Stabilization of fluorocarbon emulsions by sugar-derived perfluoroalkylated surfactants and co-surfactants

Oxygen Carriers (“Blood Substitutes”)Raison d'Etre, Chemistry, and Some PhysiologyBlut ist ein ganz besondrer Saft

“…Particle growth by Ostwald ripening in crystalline dispersions is described by the Lifshitz−Slezov−Wagner theory, , which was subsequently adapted to emulsions and predicts a linear increase in number average particle radius ā versus time (eq 5.13) where ω is the droplet's growth rate, D is the diffusion coefficient for the PFC in the aqueous phase, and γ(φ) reflects the dependence of ω on the volume fraction φ of PFC in the emulsion. Droplet volume was indeed observed to increase linearly with time ,,,,,, and growth rate to increase nearly proportionally with PFC volume fraction in the 8−57% volume fraction range . It should be noted, however, that eq 5.13 does not take into account the presence of the surfactant film and supposes that the two phases are isotropic, which may not necessarily be the case, for example, in the vicinity of the interface for a multicomponent surfactant system.…”

“…In other cases, a second surfactant was needed. For example, the closely related F -alkylated derivatives of trehalose 5.28 and maltose 5.29 demonstrated dramatically different behaviors: the former gave highly stable emulsions, while the latter did not even allow obtaining an emulsion, probably reflecting differences in polar head conformation and hydration, hence in molecular shape. , Compound 5.29 (as well as the xylitol derivative 5.27 ) provided, however, strong synergistic stabilization when used in association with a poloxamer, indicating hydrogen-bond interactions between the two species . Some such formulations showed no significant change in particle size distribution for the 6 years during which the emulsion was monitored .…”

“…Some such formulations showed no significant change in particle size distribution for the 6 years during which the emulsion was monitored . Other surfactants, such as the anionic sugar derivatives 5.30 , were synergistic with phospholipids but not with poloxamers …”

Synthesis, emulsification and self-assembly properties of sugar-containing semifluorinated amphiphiles

“…sugar phosphates, amino sugars, etc), and have been used to prepare emulsions of perfluorocarbons. 12-16 Our goal was two-fold – first, it was to investigate the use of saccharide-perfluoroalkyl amphiphiles with respect to the sevoflurane-perfluorooctyl bromide system, and second, it was to explore convenient methods of introducing a perfluoroalkyl chain into a saccharide-based hydrophilic head. Perfluoroalkyl chains have been installed into saccharides by a number of different chemistries: glycosylation, 17-22 formal glycosylation, 23-24 ether formation, 13,14,25 ether formation by way of radical addition, 14,26 acetal formation, 27 carbon-carbon bond formation, 28 urea, 29,30 thiourea 29,31 and carbamate 32 formation, phosphoester formation, 33-35 ester 15,26,36 and amide 23,37-39 formation, as well as thiol-initiated Michael 40 and free radical 41 addition.…”

Synthesis and Solution Properties of Nonionic Hybrid Surfactants with a Benzene Ring

“…In order to solve this problem, certain approaches have been attempted using prodrugs having a high affinity with fluorocarbons and supramolecular compounds containing many fluorine atoms (5,6). Some fluorocarbon surfactants including C 6 F 13 C 2 H 4 S [CH 2 CH(CONHC(CH 2 OH) 3 )] 5 H are known to form prodrugs (7,8). Yet, the number of pharmacologically active substances is limited that can combine with the surfactants to yield prodrugs and very few compounds form supramolecules, which indicate that both approaches are impractical.…”