ON HEART TISSUE REENGINEERING ?

JC Chachques, MD PhDGeorges Pompidou European Hospital

Paris, France

Stem cell therapy and CV innovations

What’s new ?

Cardiac Bioassist - Cooperative Work

Teams :

• Olivier Schussler. Ottawa Heart Institut, Canada

• Carlos Semino. MIT + Barcelona Bioengineering Center

• Jorge Genovese. Pittsburgh University, USA

• Jorge Trainini. Avellaneda Hospital, Argentina

HEART FAILURE IN EUROPE

• Heart failure is the single biggest reason for acute hospital admission.

• Around 30 million people in Europe have heart failure and its incidence is increasing.

• More people are living to an old age, and more are surviving a heart attack but with damage to the heart.

PREVALENCE of HEART FAILURE in USA (total population: 305 millions)

Evidence for cardiomyocyte renewal in humans Science 2009; 324: 98-102

Frisen J. et al, Karolinska Institut, Stockholm, Sweden

• Cardiomyocytes are generated also later in life ? • Carbon-14, generated by nuclear bomb tests during the Cold

War, integrated into DNA allows to establish the age of cardiomyocytes in humans

• Results: cardiomyocytes renew, with a gradual decrease from 1% turning over annually at age of 25, to 0.45% at age of 75

• Fewer than 50% of cardiomyocytes are exchanged during a normal life span

• Perspectives: development of therapeutic strategies aimed at stimulating this process in cardiac pathologies

STEM CELL THERAPY and

BIOARTIFICIAL MYOCARDIUM

CARDIAC BIO-ASSIST

CELLS FOR MYOCARDIAL REGENERATION

• Skeletal myoblasts • Bone marrow mononuclear cells • Bone marrow mesenchymal cells• Umbilical cord cells • Adipose tissue stroma cells• Mesothelial cells (from epiploon)• Menstrual blood endometrial cells• Stem cells from the testis• Embryonic cells (pluripotents)

BONE MARROW ASPIRATION

DEVELOPMENT OF

BIO-ARTIFICIAL MYOCARDIUM

BACKGROUNDLimitations of Cellular Cardiomyoplasty

• Cell bio-retention and engraftment within scar tissue is low

• Mortality of implanted cells in ischemic myocardium is high

• In ischemic heart disease the extracellular matrix is pathologically modified

BACKGROUND 2Limitations of Cellular Cardiomyoplasty

• Implanted cells lack both mechanical synchronization and electrical integration, forming « islands of tissue »

Questions and risks:• Excitation-contraction coupling?• Additional excitable cells?• Proarrhythmic?

RATIONALE FOR 3D CARDIAC TISSUE ENGINEERING

• The efficacy and arrhythmia occurrence of stem cell therapy depends on the surviving cell number as well as the delivery route of cells

• A cell-seeded epicardial scaffolds should offert additional niches for cell homing without the risk of a proarrhythmogenic substrate

• Allogeneic cells should be better tolerated in a matrix « niche environment »

Heart extracellular

matrix

Cell niche + cell homing

ml : muscular lacunaecl : capillary lacunae

COMPONENTS OF EXTRACELLULAR MATRIX IN HUMAN HEART

Collagen Type I (80%) : Ventricular chamber geometry, structural support

Collagen Type III (10%): Role in transduction of myocyte shortening during systole

EXTRACELLULAR MATRIX IN ISCHEMIC HEART DISEASE

Collagen Type I : Decreases from 80% to 40%

Collagen Type III : Increases from 10% to 35%

RESULTS : Ventricular dilatation, systolic + diastolic dysfunctions

COLLAGEN TYPE I MATRIX (Pangen 2, France)lyophilised, bovine collagen, 5 x 7 x 0.6 cm

DEVELOPMENT OF ARTIFICIAL MYOCARDIUM

• Collagen matrix (type I)

• 3D and Biodegradable

• Seeded with stem cells

Collagen Matrix without cells seeded with cells

Confocal Microscopy

3D matrix + cells

MATRIX

MATRIX GRAFTED ON EPICARDIUM

PRECLINICAL STUDIESPublished in Tissue Engineering 2007; 13:2681-7

Cell-seeded collagen matrix - 2 Mo Follow-up

BIOARTIFICIAL MYOCARDIUM « MAGNUM » Clinical Trial

M yocardialA ssistance byG rafting aN ew bioartificialU pgradedM yocardium

Rationale

Associate a procedure for myocardial and extracellular matrix regeneration, i.e.

Cellular cardiomyoplasty+

Collagen scaffold grafting

Cellular CMP + Cell Seeded Matrix

Clinical Collagen Matrix Implantation

MAGNUM Clinical Trial

RESULTS

Functional Outcomes: 1 year follow-upFunctional Outcomes: 1 year follow-up

Baseline End FU

p =0.005

NYHA Class

0

5

10

15

20

25

30

35

Baseline End FU

p = 0.04

LV Ejection Fraction (%)

Echocardiographic Study

p = 0.03

100

110

120

130

140

150

Baseline End FU

LV End Diastolic Volume (mL)

Echocardiographic Study

120

130

140

150

160

170

180

190

200

Baseline End FU

LV FILLINGDoppler-derived mitral deceleration time (ms)

p = 0.01

DIASTOLIC FUNCTION

0

2

4

6

8

10

Baseline End FU

Scar Area Thickness (mm)

p = 0.005

Echocardiographic Study

Cellular CMP + MatrixRadioisotopic SPECT sestamibi studies Preop 12 Months

MAGNUM CLINICAL TRIALCONCLUSIONS

• REDUCES THE SIZE AND FIBROSIS OF INFARCT SCARS

• MINIMIZES GLOBAL VENTRICULAR DILATATION

• IMPROVES DIASTOLIC FUNCTION

• INCREASES MYOCARDIAL WALL THICKNESS

• INDUCES MODULATION OF EXTRACELLULAR MATRIX

MAGNUM CLINICAL TRIALCONCLUSIONS

• The implanted matrix contributed to generate the “adequate niche” for native, transplanted and migrating stem cells

FUTURE MATRIX IMPROVEMENTS

• Crosslinking angiogenic growth factors

• Prolong absorption delay by nanotechnologies and additional chemical - physical crosslinking

• Stem cell preconditioning : hypoxic conditions (5%) during culturesin-vitro electrostimulation

Nature Clin Pract Cardiovasc Med 2009; 6: 240-9

Use of arginine-glycine-aspartic (RGD) acid adhesion peptides coupled with a new

collagen scaffold to engineer a myocardium-like tissue graft

Schussler O, Coirault C, Louis-Tisserand M, Chachques JC, Carpentier A, Lecarpentier Y

Frontiers in Bioscience. 2009; 14: 2996-3002

Cardiac pre-differentiation of human mesenchymal stem cells

by electrostimulation

Genovese J, Spadaccio C, Schussler O, Carpentier A, Chachques JC, Patel AN

Biomaterials. 2009; 30: 1156-65

The effect of self-assembling peptide nanofiber scaffolds on

mouse embryonic fibroblast implantation and proliferation

Degano IR, Quintana L, Semino C, et al.

A prototypic synthetic extracellular matrix

•Molecular designed material•Chemically defined•Synthetic process•Highly similarity to natural ECMs

structure: nano-scale fibersself-assembling processbiologically permissive non-competition with natural ECMbiodegradableMechanical properties for soft tissues

•Modification control Building up properties•Transient scaffold•Injecting biological material

A generic peptide scaffold network

Peptide nanofibers = 10-20 nmScaffold pore size = 50-200 nm

RECATABI PROJECT - European Union

RECATABI PROJECT - European Union

CARMAT ( Carpentier - Matra )Artificial Heart