Today, with advent of technologies,
transplant of live, heart, kidney etc. has helped save millions to lives. But with
time, the demand of the organs has surpassed that of the supply. Stem cells offer
a solution where the patient can have organ transplant that are derived from the
stem cells. As these organs are usually from the donors own body (fully grown stem cell)
or from people who are genetically related, the chances of organ rejection are minimal.
This is possible because stem cells have distinct properties that make them more
suitable for various therapies and organ regeneration. Stem cells can be derived
from three sources
- Umbilical cord blood cells- As the name suggests, this is derived
from the umbilical cord of the fetus, immediately after birth. Umbilical cord blood
is a rich source of hematopoietic stem cells (HSCs). These stem cells are undifferentiated
cells that can have self-renewal and differentiation into all blood types. Among
all the other stem cells, these have practical and ethical advantage.
- Human embryonic stem cells (hES)- These are derived from embryos,
taken from surplus embryos that are left in after an IVF after the donors consent.
These stem cells, on stimulation can produce organs, but the patient has a rare
chance of facing organ rejection. Latest research also suggests that they can be
found in the embryonic fluid.
- Fully grown stem cells- These are pre-specialized cells, usually from
the donors own body or from relatives and has high success rates as the chances
of the body’s immune system rejecting it are less. But they are not as versatile
as umbilical cord blood cells or hES.
Embryonic cells and umbilical cord stem cells are well suited for therapy
- Proliferation- Stem cells have the property of dividing and renewing
themselves. The rest of the body cells such as muscle cells or nerve cells do not
normally replicate themselves, but stem cells can proliferate. In case of embryonic
stem cells, they are obtained from blastocysts in the developmental stage. The stem
cells are derived from the umbilical cord blood. Both are pluripotent and due to
this they possess the flexibility to become anyone of the more than 200 cell types
that are found in the human body.
- Unspecialized cells that can produce specialized cells- Being unspecialized
makes the stem cells unique. Unlike the other body cells which serve specific functions,
these cells do not have any tissue specific structures. They remain inactive until
they receive the necessary stimuli. This process is termed as differentiation. Post
differentiation they can proliferate and produce specialized cells such as muscle
cells, blood cells and nerve cells. It allows them to have identical, well-defined
genomically and phenotypically characterized stem cell.