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Extended wear contact lenses coated in corneal stem cells have been used to successfully restore vision in three patients. Doctors with the project describe the treatment as cheap, simple, and highly promising..  (Source: GizMag)
File this one under cool -- stem cells cure blindness

While electronic eyeballs may eventually be a solution to restore sight for the visually impaired, or even to enhance vision for those with normal eyesight, they still are very crude and may have a long way to go.  In a classic race between electronics and biotechnology, it appears that biotechnology may have caught up with an incredible solution to restoring vision.

Scientists and the University of New South Wales in Australia cultured corneal stem cells on extended wear contact lenses.  They then cleaned the corneas of three patients -- two of whom were legally blind and one with limited vision (they could read the biggest row of the vision chart) -- and had the patient start wearing the lens. 

Amazingly, within 10 to 14 days the stem cells had reentered the cornea and began to recolonize it.  UNSW’s Dr Nick Di Girolamo describes, "The procedure is totally simple and cheap.  Unlike other techniques, it requires no foreign human or animal products, only the patient’s own serum, and is completely non-invasive."

The two legally blind patients can now read the top row of a vision chart, while the vision impaired patient can read enough of the chart to get their driver's license.

The technique still has unknowns.  While the patients have regained vision, lasting for over 18 months, there's a chance the gains won't last.  While the cornea has no blood supply and gets its oxygen from the air, but it remains to be seen whether the blind patient's tear fluid is sufficient to sustain the new eye tissue in the long term.

Still, Dr. Di Girolamo says the technique looks promising and holds promise even to patients with damage to both eyes.  Dr. Girolamo states, "One of our patients had aniridia, a congenital condition affecting both eyes.  In that case, instead of taking the stem cells from the other cornea, we took them from another part of the eye altogether – the conjunctiva – which also harbors stem cells."

Corneal diseases are a leading cause of blindness.  According to the World Health Organization, damage to this delicate organ causes 1.5 million people to lose sight in one of their eyes every year.

The UNSW team is looking to expand the work to cover other types of ocular damage.  Previous research by other teams has shown that stem cells could potentially be used to grow entire eyeballs.  They also believe the technique could be applied to regrowing skin and other damaged tissues.



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RE: Stem cell source
By geddarkstorm on 6/4/2009 1:19:25 PM , Rating: 5
Embryonic stem cells are highly inferior from the biological standpoint for many reasons. Easier, sure, since they are already at the stem cell stage, but rife with problems. Rejection is only one. Embryonic stem cells are known to easily form tetramers, and tumors at the site of injection -- that is, they begin to turn into multiple different tissues, not just the tissue wanted. Adult stem cells don't have this problem, as they are already prepared to only adopt the correct tissue type to do regeneration (due to epigenetic information). They also have the correct chemistry and genetics to interact correctly with the surrounding tissue. If the tissue is genetically defunct, than a slight genetic manipulation of the adult stem cells is little additional problem. Also, once again cells carry epigenetic information (DNA methylation, histone modification, histone type and placement) that is just as important as the DNA (Lamarck was actually partially right: some limited traits can be acquired through life and inherited generationally via epigenetics), and embryonic stem cells are highly dissimilar from your own in that regard too (that's part of why embryonic stem cells try to form a whole new person at the site of injection, which is not completely controllable).

So then, the genetic dissimilarity with an embryonic stem cell and your own cells rises a plethora of issues. They may not respond to your body's signals the same way as the surrounding tissue, or even grow into the correct tissue model, which, again, results in cancer or aberrant tissue behavior. And with the threat of rejection always lurking around the corner, you also get the fun times of sparking auto-immune diseases.

Embryonic stem cells have shown little utility, while iPS and adult stem cells are already set up to do everything correctly and don't take that much more work or money to make; all the while avoiding the downfalls of embryonic stem cells biologically and ethically. No, embryonic stem cells are far inferior in all regards.


RE: Stem cell source
By HeavyB on 6/4/2009 9:57:00 PM , Rating: 4
I'm not going to spend my time correcting all of the inaccuracies in your post, just a few.

quote:
Embryonic stem cells are known to easily form tetramers, and tumors at the site of injection -- that is, they begin to turn into multiple different tissues, not just the tissue wanted. Adult stem cells don't have this problem,as they are already prepared to only adopt the correct tissue type to do regeneration


Wrong, both iPS cells and embryonic stem cells form teratomas (not tetramers). http://en.wikipedia.org/wiki/Teratoma It is a defining characteristic of both cell types to form all 3 primordial germ layers, endoderm, ectoderm, and mesoderm. The epigenetic information that you mention is a drawback of iPS cells too, not a benefit. Different tissues can have different imprinting which would likely make it more difficult to take a skin sample, turn it into an iPS cell, then try to turn it into a cardiomyocyte.

In general, iPS cells will be a better solution for autologous stem cell therapies, provided they differentiate into the cell type you are looking to replace, due to the matching histocompatibility. Until very recently iPS cells were only generated by expressing the reprogramming factors using retroviral expression, which has potential to be mutagenic due to viral integration into an important area of the genome. REcent advances have made iPS cell therapies even more promising, and while I agree with your assessment that they are more promising than hES cells for theraputics and avoid many of the ethical issues, some of your statements were blatantly wrong.

Back to Bio 101 for you.


RE: Stem cell source
By geddarkstorm on 6/9/2009 3:44:06 PM , Rating: 2
Ah, but you see, I said "adult stem cells" for most things, not iPS ;). Adult stem cells are a completely different thing from an induced pluripotent cell, one of the major differences being that adult stem cells are not pluripotent and are mostly locked to make a specific tissue or set of tissues (look at mesenchymal bone marrow stem cells, for instance, which can form a variety of tissues, including myocytes, osteoblasts, and adipocytes). What I said is correct for adult stem cells, that being my subject matter (iPS still avoids several problems of embryonic stem cells, however, like MHC compatibility).

Before correcting someone, please make sure to actually read what they even said so you know what you are even trying to correct. Thank you for the spelling fix, however!


RE: Stem cell source
By sinful on 6/4/2009 10:27:15 PM , Rating: 2
quote:
So then, the genetic dissimilarity with an embryonic stem cell and your own cells rises a plethora of issues. They may not respond to your body's signals the same way as the surrounding tissue, or even grow into the correct tissue model, which, again, results in cancer or aberrant tissue behavior. And with the threat of rejection always lurking around the corner, you also get the fun times of sparking auto-immune diseases.


Of course, it should be noted that rejection is an issue due to an extremely limited number of embryonic stem cell lines (as a result of the federal ban).

It's like saying blood transfusions have problems with rejection because, hey, you can't give someone with type A blood to someone with Type B blood....
... true, but given a sufficient supply of the varying embryonic stem cell lines, rejection is pretty much a non-issue.

You also didn't mention WHY the adult stems cells are less likely to form a tumor: it's because the adult stems cells die after a short period of time; embryonic stem cells do not.
That can cause problems, but it may give the possibility to solve different types of problems; i.e. certain perpetual degenerative conditions would need a constant influx of adult stem cells to "patch" the problem; embryonic stem cells could just "keep doing the job".

It also needs to be pointed out you're comparing a technology that's had bans on it & no federal money vs. a technology that's been relatively unhindered & received federal money.

In other words, it's foolish to judge the potential of a technology when it's been held back & unfunded.

Keep in mind that "at the beginning", Adult stem cells were considered poor and destined for failure, while Embryonic stem were pegged as having great potential.

Perhaps if the reverse were true, Embryonic stem cells would be curing cancer by now.

You just don't know.


RE: Stem cell source
By sinful on 6/4/2009 10:31:36 PM , Rating: 2
quote:
Perhaps if the reverse were true, Embryonic stem cells would be curing cancer by now.


I meant that in the context of funding & bans;
i.e.
if there were bans on Adult stem cell research and funding was given (and promoted) towards Embryonic Stem Cell research, perhaps people would be saying "ZOMG Adult Stem Cells=Fail, why did we even bother with such a failed idea?"

It's premature to judge either way.


RE: Stem cell source
By bill3 on 6/6/2009 7:19:25 AM , Rating: 2
There is no federal ban on stem cell research.

Oh wait, you mean in the USA only? As if every other country on earth doesnt exist? Now I got ya.

Indeed, virtually every country except the United States funds stem cell research at the federal level. So speaking of a "federal stem cell ban" is misleading at best.

Also, there never was any federal ban in the USA either, of course any private group and any state funded huge amounts of stem cell research, including California. None have created any treatments, though.

Also, of coursr there has been no ban in America roughly since Obama has been in office.

Blaming stem cell's failure on the short lived, former, incredibly limited USA federal research ban is illogical at best.


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