title: Compartmentalized nanocomposite for dynamic nitric oxide release.
abstract: Nitric oxide (NO) is an important cell-signaling molecule whose role in a variety of cellular processes such as differentiation and apoptosis depends strongly on its concentration and flux levels. This work describes and characterizes a novel nitric oxide releasing nanocomposite, capable of photostimulated NO flux that can by dynamically modulated in within a range of biological levels. This material mimics the common compartmentalization strategies used by living cells to achieve its novel features. The material is constructed by encapsulating a photosensitive nitric oxide donor within lipid vesicles with an average diameter of 150 nm. The vesicles are then doped into the interstitial liquid phase of a solid porous silica matrix, which has previously demonstrated biological compatibility and capabilities as a growth surface for mammalian cells. Stimulation by a light source produces a step increase in NO concentration within seconds. The NO flux at the surface of the material is measured to be 14 pmol-cm(-2) sec(-1) using a NO selective self-referencing amperometric microsensor. The NO concentration profile decreases with distance perpendicular to the surface as expected for diffusion from a surface through an aqueous environment. A pattern of one minute light pulses produced uniform pulses of increased NO concentration of one minute duration. A linear relationship exists between NO surface concentration and photon flux, and this relationship can be used to tune the material response.
authors.affiliation: Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Koehler
authors.forename: Jianxiu
authors.initials: J
authors.lastname: Zhao
authors.forename: Sabrina S
authors.initials: SS
authors.lastname: Jedlicka
authors.forename: D Marshall
authors.initials: DM
authors.lastname: Porterfield
authors.forename: Jenna L
authors.initials: JL
authors.lastname: Rickus
mesh_terms: D002138:Calibration; D007700:Kinetics; D008839:Microelectrodes; D008854:Microscopy, Electron; D053758:Nanoparticles; D009569:Nitric Oxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009569:Nitric Oxide