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Addressing barriers to clinical translation of extracellular vesicle therapeutics

molecular therapy : the journal of the American Society of Gene Therapy 2025年第5期33卷 1879-1880页

作者： Steven M Jay Fischell Department of Bioengineering University of Maryland College Park MD 20742 USA Robert E. Fischell Institute for Biomedical Devices University of Maryland College Park MD USA Marlene and Stewart Greenebaum Comprehensive Cancer Center University of Maryland Medical Center Baltimore MD USA Program in Molecular and Cell Biology University of Maryland College Park MD 20742 USA. Electronic address: smjay@umd.edu.

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Integrating cell confinement in a perfusion bioreactor improves iMSC extracellular vesicle production and potency

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Cytotherapy 2025年第5期27卷 S87-S88页

作者： E.H. Powsner K. Nikolov S.M. Jay Bioengineering University of Maryland College Park MD United States Program in Molecular Biology University of Maryland College Park MD United States

Background & Aim Mesenchymal stem cell extracellular vesicles (MSC EVs) have been reported to have broad therapeutic potential and are the most investigated EVs for therapeutic applications in clinical trials. However, the translational potential of MSC EVs is limited by MSC donor variability, EV potency, and lack of a versatile scalable manufacturing approach. Our group previously established that MSC EV potency can be improved via mechanoregulation – the exposure of producer MSCs to specific physical cues during EV generation. The goal of this project is to assess the potential of mechanoregulation, specifically cell confinement, to overcome donor variability issues and to be applied for large-scale EV production, thus presenting a potential solution to the most significant limitations to MSC EV translation. Methodology Since donor MSCs exhibit significant variability and limited expansion, we evaluated an alternative, renewable cell source; MSCs derived from induced pluripotent stem cells (iMSCs). iMSCs were seeded on 5 and 50 µm micropillar arrays fabricated via photolithography and polydimethylsiloxane molding. The isolated EVs were assessed for their mechanoresponsiveness and angiogenic effects via tube formation assay. Additionally, while confinement is a promising approach to improve potency, EV yield from static culture remains low. Therefore, we designed a 3D-printed bioreactor scaffold that can incorporate MSC confinement. Flow rate was optimized based on EV production/cell, protein/EV, and the EVs’ angiogenic and wound repair activity as measured by tube formation and gap closure assays, respectively. Results The level of tube formation by the EVs corresponded with increasing confinement, so we moved forward with iMSCs in the confinement bioreactor system. We determined that a 5 mL/min flow rate achieved a 48-fold increase and 1.09-fold decrease in EV/cell and protein/EV, respectively, compared to static confinement and a 67-fold increase and 2.14-fold d

关键词： Exosome Mesenchymal stem/stromal cell

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Accelerating Radiochemistry Development: Automated Robotic Platform for Performing Up to 64 Droplet Radiochemical Reactions in a Morning

SSRN

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SSRN 2023年

作者： Jones, Jason Do, Viviann Lu, Yingqing van Dam, R. Michael Los AngelesCA United States Physics and Biology in Medicine Interdepartmental Graduate Program UCLA United States Department of Molecular & Medical Pharmacology David Geffen School of Medicine UCLA United States Department of Biochemistry UCLA United States Department of Bioengineering Henry Samueli School of Engineering and Applied Science UCLA United States

The growing discovery and development of novel radiopharmaceuticals and radiolabeling methods requires an increasing capacity for radiochemistry experiments. However, such studies typically rely on radiosynthesizers designed for clinical batch production rather than research, greatly limiting throughput. Two general solutions are being pursued to address this: developing new synthesis optimization algorithms to minimize how many experiments are needed, and developing apparatus with enhanced experiment throughput. We describe here a novel high-throughput system based on performing arrays of droplet-based reactions at 10 μL volume scale in parallel. The automatic robotic platform can perform a set of 64 experiments in ~3 h (from isotope loading to crude product, plus sampling onto TLC plates), plus ~1 h for off-line radio-TLC analysis and radioactivity measurements, rather than the weeks or months that would be needed using a conventional system. We show the high repeatability and low crosstalk of the platform and demonstrate optimization studies for two 18F-labeled tracers. This novel automated platform greatly increases the practicality of performing arrays of droplet reactions by eliminating human error, vastly reducing tedium and fatigue, minimizing radiation exposure, and freeing up radiochemist time for more intellectually valuable pursuits. © 2023, The Authors. All rights reserved.

关键词： Drops

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Optimizing Marker Design to Improve Precision of Optical Camera-Based Rigid-Body Motion Tracking and Correction in Medical Imaging

Optimizing Marker Design to Improve Precision of Optical Cam...

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2021 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2021

作者： Fisher, Jonathan Kim, Chris C. Groll, Andrew Levin, Craig S. Stanford University Department of Electrical Engineering CA United States Stanford University Department of Computer Science CA United States Stanford University Department of Radiology Molecular Imaging Program CA United States Bioengineering at Stanford University Department of Radiology and by Courtesy Physics Electrical Engineering CA United States

ISBN: (纸本)9781665421133

In this work we evaluated the performance of a camera-based rigid body motion correction solution using a 2D checkerboard marker and a 3D encoded marker. The context of the results presented is in PET/MR imaging, but in principle this motion compensation method could be used in any type of medical imaging modality. A high precision, computer-controlled motion stage with four degrees of freedom was used to control the marker positions and orientations (a.k.a. 'poses'). Still images of the markers taken in different poses mimicking a patient moving her/his head from side to side, were used to assess performance of this method. Comparing the known stage motion to the estimated motion, our results indicate that the 2D marker achieves better angular accuracy while the 3D marker's translational (linear) accuracy is superior. For all axes, the angular error was less than 0.96, 0.35 [deg], and the translational error was less than 2.24, 4.76 [mm] for the 3D and 2D markers, respectively. © 2021 IEEE.

关键词： Medical imaging

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Imaging Studies using PhytoPET, a Positron Emission Tomography (PET) scanner developed for Plant Imaging

Imaging Studies using PhytoPET, a Positron Emission Tomograp...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： M.N. Ullah S. J. Lee D. Innes A. Weisenberger S. Abbaszadeh C. Levin Radiology Stanford University Stanford California United States of America Thomas Jefferson National Accelerator Facility Newport News Virginia United States of America Electrical and Computer Engineering University of California Santa Cruz Santa Cruz California United States of America Electrical Engineering Bioengineering Physics and Molecular Imaging Program at Stanford (MIPS) Stanford University Stanford California United States of America

ISBN: (数字)9798350388152

ISBN: (纸本)9798350388169

Utilizing Positron Emission Tomography-Computed Tomography (PET-CT) for three-dimensional imaging of plant dynamic rhizosphere phenomena presents a promising avenue for quantitative analysis of soil structure challenges. Integrating such imaging technology into Earth System Models (ESMs) could enhance the precision of soil structure data. Here, we are reporting the evaluation of PhytoPET, a PET scanner developed at the Thomas Jefferson National Accelerator Facility, designed for studying rhizosphere dynamics. PhytoPET features adaptable PET detector configurations, including 5 cm x 5 cm Hamamatsu H8500 position-sensitive photomultiplier tubes (PMT) coupled to $48 \times 48$ LYSO:Ce scintillator arrays, with individual pixel dimensions of $1 \mathrm{~mm} \times 1 \mathrm{~mm} \times 10 \mathrm{~mm}$. To assess and optimize PhytoPET’s imaging performance, three data sets were acquired and reconstructed for mini-resolution phantom scans. These included scenarios without experimental sensitivity maps, with detector sensitivity map correction using experimental data, and with multi-angle scanning to mitigate limited-angle tomography artifacts present due to the relatively large gaps between detectors. The average peak-to-valley ratio (PVR) for selected line profile data with analytical sensitivity, experimental sensitivity, and experimental sensitivity correction plus multi-angle scanning were measured to be 1.90, 1.93, and 3.0, respectively. Reconstructed images from all scenarios are presented, showing that experimental sensitivity map correction combined with multi-angle scanning outperforms the other two approaches.

关键词： Temperature sensors Semiconductor device measurement Sensitivity Scintillators Statistical analysis Semiconductor detectors Positrons

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Non-invasive label-free assessment of contraction induced damage to skeletal muscle structure using second harmonic generation (SHG) microscopy 19

Non-invasive label-free assessment of contraction induced da...

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Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XIX 2021

作者： Willen, Maeve Helton, Michael Zerafa, Samantha A. Diggs, Alisha B. Young, James R. Brooks, Susan V. Larkin, Lisa M. Mycek, Mary-Ann Biomedical Engineering Department University of Michigan Ann ArborMI United States Applied Physics Program University of Michigan Ann ArborMI United States Bioengineering Department Harvard University CambridgeMA United States Molecular and Integrative Physiology Department University of Michigan Ann ArborMI United States

ISBN: (数字)9781510641303

ISBN: (纸本)9781510641297

Second harmonic generation (SHG) microscopy is a second-order nonlinear optical scattering process that can nondestructively image myosin filament microarchitecture up to 500 μm in depth due to its high spatial resolution, optical sectioning capabilities, and elastic scattering properties. The distribution, alignment, and spatial orientation of myosin filaments largely dictates the mechanical properties of skeletal muscle. Noninvasive quantification of these metrics in-vivo or in-vitro could be indicative of skeletal muscle function and viability. Here, we present a novel algorithm to quantitate sarcomere length with high spatial resolution and accuracy when compared to traditional approaches. Our approach runs in real-time and is less sensitive to instrumental noise and artifacts that shade regions of the image. We have tested this technique on ex-vivo SHG images of rat lumbrical muscles that have been damaged following standardized lengthening contraction protocols. Our approach shows accurate quantitation of sarcomere lengths within 1% compared to manual calculations. This algorithm can be used to reliably analyze SHG images in real-time to assess the structure and function of skeletal muscle tissue in a non-invasive, quantitative, and sterile manner. © 2021 SPIE

关键词： Harmonic generation

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Mitochondria-derived small RNAs as diagnostic biomarkers in lung cancer patients through a novel ratio-based expression analysis methodology

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Genes & Diseases 2023年第3期10卷 1055-1061页

作者： Zongtao Yu Shaoqiu Chen Zhenming Tang Ying Tang Zhougui Ling Hongwei Wang Ting Gong Zitong Gao Gehan Devendra Gang Huang Wei Chen Youping Deng Department of Laboratory Medicine Affiliated Taihe Hospital of Xi'an Jiaotong University Health Science CenterShiyanHubei 710061China Department of Internal Medicine Rush University Cancer CenterRush University Medical CenterKidston HouseChicagoIL 60612USA Department of Quantitative Health Sciences John A.Burns School of MedicineUniversity of Hawaii at ManoaHonoluluHI 96813USA Molecular Biosciences and Bioengineering Program College of Tropical Agriculture and Human ResourcesThe University of Hawaii at ManoaHonoluluHI 96822USA Department of Pulmonary and Critical Care Medicine The Fourth Affiliated Hospital of Guangxi Medical UniversityLiuzhouGuangxi 545005China Division of Research and Development Decoding Therapeutics CorpMt ProspectIL 60056USA Division Chief Pulmonary&Critical Care Medicine The Queen’s Medical CenterJohn A Burns School of MedicineHonoluluHI 96813USA Shanghai Key Laboratory for Molecular Imaging Shanghai University of Medicine and Health SciencesShanghai 201318China Department of Laboratory Medicine The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'anShaanxi 710061China

Small non-coding RNAs are potential diagnostic biomarkers for lung cancer. Mitochondria-derived small RNA (mtRNA) is a novel regulatory small non-coding RNA that only recently has been identified and cataloged. Currently, there are no reports of studies of mtRNA in human lung cancer. Currently, normalization methods are unstable, and they often fail to identify differentially expressed small non-coding RNAs (sncRNAs). In order to identify reliable biomarkers for lung cancer screening, we used a ratio-based method using mtRNAs newly discovered in human peripheral blood mononuclear cells. In the discovery cohort (AUC = 0.981) and independent validation cohort (AUC = 0.916) the prediction model of eight mtRNA ratios distinguished lung cancer patients from controls. The prediction model will provide reliable biomarkers that will allow blood-based screening to become more feasible and will help make lung cancer diagnosis more accurate in clinical practice.

关键词： Lung cancer Mitochondria-derived small RNAs Plasma Ratio Small non-coding RNAs

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Inter-Modular Synchronization in a TOF-PET System Using the Natural LYSO Background Radioactivity

Inter-Modular Synchronization in a TOF-PET System Using the ...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Qian Dong Salar Sajedi Craig S. Levin Departments of Electrical Engineering and Radiology Stanford University Stanford CA USA Departments of Radiology Stanford University Stanford CA USA Department of Radiology Electrical Engineering Bioengineering and Physics Stanford University and Molecular Imaging Program at Stanford (MIPS) Stanford CA USA

Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) is a promising platform for clinical and research with applications in oncology, neurology, cardiology, and inflammatory diseases. One challenge for simultaneous PET/MRI is the mutual electromagnetic interference between the two imaging modalities. MR-compatibility is required for any system integrating with an MR scanner. It is difficult to achieve both time-of-flight (TOF) capability and MR compatibility using the standard inter-modular synchronization method that uses synchronization signals based on either optical fibers or electrical cables. In this paper, we propose a new method to achieve inter-modular synchronization for PET systems without additional electrical cables or optical fibers by using the natural background radiation present in lutetium-yttrium oxyorthosilicate (LYSO) scintillator crystals. We investigated the feasibility of the approach with two full detector modules comprising 1536 one-to-one coupled 3x3x20mm 3 LYSO crystal-silicon photomultipliers (SiPM) channels. Using the natural LYSO background radiation for synchronization resulted in a CTR of 274.6ps FWHM with a peak location at -13.8ps, compared to the re-calibrated (reference) results with a CTR of 271.1ps FWHM with a peak location at -10.3ps.

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Initial System Performance Evaluation of a Second-Generation RF-Penetrable Brain TOF-PET Insert for Simultaneous PET/MRI

Initial System Performance Evaluation of a Second-Generation...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Qian Dong Chen-Ming Chang Andrew Groll Ilaria Sacco Ronald D. Watkins Derek Innes Zander Adams Craig S. Levin Departments of Electrical Engineering and Radiology Stanford University Stanford CA USA Departments of Radiology Stanford University Stanford CA USA Department of Radiology Electrical Engineering Bioengineering and Physics Stanford University Molecular Imaging Program at Stanford (MIPS) Stanford CA USA

Simultaneous positron emission tomography / magnetic resonance imaging (PET/MRI) has unique advantages in providing complementary, concurrent information about anatomic, functional, and molecular changes in diseases. We are developing an MR-compatible RF-penetrable brain time-of-flight (TOF)-PET insert with a smaller scintillation crystal size and smaller PET ring diameter compared to clinical whole-body PET scanners, which leads to higher spatial resolution and sensitivity. We reported PET performance and MR-compatibility of our MR-compatible detector modules before. This paper reports the initial PET system performance of our second-generation RF-penetrable PET insert with half of the system (8 out of 16 detector modules) assembled. The excellent global photopeak energy resolution and global CTR, 230.5 ± 0.2ps FWHM and 11.29 ± 0.01% FWHM, are preserved as we scale up the system. The coincidence count rate is 92.7 ± 0.1 kcps and the average temperature of all ASIC chips on 8 detector modules is 24.4 ± 0.2 oC over a one-hour point source experiment. The system performance during the one hour experiment is stable. For the resolution phantom study, we can resolve all 3.2mm rods and part of 2.8mm rods without applying normalization, TOF, scatter, attenuation, and random corrections. The image quality will be significantly improved after we assemble the remaining detector modules and implement all image corrections. We will report a resolution phantom study with the full 16 detector modules assembled and all image corrections implemented and MR compatibility evaluation at the conference.

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Compact Design of an FPGA Based Data Acquisition (DAQ) System for an RF-penetrable TOF-PET Brain Dedicated Insert

Compact Design of an FPGA Based Data Acquisition (DAQ) Syste...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Qian Dong Salar Sajedi Ke Cui Craig S. Levin Departments of Electrical Engineering and Radiology Stanford University Stanford CA USA Departments of Radiology Stanford University Stanford CA USA Department of Radiology Electrical Engineering Bioengineering and Physics Stanford University Molecular Imaging Program at Stanford (MIPS) Stanford CA USA

With advanced PET system development, processing a high number of channels online is necessary and critical, especially for applications with one-to-one coupled crystals and silicon photomultipliers (SiPMs). We are developing an RF-penetrable TOF-PET brain dedicated insert with lutetiumyttrium oxyorthosilicate (LYSO) crystals one-to-one coupled to SiPMs. There are 768 crystal-SiPM channels per detector module, and a PET insert ring comprises 16 detector modules. A compact design to process 12288 channels with a designed 20 kcps singles count rate per channel in real-time is challenging. In this paper, we developed an FPGA-based data acquisition (DAQ) system using a commercial evaluation board and characterized its performance with two full detector modules; each having 768 crystal-SiPM channels. We achieved a global energy resolution of 11.46 ± 0.02% FWHM and a global coincidence time resolution of 224.47 ± 0.15ps FWHM over 1536 SiPM-crystal channels with DAQ online processing. All parameters including global energy resolution, global CTR, coincidence count rate, and random count rate changed less than 3% between offline processing and online DAQ processing.

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