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STEM CELL THERAPY
Jaswinder devi
RP8003A05
11008684
What are Stem cells?
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Stem cells are “master cells “
The raw material :- from which all of
the body’s mature,
differentiated cells are made.
Stem cells give rise to brain cells,
nerve cells, heart cells, pancreatic
cells, etc.
The unique properties of all stem cells
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Undifferentiated / unspecialized cells
Undifferentiated cells can
differentiate to yield major
specialized cell types or organs
Self-renewal property is to maintain
and repair the tissue. Thus they have
potential to replace cell tissue
damaged by severe illnesses.
Stem cell
Stem cell
( unlimited
cell division )
Specialized cell
(e.g., white blood cell)
Potency definitions of stem cells
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Totipotent : can differentiate into an
entire organism , result from fusion
of egg and sperm
- can form any cell of the embryo as
well as the placenta.
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Pluripotent : can differentiate into
any tissue type except placental
tissue
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Multipotent : can differentiate
into multiple specialized cells of
a closely related family of cells
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Unipotent : these cells only
produce one cell type., but have
the property of self renewal
which distinguishes them from
the non stem cells.
Types of stem cells
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Embryonic : derived from the inner
cell mass of a blastocyst / human
embryo
Source :
1. Excess fertilized eggs from IVF (invitro fertilization) clinics
2. Therapeutic cloning (somatic cell
nuclear transfer)
Zona pellucida
Blastomeres
(Zygote)
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Adult : derived from mature organisms
that can divide to form more differentiated
cells
- but are less versatile and more difficult to
identify, isolate, and purify.
Eg: Stem cells have been found in the
blood, bone marrow, liver, kidney, cornea,
dental pulp, brain, skin, muscle
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Fetal : derived from aborted fetal tissue
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Umbilical : derived from umbilical cords
- All blood cell types (red blood cells, white
blood cells, and platelets)
Advantages of Embryonic Stem Cells
over adult stem cells
Embryonic S.C.
Adult S.C.
“Pluripotent”
(can become any cell
“Multipotent”
(“can become many
but not any”)
types present in the human
body )
E.g., blood stem cells can
develop into several blood
cell types, but cannot
develop into brain, kidney, or
liver cells
Stable. Can undergo
many cell divisions.
Less Stable. Capacity
for self-renewal is
limited.
Easy to obtain but
blastocyst is
destroyed.
Difficult to isolate in
adult tissue.
How stem cell therapy works?
When stem cells are transplanted
into the body and arrive into the
injured part, brain being targeted for
tissue regeneration, the stem cells
are coming in contact with growth
chemical’s (like EGF’s , NGF’s and
HGF’s )in the body. These chemicals
program the stem cells to
differentitate into the tissue
surrounding it.
Current stem cell therapy
Hematopoietic stem cell
transplantation (“HSCT”)
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Stem cells that give rise to the lymphocytes and
other cells of the immune system, also make blood
cells, are called hematopoietic stem cells.
HSC’s are charecterised by the presence of CD 34
antigen
The process of taking stem cells from one person
and putting them into another is therefore called “
HCST”
To treat cancer patients with conditions such as
leukemia and lymphoma, sickle cell anaemia,
Used in Providing a functional immune system in a
person with SCID.
In Restoring the haematopoietic system
Stem cells in treating baldness
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As hair follicles contain stem cells –
dermal papilla
Take stem cells from existing hair
follicles
Multiply them in cultures
Implant the new follicles into the
scalp
Stem cells from patient’s plucked hair
can be grow into skin
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Hair follicles contain skin stem cells
(keratinocyte)
Pluck the patient’s hair
Cultured to form epidermal cells
equivalents of the patients own skin
This is autologous graft thus
bypassing the problem of rejection
Used for venous ulcers and burn
victims
Diabetes
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Diabetes patients lose
the function of their
insulin-producing beta
cells of the pancreas.
Human embryonic
stem cells may be
grown in cell cultures
and stimulate to form
insulin-producing cells
, that can be
transplanted into the
patient
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Pancreas is digested with
collagenase that frees islets from
surrounding cells
Centrifugation of isolates containing
mainly alpha and beta cells
Then purified islets beta cells
And transplanted through a catheter
into the liver where they become
permanantly established.
Corneal disease / blindness
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Result in poor vision
Take stem cells from healthy eye
Grown onto contact lenses in clinical
lab
Lenses are worn by the patient for a
period of three weeks
Then migration of human stem cells
from lens to damaged eye and begin
to repair process
Thus heals the damaged cornea and
quickly improves the vision
Parkinson disease
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Caused when key brain cells that
produce message carrying
chemical/neurotransmitter
(dopamine) die off.
Symptoms start with the patients
trembling and can end up paralyzed.
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Harvesting of stem cells from
patients bone marrow, foetus or any
other source
Culturing of harvested stem cells in
lab conditions - to get high
concentrations of stem cells
Then purified and high concentration
of stem cells are surgically injected
in the brain of patient.
Brain damage
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Stroke and traumatic brain injury
lead to cell death, characterized by a
loss of neurons and
oligodendrocytes within the brain.
Healthy adult brain contain neural
stem cells, these divide and act to
maintain general stem cell numbers
or become progenitor cells.
Missing teeth
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Take stem cells/dental pulp from the patient.
Both adult mesenchymal stem cells and
embryonic stem cells can be used
Culture in lab.- into a tooth bud
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Then implant tooth bud in gum which
fuses with jaw bone and release
chemicals that encourage nerves &
blood vessels to connect with gum
As a result it will give rise to new
tooth/ dentin approximately within 2
months
Kidney Stem Cells
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Take stem cells from embryo
,bone marrow or an umbilical
cords
Culture these stem cells with
special chemical broth that
encourages the growth of
kidney cells
Then new kidney cells can
now be injected into a kidney
to repair damaged tissue
Deafness/ hearing loss
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Embryonic stem cells are capable of
differentiating into cochlear hair cells
in the adult inner ear
Orthopaedia
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Take healthy cartilage tissue
Tissue culture of isolated
chondrocytes
Inject the cultured chondrocytes in
knee under patch
Treat chondral defects
Heart damage
Stem cells for Gene Therapy
Potential obstacles
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Difficulty of performing
transplantation and caring for
post-transplantation patients.
Specific factors that aid or
hinder acceptance of the
particular transplant
Ability to obtain source material
due to ethical concerns
Advantage
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The critical shortage of organs
available for transplantation may be
solved in the future by auto-graft
techniques
Security : low toxicity or non toxic
Ethical issues
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As human embryonic stem cell are
isolated from few days old blastocyst
as well as fetal tissues
Many prolifers believe that human
life becomes a human person at the
time of fertilization
Others disagree : they believe that
an embryo has potential to develop
into a person, but is not a person
itself.
Thanks….