Pig tissue could provide solution for heart damage
The human immune system does not reject transplanted organs based on pig cells.
PROF. MARCELLE MACHLUF Photo: Courtesy Technion
Although it doesn’t sound very kosher, scientists at Haifa’s Technion-Israel
Institute of Technology have used pig tissue to create a thick “scaffold” for
heart muscle that supports human stem cells, preserves the infrastructure of
natural blood vessels and are made from extracellular matrix
Prof. Marcelle Machluf of the biotechnology and food
engineering faculty and her lab colleagues did the research, which has just been
published in the journal Tissue Engineering.
The work was financed by the
Office of the Chief Scientist of the Ministry of Industry and Trade and was
conducted in cooperation with Singapore’s research agency.
(myocardial infarctions) are one of the leading causes of death and disability
in the Western world. When they strike, the blood supply to the myocardium (the
middle of the three layers forming the wall of the heart) is impaired and, as a
result, a scar is formed in the affected area. Not only does this scar not help
pump the blood through the body, but it also significantly burdens the healthy
parts of the heart, which are now left to handle the required load by
Current clinical treatment focuses on drugs and/or surgery to
improve heart function after the infarction and prevent a recurrence. This
treatment, however, is not able to rehabilitate damaged scar tissue. Thus, the
only solutions for end-stage heart patients are heart transplantation or the use
of ventricularassist devices to keep the heart pumping.
These two options
are highly limited, both in terms of supply and cost, and this creates a
significant gap between the number of people who need treatment and those who
receive it. This gap has led to extensive tissue engineering and cell therapy
research, aiming to develop alternatives for rehabilitating and regenerating the
In recent years, several engineered tissue substitutes
were developed to rehabilitate heart function, mainly in animal models. These
substitutes are based on cells and/or a supportive scaffold comprising
biomaterials. Such an ideal engineered system should, at the cellular level,
have cells occupying the vascular system to nourish the heart tissue; myocardial
cells are the most critical. Unfortunately, despite substantial investment in
cell research, mature and beating myocardial cells still cannot be reproduced in
the lab, so production of large amounts of cells is impossible.
effort is being invested in developing scaffolds or platforms for the patients’
damaged tissue and healthy transplanted cells. These scaffolds should have
biomechanical properties that are compatible with those of the myocardium,
support the cells and the rehabilitating tissue while providing the required
biochemical signals and break down as the natural extracellular matrix is
One of the materials considered most suitable for creating such
a scaffold is the natural extracellular matrix, which maintains and supports the
cells in the healthy tissue.
According to recent publications, matrices
such as these have been produced from several tissues; one such matrix was
produced by Machluf from pig heart tissue, which is physiologically similar to
the human heart.
Because it is natural and has a protein composition that
is 98 percent identical in pigs and humans, the human immune system does not
reject transplanted organs based on pig cells.
Machluf’s work focuses on
a matrix that is as clean as possible from cellular components that could
provoke immunological rejection, while retaining its inherent
These new scaffolds, when seeded in the appropriate cells,
could serve as laboratory platforms that mimic the myocardium for research
purposes, as models for the extracellular matrix in humans, and as implants for
treatment of heart attacks,the Technion scientist said.