Stem Cells Build New Blood
Vessels to Treat Peripheral
Arterial Disease
Dorota A Kedziorek, MD, Yingli Fu, PhD, Piotr
Walczak, MD, PhD, Tina Ehtiati, PhD, Steffi
Valdeig, Gary Huang, Jeff W.M. Bulte, PhD,
Lawrence V. Hofmann, MD, Frank K. Wacker, MD,
Dara L Kraitchman, VMD, PhD
Johns Hopkins University
School of Medicine
Russell H. Morgan Department of Radiology and
Radiological Science
Baltimore, MD
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.
• Siemens Healthcare USA
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.
• Normal signals to build new
vessels are in foot, but
problem higher in the leg.
How to create new blood vessels?
Problem with Current Cell Therapy
Large numbers of cell are administered but fail to
engraft due to:
• Poor
oxygen/nutrient
supply
• Inflammatory
cytokines
• Survival signals
by cell-cell
contact lost
Zhang, Murry et al., J Mol Cell Cardiol 33, 907–921 (2001)
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
O2, Glu donor cells
VEGF, PGE2,
- Permits diffusion of
IL-8, IL-6, HGF, etc. nutrients and waste
products.
IgG, IgM
Courtesy: Ming Chen
Problem with Current Cell Therapy
Cannot “see” where cells are injected.
Needles marking injection sites
What If “Imaging Visible” Capsules Were
Possible?
“Liquid Oxygen”
•Trimodal Imaging Agent
•Bromine – X-ray
•Perfluorocarbon – U/S
•19F - MRI
C-arm CT
• Flat panel
detector
• 16 second
digital
subtraction
angiogram
(DSA)
acquisition
MRI & CT of Seaweed Bubble Cells
Comparison
Registration
Error
Post-mortem/CT 2.83 ± 0.85
mm
CT/MRI
0.32 ± 0.14
mm
19F
MRI
C-arm CT
X-ray-visible &
“Firefly” Stem Cells
Bioluminescence Signal
How to See Stem Cells in Bubble?
High
Low
In Vivo Viability of MSCs
In Vivo MSCs Viability (%)
100
Blue: Nucleus
Green: Dying cell
80
60
40
20
0
0
1
3
7
Days After Administration
Seaweed Plus Liquid Oxygen
Plus Firefly “Brew”
Seaweed (Protanal®)
Liquid
Oxygen
(Oxygent®):
_
Firefly
• 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
In Vivo Experimental Protocol
Female New Zealand White Rabbits (n=21)
72 hr
2 wk
Harvest
SFA Occlusion
• Endovascular occlusion of the superficial
femoral artery with pre-occlusion angiogram
♀
♀
Liddell et al.,
JVIR,
2005;16(7):
991-8.
In Vivo Experimental Protocol
Female New Zealand White Rabbits (n=21)
XCaps + MSCs (n=5) Naked MSCs (n=5) Sham (n=6)
XCaps + No MSCs (n=5) 72 hr
2 wk
Harvest
SFA Occlusion
• Six IM injections X-ray capsules
• X-ray Fluoroscopic documentation of:
– X-ray Cap location
– Collaterals by X-ray Angiogram
XCap
♀
In Vivo Experimental Protocol
Female New Zealand White Rabbits (n=21)
XCaps + MSCs (n=5) Naked MSCs (n=5) Saline Sham (n=6)
XCaps + No MSCs (n=5) 72 hr
2 wk
Harvest
SFA Occlusion
XCap
Histopathology
Example: Empty XCap
Pre-occlusion
Day 14 Post-occlusion
Example: Xcap with Stem Cells
Pre-occlusion
Day 14 Post-occlusion
Efficacy of Stem Cells at Day 14
Empty Capsule
XCap with Stem Cells
TIMI Frame Count @ 14 Days
P<0.002
P<0.01P<NS
Time (sec)
Time
15
10
5
0
Xcap
Blank Xcaps Naked Cells
N=16
Histopathology – Vessel Density
CD31 Staining for Endothelium
19F
and 1H MRI
Trimodal Imaging
c-arm CT
BLI
Conclusions
An X-ray-visible capsule made of clinical grade
components was developed that:
1. enabled targeting of injections where most
needed using common interventional radiology
X-ray equipment.
2. enabled determination of cell viability in vivo.
3. enhanced cell viability after administration.
4. improved therapeutic effect of creating new
blood vessels for treatment of peripheral arterial
disease.
Acknowledgments
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Aravind Arepally
Brad Barnett
Jeff Bulte
Gary Huang
Steffi Valdeig
Ron Ouwerkerk
Cliff Weiss
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Mark Pittenger
Randall Young
Christine Lorenz
Tina Ehtati
Steve Shea
Wesley Gilson
Robert Krieg
NIH R01-HL63439, R01-HL73223, K08 EB004348,
R21-HL89029, R01-EB007825, and MD-SCRFII-0399-00