Corneal Repair: A Clear Vision!

Damage to the surface of the cornea causes pain and loss of vision, but regenerative therapies are providing a clearer, brighter future.

If the eyes are the window to the soul, then it is the cornea that lets the light enter.

For more than 200 years, physicians have been preoccupied with keeping this dome-shaped, transparent surface in front of the iris and pupil clear. German surgeon Franz Reisinger was the first to attempt a corneal transplant in animals in 1818. And in 1838, US ophthalmologist Richard Kissam tried to replace the opaque cornea of a young patient with the healthy cornea of a pig, but the procedure failed when the transplant was rejected. The first successful transplant in humans was in 1905, but outcomes remained poor until the mid-twentieth century, when developments in infection control, anaesthesiology, surgical techniques and immunology vastly improved the success rate of corneal transplantation. In the twenty-first century, advances in cell-culture techniques and bioengineering have opened the door to regenerative treatments for people with damage to one or both corneas.

Unclouded vision requires a clear cornea. Its epithelial surface constantly renews itself to maintain an unblemished, uniformly refractive surface. Cells that are shed from the surface are replaced by new ones that emanate from a small population of stem cells located at the edge, or limbus, of the cornea.

If the stem cells at the limbus are damaged, the renewal process is interrupted. The complete or partial loss of these stem cells — limbal stem-cell deficiency (LSCD) — allows the opaque conjunctiva to grow over the cornea. This can lead to intense pain and, in the most-severe cases, blindness.

Let there be sight -David Holmes

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Source: Nature

We could be close enough to the stem cell revolution!

Stem cell therapy has been in use for many years, but with only limited reach. As such the oft bandied stem cell revolution has still yet to arrive. Steve Buckwell and Chris Coe explain why this is set to change and why now is the perfect time for its potential to be achieved. 

The stem cell revolution as it’s often referred to is now already in its third decade. But like the paper free office, is it just one of those envisaged futures that never seem to really happen? Embryonic stem cells were first isolated 18 years ago, but stem cell therapies have been slowed by high production costs, batch-to-batch variability and limited seed material. But we still believe the revolution will kick off some time in the second half of this decade. This is why.

Firstly the early ethical issues have, in many cases been overcome, with adult stem cells showing promise in the clinic but not requiring the embryo exploitation and destruction that made embryonic stem cell research so controversial in the years after 1998. Secondly, there is now substantial mid-stage clinical evidence that stem cells work in areas of unmet medical need, much of which has only become evident in the last five years.

There are various stem cell products in development that work allogeneically, meaning that the patient receives stem cells sourced from someone else’s body. As a general rule, allogeneic therapies are quite cost effective because they have the potential to be ‘off-the-shelf’, whereas autologous therapies (use of the patient’s own cells) can be considerably more expensive.

Read more: We could be close enough to the stem cell revolution!

Source: labnews

Organ regeneration with skin cells turning Into brain and heart cells

In a breakthrough study, researchers were able to chemically change skin cells to heart and brain cells.

When a person’s own body fails them, there are plenty of roadblocks to getting it running again. Adult hearts have a very limited ability to regenerate, so oftentimes the only way to help a person with a failing heart is to get them a new one. This is risky, though, since the patient’s body may reject even a perfectly matched organ. Scientists have been making strides in overcoming that problem by using a patient’s own stem cells to regenerate tissue, and researchers from the Gladstone Institutes have made a major breakthrough in the area — they successfully used a combination of chemicals to transform skin cells into heart and brain cells.

The feat is unprecedented, since all previous attempts to reprogram cells required scientists to add outside genes. Published in Science and Stem Cell, the research gives scientists a foundation for one day being able to regenerate lost or damaged cells with pharmaceuticals. The system is both more reliable and efficient than previous processes, and avoids medical concerns surrounding genetic engineering.

“This method brings us closer to being able to generate new cells at the site of injury in patients,” Dr. Sheng Ding, a Gladstone senior investigator, said in a press release. “Our hope is to one day treat diseases like heart failure or Parkinson’s disease with drugs that help the heart and brain regenerate damaged areas from their own existing tissue cells. This process is much closer to the natural regeneration that happens in animals like newts and salamanders, which has long fascinated us.”

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Brain cells are hard to fake, but it may now be possible.

Source: Pixabay

Roles for mesenchymal stem cells as medicinal signaling cells

Understanding the in vivo identity and function of mesenchymal stem cells (MSCs) is vital to fully exploiting their therapeutic potential. New data are emerging that demonstrate previously undescribed roles of MSCs in vivo. Understanding the behavior of MSCs in vivo is crucial as recent results suggest these additional roles enable MSCs to function as medicinal signaling cells. This medicinal signaling activity is in addition to the contribution of MSCs to the maintenance of the stem cell niche and homeostasis.

There is increasing evidence that not all cells described as MSCs share the same properties. Most MSCs reside in a perivascular location and have some functionalities in common with those of the pericytes and adventitial cells located around the microvasculature and larger vessels, respectively. 

Here we focus on the characteristics of MSCs that have been demonstrated to be similar to those of pericytes located around the microvasculature, defined as perivascular MSCs (pMSCs). Although we focus here on pMSCs, it is important to bear in mind that pericytes are found in many types of blood vessels, and that not all pericytes are thought to be MSCs.

Read more: Roles for mesenchymal stem cells as medicinal signaling cells

Source: NatureReviews