文獻名： Phospholipid bilayer responses to ultrasound-induced microbubble cavitation phenomena
作者： Martin P.Walsha, Rohan V.Tikekarb, Nitin Nitinc, Steven Wrenna
aDepartment of Chemical and Biological Engineering, Drexel University, Philadelphia, PA, 19104, USA
bDepartment of Nutrition and Food Science, University of Maryland, College Park, MD, 20740, USA
cDepartment of Food Science and Technology, University of California, Davis, CA, 95616, USA
摘要：Using liposomal bilayers as a model for bacterial cell membranes, this study investigates the extents to which high-frequency (1.0 and 3.3 MHz) ultrasound-induced microbubble cavitation phenomena are effective for bacterial inactivation. Förster Resonance Energy Transfer (FRET), acoustic scattering and a mathematical model were used to quantify the proximity of microbubbles to liposomes, establish if liposomes affect microbubble cavitation and propose bilayer alterations' mechanisms. Addition of a positive charge on microbubbles increased their proximity to liposomes through electrostatic attraction, however, dampened microbubble's oscillation compared to freely-floating microbubbles. Alleviation of energy transfer due to phospholipid mixing between microbubbles and liposomes established that close-proximity is necessary for bilayer alterations. Approximately 19% mixing of phospholipids was observed at 3.3 MHz due to microstreaming from stable cavitation, while inertial cavitation at 1.0 MHz increased this mixing to 50%. This method can damage bacterial membrane; but, whether bacterial defense mechanisms can attenuate this effect remains to be understood.
關鍵詞：Ultrasound; Microbubble; Cavitation; Sonoporation; Electrostatic interaction; Liposome
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