1
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Cheng GWY, Ma IWT, Huang J, Yeung SHS, Ho P, Chen Z, Mak HKF, Herrup K, Chan KWY, Tse KH. Cuprizone drives divergent neuropathological changes in different mouse models of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.24.547147. [PMID: 37546935 PMCID: PMC10402084 DOI: 10.1101/2023.07.24.547147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Myelin degradation is a normal feature of brain aging that accelerates in Alzheimer's disease (AD). To date, however, the underlying biological basis of this correlation remains elusive. The amyloid cascade hypothesis predicts that demyelination is caused by increased levels of the β-amyloid (Aβ) peptide. Here we report on work supporting the alternative hypothesis that early demyelination is upstream of amyloid. We challenged two different mouse models of AD (R1.40 and APP/PS1) using cuprizone-induced demyelination and tracked the responses with both neuroimaging and neuropathology. In oppose to amyloid cascade hypothesis, R1.40 mice, carrying only a single human mutant APP (Swedish; APP SWE ) transgene, showed a more abnormal changes of magnetization transfer ratio and diffusivity than in APP/PS1 mice, which carry both APP SWE and a second PSEN1 transgene (delta exon 9; PSEN1 dE9 ). Although cuprizone targets oligodendrocytes (OL), magnetic resonance spectroscopy and targeted RNA-seq data in R1.40 mice suggested a possible metabolic alternation in axons. In support of alternative hypotheses, cuprizone induced significant intraneuronal amyloid deposition in young APP/PS1, but not in R1.40 mice, and it suggested the presence of PSEN deficiencies, may accelerate Aβ deposition upon demyelination. In APP/PS1, mature OL is highly vulnerable to cuprizone with significant DNA double strand breaks (53BP1 + ) formation. Despite these major changes in myelin, OLs, and Aβ immunoreactivity, no cognitive impairment or hippocampal pathology was detected in APP/PS1 mice after cuprizone treatment. Together, our data supports the hypothesis that myelin loss can be the cause, but not the consequence, of AD pathology. SIGNIFICANCE STATEMENT The causal relationship between early myelin loss and the progression of Alzheimer's disease remains unclear. Using two different AD mouse models, R1.40 and APP/PS1, our study supports the hypothesis that myelin abnormalities are upstream of amyloid production and deposition. We find that acute demyelination initiates intraneuronal amyloid deposition in the frontal cortex. Further, the loss of oligodendrocytes, coupled with the accelerated intraneuronal amyloid deposition, interferes with myelin tract diffusivity at a stage before any hippocampus pathology or cognitive impairments occur. We propose that myelin loss could be the cause, not the consequence, of amyloid pathology during the early stages of Alzheimer's disease.
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Xiao P, Huang J, Han X, Cheu JWS, Liu Y, Law LH, Lai JHC, Li J, Park SW, Wong CCL, Lam RHW, Chan KWY. Monitor Tumor pHe and Response Longitudinally during Treatment Using CEST MRI-Detectable Alginate Microbeads. ACS APPLIED MATERIALS & INTERFACES 2022; 14:54401-54410. [PMID: 36448714 PMCID: PMC9756293 DOI: 10.1021/acsami.2c10493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 10/05/2022] [Indexed: 06/17/2023]
Abstract
Imaging pHe of the tumor microenvironment has paramount importance for characterizing aggressive, invasive tumors, as well as therapeutic responses. Here, a robust approach to image pH changes in the tumor microenvironment longitudinally and during sodium bicarbonate treatment was reported. The pH-sensing microbeads were designed and prepared based on materials approved for clinical use, i.e., alginate microbead-containing computed tomography (CT) contrast-agent (iopamidol)-loaded liposomes (Iop-lipobeads). This Iop-lipobead prepared using a customized microfluidic device generated a CEST contrast of 10.6% at 4.2 ppm at pH 7.0, which was stable for 20 days in vitro. The CEST contrast decreased by 11.8% when the pH decreased from 7.0 to 6.5 in vitro. Optimized Iop-lipobeads next to tumors showed a significant increase of 19.7 ± 6.1% (p < 0.01) in CEST contrast at 4.2 ppm during the first 3 days of treatment and decreased to 15.2 ± 4.8% when treatment stopped. Notably, percentage changes in Iop-lipobeads were higher than that of amide CEST (11.7% and 9.1%) in tumors during and after treatment. These findings demonstrated that the Iop-lipobead could provide an independent and sensitive assessment of the pHe changes for a noninvasive and longitudinal monitoring of the treatment effects using multiple CEST contrast.
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Affiliation(s)
- Peng Xiao
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Jianpan Huang
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Xiongqi Han
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Jacinth W. S. Cheu
- Department
of Pathology, Li Ka Shing Faculty of Medicine,
The University of Hong Kong, Hong Kong, China
| | - Yang Liu
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Lok Hin Law
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Joseph H. C. Lai
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Jiyu Li
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Se Weon Park
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Carmen C. L. Wong
- Department
of Pathology, Li Ka Shing Faculty of Medicine,
The University of Hong Kong, Hong Kong, China
- State
Key Laboratory of Liver Research, The University
of Hong Kong, Hong Kong, China
| | - Raymond H. W. Lam
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
| | - Kannie W. Y. Chan
- Department
of Biomedical Engineering, City University
of Hong Kong, Hong Kong, China
- City
University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Tung
Biomedical
Sciences Centre, City University of Hong
Kong, Hong Kong, China
- Hong
Kong Centre for Cerebro-Cardiovascular Health Engineering, Hong Kong, China
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Kalkowski L, Golubczyk D, Kwiatkowska J, Holak P, Milewska K, Janowski M, Oliveira JM, Walczak P, Malysz-Cymborska I. Two in One: Use of Divalent Manganese Ions as Both Cross-Linking and MRI Contrast Agent for Intrathecal Injection of Hydrogel-Embedded Stem Cells. Pharmaceutics 2021; 13:pharmaceutics13071076. [PMID: 34371767 PMCID: PMC8309201 DOI: 10.3390/pharmaceutics13071076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/02/2021] [Accepted: 07/08/2021] [Indexed: 12/04/2022] Open
Abstract
Cell therapy is a promising tool for treating central nervous system (CNS) disorders; though, the translational efforts are plagued by ineffective delivery methods. Due to the large contact surface with CNS and relatively easy access, the intrathecal route of administration is attractive in extensive or global diseases such as stroke or amyotrophic lateral sclerosis (ALS). However, the precision and efficacy of this approach are still a challenge. Hydrogels were introduced to minimize cell sedimentation and improve cell viability. At the same time, contrast agents were integrated to allow image-guided injection. Here, we report using manganese ions (Mn2+) as a dual agent for cross-linking alginate-based hydrogels and magnetic resonance imaging (MRI). We performed in vitro studies to test the Mn2+ alginate hydrogel formulations for biocompatibility, injectability, MRI signal retention time, and effect on cell viability. The selected formulation was injected intrathecally into pigs under MRI control. The biocompatibility test showed a lack of immune response, and cells suspended in the hydrogel showed greater viability than monolayer culture. Moreover, Mn2+-labeled hydrogel produced a strong T1 MRI signal, which enabled MRI-guided procedure. We confirmed the utility of Mn2+ alginate hydrogel as a carrier for cells in large animals and a contrast agent at the same time.
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Affiliation(s)
- Lukasz Kalkowski
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Dominika Golubczyk
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Joanna Kwiatkowska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Piotr Holak
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, 10-719 Olsztyn, Poland;
| | - Kamila Milewska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
| | - Miroslaw Janowski
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (M.J.); (P.W.)
| | - Joaquim Miguel Oliveira
- a3B’s Research Group, I3Bs—Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal;
- ICVS/3B’s—PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Piotr Walczak
- Center for Advanced Imaging Research, Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (M.J.); (P.W.)
| | - Izabela Malysz-Cymborska
- Department of Neurosurgery, School of Medicine, Collegium Medicum, University of Warmia and Mazury, 10-082 Olsztyn, Poland; (L.K.); (D.G.); (J.K.); (K.M.)
- Correspondence: ; Tel.: +48-605118887
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4
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Yang D, Xiao J, Wang B, Li L, Kong X, Liao J. The immune reaction and degradation fate of scaffold in cartilage/bone tissue engineering. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 104:109927. [DOI: 10.1016/j.msec.2019.109927] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/17/2019] [Accepted: 06/26/2019] [Indexed: 01/05/2023]
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5
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Arifin DR, Kulkarni M, Kadayakkara D, Bulte JWM. Fluorocapsules allow in vivo monitoring of the mechanical stability of encapsulated islet cell transplants. Biomaterials 2019; 221:119410. [PMID: 31421313 PMCID: PMC6717436 DOI: 10.1016/j.biomaterials.2019.119410] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/02/2019] [Indexed: 02/06/2023]
Abstract
Clinical trials that have used encapsulated islet cell therapy have been few and overall disappointing. This is due in part to the lack of suitable methods to monitor the integrity vs. rupture of transplanted microcapsules over time. Fluorocapsules were synthesized by embedding emulsions of perfluoro-15-crown-5-ether (PFC), a bioinert compound detectable by 19F MRI, into dual-alginate layer, Ba2+-gelled alginate microcapsules. Fluorocapsules were spherical with an apparent smooth surface and an average diameter of 428 ± 52 μm. After transplantation into mice, the 19F MRI signal of capsules remained stable for up to 90 days, corresponding to the total number of intact fluorocapsules. When single-alginate layer capsules were ruptured with alginate lyase, the 19F MRI signal dissipated within 4 days. For fluoroencapsulated luciferase-expressing mouse βTC6 insulinoma cells implanted into autoimmune NOD/ShiLtJ mice and subjected to alginate-lyase induced capsule rupture in vivo, the 19F MRI signal decreased sharply over time along with a decrease in bioluminescence imaging signal used as a measure of cell viability in vivo. These results indicate that maintenance of capsule integrity is essential for preserving transplanted cell survival, where a decrease in 19F MRI signal may serve as a predictive imaging surrogate biomarker for impending failure of encapsulated islet cell therapy.
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Affiliation(s)
- Dian R Arifin
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Mangesh Kulkarni
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Deepak Kadayakkara
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Jeff W M Bulte
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Chemical & Biomolecular Engineering, The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 21218, USA; Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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6
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Catanzaro V, Digilio G, Capuana F, Padovan S, Cutrin JC, Carniato F, Porta S, Grange C, Filipović N, Stevanović M. Gadolinium-Labelled Cell Scaffolds to Follow-up Cell Transplantation by Magnetic Resonance Imaging. J Funct Biomater 2019; 10:E28. [PMID: 31269673 PMCID: PMC6787680 DOI: 10.3390/jfb10030028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 12/21/2022] Open
Abstract
Cell scaffolds are often used in cell transplantation as they provide a solid structural support to implanted cells and can be bioengineered to mimic the native extracellular matrix. Gadolinium fluoride nanoparticles (Gd-NPs) as a contrast agent for Magnetic Resonance Imaging (MRI) were incorporated into poly(lactide-co-glycolide)/chitosan scaffolds to obtain Imaging Labelled Cell Scaffolds (ILCSs), having the shape of hollow spherical/ellipsoidal particles (200-600 μm diameter and 50-80 μm shell thickness). While Gd-NPs incorporated into microparticles do not provide any contrast enhancement in T1-weighted (T1w) MR images, ILCSs can release Gd-NPs in a controlled manner, thus activating MRI contrast. ILCSs seeded with human mesenchymal stromal cells (hMSCs) were xenografted subcutaneously into either immunocompromised and immunocompetent mice without any immunosuppressant treatments, and the transplants were followed-up in vivo by MRI for 18 days. Immunocompromised mice showed a progressive activation of MRI contrast within the implants due to the release of Gd-NPs in the extracellular matrix. Instead, immunocompetent mice showed poor activation of MRI contrast due to the encapsulation of ILCSs within fibrotic capsules and to the scavenging of released Gd-NPs by phagocytic cells. In conclusion, the MRI follow-up of cell xenografts can report the host cell response to the xenograft. However, it does not strictly report on the viability of transplanted hMSCs.
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Affiliation(s)
- Valeria Catanzaro
- Department of Science and Technologic Innovation, Università del Piemonte Orientale "Amedeo Avogadro", Viale T. Michel 11, I-15121 Alessandria, Italy
| | - Giuseppe Digilio
- Department of Science and Technologic Innovation, Università del Piemonte Orientale "Amedeo Avogadro", Viale T. Michel 11, I-15121 Alessandria, Italy.
| | - Federico Capuana
- Department of Molecular Biotechnology and Health Science & Center for Molecular Imaging, University of Turin, Via Nizza 52, 10126 Torino, Italy
| | - Sergio Padovan
- Institute for Biostructures and Bioimages (CNR) c/o Molecular Biotechnology Center Via Nizza 52, 10126 Torino, Italy
| | - Juan C Cutrin
- Department of Molecular Biotechnology and Health Science & Center for Molecular Imaging, University of Turin, Via Nizza 52, 10126 Torino, Italy
| | - Fabio Carniato
- Department of Science and Technologic Innovation, Università del Piemonte Orientale "Amedeo Avogadro", Viale T. Michel 11, I-15121 Alessandria, Italy
| | - Stefano Porta
- Department of Molecular Biotechnology and Health Science & Center for Molecular Imaging, University of Turin, Via Nizza 52, 10126 Torino, Italy
| | - Cristina Grange
- Department of Medical Sciences, University of Turin, Via Nizza 52, 10126 Torino, Italy
| | - Nenad Filipović
- Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11000 Belgrade, Serbia
| | - Magdalena Stevanović
- Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11000 Belgrade, Serbia
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7
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Qi W, Liang X, Yun T, Guo W. Growth and survival of microencapsulated probiotics prepared by emulsion and internal gelation. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2019; 56:1398-1404. [PMID: 30956319 PMCID: PMC6423195 DOI: 10.1007/s13197-019-03616-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 01/03/2019] [Accepted: 01/29/2019] [Indexed: 12/27/2022]
Abstract
Efficient microencapsulation of probiotics by most existing methods is limited by low throughput. In this work, Saccharomyces boulardii and Enterococcus faecium were microencapsulated by a method based on emulsion and internal gelation. The growth and survival of microencapsulated microbes under different stressors were investigated using free non-encapsulated ones as a control. The results showed that the prepared micro-beads by emulsion and internal gelation exhibited a spherical and smooth shape, with sizes between 300 and 500 μm. Both S. boulardii and E. faecium grew well and survived better when encapsulated in micro-beads. The survival rates were increased 25% and 40% for microencapsulated S. boulardii and E. faecium respectively when compared with non-encapsulated controls under high temperature and high humidity. The increases of survival rates were 60% for microencapsulated S. boulardii and 25% for E. faecium in simulated gastric juice. And the increases were 15% and 20% respectively when the survival rates of the microencapsulated S. boulardii and E. faecium were determined in simulated intestinal juice. The microencapsulation by emulsion and internal gelation offers an effective way to protect microbes in adverse in vitro and in vivo conditions and is promising for the large-scale production of probiotics microencapsulation.
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Affiliation(s)
- Wentao Qi
- Cereals and Oils Nutrition Research Group, Academy of State Administration of Grain, No. 11 Baiwanzhuang Street, Beijing, 100037 People’s Republic of China
| | - Xinxiao Liang
- Cereals and Oils Nutrition Research Group, Academy of State Administration of Grain, No. 11 Baiwanzhuang Street, Beijing, 100037 People’s Republic of China
| | - Tingting Yun
- Cereals and Oils Nutrition Research Group, Academy of State Administration of Grain, No. 11 Baiwanzhuang Street, Beijing, 100037 People’s Republic of China
| | - Weiqun Guo
- Cereals and Oils Nutrition Research Group, Academy of State Administration of Grain, No. 11 Baiwanzhuang Street, Beijing, 100037 People’s Republic of China
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8
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Gonzalez-Pujana A, Orive G, Pedraz JL, Santos-Vizcaino E, Hernandez RM. Alginate Microcapsules for Drug Delivery. SPRINGER SERIES IN BIOMATERIALS SCIENCE AND ENGINEERING 2018. [DOI: 10.1007/978-981-10-6910-9_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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McMahon MT, Gilad AA. Cellular and Molecular Imaging Using Chemical Exchange Saturation Transfer. Top Magn Reson Imaging 2017; 25:197-204. [PMID: 27748713 DOI: 10.1097/rmr.0000000000000105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Chemical exchange saturation transfer (CEST) is a powerful new tool well suited for molecular imaging. This technology enables the detection of low concentration probes through selective labeling of rapidly exchanging protons or other spins on the probes. In this review, we will highlight the unique features of CEST imaging technology and describe the different types of CEST agents that are suited for molecular imaging studies, including CEST theranostic agents, CEST reporter genes, and CEST environmental sensors.
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Affiliation(s)
- Michael T McMahon
- *F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute †The Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD
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10
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Appel AA, Ibarra V, Somo SI, Larson JC, Garson AB, Guan H, McQuilling JP, Zhong Z, Anastasio MA, Opara EC, Brey EM. Imaging of Hydrogel Microsphere Structure and Foreign Body Response Based on Endogenous X-Ray Phase Contrast. Tissue Eng Part C Methods 2016; 22:1038-1048. [PMID: 27796159 PMCID: PMC5116683 DOI: 10.1089/ten.tec.2016.0253] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/28/2016] [Indexed: 12/22/2022] Open
Abstract
Transplantation of functional islets encapsulated in stable biomaterials has the potential to cure Type I diabetes. However, the success of these materials requires the ability to quantitatively evaluate their stability. Imaging techniques that enable monitoring of biomaterial performance are critical to further development in the field. X-ray phase-contrast (XPC) imaging is an emerging class of X-ray techniques that have shown significant promise for imaging biomaterial and soft tissue structures. In this study, XPC imaging techniques are shown to enable three dimensional (3D) imaging and evaluation of islet volume, alginate hydrogel structure, and local soft tissue features ex vivo. Rat islets were encapsulated in sterile ultrapurified alginate systems produced using a high-throughput microfluidic system. The encapsulated islets were implanted in omentum pouches created in a rodent model of type 1 diabetes. Microbeads were imaged with XPC imaging before implantation and as whole tissue samples after explantation from the animals. XPC microcomputed tomography (μCT) was performed with systems using tube-based and synchrotron X-ray sources. Islets could be identified within alginate beads and the islet volume was quantified in the synchrotron-based μCT volumes. Omental adipose tissue could be distinguished from inflammatory regions resulting from implanted beads in harvested samples with both XPC imaging techniques. Individual beads and the local encapsulation response were observed and quantified using quantitative measurements, which showed good agreement with histology. The 3D structure of the microbeads could be characterized with XPC imaging and failed beads could also be identified. These results point to the substantial potential of XPC imaging as a tool for imaging biomaterials in small animal models and deliver a critical step toward in vivo imaging.
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Affiliation(s)
- Alyssa A. Appel
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
| | - Veronica Ibarra
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Sami I. Somo
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
| | - Jeffery C. Larson
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
| | - Alfred B. Garson
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Huifeng Guan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | | | - Zhong Zhong
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York
| | - Mark A. Anastasio
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri
| | - Emmanuel C. Opara
- Wake Forest Institute of Regenerative Medicine, Winston-Salem, North Carolina
| | - Eric M. Brey
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois
- Research Services, Edward Hines Jr. VA Hospital, Chicago, Illinois
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11
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Yang J, Zhu Y, Xu T, Pan C, Cai N, Huang H, Zhang L. The preservation of living cells with biocompatible microparticles. NANOTECHNOLOGY 2016; 27:265101. [PMID: 27189861 DOI: 10.1088/0957-4484/27/26/265101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Biomedical applications of living cells have rapidly expanded in many fields such as toxic detection, drug screening, and regenerative medicine, etc. Efficient methods to support cell survival and maintain activity in vitro have become increasingly important. However, traditional cryopreservation for living cell-based applications is limited by several problems. Here, we report that magnetic hydrogel microparticles can physically assemble into a 3D environment for efficient cell preservation in physiological conditions, avoiding any chemical reactions that would damage the cells. Two representative cell lines (loosely and firmly adherent) were tested to evaluate the versatility of this method. The results showed that cell longevity was significantly extended to at least 15 days, while the control cell samples without microparticles quickly died within 3 days. Moreover, after preservation, cells can be easily retrieved by applying a magnet to separate the magnetic particles. This strategy can also inhibit cell over-proliferation while avoiding the use of temperature extremes or toxic cryoprotectants that are essential in cryopreservation.
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Affiliation(s)
- Jing Yang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China. Key Laboratory of Systems Bioengineering of the Ministry of Education, Tianjin University, Tianjin 300072, China. Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin, 300072, China
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12
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Schmieder AH, Caruthers SD, Keupp J, Wickline SA, Lanza GM. Recent Advances in 19Fluorine Magnetic Resonance Imaging with Perfluorocarbon Emulsions. ENGINEERING (BEIJING, CHINA) 2015; 1:475-489. [PMID: 27110430 PMCID: PMC4841681 DOI: 10.15302/j-eng-2015103] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The research roots of 19fluorine (19F) magnetic resonance imaging (MRI) date back over 35 years. Over that time span, 1H imaging flourished and was adopted worldwide with an endless array of applications and imaging approaches, making magnetic resonance an indispensable pillar of biomedical diagnostic imaging. For many years during this timeframe, 19F imaging research continued at a slow pace as the various attributes of the technique were explored. However, over the last decade and particularly the last several years, the pace and clinical relevance of 19F imaging has exploded. In part, this is due to advances in MRI instrumentation, 19F/1H coil designs, and ultrafast pulse sequence development for both preclinical and clinical scanners. These achievements, coupled with interest in the molecular imaging of anatomy and physiology, and combined with a cadre of innovative agents, have brought the concept of 19F into early clinical evaluation. In this review, we attempt to provide a slice of this rich history of research and development, with a particular focus on liquid perfluorocarbon compound-based agents.
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Affiliation(s)
- Anne H. Schmieder
- Division of Cardiology, Washington University School of Medical, St. Louis, MO 63110, USA
| | - Shelton D. Caruthers
- Toshiba Medical Research Institute USA, Inc., Cleveland, OH 44143, USA
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA
| | - Jochen Keupp
- Philips Research Hamburg, Hamburg 22335, Germany
| | - Samuel A. Wickline
- Division of Cardiology, Washington University School of Medical, St. Louis, MO 63110, USA
| | - Gregory M. Lanza
- Division of Cardiology, Washington University School of Medical, St. Louis, MO 63110, USA
- Correspondence author.
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13
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Appel AA, Larson JC, Jiang B, Zhong Z, Anastasio MA, Brey EM. X-ray Phase Contrast Allows Three Dimensional, Quantitative Imaging of Hydrogel Implants. Ann Biomed Eng 2015; 44:773-81. [PMID: 26487123 DOI: 10.1007/s10439-015-1482-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/05/2015] [Indexed: 10/22/2022]
Abstract
Three dimensional imaging techniques are needed for the evaluation and assessment of biomaterials used for tissue engineering and drug delivery applications. Hydrogels are a particularly popular class of materials for medical applications but are difficult to image in tissue using most available imaging modalities. Imaging techniques based on X-ray Phase Contrast (XPC) have shown promise for tissue engineering applications due to their ability to provide image contrast based on multiple X-ray properties. In this manuscript, we investigate the use of XPC for imaging a model hydrogel and soft tissue structure. Porous fibrin loaded poly(ethylene glycol) hydrogels were synthesized and implanted in a rodent subcutaneous model. Samples were explanted and imaged with an analyzer-based XPC technique and processed and stained for histology for comparison. Both hydrogel and soft tissues structures could be identified in XPC images. Structure in skeletal muscle adjacent could be visualized and invading fibrovascular tissue could be quantified. There were no differences between invading tissue measurements from XPC and the gold-standard histology. These results provide evidence of the significant potential of techniques based on XPC for 3D imaging of hydrogel structure and local tissue response.
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Affiliation(s)
- Alyssa A Appel
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL, 60616, USA.,Research Service, Edward Hines Jr. VA Hospital, Hines, IL, USA
| | - Jeffery C Larson
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL, 60616, USA.,Research Service, Edward Hines Jr. VA Hospital, Hines, IL, USA
| | - Bin Jiang
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL, 60616, USA.,Research Service, Edward Hines Jr. VA Hospital, Hines, IL, USA
| | - Zhong Zhong
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY, USA
| | - Mark A Anastasio
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Eric M Brey
- Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn St, Chicago, IL, 60616, USA.
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14
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Köllmer M, Appel AA, Somo SI, Brey EM. Long-Term Function of Alginate-Encapsulated Islets. TISSUE ENGINEERING PART B-REVIEWS 2015; 22:34-46. [PMID: 26414084 DOI: 10.1089/ten.teb.2015.0140] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human trials have demonstrated the feasibility of alginate-encapsulated islet cells for the treatment of type 1 diabetes. Encapsulated islets can be protected from the host's immune system and remain viable and functional following transplantation. However, the long-term success of these therapies requires that alginate microcapsules maintain their immunoprotective capacity and stability in vivo for sustained periods. In part, as a consequence of different encapsulation strategies, islet encapsulation studies have produced inconsistent results in regard to graft functioning time, stability, and overall metabolic benefits. Alginate composition (proportion of M- and G-blocks), alginate purity, the cross-linking ions (calcium or barium), and the presence or absence of additional polymer coating layers influence the success of cell encapsulation. This review summarizes the outcomes of long-term studies of alginate-encapsulated islet transplants in animals and humans and provides a critical discussion of the graft failure mechanisms, including issues with graft biocompatibility, transplantation site, and integrity of the encapsulated islet grafts. Strategies to improve the mechanical stability of alginate capsules and methods for monitoring graft survival and function in vivo are presented.
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Affiliation(s)
- Melanie Köllmer
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois
| | - Alyssa A Appel
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Sami I Somo
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Eric M Brey
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
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15
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Oskolkov N, Bar-Shir A, Chan KW, Song X, van Zijl PC, Bulte JW, Gilad AA, McMahon MT. Biophysical Characterization of Human Protamine-1 as a Responsive CEST MR Contrast Agent. ACS Macro Lett 2015; 4:34-38. [PMID: 25642384 PMCID: PMC4307908 DOI: 10.1021/mz500681y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
![]()
The protamines are a low-molecular-weight,
arginine-rich family
of nuclear proteins that protect chromosomal DNA in germ cells by
packing it densely using electrostatic interactions. Human protamine-1
(hPRM1) has been developed as a magnetic resonance imaging (MRI) chemical
exchange saturation transfer (CEST) reporter gene, based on a sequence
that is approximately 50% arginine, which has a side chain with rapidly
exchanging protons. In this study, we have synthesized hPRM1 and determined
how its CEST MRI contrast varies as a function of pH, phosphorylation
state, and upon noncovalent interaction with nucleic acids and heparin
(as antagonist). CEST contrast was found to be highly sensitive to
phosphorylation on serine residues, intra- and intermolecular disulfide
bridge formation, and the binding of negatively charged nucleotides
and heparin. In addition, the nucleotide binding constants (Keq) for the protamines were determined through
plotting the molar concentration of heparin versus CEST contrast and
compared between hPRM1 and salmon protamine. Taken together, these
findings are important for explaining the CEST contrast of existing
arginine-rich probes as well as serving as a guideline for designing
new genetic or synthetic probes.
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Affiliation(s)
- Nikita Oskolkov
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Amnon Bar-Shir
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Kannie W.Y. Chan
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Xiaolei Song
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Peter C.M. van Zijl
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Jeff W.M. Bulte
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Assaf A. Gilad
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Michael T. McMahon
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
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16
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Liang Y, Bar-Shir A, Song X, Gilad AA, Walczak P, Bulte JWM. Label-free imaging of gelatin-containing hydrogel scaffolds. Biomaterials 2014; 42:144-50. [PMID: 25542802 DOI: 10.1016/j.biomaterials.2014.11.050] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/13/2014] [Accepted: 11/25/2014] [Indexed: 10/24/2022]
Abstract
Composite hyaluronic acid (HA) hydrogels containing gelatin are used in regenerative medicine as tissue-mimicking scaffolds for improving stem cell survival. Once implanted, it is assumed that these biomaterials disintegrate over time, but at present there is no non-invasive imaging technique available with which such degradation can be directly monitored in vivo. We show here the potential of chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) as a label-free non-invasive imaging technique to monitor dynamic changes in scaffold composition in vivo. The CEST properties of the three individual hydrogel components (HA, GelinS, and polyethylene glycol diacrylate) were first measured in vitro. The complete hydrogel was then injected into the brain of immunodeficient rag2(-/-) mice and CEST MR images were obtained at day 1 and 7 post-transplantation. In vitro, GelinS gave the strongest CEST signal at 3.6 ppm offset from the water peak, originating from the amide protons present in gelatin. In vivo, a significant decrease in CEST signal was observed at 1 week post-implantation. These results were consistent with the biodegradation of the GelinS component, as validated by fluorescent microscopy of implanted hydrogels containing Alexa Fluor 488-labeled GelinS. Our label-free imaging approach should be useful for further development of hydrogel formulations with improved composition and stability.
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Affiliation(s)
- Yajie Liang
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amnon Bar-Shir
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xiaolei Song
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Assaf A Gilad
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Piotr Walczak
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jeff W M Bulte
- Russell H. Morgan Dept. of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Dept. of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Dept. of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Dept. of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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