Light-induced nitric oxide release from physiologically stable porous coordination polymers

Abstract

The development of nitric oxide (NO) releasing materials has been of significant importance due to their application in cell biology and biomedicine. Besides the macromolecular scaffold dangling NO releasing moiety, porous materials have been used to host such NO releasing molecules. Here we synthesized a series of porous coordination polymers (PCPs), in which N-nitrosamine functional groups as photoactive NO donors were introduced into the framework scaffolds by post-synthetic nitrosation of amine functionalized analogous PCPs. We further demonstrated a controlled release of NO from the PCPs by light irradiation. Though isoreticular frameworks based on octanuclear clusters of titanium or aluminium ions were chosen due to their water-stability, the frameworks showed difference in stability in cell culture media; while aluminium frameworks were less stable in water and physiological media, the titanium analogue was highly stable even under physiological conditions.

Nanoscale Metal–Organic Frameworks for Therapeutic, Imaging, and Sensing Applications

“…The prefunctionalization in this work nicely took advantage of the small cargo dimension and unique NO generation chemistry, but the amount of CO released from nMOFs was likely too small for therapeutic applications. MOFs containing diazeniumdiolate and bis‐N‐nitrosoamine moieties were also explored for NO release via postsynthetic nitrosation …”

Light responsive metal–organic frameworks as controllable CO-releasing cell culture substrates

“…Indeed, we have recently demonstrated the advantage of photoactive MOFs for the controlled delivery of biologically active nitric oxide (NO) molecules at the cellular level. 24,25 Although there has been only one example of CO-releasing MOF, 26 in which CO gas is first adsorbed onto open metal sites and then steadily released through ligand exchange reaction with water in physiological media, to the best of our knowledge, highly controllable release of CO from MOFs is yet to be achieved.…”

Emerging applications of metal–organic frameworks

“…Another reaction mechanism using the bis-N-nitrosoamine moiety was introduced into the stable MOFs with high valent metal ions, 6 (NOF-11) and Al 8 (OMe) 8 (OH) 4 (MeNNO-bdc) 6 (NOF-12), which display the MIL-125 and CAU-1 structure types, respectively (MeNNO-bdc = 2,5-bis(methyl (nitroso) amino)-1,4-benzenedicarboxylate). 47 Both frameworks release NO with high photoactive efficiencies (40% and 58% for NOF-11 and -12, respectively). Importantly, the higher charge of the Ti 4+ cation compared to Al 3+ provides stronger metal-ligand bonding and an enhanced stability profile for NOF-11 compared to NOF-12 in both water and in buffer solutions.…”