Our investigation aims at the translation of heart valve tissue engineering from the laboratory bench to clinical application. In the present study, we compare different cell sources in their ability to form heart valve tissue. Furthermore, as we…
ID
Source
Brief title
Condition
- Cardiac valve disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The output of this study is composed of several components:
- Determination of expansion rate: which celltype can be expanded in the
shortest period of time to reach clinically relevant numbers.
- Determination of cell phenotype: are the isolated cells still progenitors
after in vitro expansion, or did they differentiate into a more specialized
celltype? Known markers for the cells of interest are:
o MFs: vimentin and α-smooth muscle actin.
o Cardiac auricle: c-kit, Sca1, GATA4
o Bone marrow: CD73, CD90, CD105
o Blood: CD14
For this, we will use PCR, immunocytochemistry and FACS-analysis.
- Determination of ability to produce matrix. To be suitable for heart valve
tissue engineering, cells need to be able to produce sufficient amounts of
collagen. In our investigation, we will analyze this on mRNA and protein levels
by investigating expression of marker protein Hsp47 and expression of collagen
type 1 and 3. This will be done by PCR, immunocytochemistry and western
blotting.
- Determine ability to produce proteins involved in matrix remodeling. Although
the aortic valve should be able to resists high blood pressure, excessive
production of matrix can lead to stiff (fibrotic or stenotic) valves. The cells
therefore need to be able to produce proteins that can degrade matrix and
proteins that inhibit matrix degradation. This way, excessive matrix can be
removed to prevent fibrosis, while it can be maintained at locations that bear
the heaviest loads. To evaluate ability to remodel matrix, we will look at
expression of proteases (MMP1 and 2) and their tissue inhibitors (TIMP1 and 2)
on both mRNA and protein level, using PCR, zymography and western blotting.
- Finally, we aim to seed expanded cells on a small strip of a degradable
carrier, to test the ability of the cells to make a strong tissue strip.
Strength of the tissue will be tested using straining-assays and several
histochemical analyses to evaluate production and deposition of collagen,
crosslinks between collagen fibers and deposition of other matrix proteins like
glycosaminoglycans (GAGs).
Secondary outcome
not applicable
Background summary
Approximately 3000 heart valve replacements are performed in the Netherlands
annually. The majority involves the aortic valve which (in comparison to the
mitral valve) is almost impossible to repair. Stenosis and regurgitation (back
flow through the valve) are the most important indications for aortic valve
replacement. Currently available prostheses used for valve replacement have
several disadvantages. Mechanical valves need life-long anti-coagulation
therapy and biological prosthese have a limited durability. These valves also
lack the ability to grow and remodel. The ideal prosthesis would be a living
(growing) valve that does not cause thrombotic effects and does not evoke
immune responses.
Tissue engineering is a technique in which autologous cells are seeded
on an (artificial) carrier, or scaffold, to create a specified tissue. For
heart valve tissue engineering, this would mean that cells derived from a
patient that suffers from a valvular disease could be used to form a healthy
living, functional heart valve. Proof of principle for this application has
been provided by successful implantation of tissue engineered valves in
pulmonary position in sheep.
Study objective
Our investigation aims at the translation of heart valve tissue engineering
from the laboratory
bench to clinical application. In the present study, we compare different cell
sources in their ability to form heart valve tissue. Furthermore, as we focus
on translational medicine, it is necessary to use Good Tissue Practice (GTP)
protocols.
Study design
in vitro
Study burden and risks
There is only very minor burden for these patients and no extra risk.
Requested samples:
- Great Saphenous Vein: ± 2 cm (For CABG usually a total of 25-35 cm of the GSV
is required, for the study we will take out 2 cm extra). The scar on the leg
will be 2 cm longer.
- Bone marrow: ± 2 cc (Following median sternotomy, bone marrow leaks out of
the sternum, but perhaps some extra bone marrow needs to be scraped out of the
sternum to obtain this volume). We expect no aaditional risk for the patient.
- Cardiac auricle: 2 g (In patient undergoing on pump CABG, a small piece of
the cardiac auricle is removed for venous canulation and normally thrown away.
The total weight of the heart is approximately 350 g).
- Blood: ± 20 mL (total volume of blood is approximately 5000 mL).
No other visits, questionnaires or examinations are required what so ever. No
additional discomfort will occur. There will be no benefit either.
Postbus 85500
3508GA Utrecht
Nederland
Postbus 85500
3508GA Utrecht
Nederland
Listed location countries
Age
Inclusion criteria
Patients that must undergo on pump coronary artery bypass-grafting including a venous graft.
Exclusion criteria
None
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL27353.041.09 |