S-nitrosylation of Poly(propylene sulfide) Nanoparticles for Controlled Nitric Oxide Delivery
Alex Schudel; School of Materials Science and Engineering

Nitric oxide (NO) is one of the most important small molecules in biology. Its large diffusivity and high reactivity allow it to contribute to a wide spectrum of physiological functions including vasodilation, immune-cytotoxic defenses, lymphatic pumping, and cellular respiration. One of the more interesting reactions of NO occurs with thiols (-SH), including those found on gluthatione and albumin, through the formation of an s-nitrosothiol adduct. This adduct is implicated in stabilizing NO for transport throughout the body (albumin) and for mediating some of NO's signalling properties (gluthatione). We have exploited this chemistry to develop s-ntirosylated polypropylene sulfide nanoparticles that take advantage of the functionality of micelles as controlled drug delivery vehicles and can exert the physiological signaling activity of NO for therapeutic purposes.

On the Role of Bromide Ions in Shaping Palladium Nanocrystals
Hsin-Chieh Peng; School of Chemistry and Biochemistry

Br- is a typical {100}-specific capping agent for several noble metals, including Pd, Pt, and Rh. We demonstrate an approach based on a combination of inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy for quantitative analysis of the role played by Br− ions in the synthesis of Pd nanocrystals. The Br− ions were found to adsorb onto Pd{100} facets selectively with a coverage density of ca. 0.8 ion per surface Pd atom.  Based on the coverage density information, we were able to estimate the minimum amount of Br- ions needed to generate Pd nanocrystals with specific proportions of {100} and {111} facets.