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Pratik Ambekar

Research Assistant

Email

pambekar@apl.washington.edu

Phone

206-543-4081

Publications

2000-present and while at APL-UW

Histotripsy-induced bactericidal activity correlates to size of cavitation cloud in vitro

Ambekar, P.A., Y.-N. Wang, T.D. Khokhlova, G.P.L. Thomas, P.B. Rosnitskiy, K. Contreras, D.F. Leotta, A.D. Maxwell, M. Bruce, S. Pierson, S. Totten, Y.N. Kumar, J. Thiel, K.T. Chan, W.C. Liles, E.P. Dellinger, A. Adedipe, W.L. Monsky, and T.J. Matula, "Histotripsy-induced bactericidal activity correlates to size of cavitation cloud in vitro," IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 71, 1868-1878, doi:10.1109/TUFFC.2024.3476438, 2024.

More Info

9 Oct 2024

Large abscesses are walled-off collections of pus and bacteria that often do not respond to antibiotic therapy. Standard of care involves percutaneous placement of indwelling catheter(s) for drainage, a long and uncomfortable process with high rehospitalization rates. The long-term goal of this work is to develop therapeutic ultrasound approaches to eradicate bacteria within abscesses as a noninvasive therapeutic alternative. Inertial cavitation induced by short pulses of focused ultrasound (histotripsy) is known to generate lethal mechanical damage in bacteria. Prior studies with Escherichia coli (E. coli) in suspension demonstrated that bactericidal effects increase with increasing peak negative amplitude, treatment time, and duty cycle. The current study investigated correlates of bactericidal activity with histotripsy cavitation cloud size. Histotripsy was applied to E. coli suspensions in 10-mL sample vials at 810 kHz, 1.2 MHz, or 3.25 MHz for 40 min. The cavitation activity in the sample vials was separately observed with high-speed photography. The cavitation cloud area was quantified from those images. A linear relationship was observed between bacterial inactivation and cavitation cloud size ( R2 = 0.98 ), regardless of the acoustic parameters (specifically frequency, pulse duration, and power) used to produce the cloud.

Comparative study of histotripsy pulse parameters used to inactivate Escherichia coli in suspension

Ambedkar, P.A., Y.-N. Wang, T. Khokhlova, M. Bruce, D.F. Leotta, S. Totten, A.D. Maxwell, K.T. Chan, W.C. Liles, E.P. Dellinger, W. Monsky, A.A. Adedipe, and T.J. Matula, "Comparative study of histotripsy pulse parameters used to inactivate Escherichia coli in suspension," Ultrasound Med. Biol., 49, 2451-2458, doi:10.1016/j.ultrasmedbio.2023.08.004, 2023.

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1 Dec 2023

Bacterial loads can be effectively reduced using cavitation-mediated focused ultrasound, or histotripsy. In this study, gram-negative bacteria (Escherichia coli) in suspension were used as model bacteria to evaluate the effectiveness of two regimens of histotripsy treatments: cavitation histotripsy (CH) and boiling histotripsy (BH).

The results of this study suggest that both CH and BH can be used to inactivate E. coli in suspension, with the optimal regimen depending on the attainable peak negative focal pressure at the target.

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center
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