Ethoxylated copolymersurfactants for the HFA134a- interface: interfacial activity, aggregate microstructure and...

Area of Science:

• Colloid and Surface Chemistry
• Materials Science
• Biophysical Chemistry

Background:

• Ethoxylated copolymer surfactants exhibit unique interfacial behavior in fluorinated propellants.
• Understanding aggregate formation is crucial for developing novel drug delivery systems.

Purpose of the Study:

• To investigate the aggregation behavior of ethoxylated copolymer surfactants in 1,1,1,2-tetrafluoroethane (HFA134a) and water.
• To determine the capacity of these aggregates to uptake model biomolecules.

Main Methods:

• In situ high-pressure tensiometry to determine interfacial properties.
• UV-vis spectroscopy to assess water solubilization capacity.
• Small-angle neutron scattering (SANS) to investigate aggregate microstructure and biomolecule uptake.

Main Results:

• The optimal hydrophilic-to-HFA-philic balance (HFB) for EO3PO43EO3 surfactants at the HFA134a|W interface was identified.
• Spectroscopic data confirmed water solubilization within surfactant aggregates.
• SANS confirmed the uptake of a model protein within reverse aggregates.

Conclusions:

• Ethoxylated copolymer surfactants can form reverse aggregates in HFA134a capable of encapsulating hydrophilic biomolecules.
• These reverse aggregates show promise as formulations for lung delivery of drugs and biomolecules.