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Seeing Stem Cells Helps in Fight Against
Peripheral Arterial Disease
Dorota A Kedziorek, MD, Piotr Walczak, MD, PhD,
Yingli Fu, PhD, Frank Wacker, MD, Dara L
Kraitchman, VMD, PhD Johns Hopkins
University School of Medicine Russell H. Morgan
Department of Radiology and Radiological
Science Baltimore, MD
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Presenter Disclosure Information

• I will discuss off label use and/or
  investigational use of contrast agents in my
  presentation.
• Financial Relationships to disclose
• Bayer Schering Pharma AG
• Boston Scientific Corporation
• Surgi-vision, Inc.

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Peripheral Arterial Disease (PAD)

• PAD affects 8-12 million Americans.
• 1 in 5 patients with critical limb ischemia have
  severe enough disease to be ineligible for
  conventional medical or surgical
  revascularization therapy.

• Gene, protein, and cellular therapies offer an
  alternative means to attack the response
  to occlusion by therapeutic arteriogenesis.

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How to create new blood vessels?
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Problems with Current Cell Therapy

1. Cannot see where cells are injected.

Needles marking injection sites
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Problems with Cell Therapy

1. Cannot see where cells are injected.
2. Large number of cells die after administration

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Solution Place Cells in Seaweed Bubble
APA Alginate-poly-L-lysine-alginate
Lim and Sun, Science 1980

• Biocompatible
• - Provides surface for cell adhesion
• Selective permeability
• - Blocks antibody and cellular destruction good
  for transplanted donor cells
• - Permits diffusion of nutrients and waste
  products.

IgG, IgM
O2, Glu
VEGF, PGE2, IL-8, IL-6, HGF, etc.

Courtesy Ming Chen
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What If Imaging Visible Capsules Were Possible?
Liquid Oxygen

• Trimodal Imaging Agent
• Bromine X-ray
• Perfluorocarbon U/S
• 19F - MRI

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Imaging Sensitivity to PFOB Caps
capsules/dot
5
10
25
c-arm CT
19F MRI
2 cm
Fu et al., SCMR 2009
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X-ray Monitoring of PFOB Caps Delivery in a
Rabbit PAD Model
Immediately after injection
Five weeks post-injection
PFOB Caps
Unlabeled
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Can see the PFOB Cap, but is the cell alive?
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Bioluminescence Imaging
Oxyluciferin
Luciferin
Luciferase
ATP
Light
High
Bioluminescence Signal
Cells expressing luciferase
Low
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Bioluminescence imaging of Embryonic Stem Cells
A
P/s/cm2/sr
P/s/cm2/sr
P/s/cm2/sr
P/s/cm2/sr
P/s/cm2/sr
Cao F, et al. Circulation 20061131005-14
Day 5
Control
Day 10

• Reporter Probe Dose Intravenous Injection
• Rabbit 10 X Rat!
• Patient 150 X Rat!

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Animal study 1
Immediately post injection
24 hrs post injection
PFOB encapsulated transfected MSCs
Naked transfected MSCs
Naked transfected MSCs
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How to Administer Reporter Probe?
DynaCT 24 hrs post
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Using Interventional Radiology to Guide Reporter
Probe Injections
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C-arm CT Targeting
Immediately post injection
Pure alginate caps
PFOB encapsulated transfected MSCs
48 hrs post injection
24 hrs post injection
PFOB encapsulated transfected MSCs
PFOB encapsulated transfected MSCs
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Seaweed Plus Liquid Oxygen Plus Firefly Brew
Seaweed (Protanal)

• Happy Cells
• FDA-approved agents in bubble
• Better able to survive to create new blood
  vessels for PAD
• Visible by X-ray for Interventional Radiologist
  to tailor therapy

Liquid Oxygen (Oxygent)
_
Firefly
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Acknowledgments

• Mark Pittenger
• Randall Young
• Christine Lorenz
• Tina Ehtati
• Steve Shea
• Wesley Gilson
• Robert Krieg

• Aravind Arepally
• Brad Barnett
• Jeff Bulte
• Lawrence Hofmann
• Gary Huang

NIH R01-HL63439, R01-HL73223, K08 EB004348,
R21-HL89029, R01-EB007825, and
MD-SCRFII-0399-00
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Conclusions

• Seaweed plus liquid oxygen plus firefly brew
• Enhanced cell viability
• Enables visualization with X-ray and Optical
  Imaging
• C-arm CT provides a minimally invasive method to
  target the reporter probe for localized
  injections to our X-ray visible capsules to
  reduce dose of reporter probe.
• First demonstration of X-ray visible stem cell
  therapeutic with ability to measure
  cell viability by imaging.

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Trimodal Imaging
MRI
c-arm CT
US