Details

Autor(en) / Beteiligte

• Kwan, James J.
• Borden, Mark A.

Titel

Lipid monolayer collapse and microbubble stability

Ist Teil von

• Advances in colloid and interface science, 2012-11, Vol.183-184, p.82-99

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2012

Quelle

MEDLINE

Beschreibungen/Notizen

• Microbubbles are micrometer-size gaseous particles suspended in water, and they are often stabilized by a lipid monolayer shell. Natural microbubbles are found in freshwater and saltwater systems, and engineered microbubbles have a variety of applications in food sciences, biotechnology and medicine. Lipid-coated microbubbles are found to have remarkable stability and mechanical behavior owing to the resistance of the lipid monolayer encapsulation to collapse. The purpose of this review is to tie in recent observations of lipid-coated microbubble dissolution and gas exchange with current literature on the physics of lipid monolayer collapse in the context of lung surfactant. Based on this analysis, we conclude that microbubble shells collapse through the nucleation of microscopic folds, which then catalyze the formation and aggregation of new folds, leading to macroscopic folding events. This process results in a cyclic behavior of crumple-to-smooth transitions, which can be modulated through lipid composition. Eventually, the microbubbles stabilize at 1–2μm diameter, regardless of initial size or lipid composition, and various mechanisms for this stabilization are postulated. Our ultimate goal is to inspire the reader to consider lipid monolayer collapse as the main long-term stabilizing mechanism for lipid-coated microbubbles, and to stimulate the use of microbubbles as a platform for studying monolayer collapse phenomena. [Display omitted] ► Lipid-coated microbubbles and their applications are introduced. ► Microbubble generation, structure and stability are discussed. ► Current theory on lipid monolayer collapse is reviewed. ► New data on microbubble dissolution are analyzed. ► Mechanisms for stabilization at a size of 1–2μm are proposed.