Fluorine-19 Labeling of Stromal Vascular Fraction Cells for Clinical Imaging Applications.
Stromal vascular fraction (SVF) cells are used clinically for various therapeutic targets. The location and persistence of engrafted SVF cells are important parameters for determining treatment failure versus success. We used the GID SVF-1 platform and a clinical protocol to harvest and label SVF cells with the fluorinated ((19)F) agent CS-1000 as part of a first-in-human phase I trial (clinicaltrials.gov identifier NCT02035085) to track SVF cells with magnetic resonance imaging during treatment of radiation-induced fibrosis in breast cancer patients. Flow cytometry revealed that SVF cells consisted of 25.0% ± 15.8% CD45+, 24.6% ± 12.5% CD34+, and 7.5% ± 3.3% CD31+ cells, with 2.1 ± 0.7 × 10⁵ cells per cubic centimeter of adipose tissue obtained. Fluorescent CS-1000 (CS-ATM DM Green) labeled 87.0% ± 13.5% of CD34+ progenitor cells compared with 47.8% ± 18.5% of hematopoietic CD45+ cells, with an average of 2.8 ± 2.0 × 10¹² ¹⁹F atoms per cell, determined using nuclear magnetic resonance spectroscopy. The vast majority (92.7% ± 5.0%) of CD31+ cells were also labeled, although most coexpressed CD34. Only 16% ± 22.3% of CD45-/CD31-/CD34- (triple-negative) cells were labeled with CS-ATM DM Green. After induction of cell death by either apoptosis or necrosis, >95% of ¹⁹F was released from the cells, indicating that fluorine retention can be used as a surrogate marker for cell survival. Labeled-SVF cells engrafted in a silicone breast phantom could be visualized with a clinical 3-Tesla magnetic resonance imaging scanner at a sensitivity of approximately 2 × 10⁶ cells at a depth of 5 mm. The current protocol can be used to image transplanted SVF cells at clinically relevant cell concentrations in patients.


CONCLUSIONS
Stromal vascular fraction (SVF) cells harvested from adipose tissue offer great promise in regenerative medicine, but methods to track such cell therapies are needed to ensure correct administration and monitor survival. A clinical protocol was developed to harvest and label SVF cells with the fluorinated (¹⁹F) agent CS-1000, allowing cells to be tracked with (19)F magnetic resonance imaging (MRI). Flow cytometry evaluation revealed heterogeneous ¹⁹F uptake in SVF cells, confirming the need for careful characterization. The proposed protocol resulted in sufficient ¹⁹F uptake to allow imaging using a clinical MRI scanner with point-of-care processing.
Division of Magnetic Resonance Research, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Laura C
LC
Rose
Division of Magnetic Resonance Research, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Deepak K
DK
Kadayakkara
Department of Electrical and Computer Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Guan
G
Wang
Division of Magnetic Resonance Research, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Amnon
A
Bar-Shir
Celsense Inc., Pittsburgh, Pennsylvania, USA.
Brooke M
BM
Helfer
Celsense Inc., Pittsburgh, Pennsylvania, USA.
Charles F
CF
O'Hanlon
Division of Magnetic Resonance Research, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Dara L
DL
Kraitchman
CosmeticSurg, LLC, Luthersville, Maryland, USA.
Ricardo L
RL
Rodriguez
Division of Magnetic Resonance Research, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA Department of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA jwmbulte@mri.jhu.edu.
Jeff W M
JW
Bulte
D000328:Adult; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D002470:Cell Survival; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D005434:Flow Cytometry; D005461:Fluorine / Q000737:chemistry* / Q000494:pharmacology; D066235:Fluorine-19 Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D011832:Radiation Injuries / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy; D011859:Radiography; D013194:Staining and Labeling / Q000379:methods*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000000981:diagnostic imaging* / Q000378:metabolism*; D017154:Stromal Cells / Q000000981:diagnostic imaging / Q000378:metabolism
D005461:Fluorine
Breast cancer; Cell tracking; Fluorine; Liposuction; Magnetic resonance imaging; Radiation-induced fibrosis; Stromal vascular fraction