Fluorocarbons and fluorinated amphiphiles in drug delivery and biomedical research

3.2.1. Linear F-Alkyl/H-Alkyl Diblocks 1720 3.2.2. Unsaturated Diblocks 1721 3.2.3. Branched Diblocks 1722 3.2.4. Diblocks with Heteroatoms 1723 3.2.5. Diblocks with Heavy Halogens 1724 3.3. Triblocks and Multiblocks 1724 3.3.1. FnHmFn Triblocks 1724 3.3.2. HmFnHm Triblocks 1725 3.3.3. Star-Shaped Triblocks 1725 3.3.4. Multiblocks and Polyaffine Compounds 1726 4. Basic Properties of (F-Alkyl)alkyl Diblocks 1726 4.1. The “Polarity” Issues“Apolar”, yet Dipolar 1726 4.2. Surfactant Properties 1727 4.2.1. Surfactant Effects of FnHm Diblocks at Interfaces with Air, Fluorocarbons, and Hydrocarbons 1728

Chemistry, physical chemistry, and uses of molecular fluorocarbon--hydrocarbon diblocks, triblocks, and related compounds--unique "apolar" components for self-assembled colloid and interface engineering.

Emulsions are of critical importance for research and for applications in the medical sciences, food industry and elsewhere. This paper describes a one-step method that exploits the temperature-sensitive miscibility of hydrocarbon, silicone and fluorocarbon liquids to make three- and four-phase complex emulsions with highly controllable morphologies. The geometry of the emulsions can be accurately tuned between encapsulated and Janus configurations by varying the balance of interfacial tensions controlled through mixtures of surfactant or by stimuli such as light or pH. The ability to reversibly 'present' and 'hide' specific liquidliquid interfaces within the droplet and tune the droplet morphology offers interesting practical possibilities.

Dynamically reconfigurable complex emulsions via tunable interfacial tensions

Fluorous micro- and nanophases with a biomedical perspective

Direct delivery of proteins into cells avoids many drawbacks of gene delivery, and thus has emerging applications in biotherapy. However, it remains a challenging task owing to limited charges and relatively large size of proteins. Here, we report an efficient protein delivery system via the co-assembly of fluoroamphiphiles and proteins into nanoparticles. Fluorous substituents on the amphiphiles play essential roles in the formation of uniform nanoparticles, avoiding protein denaturation, efficient endocytosis, and maintaining low cytotoxicity. Structure-activity relationship studies reveal that longer fluorous chain length and higher fluorination degree contribute to more efficient protein delivery, but excess fluorophilicity on the polymer leads to the pre-assembly of fluoroamphiphiles into stable vesicles, and thus failed protein encapsulation and cytosolic delivery. This study highlights the advantage of fluoroamphiphiles over other existing strategies for intracellular protein delivery.

The fluorination effect of fluoroamphiphiles in cytosolic protein delivery.

Surface and interfacial tensions of dilute aqueous solutions of sodium perfluorobutyrate, sodium perfluorooctanoate, sodium perfluorodecanoate, sodium octyl sulfate, and sodium decyl sulfate at the air-water (a/w), hexane-water (h/w), and perfluorohexane-water (p-f-h/w) interfaces have been measured with the objective of determining the relative affinities for the interfaces at low degrees of adsorption. Up to approximately 2 dyn/cm the surface pressures were found to increase linearly with surfactant concentration (activity), in agreement with a thermodynamic model of adsorption. The free energies of adsorption, have been estimated by using the thermodynamic model. From these data the incremental changes in free energy of adsorption, ..delta.. free energy of adsorption values, on adding a-CH/sub 2/-group to the hydrocarbon chain and a-CF/sub 2/-group to the fluorocarbon chain have been calculated. The affinity of a hydrocarbon surfactant for the h/w interface is markedly higher than that for the a/w interface. A fluorocarbon surfactant at the p-f-h/w interface shows a much smaller increase in affinity as compared to the a/w interface. 31 references.

Adsorption of fluorocarbon and hydrocarbon surfactants to air-water, hexane-water and perfluorohexane-water interfaces. Relative affinities and fluorocarbon-hydrocarbon nonideality effects

Tetsurou Handa

Papers

Adsorption of fluorocarbon and hydrocarbon surfactants to air-water, hexane-water and perfluorohexane-water interfaces. Relative affinities and fluorocarbon-hydrocarbon nonideality effects

Surface tensions of nonideal mixtures of fluorocarbons and hydrocarbons and their interfacial tensions against water