Cardiac ‘patch’ to replace damaged heart tissue
A cardiac patch which incorporates biomaterial
harvested from patients and gold nanoparticles could be transplanted
into the body to replace damaged tissue after a heart attack, scientists
say.
Tel Aviv University researchers have been
developing sophisticated micro— and nanotechnological tools to develop
functional substitutes for damaged heart tissues.
Dr
Tal Dvir and his graduate student Michal Shevach of TAU’s Department of
Biotechnology, Department of Materials Science and Engineering, and
Center for Nanoscience and Nanotechnology, have now discovered that gold
particles are able to increase the conductivity of biomaterials.
In
a study published in the journal Nano Letters, Dvir’s team described
their model for a superior hybrid cardiac patch, which incorporates
biomaterial harvested from patients and gold nanoparticles.
Cardiac
tissue is engineered by allowing cells, taken from the patient or other
sources, to grow on a three-dimensional scaffold, similar to the
collagen grid that naturally supports the cells in the heart.
Over
time, the cells come together to form a tissue that generates its own
electrical impulses and expands and contracts spontaneously.
The tissue can then be surgically implanted as a patch to replace damaged tissue and improve heart function in patients.
According
to Dvir, recent efforts in the scientific world focus on the use of
scaffolds from pig hearts to supply the collagen grid, called the
extracellular matrix, with the goal of implanting them in human
patients.
However, due to residual remnants of
antigens such as sugar or other molecules, the human patients’ immune
cells are likely to attack the animal matrix.
In
order to address this immunogenic response, Dvir’s group suggested a new
approach. Fatty tissue from a patient’s own stomach could be easily and
quickly harvested, its cells efficiently removed, and the remaining
matrix preserved. This scaffold does not provoke an immune response.
The second dilemma, to establish functional network signals, was complicated by the use of the human extracellular matrix.
“Engineered
patches do not establish connections immediately. Biomaterial harvested
for a matrix tends to be insulating and thus disruptive to network
signals,” said Dvir.
Dvir explored the integration of gold nanoparticles into cardiac tissue to optimise electrical signalling between cells.
“To
address our electrical signalling problem, we deposited gold
nanoparticles on the surface of our patient-harvested matrix,
‘decorating’ the biomaterial with conductors,” said Dvir.
“The
result was that the nonimmunogenic hybrid patch contracted nicely due
to the nanoparticles, transferring electrical signals much faster and
more efficiently than non-modified scaffolds,” Dvir added.
Labels: biomaterial, cardiac patch, collagen grid, damaged, gold, heart attack, replacement, tissues
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