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Hosseindokht Z, Kolahdouz M, Hajikhani B, Sasanpour P. Photoacoustic based evaluation of viscoelastic properties of Gram-negative and Gram-positive bacterial colonies. Sci Rep 2023; 13:14656. [PMID: 37670076 PMCID: PMC10480163 DOI: 10.1038/s41598-023-41663-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/29/2023] [Indexed: 09/07/2023] Open
Abstract
Mechanical properties of bacterial colonies are crucial considering both addressing their pathogenic effects and exploring their potential applications. Viscoelasticity is a key mechanical property with major impacts on the cell shapes and functions, which reflects the information about the cell envelope constituents. Hereby, we have proposed the application of photoacoustic viscoelasticity (PAVE) for studying the rheological properties of bacterial colonies. In this regard, we employed an intensity-modulated laser beam as the excitation source followed by the phase delay measurement between the generated PA signal and the reference for the characterization of colonies of two different types of Gram-positive and Gram-negative bacteria. The results of our study show that the colony of Staphylococcus aureus as Gram-positive bacteria has a significantly higher viscoelasticity ratio compared to that value for Acinetobacter baumannii as Gram-negative bacteria (77% difference). This may be due to the differing cell envelope structure between the two species, but we cannot rule out effects of biofilm formation in the colonies. Furthermore, a lumped model has been provided for the mechanical properties of bacterial colonies.
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Affiliation(s)
- Zahra Hosseindokht
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Mohammadreza Kolahdouz
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran.
| | - Bahareh Hajikhani
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Pezhman Sasanpour
- Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Zheng Q, Wang H, Yang H, Jiang H, Chen Z, Lu Y, Feng PXL, Xie H. Thin ceramic PZT dual- and multi-frequency pMUT arrays for photoacoustic imaging. MICROSYSTEMS & NANOENGINEERING 2022; 8:122. [PMID: 36407887 PMCID: PMC9668999 DOI: 10.1038/s41378-022-00449-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 08/07/2022] [Accepted: 08/16/2022] [Indexed: 06/16/2023]
Abstract
Miniaturized ultrasonic transducer arrays with multiple frequencies are key components in endoscopic photoacoustic imaging (PAI) systems to achieve high spatial resolution and large imaging depth for biomedical applications. In this article, we report on the development of ceramic thin-film PZT-based dual- and multi-frequency piezoelectric micromachined ultrasonic transducer (pMUT) arrays and the demonstration of their PAI applications. With chips sized 3.5 mm in length or 10 mm in diameter, square and ring-shaped pMUT arrays incorporating as many as 2520 pMUT elements and multiple frequencies ranging from 1 MHz to 8 MHz were developed for endoscopic PAI applications. Thin ceramic PZT with a thickness of 9 μm was obtained by wafer bonding and chemical mechanical polishing (CMP) techniques and employed as the piezoelectric layer of the pMUT arrays, whose piezoelectric constant d 31 was measured to be as high as 140 pm/V. Benefiting from this high piezoelectric constant, the fabricated pMUT arrays exhibited high electromechanical coupling coefficients and large vibration displacements. In addition to electrical, mechanical, and acoustic characterization, PAI experiments with pencil leads embedded into an agar phantom were conducted with the fabricated dual- and multi-frequency pMUT arrays. Photoacoustic signals were successfully detected by pMUT elements with different frequencies and used to reconstruct single and fused photoacoustic images, which clearly demonstrated the advantages of using dual- and multi-frequency pMUT arrays to provide comprehensive photoacoustic images with high spatial resolution and large signal-to-noise ratio simultaneously.
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Affiliation(s)
- Qincheng Zheng
- School of Integrated Circuits and Electronics, Beijing Institute of Technology (BIT), 100081 Beijing, China
| | - Haoran Wang
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611 USA
| | - Hao Yang
- Department of Medical Engineering, University of South Florida, Tampa, FL 33620 USA
| | - Huabei Jiang
- Department of Medical Engineering, University of South Florida, Tampa, FL 33620 USA
| | - Zhenfang Chen
- MEMS Engineering and Materials Inc., Sunnyvale, CA 94086 USA
| | - Yao Lu
- School of Integrated Circuits and Electronics, Beijing Institute of Technology (BIT), 100081 Beijing, China
| | - Philip X.-L. Feng
- Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL 32611 USA
| | - Huikai Xie
- School of Integrated Circuits and Electronics, Beijing Institute of Technology (BIT), 100081 Beijing, China
- BIT Chongqing Institute of Microelectronics and Microsystems, 400030 Chongqing, China
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Zhang D, Li R, Lou X, Luo J. Hessian filter-assisted full diameter at half maximum (FDHM) segmentation and quantification method for optical-resolution photoacoustic microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:4606-4620. [PMID: 36187248 PMCID: PMC9484426 DOI: 10.1364/boe.468685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/28/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
Optical-resolution photoacoustic microscopy has been validated as an ideal tool for angiographic studies. Quantitative vascular analysis reveals critical information where vessel segmentation plays the key step. The comm-only used Hessian filter method suffers from varying accuracy due to the multi-kernel strategy. In this work, we developed a Hessian filter-assisted, adaptive thresholding vessel segmentation algorithm. Its performance is validated by a digital phantom and in vivo images which demonstrates a superior and consistent accuracy of 0.987 regardless of kernel selection. Subtle vessel change detection is further tested in two longitudinal studies on blood pressure agents. In the antihypotensive case, the proposed method detected a twice larger vasoconstriction over the Hessian filter method. In the antihypertensive case, the proposed method detected a vasodilation of 21.2%, while the Hessian filter method failed in change detection. The proposed algorithm may further push the limit of quantitative imaging on angiographic applications.
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Affiliation(s)
- Dong Zhang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
- Department of Radiology,
Chinese PLA General Hospital, Beijing
100853, China
| | - Ran Li
- School of Basic Medical Sciences,
North China University of Science and
Technology, Tangshan, Hebei 063210, China
| | - Xin Lou
- Department of Radiology,
Chinese PLA General Hospital, Beijing
100853, China
| | - Jianwen Luo
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
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Zhu X, Huang Q, DiSpirito A, Vu T, Rong Q, Peng X, Sheng H, Shen X, Zhou Q, Jiang L, Hoffmann U, Yao J. Real-time whole-brain imaging of hemodynamics and oxygenation at micro-vessel resolution with ultrafast wide-field photoacoustic microscopy. LIGHT, SCIENCE & APPLICATIONS 2022; 11:138. [PMID: 35577780 PMCID: PMC9110749 DOI: 10.1038/s41377-022-00836-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/27/2022] [Accepted: 05/04/2022] [Indexed: 05/10/2023]
Abstract
High-speed high-resolution imaging of the whole-brain hemodynamics is critically important to facilitating neurovascular research. High imaging speed and image quality are crucial to visualizing real-time hemodynamics in complex brain vascular networks, and tracking fast pathophysiological activities at the microvessel level, which will enable advances in current queries in neurovascular and brain metabolism research, including stroke, dementia, and acute brain injury. Further, real-time imaging of oxygen saturation of hemoglobin (sO2) can capture fast-paced oxygen delivery dynamics, which is needed to solve pertinent questions in these fields and beyond. Here, we present a novel ultrafast functional photoacoustic microscopy (UFF-PAM) to image the whole-brain hemodynamics and oxygenation. UFF-PAM takes advantage of several key engineering innovations, including stimulated Raman scattering (SRS) based dual-wavelength laser excitation, water-immersible 12-facet-polygon scanner, high-sensitivity ultrasound transducer, and deep-learning-based image upsampling. A volumetric imaging rate of 2 Hz has been achieved over a field of view (FOV) of 11 × 7.5 × 1.5 mm3 with a high spatial resolution of ~10 μm. Using the UFF-PAM system, we have demonstrated proof-of-concept studies on the mouse brains in response to systemic hypoxia, sodium nitroprusside, and stroke. We observed the mouse brain's fast morphological and functional changes over the entire cortex, including vasoconstriction, vasodilation, and deoxygenation. More interestingly, for the first time, with the whole-brain FOV and micro-vessel resolution, we captured the vasoconstriction and hypoxia simultaneously in the spreading depolarization (SD) wave. We expect the new imaging technology will provide a great potential for fundamental brain research under various pathological and physiological conditions.
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Affiliation(s)
- Xiaoyi Zhu
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Qiang Huang
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
- Department of Pediatric Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Anthony DiSpirito
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Tri Vu
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Qiangzhou Rong
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Xiaorui Peng
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Huaxin Sheng
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Xiling Shen
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Qifa Zhou
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Laiming Jiang
- Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, 90089, USA.
| | - Ulrike Hoffmann
- Department of Anesthesiology, Duke University, Durham, NC, 27708, USA.
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
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