These weak heart
muscle cells called cardiomyocytes are usually repaired by injecting healthy
cardiomyocytes into the damaged heart muscle. The healthy cardiomyocytes are
derived from
. Using biochemical
signals these stem cells can be reprogrammed to become any type of cell in the
body including heart muscle cells.
Converting PSCs
into cardiomyocytes occurs in a two-dimensional setting, usually in petri
plates. However, in-vivo, the growth environment plays a large role in the way
the cells develop. Due to lack of an appropriate growth environment, PSC
derived cardiomyocytes are underdeveloped and do not gain their full potential
functionality.
‘Using 3D molds or substrates to grow heart muscle cells allows them to mature more quickly and with better functionality.’
"Unfortunately
stem cell therapeutics don't have high success rates partly because the cells
are not mature and fully functional. The maturation and functionality are essential,"
says Parisa Pour Shahid Saeed Abadi, assistant professor of mechanical
engineering working on creating heart cell growth environments.
Induced pluripotent stem
cell-derived cardiomyocytes using substrates
To provide the
right growth environment to PSCs, Abadi and team have developed
three-dimensional substrates that create a heart-like environment for the
cells. Cardiomyocytes grown in these 3D substrates or molds mature more
quickly, have improved functionality and are less likely to be rejected by
patients' bodies.
The biomechanical
properties of the substrates simulate the actual
heart
environment; one with lots of pressure and specific forces acting on the
growing cells. This pressure leads to more robust cardiomyocytes.
Photolithography and re-flow processing were used to pattern the substrates at
the micron and submicron levels to approximately resemble the natural physical
forces cells experience.
"The mechanical
properties of substrates play an important role in the cell behavior because
the mechanical cues that cells sense in the actual (heart) environment is
unique," Abadi says. "We are using biochemical and biomechanical cues
to enhance the differentiation and maturation. If we don't take advantage of
the physical cues and only rely on chemical cues, the process suffers from low
efficiency and batch-to-batch inconsistency."
The team hopes to improve
the substrate preparation methods to stimulate electrical conductivity between
cells. Since cardiomyocytes need to communicate with each other during their
growth, this inclusion is thought to make the cells closer to cardiomyocytes in
vivo.
Reference : - Mending broken hearts with cardiomyocyte molds - (http://www.sciencenewsline.com/news/2018031321180056.html)
Source: Medindia
