Emulsification
of immiscible two-phase fluids, i.e., one condensed
phase dispersed homogeneously as tiny droplets in an outer continuous
medium, plays a key role in medicine, food, chemical separations,
cosmetics, fabrication of micro- and nanoparticles and capsules, and
dynamic optics. Herein, we demonstrate that water clusters/droplets
can be formed in an organic phase via the spontaneous assembling of
ionic bilayers. We term these clusters ionosomes, by analogy with
liposomes where water clusters are encapsulated in a bilayer of lipid
molecules. The driving force for the generation of ionosomes is a
unique asymmetrical electrostatic attraction at the water/oil interface:
small and more mobile hydrated ions reside in the inner aqueous side,
which correlate tightly with the lipophilic bulky counterions in the
adjacent outer oil side. These ionosomes can be formed through electrochemical
(using an external power source) or chemical (by salt distribution)
polarization at the liquid–liquid interface. The charge density
of the cations, the organic solvent, and the synergistic effects between
tetraethylammonium and lithium cations, all affecting the formation
of ionosomes, were investigated. These results clearly prove that
a new emulsification strategy is developed providing an alternative
and generic platform, besides the canonical emulsification procedure
with either ionic or nonionic surfactants as emulsifiers. Finally,
we also demonstrate the detection of individual ionosomes via single-entity
electrochemistry.
Background and Objectives Red blood cells (RBCs) suffer from lesions during cold storage, depending in part on their ability to counterbalance oxidative stress by activating their antioxidant defence. The aim of this study was to monitor the antioxidant power (AOP) in erythrocyte concentrates (ECs) during cold storage.
Materials and MethodsSix ECs were prepared in saline-adenine-glucose-mannitol (SAGM) additive solution and followed during 43 days. The AOP was quantified electrochemically using disposable electrode strips and compared with results obtained from a colorimetric assay. Haematological data, data on haemolysis and the extracellular concentration of uric acid were also recorded. Additionally, a kinetic model was developed to extract quantitative kinetic data on the AOP behaviour.Results The AOP of total ECs and their extracellular samples attained a maximum after 1 week of storage prior to decaying and reaching a plateau, as shown by the electrochemical measurements. The observed trend was confirmed with a colorimetric assay. Uric acid had a major contribution to the extracellular AOP. Interestingly, the AOP and uric acid levels were linked to the sex of the donors.
ConclusionThe marked increase in AOP during the first week of storage suggests that RBCs are impacted early by the modification of their environment. The AOP behaviour reflects the changes in metabolism activity following the adjustment of the extracellular uric acid level. Knowing the origin, interdonor variability and the effects of the AOP on the RBCs could be beneficial for the storage quality, which will have to be further studied.
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