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Protein-conjugated microbubbles for the selective targeting of S. aureus biofilms. Biofilm 2022; 4:100074. [PMID: 35340817 PMCID: PMC8942837 DOI: 10.1016/j.bioflm.2022.100074] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/01/2022] [Accepted: 03/06/2022] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is an important human pathogen and a common cause of bloodstream infection. The ability of S. aureus to form biofilms, particularly on medical devices, makes treatment difficult, as does its tendency to spread within the body and cause secondary foci of infection. Prolonged courses of intravenous antimicrobial treatment are usually required for serious S. aureus infections. This work investigates the in vitro attachment of microbubbles to S. aureus biofilms via a novel Affimer protein, AClfA1, which targets the clumping factor A (ClfA) virulence factor – a cell-wall anchored protein associated with surface attachment. Microbubbles (MBs) are micron-sized gas-filled bubbles encapsulated by a lipid, polymer, or protein monolayer or other surfactant-based material. Affimers are small (∼12 kDa) heat-stable binding proteins developed as replacements for antibodies. The binding kinetics of AClfA1 against S. aureus ClfA showed strong binding affinity (KD = 62 ± 3 nM). AClfA1 was then shown to bind S. aureus biofilms under flow conditions both as a free ligand and when bound to microparticles (polymer beads or microbubbles). Microbubbles functionalized with AClfA1 demonstrated an 8-fold increase in binding compared to microbubbles functionalized with an identical Affimer scaffold but lacking the recognition groups. Bound MBs were able to withstand flow rates of 250 μL/min. Finally, ultrasound was applied to burst the biofilm bound MBs to determine whether this would lead to biofilm biomass loss or cell death. Application of a 2.25 MHz ultrasound profile (with a peak negative pressure of 0.8 MPa and consisting of a 22-cycle sine wave, at a pulse repetition rate of 10 kHz) for 2 s to a biofilm decorated with targeted MBs, led to a 25% increase in biomass loss and a concomitant 8% increase in dead cell count. The results of this work show that Affimers can be developed to target S. aureus biofilms and that such Affimers can be attached to contrast agents such as microbubbles or polymer beads and offer potential, with some optimization, for drug-free biofilm treatment.
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Thalji MR, Ibrahim AA, Ali GA. Cutting-edge development in dendritic polymeric materials for biomedical and energy applications. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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The effects of ultrasound-targeted microbubble destruction (UTMD) carrying IL-8 monoclonal antibody on the inflammatory responses and stability of atherosclerotic plaques. Biomed Pharmacother 2019; 118:109161. [DOI: 10.1016/j.biopha.2019.109161] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 06/10/2019] [Accepted: 06/19/2019] [Indexed: 01/01/2023] Open
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Sciallero C, Daglio E, Trucco A. In vivo quantification of ultrasound targeted microbubbles to enhance cancer assessment. CONTRAST MEDIA & MOLECULAR IMAGING 2016; 11:313-8. [PMID: 27157493 DOI: 10.1002/cmmi.1694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 01/27/2016] [Accepted: 03/04/2016] [Indexed: 11/08/2022]
Abstract
Contrast-enhanced ultrasound with targeted microbubble contrast agents is an emerging technique for imaging biological processes at the molecular level. The accumulation of targeted microbubbles at tissue sites overexpressing specific molecular markers increases the backscattered signal for noninvasive evaluations of diseases. The aim of this preliminary study was to combine molecular imaging with an in vivo contrast agent quantification to support the early diagnosis of the pathology and to enhance the assessment of neoplastic tissues. Tumor growth was induced by subcutaneous injection of prostate cancer cells in four rats. Microbubbles targeted to tissue factor (TF) were administered. A vascularized region located in proximity to the tumor and centered around the focus depth was analyzed in each animal. The backscattered signals (i.e. the radio-frequency data) were acquired during two different perfusion conditions to evaluate the contribution of attached microbubbles. After image generation by means of a multi-pulse contrast-enhanced technique, a nonlinear regression method based on the support vector machine was employed to estimate the contrast agent concentrations in cubic voxels (1-mm side length). The number of attached microbubbles per mm(3) was estimated based on a multi-dimensional vector of features extracted from the processed radio-frequency signals. A significant correlation (p < 0.05) between the size of the tumors and the estimated microbubble concentration was found, thus opening the possibility for combining molecular imaging and contrast agent concentration mapping to refine pathology evaluation. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Claudia Sciallero
- Department of Electrical, Electronic, Telecommunications Engineering, and Naval Architecture (DITEN), University of Genoa, 16145, Genoa, Italy
| | - Emanuele Daglio
- Division of Urology, Ospedale Evangelico Internazionale, 16158, Genoa, Italy
| | - Andrea Trucco
- Department of Electrical, Electronic, Telecommunications Engineering, and Naval Architecture (DITEN), University of Genoa, 16145, Genoa, Italy.,Pattern Analysis & Computer Vision, Istituto Italiano di Tecnologia (IIT), 16163, Genoa, Italy
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Shapiro MG, Goodwill PW, Neogy A, Yin M, Foster FS, Schaffer DV, Conolly SM. Biogenic gas nanostructures as ultrasonic molecular reporters. NATURE NANOTECHNOLOGY 2014; 9:311-6. [PMID: 24633522 PMCID: PMC4023545 DOI: 10.1038/nnano.2014.32] [Citation(s) in RCA: 217] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/28/2014] [Indexed: 05/04/2023]
Abstract
Ultrasound is among the most widely used non-invasive imaging modalities in biomedicine, but plays a surprisingly small role in molecular imaging due to a lack of suitable molecular reporters on the nanoscale. Here, we introduce a new class of reporters for ultrasound based on genetically encoded gas nanostructures from microorganisms, including bacteria and archaea. Gas vesicles are gas-filled protein-shelled compartments with typical widths of 45-250 nm and lengths of 100-600 nm that exclude water and are permeable to gas. We show that gas vesicles produce stable ultrasound contrast that is readily detected in vitro and in vivo, that their genetically encoded physical properties enable multiple modes of imaging, and that contrast enhancement through aggregation permits their use as molecular biosensors.
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Affiliation(s)
- Mikhail G. Shapiro
- Miller Research Institute, University of California at Berkeley, Berkeley, CA, USA 94720
- Department of Bioengineering, University of California at Berkeley, Berkeley, CA, USA 94720
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA 94720
- Correspondence to: M.G.S.:
| | - Patrick W. Goodwill
- Department of Bioengineering, University of California at Berkeley, Berkeley, CA, USA 94720
- Department of Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, CA, USA 94720
| | - Arkosnato Neogy
- Department of Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, CA, USA 94720
| | - Melissa Yin
- Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada, M4N 3M5
| | - F. Stuart Foster
- Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada, M4N 3M5
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, M4N 3M5
| | - David V. Schaffer
- Department of Bioengineering, University of California at Berkeley, Berkeley, CA, USA 94720
- Department of Chemical and Biomolecular Engineering, University of California at Berkeley, Berkeley, CA, USA 94720
| | - Steven M. Conolly
- Department of Bioengineering, University of California at Berkeley, Berkeley, CA, USA 94720
- Department of Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, CA, USA 94720
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Laing ST, McPherson DD. Cardiovascular therapeutic uses of targeted ultrasound contrast agents. Cardiovasc Res 2009; 83:626-35. [PMID: 19581314 DOI: 10.1093/cvr/cvp192] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The therapeutic use of ultrasound contrast agents (UCAs) is an emerging methodology with high potential for enhanced directed therapeutic gene, bioactive gas, drug, and stem cell delivery. Ultrasound-targeted microbubble destruction has already demonstrated feasibility for plasmid DNA delivery. Similarly, therapeutic ultrasound for thrombolysis treatment has been taken into the clinical setting, and the addition of UCAs for therapeutic delivery or enhanced effect through cavitation is a natural progression to this investigation. However, as with any new technique, safety needs to be first demonstrated before translation into clinical practice. This review article will focus on the development of UCAs for cardiac and vascular therapeutics as well as the limitations/concerns for the use of therapeutic ultrasound in clinical medicine in order to lay a foundation for investigators planning to enter this exciting field or for those who want to broaden their understanding.
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Affiliation(s)
- Susan T Laing
- Division of Cardiology, Department of Internal Medicine, University of Texas Health Sciences Center-Houston, 6431 Fannin Street, MSB 1.246, Houston, TX 77030, USA.
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Abstract
The definition of molecular imaging provided by the Society of Nuclear Medicine is "the visualization, characterization and measurement of biological processes at the molecular and cellular levels in humans and other living systems". This review gives an overview of the technologies available for and the potential benefits from molecular imaging at the preclinical stage. It focuses on the use of imaging probes based on bioconjugates and for reasons of brevity confines itself to discussion of applications in the field of oncology, although molecular imaging can be equally useful in many fields including cardiovascular medicine, neurosciences, infection, and others.
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Affiliation(s)
- Stephen Mather
- Barts and The London Queen Mary's School of Medicine and Dentistry, Centre for Cancer Imaging Institute of Cancer and the CR-UK Clinical Centre, St. Bartholomew's Hos, United Kingdon.
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