Stem Cells in Medicine: Uses, Risks, and Ethical Considerations

in this video we're looking at the use of stem cells in medicine so we'll start by explaining how stem

cells can be used to treat conditions like diabetes and paralysis then we'll look at some of the risks

involved in the process and finally we'll consider the ethical implications and see why some people

think that we shouldn't use stem cells in this way before we start i want to quickly recap

what stem cells are and there are really two important features about them that you need to

remember one they can divide by mitosis to produce more cells

and two they can differentiate into different types of specialized cells now there are lots of different kinds of

stem cells but the main two that you need to know about are embryonic stem cells

which are found in the early embryo and can differentiate into absolutely any type of specialized cell

and adult stem cells which are found in the bone marrow of people of all ages but can only differentiate into

different types of blood cells the other bit of background we need to know for this topic

is that lots of conditions are due to faulty cells which just means cells that are damaged

in some way or that don't work properly for example type 1 diabetes is caused by damage to the pancreas cells that

normally produce insulin while paralysis is sometimes caused by damaged nerve cells

and sickle cell anemia is caused by misshapen red blood cells so if you think about it if we could

somehow replace these faulty cells with properly working cells then we could treat these conditions

and this is the basic idea behind using stem cells in medicine we use stem cells to replace the faulty

cells the most common technique for actually doing this would be for scientists to

extract embryonic stem cells from early embryos grow them in a laboratory

and then stimulate them to differentiate into whichever type of specialized cell that we want

so that we can then give them to the patient to replace their faulty cells for example in the case of a diabetic

patient where the issue is that some of their pancreas cells have been damaged and don't produce insulin anymore

these scientists would take some embryonic stem cells and grow them in a laboratory

then stimulate them to differentiate in the pancreas cells so that they can produce insulin

and then they could inject those cells into the patient's pancreas where they could continue to divide and produce the

insulin that the patient needs or in a similar way if we wanted to treat somebody for paralysis

we could use the same process to produce healthy nerve cells or to treat them for circle cell anemia

we would differentiate them into healthy blood cells now this method of using embryonic stem

cells sounds great in theory but in practice it has a couple of drawbacks

the first is the fact that it requires embryonic stem cells because remember those are the only ones

that are able to differentiate into any type of cell however because embryonic stem cells

only come from embryos there's a very limited supply of them and there are also some ethical issues

around using them as we'll see later the second drawback is the idea of rejection

because the embryo and the patient have different genomes the patient's immune system may reject

the stem cells which means it tries to destroy them because identifies them as foreign

we can reduce the risk of this happening by giving the patient medications to suppress their immune system but it

doesn't always work and often has side effects now an alternative to this we should

overcome both of these issues would be to use adult stem cells instead these are easy to get hold of and also

won't cause rejection because they can be taken from the patient themselves the downside of adult stem cells though

is that they can only differentiate into different types of blood cells so while we could use them to treat

blood cell disorders like sickle cell anemia we couldn't use them to treat other conditions like diabetes or

paralysis one caveat to this though is that there is some new research exploring how we

could use adult stem cells to produce any type of cell regardless of which type of stem cell we

use though there are two potential risks involved with using stem cells namely virus transmission

and tumor development virus transmission refers to the idea that if the donor stem cells are

infected with a virus either before they were taken by the scientists or while they were in the lab

then when they're transferred into the patients they had also transferred that virus

which could then infect the patient and cause even more problems on the other hand tumor development is

the idea that because stem cells can divide so quickly there's a chance that they could get out

of control once they've been transplanted into the patient and so they could go on to develop into

a tumor or a cancer okay so the final thing we discover is the ethical objection to using embryonic

stem cells this is the idea that the human embryos that are being used have the potential

for human life and so on religious or moral grounds some people object to their use in

research on the other hand other people think that the benefits of curing existing

people who are suffering is more important than the rights of embryos either way though an important point to

remember is that the embryos that are used are usually the unwanted ones from fertility clinics

that would otherwise have been destroyed so they probably wouldn't have developed into human anyway

also governments normally heavily regulate this area of research with some countries banning it completely

in the uk embryonic research is legal but it's tightly controlled and scientists have to follow strict rules

hey everyone amadeus here i just wanted to let you know that we also have a learning platform where you can watch

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that's all though so hope you enjoy and i'll see you next time thanks