Affiliation:
1. Institute for Experimental Molecular Imaging Medical Faculty RWTH Aachen University Aachen Germany
2. Institute of Inorganic Chemistry RWTH Aachen University Aachen Germany
3. Institute for Occupational Social and Environmental Medicine Medical Faculty RWTH Aachen University Aachen Germany
Abstract
AbstractCobalt complexes exhibit versatile reactivity with nitric oxide (NO), enabling their utilization in applications ranging from homogeneous catalysis to NO‐based modulation of biological processes. However, the coordination geometry around the cobalt center is complex, the therapeutic window of NO is narrow, and controlled NO delivery is difficult. To better understand the complexation of cobalt with NO, we prepared four cobalt nitrato complexes and present a structure‐property relationship for ultrasound‐triggerable NO release. We hypothesized that modulation of the coordination geometry by ligand‐modification would improve responsiveness to mechanical stimuli, like ultrasound. To enable eventual therapeutic testing, we here first demonstrate the in vitro tolerability of [Co(ethylenediamine)2(NO)(NO3)](NO3) in A431 epidermoid carcinoma cells and J774A.1 murine macrophages, and we subsequently show successful encapsulation of the complex in poly(butyl cyanoacrylate) microbubbles. These hybrid Co‐NO‐containing microbubbles may in the future aid in ultrasound imaging‐guided treatment of NO‐responsive vascular pathologies.