Effect of Anesthetic Carrier Gas on In Vivo Circulation Times of Intravenously Administered Phospholipid Oxygen Microbubbles in Rats.

Autor:	Durham PG; Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA; Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC, USA., Upadhyay A; Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA., Navarro-Becerra JA; Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA., Moon RE; Departments of Anesthesiology and Medicine, Center for Hyperbaric Medicine and Environmental Physiology, Duke University, NC, USA., Borden MA; Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA., Dayton PA; Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA; Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC, USA., Papadopoulou V; Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC, USA. Electronic address: papadopoulou@unc.edu.
Jazyk:	angličtina
Zdroj:	Ultrasound in medicine & biology [Ultrasound Med Biol] 2023 Aug; Vol. 49 (8), pp. 1861-1866. Date of Electronic Publication: 2023 May 27.
DOI:	10.1016/j.ultrasmedbio.2023.04.016
Abstrakt:	Objective: For the treatment of tumor hypoxia, microbubbles comprising oxygen as a majority component of the gas core with a stabilizing shell may be used to deliver and release oxygen locally at the tumor site through ultrasound destruction. Previous work has revealed differences in circulation half-life in vivo for perfluorocarbon-filled microbubbles, typically used as ultrasound imaging contrast agents, as a function of anesthetic carrier gas. These differences in circulation time in vivo were likely due to gas diffusion as a function of anesthetic carrier gas, among other variables. This work has motivated studies to evaluate the effect of anesthetic carrier gas on oxygen microbubble circulation dynamics. Methods: Circulation time for oxygen microbubbles was derived from ultrasound image intensity obtained during longitudinal kidney imaging. Studies were constructed for rats anesthetized on inhaled isoflurane with either pure oxygen or medical air as the anesthetic carrier gas. Results: Results indicated that oxygen microbubbles were highly visible via contrast-specific imaging. Marked signal enhancement and duration differences were observed between animals breathing air and oxygen. Perhaps counterintuitively, oxygen microbubbles disappeared from circulation significantly faster when the animals were breathing pure oxygen compared with medical air. This may be explained by nitrogen counterdiffusion from blood into the bubble, effectively changing the gas composition of the core, as has been observed in perfluorocarbon core microbubbles. Conclusion: Our findings suggest that the apparent longevity and persistence of oxygen microbubbles in circulation may not be reflective of oxygen delivery when the animal is anesthetized breathing air. Competing Interests: Conflict of interest P.G.D., M.B., P.A.D. and V.P. are all inventors or co-inventors on patents related to oxygen microbubble formulation and/or use. M.B. is also a founder and the chief scientific officer of Respirogen Inc. (Boulder, CO, USA). The other authors declare no competing interests. (Copyright © 2023 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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