Xerogel mesoporous materials based on ultrastable Blatter radicals for efficient sorption of nitric oxide.

The reduction of hazardous nitric oxide emissions remains a significant ecological challenge. Despite the variety of possibilities, sorbents able to capture low concentrations of NO from flue gas with high selectivity are still in demand. In this work a new type of mesoporous xerogel material highly loaded with ultrastable Blatter radicals (BTR, >60 % by mass) that act as selective NO sorption sites is developed. Electron Paramagnetic Resonance (EPR) spectroscopy evidences reversible NO sorption in nanometer-scale pores of BTR-based xerogels and indicates the high NO capacity of such radical-rich sorbent. Efficient NO capture from model flue gas mixture is also evidenced in experiments with a fixed bed reactor. Such advanced properties of new materials as selectivity, strong binding with NO and an ability for mild regeneration via thermodesorption promote them for future ecological applications.

Blatter Radical-Decorated Silica as a Prospective Adsorbent for Selective NO Capture from Air.

Nitrogen oxides are adverse poisonous gases present in the atmosphere and having detrimental effects on the human health and environment. In this work, we propose a new type of mesoporous materials capable of capturing nitrogen monoxide (NO) from air. The designed material combines the robust Santa Barbara Amorphous-15 silica scaffold and ultrastable Blatter-type radicals acting as NO traps. Using in situ electron paramagnetic resonance spectroscopy, we demonstrate that NO capture from air is selective and reversible at practical conditions, thus making Blatter radical-decorated silica highly promising for environmental applications.

Stability of ZIF-8 Nanoparticles in Most Common Cell Culture Media.

Zeolite imidazolate framework-8 (ZIF-8) is a promising platform for drug delivery, and information regarding the stability of ZIF-8 nanoparticles in cell culture media is essential for proper interpretation of in vitro experimental results. In this work, we report a quantitative investigation of the ZIF-8 nanoparticle's stability in most common cell culture media. To this purpose, ZIF-8 nanoparticles containing sterically shielded nitroxide probes with high resistance to reduction were synthesized and studied using electron paramagnetic resonance (EPR). The degradation of ZIF-8 in cell media was monitored by tracking the cargo leakage. It was shown that nanoparticles degrade at least partially in all studied media, although the degree of cargo leakage varies widely. We found a strong correlation between the amount of escaped cargo and total concentration of amino acids in the environment. We also established the role of individual amino acids in ZIF-8 degradation. Finally, 2-methylimidazole preliminary dissolved in cell culture media partially inhibits the degradation of ZIF-8 nanoparticles. The guidelines for choosing the proper cell culture medium for the in vitro study of ZIF-8 nanoparticles have been formulated.