Biomedical Engineering Reference
In-Depth Information
one of the nongenetic methods for the fractionation of ESC-/iPSC-
derived cardiomyocytes [23, 42]. Laflamme et al
succeeded in
fractionating ESC-/iPSC-derived cardiomyocytes with a purity of
about 80% by Percoll (GE Healthcare) gradient centrifugation [23].
The density-gradient centrifugation method enables simple, low-
cost, and scalable enrichment of ESC-/iPSC-derived cardiomyocytes.
Therefore, this method is highly valuable for the rough enrichment
of cardiomyocytes. On the other hand, complete purification is
impossible, and unknown types of cells inevitably remain in the
fractionated cell population, which is a potential risk for clinical use.
Another strategy of ESC-/iPSC-derived cardiomyocyte enrichment
is to fractionate the progenitor cells of cardiomyocytes by targeting
specific surface antigens. Although a specific surface antigen of
cardiomyocytes has not been identified, the specific expression
pattern of surface antigens of cardiomyocyte progenitor cells is
becoming clarified [24, 43]. Yang et al
.
low
neg
.
identified KDR
/C-KIT
cells in differentiated hESCs as the progenitor cells of cardiomyocytes,
endothelial cells, and vascular smooth muscle cells [43]. They
fractionated KDR
low
neg
cells from differentiated hESCs by FACS
and cultured them for further differentiation. Consequently, it was
demonstrated that the population derived from these cells consisted
of more than 50% cardiomyocytes and the rest were endothelial
cells and vascular smooth muscle cells. Recently, another method
to fractionate cardiomyocytes by targeting mitochondria was newly
developed. In cardiomyocytes, aerobic metabolism is highly active
and mitochondria content is higher than in the other types of cells.
Hattori et al
/C-KIT
fluorescently labeled the mitochondria of differentiated
ESCs/iPSCs and fractionated the highly labeled population [44]. It
was confirmed that this population consisted of cardiomyocytes
with a purity of more than 99%. In spite of the drawback of FACS
described above, these FACS-based fractionation methods certainly
have the prospect of being used clinically in the near future.
As described above, there are several technologies to enrich
ESC-/iPSC-derived cardiomyocytes. It is repeated again that these
technologies should be assessed from the cost-effectiveness and
safety of prepared cells. Cost reduction of the whole process of cell
preparation is indispensable to the popularization of cell therapies
and must be addressed continuously.
.
