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Compartmentalized Nanocomposite for Dynamic Nitric Oxide Release

2008; American Chemical Society; Volume: 112; Issue: 47 Linguagem: Inglês

10.1021/jp803276u

1520-6106

John J. Koehler, Jianxiu Zhao, Sabrina S. Jedlicka, D. Marshall Porterfield, Jenna L. Rickus,

Advanced Nanomaterials in Catalysis

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.