Oxygen transport to tissue by persistent bubbles: theory and simulations

Abstract

Persistent gas bubbles able to traverse capillaries can be prepared from a slowly permeating gas or with a mechanical structure surrounding a gas phase. If they are permeable to gases, such bubbles will carry O2 from the lungs to the tissues via the blood stream. Using a mathematical model based on physical laws, we present simulations of the behavior of bubbles stabilized by a slowly permeating gas (gas X). We show that the bubble persists longer if the tissue and venous blood contain N2 to dilute gas X and slow its outward diffusion. A 6-microns -diam bubble carries 0.11 pl of O2 during the breathing of pure O2, so 4.6 x 10(8) bubbles/ml in the blood will supply a normal arteriovenous difference. In conditions used for hyperbaric O2 therapy, a bubble carries approximately 0.26 pl of O2. Stabilized bubbles have the potential to transport O2 efficiently; they release O2 to tissue at high PO2 and require injection of only small amounts of a foreign substance.

Microbubble size isolation by differential centrifugation

“…Microbubbles are being employed for several biomedical applications, including contrast enhanced ultrasound [1,2], drug and gene delivery [3,4] and metabolic gas delivery [5,6]. Microbubbles react strongly to ultrasonic pressure waves by virtue of their compressible gas cores, which resonate at the MHz-frequencies used by current clinical scanners.…”

Ultrasound-mediated oxygen delivery from chitosan nanobubbles

“…Formulation B was prepared likewise, but perfluoropentane was added to increase oxygen loading, since oxygen can be stored in perfluorocarbons (Van Liew and Burkard, 1996;Burkard and Van Liew, 1994). The compositions of the two formulations are in Table 1.…”

Bubble Liposome: A Modern Theranostic Approach of New Drug Delivery

“…[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. [24] At last, the shell may improve the wellbeing of bioactive gas conveyance by decreasing coordinate contact between the gas and surrounding blood and tissue.…”