Unconventional Non‐Aqueous Emulsions for the Encapsulation of a Phototriggerable NO‐Donor Complex in Polymer Nanoparticles

Abstract

A non‐aqueous emulsion system with hexafluoroisopropanol (HFIP) provides nanoparticles from gelatin, polylactide, poly(vinyl formal), and poly(ethylene terephthalate). Poly(vinyl formal) particles can embed a ruthenium nitrosyl complex for phototriggered NO release.

Sensitization of NO‐Releasing Ruthenium Complexes to Visible Light

“…In our previous studies, the synthesis of aliphatic and aromatic imidazole biscarboxamides has been described. [48][49][50][51] For example, the ligand N,N'-(1,2-phenylene)bis(1-methylimidazole-2-carboxamide) (mib) in reference compound 3 was rapidly prepared by lithiation of 1,2-phenylenediamine with n-butyllithium. [49] After addition of ethyl 1-methyl-imidazole-2-carboxylate and reprotonation, the desired ligand could be isolated.…”

“…The isolated compounds 1 and 2 are compared with the previously described complex [(mib)Ru(NO)Cl] (3)i n terms of their photophysical and photochemical properties. [48,49] All compounds contain dianionic, tetradentate bisimidazole biscarboxamide ligands. In contrast to 3,t he ligands from 1 and 2 exhibit an extended p-system with a2 ,3-phenazinediamine unit.…”

“…[7,8,12,[43][44][45][46][47] So far,w eh ave reported photo-triggerable metal NO donors encapsulated in polymer matrices that retain the photoproducts after NO release into the aqueouse nvironment. [48,49] In this study,w ep resent {RuNO} 6 nitrosyl complexes as NO-releasing systems with as trong bathochromic shift of the UV/Vis absorption band and, at the same time, an increased extinction coefficient, achieved by expanding the p-system of the tetradentate biscarboxamide N 4 ligand frame. Concomitantly,w ei ntroduce an unitless expression, G,t oe stimate the efficiency of NO release of the designed {RuNO} 6 nitrosyl complexes.T he value G can be assessed from experimental absorption spectra and quantum chemicalc alculations and can be used to evaluate the sensitization design towards visible light within as imilar set of {RuNO} 6 nitrosyl complexes.…”

Nonaqueous Dispersion Formed by an Emulsion Solvent Evaporation Method Using Block–Random Copolymer Surfactant Synthesized by RAFT Polymerization

“…Various methods have been reported for colorant encapsulation, including solvent evaporation, [9][10][11][12][13] emulsion polymerization, [14][15] miniemulsion polymerization, 16-17 and coacervation; 18-19 however, most of these methods have limitations that hamper their application to industrial printing. For example, miniemulsion polymerization is limited in that only colorants that are completely dissolved or dispersed in a monomer can be used.…”

“…23 As the emulsifiers for non-aqueous emulsions, low molecular surfactants, 10 particles, 24 and polymeric surfactants 11,[25][26][27][28][29] are generally used. Polymeric surfactants, especially block copolymers, have been frequently used as the emulsifiers for non-aqueous emulsions because the large block lengths in copolymers allow for efficient steric stabilization.…”