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Miller ADC, Chowdhury SP, Hanson HW, Linderman SK, Ghasemi HI, Miller WD, Morrissey MA, Richardson CD, Gardner BM, Mukherjee A. Engineering water exchange is a safe and effective method for magnetic resonance imaging in diverse cell types. J Biol Eng 2024; 18:30. [PMID: 38649904 PMCID: PMC11035135 DOI: 10.1186/s13036-024-00424-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/08/2024] [Indexed: 04/25/2024] Open
Abstract
Aquaporin-1 (Aqp1), a water channel, has garnered significant interest for cell-based medicine and in vivo synthetic biology due to its ability to be genetically encoded to produce magnetic resonance signals by increasing the rate of water diffusion in cells. However, concerns regarding the effects of Aqp1 overexpression and increased membrane diffusivity on cell physiology have limited its widespread use as a deep-tissue reporter. In this study, we present evidence that Aqp1 generates strong diffusion-based magnetic resonance signals without adversely affecting cell viability or morphology in diverse cell lines derived from mice and humans. Our findings indicate that Aqp1 overexpression does not induce ER stress, which is frequently associated with heterologous expression of membrane proteins. Furthermore, we observed that Aqp1 expression had no detrimental effects on native biological activities, such as phagocytosis, immune response, insulin secretion, and tumor cell migration in the analyzed cell lines. These findings should serve to alleviate any lingering safety concerns regarding the utilization of Aqp1 as a genetic reporter and should foster its broader application as a noninvasive reporter for in vivo studies.
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Affiliation(s)
- Austin D C Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Soham P Chowdhury
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Hadley W Hanson
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Sarah K Linderman
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Hannah I Ghasemi
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Wyatt D Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Meghan A Morrissey
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Chris D Richardson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Brooke M Gardner
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Arnab Mukherjee
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA.
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA.
- Department of Bioengineering, University of California, Santa Barbara, CA, 93106, USA.
- Department of Chemistry, University of California, Santa Barbara, CA, 93106, USA.
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.
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2
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Pan T, Su L, Zhang Y, Xu L, Chen Y. Advances in Bio-Optical Imaging Systems for Spatiotemporal Monitoring of Intestinal Bacteria. Mol Nutr Food Res 2024; 68:e2300760. [PMID: 38491399 DOI: 10.1002/mnfr.202300760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 01/26/2024] [Indexed: 03/18/2024]
Abstract
Vast and complex intestinal communities are regulated and balanced through interactions with their host organisms, and disruption of gut microbial balance can cause a variety of diseases. Studying the mechanisms of pathogenic intestinal flora in the host and early detection of bacterial translocation and colonization can guide clinical diagnosis, provide targeted treatments, and improve patient prognosis. The use of in vivo imaging techniques to track microorganisms in the intestine, and study structural and functional changes of both cells and proteins, may clarify the governing equilibrium between the flora and host. Despite the recent rapid development of in vivo imaging of intestinal microecology, determining the ideal methodology for clinical use remains a challenge. Advances in optics, computer technology, and molecular biology promise to expand the horizons of research and development, thereby providing exciting opportunities to study the spatio-temporal dynamics of gut microbiota and the origins of disease. Here, this study reviews the characteristics and problems associated with optical imaging techniques, including bioluminescence, conventional fluorescence, novel metabolic labeling methods, nanomaterials, intelligently activated imaging agents, and photoacoustic (PA) imaging. It hopes to provide a valuable theoretical basis for future bio-intelligent imaging of intestinal bacteria.
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Affiliation(s)
- Tongtong Pan
- Hepatology Diagnosis and Treatment Center, The First Affiliated Hospital of Wenzhou Medical University & Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Ouhai District, Wenzhou, Zhejiang, 325035, China
| | - Lihuang Su
- The First Affiliated Hospital of Wenzhou Medical University, Ouhai District, Wenzhou, Zhejiang, 325035, China
| | - Yiying Zhang
- Alberta Institute, Wenzhou Medical University, Ouhai District, Wenzhou, Zhejiang, 325035, China
| | - Liang Xu
- Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China
| | - Yongping Chen
- Hepatology Diagnosis and Treatment Center, The First Affiliated Hospital of Wenzhou Medical University & Zhejiang Provincial Key Laboratory for Accurate Diagnosis and Treatment of Chronic Liver Diseases, Ouhai District, Wenzhou, Zhejiang, 325035, China
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3
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Miller ADC, Chowdhury SP, Hanson HW, Linderman SK, Ghasemi HI, Miller WD, Morrissey MA, Richardson CD, Gardner BM, Mukherjee A. Engineering water exchange is a safe and effective method for magnetic resonance imaging in diverse cell types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566095. [PMID: 37986852 PMCID: PMC10659288 DOI: 10.1101/2023.11.07.566095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Aquaporin-1 (Aqp1), a water channel, has garnered significant interest for cell-based medicine and in vivo synthetic biology due to its ability to be genetically encoded to produce magnetic resonance signals by increasing the rate of water diffusion in cells. However, concerns regarding the effects of Aqp1 overexpression and increased membrane diffusivity on cell physiology have limited its widespread use as a deep-tissue reporter. In this study, we present evidence that Aqp1 generates strong diffusion-based magnetic resonance signals without adversely affecting cell viability or morphology in diverse cell lines derived from mice and humans. Our findings indicate that Aqp1 overexpression does not induce ER stress, which is frequently associated with heterologous expression of membrane proteins. Furthermore, we observed that Aqp1 expression had no detrimental effects on native biological activities, such as phagocytosis, immune response, insulin secretion, and tumor cell migration in the analyzed cell lines. These findings should serve to alleviate any lingering safety concerns regarding the utilization of Aqp1 as a genetic reporter and should foster its broader application as a noninvasive reporter for in vivo studies.
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Affiliation(s)
- Austin D C Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Soham P Chowdhury
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Hadley W Hanson
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Sarah K Linderman
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Hannah I Ghasemi
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Wyatt D Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Meghan A Morrissey
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Chris D Richardson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Brooke M Gardner
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Arnab Mukherjee
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
- Department of Bioengineering, University of California, Santa Barbara, CA 93106, USA
- Department of Chemistry, University of California, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
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4
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Dan Q, Jiang X, Wang R, Dai Z, Sun D. Biogenic Imaging Contrast Agents. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207090. [PMID: 37401173 PMCID: PMC10477908 DOI: 10.1002/advs.202207090] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 06/08/2023] [Indexed: 07/05/2023]
Abstract
Imaging contrast agents are widely investigated in preclinical and clinical studies, among which biogenic imaging contrast agents (BICAs) are developing rapidly and playing an increasingly important role in biomedical research ranging from subcellular level to individual level. The unique properties of BICAs, including expression by cells as reporters and specific genetic modification, facilitate various in vitro and in vivo studies, such as quantification of gene expression, observation of protein interactions, visualization of cellular proliferation, monitoring of metabolism, and detection of dysfunctions. Furthermore, in human body, BICAs are remarkably helpful for disease diagnosis when the dysregulation of these agents occurs and can be detected through imaging techniques. There are various BICAs matched with a set of imaging techniques, including fluorescent proteins for fluorescence imaging, gas vesicles for ultrasound imaging, and ferritin for magnetic resonance imaging. In addition, bimodal and multimodal imaging can be realized through combining the functions of different BICAs, which helps overcome the limitations of monomodal imaging. In this review, the focus is on the properties, mechanisms, applications, and future directions of BICAs.
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Affiliation(s)
- Qing Dan
- Shenzhen Key Laboratory for Drug Addiction and Medication SafetyDepartment of UltrasoundInstitute of Ultrasonic MedicinePeking University Shenzhen HospitalShenzhen Peking University‐The Hong Kong University of Science and Technology Medical CenterShenzhen518036P. R. China
| | - Xinpeng Jiang
- Department of Biomedical EngineeringCollege of Future TechnologyPeking UniversityBeijing100871P. R. China
| | - Run Wang
- Shenzhen Key Laboratory for Drug Addiction and Medication SafetyDepartment of UltrasoundInstitute of Ultrasonic MedicinePeking University Shenzhen HospitalShenzhen Peking University‐The Hong Kong University of Science and Technology Medical CenterShenzhen518036P. R. China
| | - Zhifei Dai
- Department of Biomedical EngineeringCollege of Future TechnologyPeking UniversityBeijing100871P. R. China
| | - Desheng Sun
- Shenzhen Key Laboratory for Drug Addiction and Medication SafetyDepartment of UltrasoundInstitute of Ultrasonic MedicinePeking University Shenzhen HospitalShenzhen Peking University‐The Hong Kong University of Science and Technology Medical CenterShenzhen518036P. R. China
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5
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Zeng W, Yue X, Dai Z. Ultrasound contrast agents from microbubbles to biogenic gas vesicles. MEDICAL REVIEW (2021) 2023; 3:31-48. [PMID: 37724107 PMCID: PMC10471104 DOI: 10.1515/mr-2022-0020] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/11/2022] [Indexed: 09/20/2023]
Abstract
Microbubbles have been the earliest and most widely used ultrasound contrast agents by virtue of their unique features: such as non-toxicity, intravenous injectability, ability to cross the pulmonary capillary bed, and significant enhancement of echo signals for the duration of the examination, resulting in essential preclinical and clinical applications. The use of microbubbles functionalized with targeting ligands to bind to specific targets in the bloodstream has further enabled ultrasound molecular imaging. Nevertheless, it is very challenging to utilize targeted microbubbles for molecular imaging of extravascular targets due to their size. A series of acoustic nanomaterials have been developed for breaking free from this constraint. Especially, biogenic gas vesicles, gas-filled protein nanostructures from microorganisms, were engineered as the first biomolecular ultrasound contrast agents, opening the door for more direct visualization of cellular and molecular function by ultrasound imaging. The ordered protein shell structure and unique gas filling mechanism of biogenic gas vesicles endow them with excellent stability and attractive acoustic responses. What's more, their genetic encodability enables them to act as acoustic reporter genes. This article reviews the upgrading progresses of ultrasound contrast agents from microbubbles to biogenic gas vesicles, and the opportunities and challenges for the commercial and clinical translation of the nascent field of biomolecular ultrasound.
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Affiliation(s)
- Wenlong Zeng
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Xiuli Yue
- School of Environment, Harbin Institute of Technology, Harbin, China
| | - Zhifei Dai
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
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6
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Microbiota in vivo imaging approaches to study host-microbe interactions in preclinical and clinical setting. Heliyon 2022; 8:e12511. [PMID: 36593827 PMCID: PMC9803719 DOI: 10.1016/j.heliyon.2022.e12511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 10/14/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
In vivo imaging in preclinical and clinical settings can enhance knowledge of the host-microbiome interactions. Imaging techniques are a crucial node between findings at the molecular level and clinical implementation in diagnostics and therapeutics. The purpose of this study was to review existing knowledge on the microbiota in the field of in vivo imaging and provide guidance for future research, emphasizing the critical role that molecular imaging plays in increasing understanding of the host-microbe interaction. Preclinical microbiota animal models lay the foundation for the clinical translatability of novel microbiota-based therapeutics. Adopting animal models in which factors such as host genetic landscape, microbiota profile, and diet can be controlled enables investigating how the microbiota contributes to immunological dysregulation and inflammatory disorders. Current preclinical imaging of gut microbiota relies on models where the bacteria can be isolated, labelled, and re-administered. In vivo, optical imaging, ultrasound and magnetic resonance imaging define the bacteria's biodistribution in preclinical models, whereas nuclear imaging investigates bacterial metabolic activity. For the clinical investigation of microbe-host interactions, molecular nuclear imaging is increasingly becoming a promising approach. Future microbiota research should develop selective imaging probes to investigate in vivo microbiota profiles and individual strains of specific microbes. Preclinical knowledge can be translated into the molecular imaging field with great opportunities for studying the microbiome.
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Abstract
The authors define molecular imaging, according to the Society of Nuclear Medicine and Molecular Imaging, as the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans and other living systems. Although practiced for many years clinically in nuclear medicine, expansion to other imaging modalities began roughly 25 years ago and has accelerated since. That acceleration derives from the continual appearance of new and highly relevant animal models of human disease, increasingly sensitive imaging devices, high-throughput methods to discover and optimize affinity agents to key cellular targets, new ways to manipulate genetic material, and expanded use of cloud computing. Greater interest by scientists in allied fields, such as chemistry, biomedical engineering, and immunology, as well as increased attention by the pharmaceutical industry, have likewise contributed to the boom in activity in recent years. Whereas researchers and clinicians have applied molecular imaging to a variety of physiologic processes and disease states, here, the authors focus on oncology, arguably where it has made its greatest impact. The main purpose of imaging in oncology is early detection to enable interception if not prevention of full-blown disease, such as the appearance of metastases. Because biochemical changes occur before changes in anatomy, molecular imaging-particularly when combined with liquid biopsy for screening purposes-promises especially early localization of disease for optimum management. Here, the authors introduce the ways and indications in which molecular imaging can be undertaken, the tools used and under development, and near-term challenges and opportunities in oncology.
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Affiliation(s)
- Steven P. Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G. Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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8
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Peng C, Chen M, Spicer JB, Jiang X. Acoustics at the nanoscale (nanoacoustics): A comprehensive literature review.: Part II: Nanoacoustics for biomedical imaging and therapy. SENSORS AND ACTUATORS. A, PHYSICAL 2021; 332:112925. [PMID: 34937992 PMCID: PMC8691754 DOI: 10.1016/j.sna.2021.112925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In the past decade, acoustics at the nanoscale (i.e., nanoacoustics) has evolved rapidly with continuous and substantial expansion of capabilities and refinement of techniques. Motivated by research innovations in the last decade, for the first time, recent advancements of acoustics-associated nanomaterials/nanostructures and nanodevices for different applications are outlined in this comprehensive review, which is written in two parts. As part II of this two-part review, this paper concentrates on nanoacoustics in biomedical imaging and therapy applications, including molecular ultrasound imaging, photoacoustic imaging, ultrasound-mediated drug delivery and therapy, and photoacoustic drug delivery and therapy. Firstly, the recent developments of nanosized ultrasound and photoacoustic contrast agents as well as their various imaging applications are examined. Secondly, different types of nanomaterials/nanostructures as nanocarriers for ultrasound and photoacoustic therapies are discussed. Finally, a discussion of challenges and future research directions are provided for nanoacoustics in medical imaging and therapy.
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Affiliation(s)
- Chang Peng
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Mengyue Chen
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - James B. Spicer
- Department of Materials Science and Engineering, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| | - Xiaoning Jiang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
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9
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Sugaya K. Characterization of cells expressing MRI reporters for the analysis of epigenetics. Anal Biochem 2021; 633:114395. [PMID: 34600867 DOI: 10.1016/j.ab.2021.114395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/25/2021] [Indexed: 11/17/2022]
Abstract
Epigenetics is thought to be involved in highly advanced life phenomena, and its regulation has created new opportunities in regenerative medicine. Mintbody (modification-specific intracellular antibody) can track a posttranslational protein modification in epigenetics using a genetic system encoded within a single chain of variable fragments tagged with a fluorescent protein. Magnetic resonance imaging (MRI) is a technique that allows observation of specific molecules in living organisms. The ferritin heavy chain (FTH1) is one of the MRI reporters used in mammals. The combination of FTH1 with mintbody may show remarkable ability as a reporter for MRI to investigate epigenetics in the deep part of a living organism. This article discusses the suitability and safety of FTH1 for use in the analysis of epigenetics by MRI. Cells expressing the FTH1 hybrid of mintbody showed insufficiently increased sensitivity by MRI even in the presence of excess iron. After incubation with ferric ammonium citrate, DNA damage was found in cells expressing the FTH1 hybrid of mintbody. The use of FTH1 as a genetically encoded reporter for MRI appears to be limited by the requirement of metal and its relatively low sensitivity. These results suggest future directionality and the possibility of studying epigenetics in vivo.
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Affiliation(s)
- Kimihiko Sugaya
- Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan.
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10
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Ultrasensitive ultrasound imaging of gene expression with signal unmixing. Nat Methods 2021; 18:945-952. [PMID: 34354290 PMCID: PMC8363212 DOI: 10.1038/s41592-021-01229-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 06/30/2021] [Indexed: 12/28/2022]
Abstract
Acoustic reporter genes (ARGs) encoding air-filled gas vesicles enable ultrasound-based imaging of gene expression in genetically modified bacteria and mammalian cells, facilitating the study of cellular function in deep tissues. Despite the promise of this technology for biological research and potential clinical applications, the sensitivity with which ARG-expressing cells can be visualized is currently limited. Here we present BURST – an ARG imaging paradigm that improves the cellular detection limit by more than 1000-fold compared to conventional methods. BURST takes advantage of the unique temporal signal pattern produced by gas vesicles as they collapse under acoustic pressure above a threshold defined by the ARG. By extracting the unique pattern of this signal from total scattering, BURST boosts the sensitivity of ultrasound to image ARG-expressing cells, as demonstrated in vitro and in vivo in the mouse gastrointestinal tract and liver. Furthermore, in dilute cell suspensions, BURST imaging enables the detection of gene expression in individual bacteria and mammalian cells. The resulting capabilities expand the potential utility of ultrasound for non-invasive imaging of cellular function.
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Giampetraglia M, Weigelin B. Recent advances in intravital microscopy for preclinical research. Curr Opin Chem Biol 2021; 63:200-208. [PMID: 34274700 DOI: 10.1016/j.cbpa.2021.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/08/2021] [Accepted: 05/14/2021] [Indexed: 12/14/2022]
Abstract
Intravital microscopy (IVM) has revolutionized our understanding of single-cell behavior in complex tissues by enabling real-time observation of molecular and cellular processes in their natural environment. In preclinical research, IVM has emerged as a standard tool for mechanistic studies of therapy response and the rational design of new treatment strategies. Technological developments keep expanding the imaging depth and quality that can be achieved in living tissue, and the maturation of imaging modalities such as fluorescence and phosphorescence lifetime imaging facilitates co-registration of individual cell dynamics with metabolic tissue states. Correlation of IVM with mesoscopic and macroscopic imaging modalities further promotes the translation of mechanistic insights gained by IVM into clinically relevant information. This review highlights some of the recent advances in IVM that have made the transition from experimental optical techniques to practical applications in basic and preclinical research.
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Affiliation(s)
- Martina Giampetraglia
- David H. Koch Center for Applied Research of Genitourinary Cancers, Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, USA
| | - Bettina Weigelin
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University Tübingen, Tübingen, Germany; Cluster of Excellence iFIT (EXC 2180) "Image-Guided and Functionally Instructed Tumor Therapies", University of Tübingen, Germany.
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12
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Jacobs AH, Schelhaas S, Viel T, Waerzeggers Y, Winkeler A, Zinnhardt B, Gelovani J. Imaging of Gene and Cell-Based Therapies: Basis and Clinical Trials. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00060-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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13
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Noonan AJC, Qiu Y, Ho JCH, Ocampo J, Vreugdenhil KA, Marr RA, Zhao Z, Yoshikuni Y, Hallam SJ. CRAGE-mediated insertion of fluorescent chromosomal markers for accurate and scalable measurement of co-culture dynamics in Escherichia coli. Synth Biol (Oxf) 2021; 5:ysaa015. [PMID: 33381654 PMCID: PMC7751189 DOI: 10.1093/synbio/ysaa015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/06/2020] [Accepted: 07/28/2020] [Indexed: 11/13/2022] Open
Abstract
Monitoring population dynamics in co-culture is necessary in engineering microbial consortia involved in distributed metabolic processes or biosensing applications. However, it remains difficult to measure strain-specific growth dynamics in high-throughput formats. This is especially vexing in plate-based functional screens leveraging whole-cell biosensors to detect specific metabolic signals. Here, we develop an experimental high-throughput co-culture system to measure and model the relationship between fluorescence and cell abundance, combining chassis-independent recombinase-assisted genome engineering (CRAGE) and whole-cell biosensing with a PemrR-green fluorescent protein (GFP) monoaromatic reporter used in plate-based functional screening. CRAGE was used to construct Escherichia coli EPI300 strains constitutively expressing red fluorescent protein (RFP) and the relationship between RFP expression and optical density (OD600) was determined throughout the EPI300 growth cycle. A linear equation describing the increase of normalized RFP fluorescence during deceleration phase was derived and used to predict biosensor strain dynamics in co-culture. Measured and predicted values were compared using flow cytometric detection methods. Induction of the biosensor lead to increased GFP fluorescence normalized to biosensor cell abundance, as expected, but a significant decrease in relative abundance of the biosensor strain in co-culture and a decrease in bulk GFP fluorescence. Taken together, these results highlight sensitivity of population dynamics to variations in metabolic activity in co-culture and the potential effect of these dynamics on the performance of functional screens in plate-based formats. The engineered strains and model used to evaluate these dynamics provide a framework for optimizing growth of synthetic co-cultures used in screening, testing and pathway engineering applications.
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Affiliation(s)
- Avery J C Noonan
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yilin Qiu
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Joe C H Ho
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Jewel Ocampo
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - K A Vreugdenhil
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - R Alexander Marr
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Zhiying Zhao
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Yasuo Yoshikuni
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Steven J Hallam
- Genome Science and Technology Program, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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14
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Jayapaul J, Schröder L. Molecular Sensing with Host Systems for Hyperpolarized 129Xe. Molecules 2020; 25:E4627. [PMID: 33050669 PMCID: PMC7587211 DOI: 10.3390/molecules25204627] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/27/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Hyperpolarized noble gases have been used early on in applications for sensitivity enhanced NMR. 129Xe has been explored for various applications because it can be used beyond the gas-driven examination of void spaces. Its solubility in aqueous solutions and its affinity for hydrophobic binding pockets allows "functionalization" through combination with host structures that bind one or multiple gas atoms. Moreover, the transient nature of gas binding in such hosts allows the combination with another signal enhancement technique, namely chemical exchange saturation transfer (CEST). Different systems have been investigated for implementing various types of so-called Xe biosensors where the gas binds to a targeted host to address molecular markers or to sense biophysical parameters. This review summarizes developments in biosensor design and synthesis for achieving molecular sensing with NMR at unprecedented sensitivity. Aspects regarding Xe exchange kinetics and chemical engineering of various classes of hosts for an efficient build-up of the CEST effect will also be discussed as well as the cavity design of host molecules to identify a pool of bound Xe. The concept is presented in the broader context of reporter design with insights from other modalities that are helpful for advancing the field of Xe biosensors.
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Affiliation(s)
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany;
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15
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Lu GJ, Chou LD, Malounda D, Patel AK, Welsbie DS, Chao DL, Ramalingam T, Shapiro MG. Genetically Encodable Contrast Agents for Optical Coherence Tomography. ACS NANO 2020; 14:7823-7831. [PMID: 32023037 PMCID: PMC7685218 DOI: 10.1021/acsnano.9b08432] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Optical coherence tomography (OCT) has gained wide adoption in biological research and medical imaging due to its exceptional tissue penetration, 3D imaging speed, and rich contrast. However, OCT plays a relatively small role in molecular and cellular imaging due to the lack of suitable biomolecular contrast agents. In particular, while the green fluorescent protein has provided revolutionary capabilities to fluorescence microscopy by connecting it to cellular functions such as gene expression, no equivalent reporter gene is currently available for OCT. Here, we introduce gas vesicles, a class of naturally evolved gas-filled protein nanostructures, as genetically encodable OCT contrast agents. The differential refractive index of their gas compartments relative to surrounding aqueous tissue and their nanoscale motion enables gas vesicles to be detected by static and dynamic OCT. Furthermore, the OCT contrast of gas vesicles can be selectively erased in situ with ultrasound, allowing unambiguous assignment of their location. In addition, gas vesicle clustering modulates their temporal signal, enabling the design of dynamic biosensors. We demonstrate the use of gas vesicles as reporter genes in bacterial colonies and as purified contrast agents in vivo in the mouse retina. Our results expand the utility of OCT to image a wider variety of cellular and molecular processes.
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Affiliation(s)
- George J. Lu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Li-dek Chou
- OCT Medical Imaging Inc., 9272 Jeronimo Road, Irvine, CA 92618, USA
| | - Dina Malounda
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Amit K. Patel
- Shiley Eye Institute, Andrew Viterbi Department of Ophthalmology, University of California San Diego, La Jolla, CA 92093, USA
| | - Derek S. Welsbie
- Shiley Eye Institute, Andrew Viterbi Department of Ophthalmology, University of California San Diego, La Jolla, CA 92093, USA
| | - Daniel L. Chao
- Shiley Eye Institute, Andrew Viterbi Department of Ophthalmology, University of California San Diego, La Jolla, CA 92093, USA
| | | | - Mikhail G. Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
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16
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Ozbakir HF, Anderson NT, Fan KC, Mukherjee A. Beyond the Green Fluorescent Protein: Biomolecular Reporters for Anaerobic and Deep-Tissue Imaging. Bioconjug Chem 2020; 31:293-302. [PMID: 31794658 PMCID: PMC7033020 DOI: 10.1021/acs.bioconjchem.9b00688] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fluorescence imaging represents cornerstone technology for studying biological function at the cellular and molecular levels. The technology's centerpiece is a prolific collection of genetic reporters based on the green fluorescent protein (GFP) and related analogs. More than two decades of protein engineering have endowed the GFP repertoire with an incredible assortment of fluorescent proteins, allowing scientists immense latitude in choosing reporters tailored to various cellular and environmental contexts. Nevertheless, GFP and derivative reporters have specific limitations that hinder their unrestricted use for molecular imaging. These challenges have inspired the development of new reporter proteins and imaging mechanisms. Here, we review how these developments are expanding the frontiers of reporter gene techniques to enable nondestructive studies of cell function in anaerobic environments and deep inside intact animals-two important biological contexts that are fundamentally incompatible with the use of GFP-based reporters.
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Affiliation(s)
- Harun F. Ozbakir
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Nolan T. Anderson
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Kang-Ching Fan
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Arnab Mukherjee
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Department of Chemistry, University of California, Santa Barbara, California 93106, United States
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
- Center for Bioengineering, University of California, Santa Barbara, California 93106, United States
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17
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Wang W, Yang Q, Du Y, Zhou X, Du X, Wu Q, Lin L, Song Y, Li F, Yang C, Tan W. Metabolic Labeling of Peptidoglycan with NIR‐II Dye Enables In Vivo Imaging of Gut Microbiota. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201910555] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Wei Wang
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
| | - Qinglai Yang
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
- Research Center for Advanced Materials and BiotechnologyResearch Institute of Tsinghua University in Shenzhen Shenzhen 518057 China
| | - Yahui Du
- Collaborative Innovation Center of Chemistry for Energy MaterialsThe MOE Key Laboratory of Spectrochemical Analysis and InstrumentationState Key Laboratory of Physical Chemistry of Solid SurfacesDepartment of Chemical BiologyCollege of Chemistry and Chemical EngineeringXiamen University Xiamen 361005 China
| | - Xiaobo Zhou
- Department of ChemistryFudan University Shanghai 200433 China
| | - Xiaochen Du
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
| | - Qiuyue Wu
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
| | - Liyuan Lin
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
| | - Yanling Song
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
| | - Fuyou Li
- Department of ChemistryFudan University Shanghai 200433 China
| | - Chaoyong Yang
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
- Collaborative Innovation Center of Chemistry for Energy MaterialsThe MOE Key Laboratory of Spectrochemical Analysis and InstrumentationState Key Laboratory of Physical Chemistry of Solid SurfacesDepartment of Chemical BiologyCollege of Chemistry and Chemical EngineeringXiamen University Xiamen 361005 China
| | - Weihong Tan
- Institute of Molecular Medicine (IMM)Renji HospitalShanghai Jiao Tong University School of MedicineSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong University Shanghai 200127 China
- Molecular Science and Biomedicine Laboratory (MBL)State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha 410082 China
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18
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Wang W, Yang Q, Du Y, Zhou X, Du X, Wu Q, Lin L, Song Y, Li F, Yang C, Tan W. Metabolic Labeling of Peptidoglycan with NIR-II Dye Enables In Vivo Imaging of Gut Microbiota. Angew Chem Int Ed Engl 2020; 59:2628-2633. [PMID: 31793153 DOI: 10.1002/anie.201910555] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 11/09/2019] [Indexed: 12/23/2022]
Abstract
Deepening our understanding of mammalian gut microbiota has been greatly hampered by the lack of a facile, real-time, and in vivo bacterial imaging method. To address this unmet need in microbial visualization, we herein report the development of a second near-infrared (NIR-II)-based method for in vivo imaging of gut bacteria. Using d-propargylglycine in gavage and then click reaction with an azide-containing NIR-II dye, gut microbiota of a donor mouse was strongly labeled with NIR-II fluorescence on their peptidoglycan. The bacteria could be readily visualized in recipient mouse gut with high spatial resolution and deep tissue penetration under NIR irradiation. The NIR-II-based metabolic labeling strategy reported herein, provides, to the best of our knowledge, the first protocol for facile in vivo visualization of gut microbiota within deep tissues, and offers an instrumental tool for deciphering the complex biology of these gut "dark matters".
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Affiliation(s)
- Wei Wang
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Qinglai Yang
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China.,Research Center for Advanced Materials and Biotechnology, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Yahui Du
- Collaborative Innovation Center of Chemistry for Energy Materials, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xiaobo Zhou
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Xiaochen Du
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Qiuyue Wu
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Liyuan Lin
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Yanling Song
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Fuyou Li
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Chaoyong Yang
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China.,Collaborative Innovation Center of Chemistry for Energy Materials, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Weihong Tan
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200127, China.,Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China
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19
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Jayapaul J, Schröder L. Nanoparticle-Based Contrast Agents for 129Xe HyperCEST NMR and MRI Applications. CONTRAST MEDIA & MOLECULAR IMAGING 2019; 2019:9498173. [PMID: 31819739 PMCID: PMC6893250 DOI: 10.1155/2019/9498173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/15/2019] [Indexed: 02/06/2023]
Abstract
Spin hyperpolarization techniques have enabled important advancements in preclinical and clinical MRI applications to overcome the intrinsic low sensitivity of nuclear magnetic resonance. Functionalized xenon biosensors represent one of these approaches. They combine two amplification strategies, namely, spin exchange optical pumping (SEOP) and chemical exchange saturation transfer (CEST). The latter one requires host structures that reversibly bind the hyperpolarized noble gas. Different nanoparticle approaches have been implemented and have enabled molecular MRI with 129Xe at unprecedented sensitivity. This review gives an overview of the Xe biosensor concept, particularly how different nanoparticles address various critical aspects of gas binding and exchange, spectral dispersion for multiplexing, and targeted reporter delivery. As this concept is emerging into preclinical applications, comprehensive sensor design will be indispensable in translating the outstanding sensitivity potential into biomedical molecular imaging applications.
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Affiliation(s)
- Jabadurai Jayapaul
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
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20
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Farhadi A, Ho GH, Sawyer DP, Bourdeau RW, Shapiro MG. Ultrasound imaging of gene expression in mammalian cells. Science 2019; 365:1469-1475. [PMID: 31604277 PMCID: PMC6860372 DOI: 10.1126/science.aax4804] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022]
Abstract
The study of cellular processes occurring inside intact organisms requires methods to visualize cellular functions such as gene expression in deep tissues. Ultrasound is a widely used biomedical technology enabling noninvasive imaging with high spatial and temporal resolution. However, no genetically encoded molecular reporters are available to connect ultrasound contrast to gene expression in mammalian cells. To address this limitation, we introduce mammalian acoustic reporter genes. Starting with a gene cluster derived from bacteria, we engineered a eukaryotic genetic program whose introduction into mammalian cells results in the expression of intracellular air-filled protein nanostructures called gas vesicles, which produce ultrasound contrast. Mammalian acoustic reporter genes allow cells to be visualized at volumetric densities below 0.5% and permit high-resolution imaging of gene expression in living animals.
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Affiliation(s)
- Arash Farhadi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Gabrielle H Ho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Daniel P Sawyer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Raymond W Bourdeau
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
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21
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Szablowski JO, Bar-Zion A, Shapiro MG. Achieving Spatial and Molecular Specificity with Ultrasound-Targeted Biomolecular Nanotherapeutics. Acc Chem Res 2019; 52:2427-2434. [PMID: 31397992 PMCID: PMC7462121 DOI: 10.1021/acs.accounts.9b00277] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The precise targeting of cells in deep tissues is one of the primary goals of nanomedicine. However, targeting a specific cellular population within an entire organism is challenging due to off-target effects and the need for deep tissue delivery. Focused ultrasound can reduce off-targeted effects by spatially restricting the delivery or action of molecular constructs to specific anatomical sites. Ultrasound can also increase the efficiency of nanotherapeutic delivery into deep tissues by enhancing the permeability of tissue boundaries, promoting convection, or depositing energy to actuate cellular activity. In this review we focus on the interface between biomolecular engineering and focused ultrasound and describe the applications of this intersection in neuroscience, oncology, and synthetic biology. Ultrasound can be used to trigger the transport of therapeutic payloads into a range of tissues, including specific regions of the brain, where it can be targeted with millimeter precision through intact skull. Locally delivered molecular constructs can then control specific cells and molecular pathways within the targeted region. When combined with viral vectors and engineered neural receptors, this technique enables noninvasive control of specific circuits and behaviors. The penetrant energy of ultrasound can also be used to more directly actuate micro- and nanotherapeutic constructs, including microbubbles, vaporizable nanodroplets, and polymeric nanocups, which nucleate cavitation upon ultrasound exposure, leading to local mechanical effects. In addition, it was recently discovered that a unique class of acoustic biomolecules-genetically encodable nanoscale protein structures called gas vesicles-can be acoustically "detonated" as sources of inertial cavitation. This enables the targeted disruption of selected cells within the area of insonation by gas vesicles that are engineered to bind cell surface receptors. It also facilitates ultrasound-triggered release of molecular payloads from engineered therapeutic cells heterologously expressing intracellular gas vesicles. Finally, focused ultrasound energy can be used to locally elevate tissue temperature and activate temperature-sensitive proteins and pathways. The elevation of temperature allows noninvasive control of gene expression in vivo in cells engineered to express thermal bioswitches. Overall, the intersection of biomolecular engineering, nanomaterials and focused ultrasound can provide unparalleled specificity in controlling, modulating, and treating physiological processes in deep tissues.
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Affiliation(s)
- Jerzy O. Szablowski
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Avinoam Bar-Zion
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Mikhail G. Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
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22
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Edwardson TGW, Hilvert D. Virus-Inspired Function in Engineered Protein Cages. J Am Chem Soc 2019; 141:9432-9443. [PMID: 31117660 DOI: 10.1021/jacs.9b03705] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The structural and functional diversity of proteins combined with their genetic programmability has made them indispensable modern materials. Well-defined, hollow protein capsules have proven to be particularly useful due to their ability to compartmentalize macromolecules and chemical processes. To this end, viral capsids are common scaffolds and have been successfully repurposed to produce a suite of practical protein-based nanotechnologies. Recently, the recapitulation of viromimetic function in protein cages of nonviral origin has emerged as a strategy to both complement physical studies of natural viruses and produce useful scaffolds for diverse applications. In this perspective, we review recent progress toward generation of virus-like behavior in nonviral protein cages through rational engineering and directed evolution. These artificial systems can aid our understanding of the emergence of viruses from existing cellular components, as well as provide alternative approaches to tackle current problems, and open up new opportunities, in medicine and biotechnology.
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Affiliation(s)
| | - Donald Hilvert
- Laboratory of Organic Chemistry , ETH Zurich , 8093 Zurich , Switzerland
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23
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Bose RJC, Mattrey RF. Accomplishments and challenges in stem cell imaging in vivo. Drug Discov Today 2018; 24:492-504. [PMID: 30342245 DOI: 10.1016/j.drudis.2018.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 09/24/2018] [Accepted: 10/13/2018] [Indexed: 02/08/2023]
Abstract
Stem cell therapies have demonstrated promising preclinical results, but very few applications have reached the clinic owing to safety and efficacy concerns. Translation would benefit greatly if stem cell survival, distribution and function could be assessed in vivo post-transplantation, particularly in patients. Advances in molecular imaging have led to extraordinary progress, with several strategies being deployed to understand the fate of stem cells in vivo using magnetic resonance, scintigraphy, PET, ultrasound and optical imaging. Here, we review the recent advances, challenges and future perspectives and opportunities in stem cell tracking and functional assessment, as well as the advantages and challenges of each imaging approach.
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Affiliation(s)
- Rajendran J C Bose
- Department of Radiology and Advanced Imaging Research Center, 5323 Harry Hines Blvd, UT Southwestern Medical Center, Dallas, TX 75390-8514, USA; Current affiliation: Molecular Imaging Program at Stanford (MIPS) and the Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Stanford University, Stanford, CA 94305-5427, USA
| | - Robert F Mattrey
- Department of Radiology and Advanced Imaging Research Center, 5323 Harry Hines Blvd, UT Southwestern Medical Center, Dallas, TX 75390-8514, USA.
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