Physical chemistry of experimental models for lipid shells of medical microbubbles

Micrometre scale gas in liquid bubbles (microbubbles) can be stabilised by a thin shell composed of proteins, surfactants, lipopolymers, and/or lipids. The objective of this paper is to review a number of the physical chemical properties of microbubble shells, primarily composed of semi-ordered or ordered alkyl chains such as lipids, we have systematically investigated. These properties include shell collapse and shedding, resistance to gas mass transfer, and phase behaviour (phase diagrams). We relate our investigations and findings to the most closely relevant literature and practical use and design principles of shells for medical microbubbles.