasing low levels of nitric oxide are reported as a viable means for improving the blood compatibility of a surface without fully modifying the underlying substrate. Several parameters are characterized including: (1) NO surface flux as a function of sol-gel composition and microarray geometry; (2) microstructure dimensions and spacing for optimal blood compatibility; and (3) the effect of sol-gel surface modification on analyte accessibility to platinum electrodes. The sol-gel microarrays release biologically relevant levels of NO under physiological conditions for >24 h. In vitro platelet adhesion assays indicate that a NO surface flux of 2.2 pmol cm(-2) s(-1) effectively reduces platelet adhesion to glass substrates modified with sol-gel microstructures separated by 50 microm. The blood compatibility observed for these micropatterned surfaces is comparable to NO-releasing sol-gel films. When the separation between NO-releasing microstructures is reduced to 10 microm, the NO surface flux required to reduce platelet adhesion is lowered to 0.4 pmol cm(-2) s(-1). Finally, the oxygen response of platinum electrodes modified with NO-releasing sol-gel microarrays indicates that selective modification via micropatterning enhances analyte accessibility to the sensor surface.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Robbins
authors.forename: Erin D
authors.initials: ED
authors.lastname: Hopper
authors.forename: Mark H
authors.initials: MH
authors.lastname: Schoenfisch
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D001769:Blood; D003692:Delayed-Action Preparations; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004566:Electrodes; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D046228:Microarray Analysis; D018625:Microscopy, Atomic Force; D009569:Nitric Oxide / Q000008:administration & dosage*; D009757:Nylons / Q000737:chemistry; D010973:Platelet Adhesiveness; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D004129:Dimethylpolysiloxanes; D005782:Gels; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer; D009569:Nitric Oxide