STEM the damage
Stem cell therapy, though in a nascent stage, has been a promising
area. Here in Bangalore, Manipal Hospital has been at the forefront
in the field. A drug based on stem cells will be ready by next year
end, the researchers assure. Jayalakshmi K reports.
Predicting human birth defects in a developing foetus by studying
embryonic stem cells on a Petri dish, as also testing drugs in a more
quicker and cost-effective way, is now possible, thanks to work done
by a group of scientists.
Researchers at the Manipal Institute of Regenerative Medicine and
Stempeutics have come up with a way of designing safer drugs and
understanding their effects on pregnancy and the development of the
foetus.
Embryonic stem cells provide a reliable source for studying in a
Petri dish, the formation of all the 220 different tissues of the
human body. They produce early embryo-like entities, known as
embryoid bodies (EBs). These make a population of cells representing
all the germ layers (the ectoderm, endoderm and mesoderm). The skin
and the nervous system arise from the ectoderm, the mesoderm forms
tissues like the cardiomyocytes, bone and blood, and the endoderm
forms the liver, lungs, intestine, etc. of the developing embryo.
The early embryo growing in the mother's womb can cross-talk with the
maternal environment, and responds to the factors around it. Common
bacterial infections of the maternal genital tract, like bacterial
vaginosis, can lead to poor pregnancy outcomes. The EBs closely mimic
a growing embryo in a mother's womb. As ethical issues limit studies
on the molecular in human embryos, the EBs are handy.
The team led by Dr Kaushik Deb (Group leader and Principal Scientist,
Embryonic Stem Cell Program) has shown that the presence of very low
amounts of bacterial lipopolysaccahrides (LPS), a toxin found in E-
coli in the environment, can cause defects in the development of
tissues like the bones in the growing foetus.
By testing drugs and toxins on these cells, drug discovery can skip
valuable time spent on animal studies as well as cost. "The time for
drug discovery can be cut from 14 to seven years on an average," says
Dr Satish Totey, Chief Scientific Officer, Stempeutics Research. It
would also be a good tool for IVF clinics, he adds.
The findings were recently published in the online version of the
journal Regenerative Medicine.
MIRM is a constituent institute of Manipal University focusing on
fundamental research and education. Work done here is taken across by
Stempeutics which does the pilot studies and clinical trails.
Stempeutics has been doing some pioneering work on stem cells with a
focus on "benchside to bedside", as the manager, Manohar says. "We do
not want to be doing research that is too basic to be applied."
At present, four major clinical trials with 100 patients each are
ongoing in cerebral strokes, limb eschaemia, myocardial infarction
and multiple sclerosis. These are some diseases for which pilot tests
have shown satisfactory to good results. Parkinson's is another
ailment that has responded well but as it involves brain surgery, is
a bit more complicated.
Calling it experimental therapy, Manohar says that almost 80 patients
have been treated using mesenchymal stem cells, found in the bone
marrow. "In the last six months alone almost 40 patients have been
treated and in 25 per cent of the cases, the results were good. While
the Parkinson's patients showed remarkable recovery with many even
stopping the drug, with spinal cord injuries there was mixed
results," says Dr Totey. It was found that the cells were not
migrating to the site.
One of the reasons he cited could be the mode of delivery of stem
cells. Usually it is delivered at the site of injury, or through
lumbar puncture or the arterial route. The site of injury is the best
approach, though in the case of brain diseases, this means
complications.
The stem cell treatment works well for fresh injuries but some
experts believe that the body sends stem cells naturally in this
period. After six months or so, the scar tissue forms and can hinder
the migration of stem cells administered.
A patient from Rajkot had been paralysed after falling from a giant
wheel at Essel World. After two years the family contacted Manipal
hospital in 2006. "We did the MRI scan and identified the injury
points on the spine and at these places we made incisions to take out
the scar tissue. It became a fresh injury so the stem cells we
injected went unhindered to the damaged spot," notes Dr Totey.
Now she has recovered to a large extent, can move around and has
control of the bladder, etc. She required two injections so far, of
stem cells drawn from her bone marrow.
Unlike usual bone marrow transplants where a litre of the liquid is
drawn each time, with mesenchymal adult stem cells, all that is
required is 30-60 ml which can be cultured in the lab for future use
as well, he says.
Unlike most other adult stem cells, mesenchymal are pluripotent and
can grow into any tissue. The other big advantage is that there is no
need for matching. Any donor can donate cells from his bone marrow.
As it takes 20-25 days to culture the stem cells in lab, this is an
advantage as readily available cells can be administered in emergency
situations instead of having to draw from the patient's bone marrow
and culture.
"The problem is in isolation and culturing. Very small quantities of
the cell are present in the bone marrow. We have patented the
technology," says Totey.
In the case of cerebral stroke, the problem arises in delivering stem
cells due to the blood brain barrier. This is a natural barrier of
the body which prevents most antibodies and toxins, even cells, from
going into the brain. During an injury, just for very short time the
diaphragm is also damaged and allows passage. Unless the patient
comes in this time, stem cells can't be delivered through the blood
route.
Despite the country still lacking a law on stem cell therapy, the
DCGI has allowed Stempeutics to conduct trials at multiple sites. The
draft guidelines have been awaiting discussion almost since two years
now. It is expected to be tabled in Parliament this summer.
There are plans to add a few more diseases to the present list under
study. These include vitiligo (a skin eruption), dilated
cardiomyopathy, end-stage liver disease, etc.
"By end 2009, we hope to have the first defined stem cell based drug
for standard therapy on the shelf, just like all other medicines.
This will be for a few of the diseases studied," says Manohar.
In the area of transplants too, stem cells can do miracles as
witnessed when a heart taken from a cadaver came alive when a "stem
cell scaffold" was introduced. Essentially, a 3-dimensional makes it
easy for stem cells to multiply and form a whole new organ.
"This needs some amount of tissue engineering and we are working with
some US universities as also Sri Thirunal Institute in Trivandrum who
are experts in polymer science. Using biomimetic material which is
also bio-degradable, we introduce a small heart inside the dead one.
Eventually the scaffolding falls off and the stem cells have done
their job," explains Dr Totey. This will be a big boon for
transplants because stem cells can only help repair a damaged tissue
if the damage is small but if the whole organ has failed, we need
transplants, he adds.
Patients come in scores seeking the miracle treatment but the
hospital has a strict inclusion and exclusion criteria in place that
goes through every aspect of the case history and admits them into
the therapy only if these are satisfied. "We have an ethics committee
which screens each case. Our patient counselling is elaborate where
we tell them that we cannot guarantee anything. Only after that we
obtain the consent and proceed," says Dr Totey.
Those interested can log onto the website www.stempeutics.
register their case.
http://www.deccanhe
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StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
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