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Andrew Brayman

Principal Physicist





Research Interests

Acoustic Cavitation, Ultrasonic Drug Delivery, Microbubble Dynamics


Dr. Brayman's research interests include acoustic cavitation, ultrasonic delivery of non-viral gene vectors and drugs, acoustically-activated microbubble interactions with cells and tissues, non-thermal therapeutic application of ultrasound, and thermal ablation of tissues with high-frequency focused ultrasound.

Topics of his current research projects include:

- Image-guided HIFU for tumor ablation
- Dynamics of contrast agent microbubbles in intravascular environments
- Ultrasound- and microbubble-enhanced non-viral gene delivery for the treatment of hemophilia A and B
- The influence of microbubble shell loading on acoustically-induced bubble dynamics

Dr. Brayman joined APL-UW's Center for Industrial and Medical Ultrasound in 1999.


B.S. Biology, SUNY, Fredonia, 1976

M.S. Plant Physiology, SUNY, College of Environ. Sci. & Forestry/Syracuse University, 1980

Ph.D. Plant Physiology & Biophysics, SUNY, College of Environ. Sci. & Forestry/Syracuse University, 1985


Non-invasive Treatment of Abscesses with Ultrasound

Abscesses are walled-off collections of fluid and bacteria within the body. They are common complications of surgery, trauma, and systemic infections. Typical treatment is the surgical placement of a drainage catheter to drain the abscess fluid over several days. Dr. Keith Chan and researchers at APL-UW's Center for Industrial + Medical Ultrasound are exploring how to treat abscesses non-invasively, that is, from outside the body, with high-intensity focused ultrasound (HIFU). This experimental therapy could reduce pain, radiation exposure, antibiotic use, and costs for patients with abscesses. Therapeutic ultrasound could also treat abscesses too small or inaccessible for conventional drainage.

20 Jun 2016

Flow Cytometry Techniques Advance Microbubble Science

Researchers at the Center for Industrial and Medical Ultrasound (CIMU) are measuring the physical properties of ultrasound contrast agents — tiny gas bubbles several microns in diameter used to increase sonogram imaging efficiency in the body. When injected to the general circulation they can act as probes and beacons within the body, and can carry and deploy chemotherapeutic payloads.

CIMU researchers have developed a hybrid instrument that combines an off-the-shelf flow cytometer with an acoustic transducer. The cytometer's laser interrogation counts and measures the bubbles while the acoustic interrogation reveals the bubbles' viscosity and elasticity at megahertz frequencies.

5 Dec 2013


2000-present and while at APL-UW

Inactivation of planktonic Escherichia coli by focused 1-MHz ultrasound pulses with shocks: Efficacy and kinetics upon volume scale-up

Brayman, A.A., B.E. MacConaghy, Y.-N. Wang, K.T. Chan, W.L. Monsky, V.P. Chernikov, S.V. Buravkov, V.A. Khokhlova, and T.J. Matula, "Inactivation of planktonic Escherichia coli by focused 1-MHz ultrasound pulses with shocks: Efficacy and kinetics upon volume scale-up," Ultrasound Med. Biol., 44, 1996-2008, doi:10.1016/j.ultrasmedbio.2018.05.010, 2018.

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1 Sep 2018

This study addresses inactivation of E. coli in either 5- or 10-mL volumes, which were 50- to 100-fold greater than used in an earlier study (Brayman et al. 2017). Cells were treated with 1-MHz pulsed high-intensity focused ultrasound (10 cycles, 2-kHz repetition frequency, +65/–12.8 MPa focal pressures). The surviving fraction was assessed by coliform assay, and inactivation demonstrated curvilinear kinetics. The reduction of surviving fraction to 50% required 2.5 or 6 min in 5- or 10-mL samples, respectively. Exposure of 5 mL for 20 min reduced the surviving fraction to ~1%; a similar exposure of 10-mL samples reduced the surviving fraction to ~10%. Surviving cells from 5-min exposures appeared normal under light microscopy, with minimal debris; after 20 min, debris dominated. Transmission electron microscopy images of insonated samples showed some undamaged cells, a few damaged but largely intact cells and comminuted debris. Cellular damage associated with substantive but incomplete levels of inactivation can be variable, ranging from membrane holes tens of nanometers in diameter to nearly complete comminution.

Ultrasound-based cell sorting with microbubbles: A feasibility study

Matula, T.J. O.A. Sapozhnikov, L.A. Ostrovsky, A.A. Brayan, J. Kucewicz, B.E. MacConaghy, and D. De Raad, "Ultrasound-based cell sorting with microbubbles: A feasibility study," J. Acoust. Soc. Am., 144, doi:10.1121/1.5044405, 2018.

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1 Jul 2018

The isolation and sorting of cells is an important process in research and hospital labs. Most large research and commercial labs incorporate fluorescently or magnetically labeled antibodies adherent to cell surface antigens for cell identification and separation. In this paper, a process is described that merges biochemical labeling with ultrasound-based separation. Instead of lasers and fluorophore tags, or magnets and magnetic particle tags, the technique uses ultrasound and microbubble tags. Streptavidin-labeled microbubbles were mixed with a human acute lymphoblastic leukemia cell line, CCL 119, conjugated with biotinylated anti-CD7 antibodies. Tagged cells were forced under ultrasound, and their displacement and velocity quantified. Differential displacement in a flow stream was quantified against erythrocytes, which showed almost no displacement under ultrasound. A model for the acoustic radiation force on the conjugated pairs compares favorably with observations. This technology may improve on current time-consuming and costly purification procedures.

Inactivation of planktonic Escherichia coli by focused 2-MHz ultrasound

Brayman, A.A., B.E. MacConaghy, Y.-N. Wang, K.T. Chan, W.L. Monsky, A.J. McClenny, and T.J. Matula, "Inactivation of planktonic Escherichia coli by focused 2-MHz ultrasound," Ultrasound Med. Biol., 43, 1476-1485, doi:10.1016/j.ultrasmedbio.2017.03.009, 2017.

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1 Jul 2017

This study was motivated by the desire to develop a non-invasive means to treat abscesses, and represents the first steps toward that goal. Non-thermal, high-intensity focused ultrasound (HIFU) was used to inactivate Escherichia coli (~1 x 109

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Systems, Devices, and Methods for Separating, Concentrating, and/or Differentiating Between Cells from a Cell Sample

Embodiments are generally related to differentiating and/or separating portions of a sample that are of interest from the remainder of the sample. Embodiments may be directed towards separating cells of interest from a cell sample. In some embodiments, acoustic impedances of the cells of interest may be modified. For example, the acoustic properties of the cells of interest may be modified by attaching bubbles to the cells of interest. The cell sample may then be subjected to an acoustic wave. The cells of interest may be differentiated and/or separated from the remainder of the sample based on relative displacements and/or volumetric changes experienced by the cells of interest in response thereto. The cells of interest may be separated using a standing wave and sorted into separate channels of a flow cell. Optionally, the cells may be interrogated by a light source and differentiated by signals generated in response thereto.

Patent Number: 9,645,080

Tom Matula, Andrew Brayman, Oleg Sapozhnikov, Brian MacConaghy, Jarred Swalwell, Camilo Perez


9 May 2017

Ultrasonic Persistence Imaging of Tissues in Which Acoustic Microbubble Destruction has Occurred

Record of Invention Number: 46066

Andrew Brayman


3 May 2012

Ultrasound Target Vessel Occlusion Using Microbubbles

Patent Number: US 7,591,996 B2

Joo Ha Hwang, Andrew Brayman

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22 Sep 2009

Selective occlusion of a blood vessel is achieved by selectively damaging endothelial cells at a target location in the blood vessel, resulting in the formation of a fibrin clot proximate to the damaged endothelial cells. Additional fibrinogen can then be introduced into the blood vessel if occlusion is not achieved, as the fibrinogen is converted to fibrin by enzymes released by the exposed thrombogenic tissue and activated platelets. Endothelial cells are selectively damaged using thermal effects induced by ultrasound, by mechanical effects induced by ultrasound, or by mechanical effects produced by a tool introduced into the blood vessel (such as catheter-based tool). A particularly preferred technique for selectively damaging endothelial cells involves introducing an ultrasound activatable agent into the blood vessel, and causing cavitation in that agent using pulses of high-intensity focused ultrasound having a duration insufficient to induce thermal damage in adjacent perivascular tissue.

More Inventions

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