Bubbles in circulating blood: stabilization and simulations of cyclic changes of size and content

Abstract

Surface tension, blood pressure, and inherent unsaturation due to O2 metabolism promote diffusion of gases out of bubbles in the bloodstream. We review the mechanisms that can overcome the absorptive tendencies so small spherical bubbles can persist. One general type of stabilizer is a mechanical structure at the gas-liquid interface that can support a negative pressure so that gases inside can be in diffusion equilibrium with their counterparts outside; one possibility for mechanical stabilizers are surfactant films. We show that a slowly permeating gas is analogous to a mechanical stabilizer; it allows equilibration of other gases inside-to-outside by diluting the gases inside. By using numerically solved equations based on physics of diffusion, we demonstrate how nonrigid stabilized bubbles change size as they move through the circulatory system. In small pulmonary vessels, the bubbles enlarge because blood pressure is low, there is no inherent unsaturation, and O2 and N2 diffuse from lung gas into the bubble; these gases diffuse out again in the systemic circulation.

Quantitative contrast-enhanced ultrasound imaging: a review of sources of variability

“…Consequently, the acoustic signal and dissolution kinetics of the bubbles that remain in circulation will be influenced. In addition to filtration, the passage of bubbles through the lungs and exposure to blood at low pressure with a high oxygen and nitrogen concentration can cause diffusion of these gases into the bubbles as they pass through the pulmonary circulation [57]. While this gas will later diffuse out as local conditions within the systemic circulation change, the immediate effect will be to increase the number of large bubbles, which may in turn increase the influence of lung filtration.…”

Scavenging dissolved oxygen via acoustic droplet vaporization

“…From these results, the amount of ingassing and thus the expansion factor appear to depend on the experimental conditions, potentially including the gas saturation of the fluid, formulation of the droplet, and concentration of the droplets. The diffusion of gases into perfluorocarbon-based ultrasound contrast agents has also been discussed in other studies [18][19][20][21]. Further, the high solubility of oxygen in perfluorochemicals [22,23] and the use of perfluorochemicals as blood substitute agents have been demonstrated in previous studies [24,25].…”

Bubble Liposome: A Modern Theranostic Approach of New Drug Delivery

“…To begin with, it gives mechanical strength to the air pocket, supporting against breakdown and permitting the gas inside the rise to be in dissemination harmony with gas outside the air pocket. [21] Second, the shell protect the bubble from destructive environment, for example, colleseance, Laplace pressure driven disintegration and Ostwald aging and it in this way permits the gas bubbles to intact in systemic circulations. [21,22] Recreations of oxygen microbubbles recommend that since the shell is gas penetrable, the volume of transported oxygen may leads to changes towads rise the of the oxygen level in systemic blood.…”

“…[21] Second, the shell protect the bubble from destructive environment, for example, colleseance, Laplace pressure driven disintegration and Ostwald aging and it in this way permits the gas bubbles to intact in systemic circulations. [21,22] Recreations of oxygen microbubbles recommend that since the shell is gas penetrable, the volume of transported oxygen may leads to changes towads rise the of the oxygen level in systemic blood. [23] For example, rises can pick up the oxygen level in the high pO 2 condition of the lungs and release O 2 in tissues.…”