OXYGEN-TRANSPORT TO TISSUE BY PERSISTENT BUBBLES - THEORY AND SIMULATIONS

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 O-2 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 N-2 to dilute gas X and slow its outward diffusion. A 6-mu m-diam bubble carries 0.11 pl of O-2 during the breathing of pure O-2 so 4.6 X 10 degrees bubbles/ml in the blood will supply a normal arteriovenous difference. In conditions used for hyperbaric O-2 therapy, a bubble carries similar to 0.26 pl of2 O-2. Stabilized bubbles have the potential to transport O-2 efficiently; they release O-2 to tissue at high Po-2 and require injection of only small amounts of a foreign substance.