This document summarizes tissue engineering approaches for engineering cardiovascular tissues. It discusses how cardiovascular disease is a leading cause of death and current treatment limitations. The main targets for tissue engineering are blood vessels, heart muscle, and heart valves. Commonly used biomaterials include polymeric scaffolds, hydrogels, and decellularized tissues. Appropriate cell types and biomolecules are also discussed. The challenges of engineering different cardiovascular tissues like blood vessels, heart valves, and heart muscle are briefly outlined.

1. http://www.tissuegrowth.com/tissuegrowt
Raul Soto
h/images/cardiovascular%20system%2024
8px.jpg
BME501 Tissue Engineering

2. http://www.2n2u.com/wp-content/uploads/2011/05/image6.png
 Introduction
 Biomaterials
 Cells
 Biomolecules
 TE Product Requirements
 Heart Valves
 Blood Vessels
 Myocardium
 Companies
 Products & Therapies
 Proposed Product

3.  Cardiovascular diseases
 Leading cause of death worldwide for both men and
women.
 Treatment Limitations:
 restricted intrinsic regeneration capacity of the heart
 Cardiomyocytes (adult heart muscle cells) cannot divide to
replace injured cells
 lack of organs for transplantation.
 Main Targets for Tissue Engineering
 Blood vessels
 Heart muscle – myocardium
 Heart valves

5. http://www.sciencecodex.com/files/different%20ways%20in%20which%20tissue%20engineers%20believe%20that%20heart%20muscle.jpg

6.  Most commonly used
biomaterials for cardio
Polymer scaffold
tissue engineering are:
 Biodegradable Polymeric
scaffolds (polyglycolic acid -
PGA)
http://union.igic.bas.bg/content_images/fe47f119130b1ae60
0f5ad23b26813eb.jpg
 Hydrogels (seeded with
collagen, fibrin, alginate)
Biodegradale scaffold
 Decellularized tissue
(composed of natural
ECMproteins: collagen,
elastin, fibronectin, etc)
http://www.ibi-sa.com/site/images/stories/prodotti22/cells-scaffold-
2d.jpg

7.  Scaffold provides
250-for-tridion_tcm18-95841.jpg
http://www.rsc.org/images/b706654f-
structure for cells / tissue
to grow and deliver
biomolecules (growth
factors, cytokines, etc.)
 Properties [chemical,
mechanical, biological]
should be adjusted to
provide appropriate
performance

8.  Appropriate mechanical
and physical properties
 Proper degradation rate
 No production of toxic
degradation products
 Promotes cell adhesion
http://www.nature.com/nmat/journal/v4/n7/images/nmat1421-f6.jpg  Integration into
surrounding tissue
 Minimal inflammatory /
immune response

9.  Cell types most commonly used for Cardiac
Tissue Engineering [Smart 2008]:
 Embryonic Stem Cells
 Bone Marrow-Derived Mesenchymal Stem Cells
 Skeletal Myoblasts
 Induced Pluripotent Stem Cells
 Multipotent Adult Germline Stem Cells
 Endothelial Progenitor Stem Cells
 Very Small Embryonic-like Stem Cells
 Endogenous Cardiac Stem Cells

10.  Found in many tissues and
organs
 Multipotent
 Extensive proliferation
potential
 Bone marrow-derived adult
stem cells can be differentiated
to many cell types :
 Cartilage
 Bone
http://www.sigmaaldrich.com/etc/medialib/life-science/stem-cell-
 Adipose (fat)
biology/mesenchymal-stem-cell.Par.0001.Image.457.gif
 Using adult stem cells allows
autologous cell transplantation

11.  Can differentiate into cells
from all three germ layers
of the body
 Ectoderm
 Endoderm
 Mesoderm
 Can self-renew http://www.openbiosystems.com/collateral/genomics/images/Cells%20and%20cell%20line
s/ES_cell_isolation.jpg
 Capable of
undifferentiated
proliferation in culture for
extended time

12.  Angiogenic factors
 Vasculogenic factors
 Growth factors
 Differentiation factors

13.  FGF :
 promotes proliferation and differentiation of endothelial cells,
smooth muscle cells, fibroblasts
 Ang1, Ang2
 Stabilize blood vessels
 PDGF and PDGFR
 Recruit smooth muscle cells
 TGF-β, endoglin and TGF-β receptors
 Produce ECM
 VE-cadherin, CD31
 Promote endothelial junctions
 Eprin
 Formation of veins or arteries
 Plasminogen activator inhibitor – 1
 Stabilize nearby vessels

14.  Biocompatibility:
 Minimize inflammatory and immunological responses
 Should have growth and healing capabilities similar to
native tissue
 Tissue strength, stiffness, cellularity, composition
should be similar to native tissue
 Functionality:
 Appropriate mechanical and hemodynamic
functionality
 Must be durable

15.  Blood Vessels:
 Must be able to withstand high-pressure fluid dynamics,
turbulence
 Valves
 Must be able to operate in a very dynamic and severe
environment.
 Open and close at 1 Hz, exposed to mechanical stresses, high-
pressure fluid dynamics, turbulence, etc.
 Myocardium Patch
 High vascularity is critical
 Mechanical and electrical anisotropy

16.  Valves have complex architecture
 TEHVs require complex molds
 Cellularize with myofibroblasts to obtain a
functional valve
http://www.sciencecodex.com/files/different%20ways%20in%20which%20tissue%20engineers%20believe%20that%20heart%20muscle.jpg

17.  Overview
The heart consists of four chambers
• Two atria (upper chambers)
• Two ventricles (lower chambers).
Valves are flaps that located on each
end of the two ventricles (lower
chambers of the heart).
Valves prevent the backward flow of
blood.
As the heart muscle contracts and
relaxes, the valves open and shut,
letting blood flow into the ventricles
and atria at alternate times.
http://www.edoctoronline.com/medical-atlas.asp?c=4&id=22190

18. American Heart Association • Approximately 90,000 heart valve
Heart Disease and Stroke Statistics 2011 replacements per year in the United
States
Valvular Heart Disease
ICD-9 424; ICD-10 I34 to I38. • Approximately 275,000 per year
Mortality 23,313 worldwide
Any-mention mortality 44,149
Hospital discharges 98,000 • In the pediatric population, 15–25% of
the congenital heart defects (>36,000/
year) are associated with the
pulmonary position, requiring repair or
replacement of the pulmonary valve.
http://circ.ahajournals.org/content/123/4/e18.full.pdf

19. ardiotext/tissueengineering.html
http://www.chir.uzh.ch/cardio/c
• Limitations of Mechanical valves
• Infections
• Thromboembolism
• Cannot grow
• important for pediatric
ypes_of_heart_valves.png
http://www.pages.drexel.edu/~nag38/Images/t
patients Caged
• No self-repair capability
Tilting
disc
• Limitations of Tissue-Engineered
valves Single
• Calcification of tissue leaflet
Bi-
leaflet

20.  3 main approaches [Nerem,
2004]:
 Cell seeding of biodegradable
valve matrices
 Cell seeding of decellularized
allograft or xenograft valves
 Promote repopulation and
adaptive remodeling of
decellularized allograft valves http://en.wikipedia.org/wiki/File:Apikal4D.gif

21.  Graft fabrication requires design of a suitable mold
 Walls are cellularized with smooth muscle cells
 Lumen is cellularized with endothelial cells
 Typical use is for coronary bypass surgery
http://www.sciencecodex.com/files/different%20ways%20in%20which%20tissue%20engineers%20believe%20that%20heart%20muscle.jpg

22.  Overview – Veins & Arteries
•Arteries carry oxygenated blood from
the heart to the body (except the
pulmonary artery).
• Veins carry deoxygenated blood used
by the body back to the heart (except
the pulmonary vein)
• Arteries are larger, thicker, and more
elastic than veins.
• Blood in arteries is at pressure
• Veins contain valves to prevent
backflow of blood
http://1.bp.blogspot.com/_Obwvpc-KSC4/S8Ud-
y0xQyI/AAAAAAAAAa8/QTBY1SKf_Z0/s1600/arterial%20stru
cture%20vs%20venous.JPG

23.  Atherosclerosis: approximately
515,000 coronary artery bypass
graft surgeries performed in the
USA per year
 Due to age or state of health,
many patients cannot provide an
appropriate vessel for a graft
http://healthguru.biz/wp-content/uploads/2011/02/Atherosclerosis.jpg

24.  x
 Integrate primary contractile-phenotype cells with
biomaterials
 Tissue-engineered cardiac patches can be used to
treat acute myocardial infarction
 Augment contractile function
 Promote revascularization of ischemic tissue
http://www.sciencecodex.com/files/different%20ways%20in%20which%20tissue%20engineers%20believe%20that%20heart%20muscle.jpg

25.  Overview – Myocardial Infarction (Heart Attack)
One or more regions of the
heart muscle experience a
severe and prolonged
decrease in oxygen supply
because of insufficient
coronary blood flow.
The affected muscle tissue
subsequently becomes
necrotic.
http://nursingcrib.com/nursing-notes-reviewer/myocardial-infarction/

26. • 425,000 deaths in the United States in 2006
(about one of every six deaths)
• 1,255,000 new and recurrent attacks per
year.
• About 34 percent of people who experience
a coronary attack in a given year die from it.
• 17,600,000 victims of angina (chest pain due
to coronary heart disease), heart attack and
other forms of coronary heart disease are
still living.

27. [Curtis, 2009]

28.  Hollow structure with cardiac cells
 Wall surface : Cardiac myocytes
 Lumen: Endothelial cells
 Can generate intramural pressure when electrically
stimulated
 Can contract in sync with host heart
 Proposed for chronic heart failure
http://www.sciencecodex.com/files/different%20ways%20in%20which%20tissue%20engineers%20believe%20that%20heart%20muscle.jpg

30.  $6.9 billion global market
 forecast to exceed $30 billion by 2018
 Source:
 http://mediligence.com/blog/2010/10/02/cardiology-
and-cardiovascular-cell-therapy-and-tissue-
engineering/

31.  AorTech International (UK/Australia)
 Use of polymer Elast-Eon for heart valves
 Autogenics (USA)
 Autologous tissue cardiac valves
 CryoLife (USA/UK)
 Preserving human heart valves, veins, connective tissue for cardiac / vascular
surgical reconstruction
 75% cardiovascular procedures involving allograft tissue in USA use
cryopreserved human heart valves from CryoLife
 TiGenix (Belgium)
 Cell-based TE HVs
Source: Tissue Engineering, Cell Therapy and Transplantation: Products, Technologies & Market Opportunities, Worldwide, 2009-2018
Published Feb 2010
http://www.mediligence.com/rpt/rpt-s520.htm

32.  Vascular Biotech GmbH (Germany)
 Patented TE aorto-coronary bypass graft in Clinical Trials
 Consists of cryopreserved donor veins, lined with recipient-own endothelial
cells
 Co.don (Germany)
 Endothelialized vessels ,in Clinical Trials
 BioTissue Technologies (Germany)
 Vessel prostheses coated with autologous cells, in Preclinical development
 AngioGenetics (Sweden)
 Drug discovery in angiogenesis regeneration
 Applicable in treatment of ischemic heart disease, chronic wounds
 Ark Therapeutics (Finland)
 Vascular endothelial growth factor gene packed with adenoviral vector and
biodegradable local drug delivery device
Source: Tissue Engineering, Cell Therapy and Transplantation: Products, Technologies & Market Opportunities, Worldwide, 2009-2018
Published Feb 2010
http://www.mediligence.com/rpt/rpt-s520.htm

33.  Genzyme Biosurgery (USA/ Europe)
 Cardiac myoblast cell transplantation, in Clinical Trials
 Autologous skeletal muscle cells from patient injected on scarred region of heart
 Diacrin (USA)
 Treatment for ischemia damaged myocardium with autologous skeletal
myoblasts. In Clinical Trials
 BioHeart (USA)
 MyoCell: autologous cell-based product, in Clinical Trials
 MyoCath: percutaneous needle injection to deliver cell therapy to myocardial
tissue, in Clinical Trials
 MyoCell VT: cell-based product for ventricular tachycardia, in PreClinical
 BioPace: cell-based product for sinoatrial nodal dysfunction, in PreClinical
 Osiris Therapeutics (USA)
 Differentiation of hMSC into specialized cell types, sells them to other
companies
Source: Tissue Engineering, Cell Therapy and Transplantation: Products, Technologies & Market Opportunities, Worldwide, 2009-2018
Published Feb 2010
http://www.mediligence.com/rpt/rpt-s520.htm

34. Company Development Clinical Approved /
al/ Preclinical Marketed
Orthopedic, cardio
3DM Inc. scaffolds
Cardio: IMPACT-DCM, Phase II; Vascular:
Aastrom Bioscience Inc. RESTORE-CLI
Advanced Cell Technology, Myoblasts for heart failure, completed Phase I
Inc. human
AdvanSource Biomaterials CardioPass
Aldagen, Inc. Ischemic heart failure, 2013
Adult stem cells for CHF, acute, MI, macular
degeneration, and cord blood transplantation,
Angioblast Systems, Inc. 2012
Angiotech Pharmaceuticals, Working with Athersys to develop MultiStem Collagraft, Neugraft
Inc. for heart damage bone graft matrices
ACY001 and ALO212
Arteriocyte Medical Systems, for lower extremity
Inc. ischemia ACY001 for chronic cardiac ischemia (Phase I)
Athersys, Inc. MultiStem AMI
Isolex stem cell therapy for chronic myocardial
ischemia and critical limb ischemia; ACT34-
CMI (adult autologous cellular therapy CD34+
stem cells for chronic myocardial ischemia);
ACT34-CLI (injection of autologous CD34+
Baxter International Inc. positive cells for critical limb ischemia)

35. Company Developmental/ Preclinical Clinical Approved /
Marketed
BeFutur Cellular implants for the regeneration of
Biotechnologies damaged heart tissue
Omniflow II (biosynthetic
vascular prosthesis for
peripheral
Bio Nova revascularization and
International CABG graft arteriovenous access)
MyoCell for heart failure (MARVEL,
SEISMIC, MYOHEART, REGEN; ASC
BioPace biological "pacemaker"; Allocell Treatment (generate adipose-derived Bioheart Acute Cell
allogenic cell therapy for severe chronic stem cells from patient's fat tissue, not Therapy (TGI 1200) for
Bioheart Inc. heart damage FDA evaluated yet, for research only) acute MI
California Stem
Cell Inc. Therapeutics for coronary heart disease
Autologous cardiac stem cells for direct Autologous cardiac stem cells for
injection and matrix delivery treatment of catheter infusion treatment of
Capricor, Inc. myocardial infarction myocardial infarction and heart failure
Chrysalin (Rusalatide Acetate or TP508) for
angiogenesis, revascularization, vascular
Capstone endothelial dysfunction (AMI, chronic
Therapeutics myocardial ischemia)
Regenerative cardiac patch (pulsating, living
CellSeed, Inc. cardiomyocyte cardiac patch on the heart)

36. Company Developmental/ Preclinical Clinical Approved / Marketed
Cook Group Regenerative tissue scaffolds
CryoValve SG pulmonary heart
valve and the CryoPatch SG
pulmonary cardiac patch
CryoLife, Inc. (CryoPatch SG)
LifeLine TE blood vessel (TEBV), LifeJacket
Cytograft Tissue Stent Graft (AAA), LifeGuard soft tissue
Engineering reinforcement patch
Adipose-derived stem and
Cytori Therapeutics regenerative cells for AMI,
Inc. chronic myocardial ischemia
ES Cell Neural progenitor cells (w/ CellCure); Embryonic stem cell lines
International pancreatic progenitor cells (cardiomyocytes)
Cell therapy for scar
Garnet reduction, myocardial
BioTherapeutics infarction
Biopharm for
Genzyme cardiometabolic/renal Biopharm for genetic diseases,
Corporation diseases cardiometabolic/renal diseases
Regenerative medicine (glial cells,
cardiomyocytes, islets, chondrocytes,
Geron Corporation osteoblasts, hepatocytes)
Proof of concept for a Vascular
replacement (also R&D for products for
cardiovascular, cosmetic, soft tissue
reconstruction, neurosurgical and
Humacyte orthopedic)

37. Company Developmental/ Preclinical Clinical Approved / Marketed
Collagen biomaterials for
Kensey Nash regeneration of cardiac tissue
Invested in cardiovascular research efforts
at MG Biotherapeutics, REMEDI, Scill Cardio, ortho, neuro stem cell-
Medtronic Technology (dental implant) based products
Mesenchymal precursor cells for
Mesoblast Limited cardiovascular regeneration
MG MAGIC trial (myoblast
Biotherapeutics, Autologous cell therapies for damaged autologous grafting in
LLC heart tissue ischemic cardiomyopathy)
Adult, autologous stem cell therapy for
Miltenyi Biotec myocardial regeneration
NellOne
Therapeutics, Inc. Therapeutics to treat heart damage
NovoGen 3-D bioprinter to create NovoGen 3-D bioprinter being
Organovo artificial arteries and tissue distributed to researchers
Osiris Therapeutics Prochymal for heart tissue repair after
Inc. heart attack
Pluristem PLX-PAD therapeutic for
Therapeutics, Inc. critical limb ischemia

38. Company Developmental/ Preclinical Clinical Approved / Marketed
ReN009 stem cell therapy for
peripheral artery disease
ReNeuron Ltd. (uses CTX stem cell line)
Stem Cell Therapy
International, Inc. /
Histostem Regenerative stem cell transplantation
MYDICAR enzyme
Targeted Genetics replacement therapy for
Corporation heart failure
Intracardiac defect closure, absorbable
Tepha Inc. cardiovascular stents
Creating stem cells from adult cells
(retrodifferentiation technology) for
TriStem cancer (leukemia), organ, neurology,
Corporation cardiology
source: http://mediligence.com/blog/2010/10/02/cardiology-and-cardiovascular-cell-therapy-and-tissue-engineering/

40.  Composite Scaffold
 Scaffold:
 PEG (polyethylene) 3D MMP-
responsive hydrogel
 Mimics biochemical properties of
collagen
 Can direct differentiation of
pluripotent cardio progenitor stem
cells
 Cells
 Mesenchymal Progenitor Stem Cells

41.  Myocardial Patch – Composite Scaffold
 Biomolecules
 Tβ4: Thymosin β4
 Enhances survival of vascular cells and
cardiomyocytes in ischemic environments
 Stimulates neovascularization after cardiac injury
 Down-regulates expression of inflammatory
cytokines
http://www.pdb.org/pdb/images/1T44_bio_r_25
0.jpg?bioNum=1
 TGF-β : Transforming growth factor beta
 controls cell proliferation and differentiation
 Vascular homeostasis
 Angiogenesis
 Vascular morphogenesis
 Antiproliferative factor in normal epithelial cells
http://www.pdb.org/pdb/images/3kfd_bio_r_500.jp
g?bioNum=1

42. http://3.bp.blogspot.com/__AuwUApfR
b4/STRqdiwqe-
I/AAAAAAAADNE/NnYvA5fL-
x8/s320/tgfbeta.jpg
Tβ4, TGF-β
Tissue Engineered Myocardial Patch
http://www.flickr.com/photos/cirm/320
0118268/
MSC
Hydrogel
PEG
mages/MToner_cellarray.jpg
http://www.nibib.nih.gov/nibib/image/Research/P41I

43.  Manufacture PEG scaffolds
synthetically
 Treat scaffold with Tβ4 and
TGF-β
http://technewslit.com/sciencebusiness/wp-
 Seed it with MSCs
content/uploads/2011/05/HeartNanoscaffold_Frank-
Mullin_Brown-University.jpg
 Implant : patient’s ischemic
myocardium

44.  Angiogenesis. Wikipedia. http://en.wikipedia.org/wiki/Angiogenesis. Accessed 15 September 2011.
 Curtis, M and Russell, B. Cardiac Tissue Engineering. Journal of Cardiovascular Nursing. 2009; 24(2):87-92.
 Khait, L et al. Getting to the Heart of Tissue Engineering. J of CardiovascTrans Res. 2008; 1:71-84.
 Nerem, R and Ensley , A. The Tissue Engineering of Blood Vessels and the Heart. American Journal of
Transplantation. 2004; 4:36-42.
 Roger, V et al. Heart Disease and Stroke Statistics - 2011 Update: A Report From the American Heart
Association. Circulation. 2011; 123:e18-e209.
 Smart, N and Riley, P. The Stem Cell Movement. Circulation Research. 2008; 102:1155-1168.