Stem Cell Update: Nano-robots, Micro-organs and Healing The Central Nervous System

Scientists have figured out a way to coax a spherical colony of adult human stem cells in to separate types of neural tissue based on their position inside a fabricated geometry. While another team has tested liquid handling nano-robots for the molding of stem cells in to miniature organs.

 

Toward a stem cell model of human nervous system development

 

The former findings raise the question of a stem cell based developmental theory as they resemble the first stages of in vivo growth down to the exact cell type. While the latter is more concerned with testing chemicals on smaller organoids in order to screen for potentially dangerous compounds in normal sized kidneys.

Interest in stem cells has exploded over the past ten years and increasing research is mounting for it’s use in treating a number of chronic conditions. The main technique for regeneration is quite clever.

You extract this type of shape-shifting proto cell from the parts of the body where there is plenty, purify the sample and then re-inject them in to degenerating tissues. The purified shot of stem cells will pick up on the surrounding morphogenetic signals and differentiate in to the closest cell group which speeds up the entire healing process.

 

Image result for stem cells

 

Every tissue in the body has stem cells laying dormant somewhere. You can for example extract some from blood or even fat tissue.  Since the heart and lungs power the production of blood in the circulatory system stem cells can regenerate more quickly in those areas than the ones that are overused in the case of arthritis.

 

Image result for stem cells arthritis

 

Using modern medicine to speed up the natural cycle of endogenous stem cells makes sense at least as far as chronic conditions such as Parkinson’s disease, type 1 diabetes, spinal cord injury, Alzheimer’s disease, and others are concerned. Their application is also becoming popular among injured athletes. Economic predictions speak for themselves.

” The global stem cell market is projected to reach a value of USD 15.63 billion by 2025, while growing at a CAGR of 9.2%. The increasing number of research studies that aim at broadening the scope of stem cells associated products is on the strongest drivers of this market.”

In the most recent experiment carried out at the University of Michigan Stem cells were arranged in a circular colony where the cells in the middle are more closely packed together and the ones the border/edge are more loosely bound.

 

Toward a stem cell model of human nervous system development

 

What they found was that stem cells in the middle transform in to Neurepithelial cells (red) while the ones on the outside turned in to Neural plate cells (green) mimicking the first two cells to develop in the nervous system of an unborn fetus. Researchers attempted to identify the cause further by either stretching a cell or providing it with more room. In both cases they became neural plate cells, whereas when they are contracted or given less space they become neuroepithelial cells.

So it appears that morphological conditions in both the environment and cytoskeleton play a key role in how stem cells respond to protein signals like BMP -SMAD in this case, leading to separate differentiating tissues. Scientists have proposed that this may help treat neural plate disorder among women trying to conceive.

The discovery also reinforces stem cell based theories of zygote/blastocysts development inside the egg, Since stem cells are the only thing we know capable of differentiating in to these two neural tissues they are the best contender for developmental theory.

 

Blastocyst with inner cell mass

 

The second experiment performed at the University of Wasshington Seattle branch used a series of liquid handling nano robots to fit stem cells in to 400 miniature sized wells. Akin to the previous experiment these boundaries modulate cell shape and cytoskeletal contractile force invoking the type of morphological state required for protein signalling to work.

Over the course of 21 days robots adjust the cells at various stages in order to  accurately guide the development of different compartments within each organoid. Near the end they are left with a much smaller version of the kidney that possesses all of the distinguishing characteristics you would use to classify the organ normally.

 

Image result for kidney organoid

Kidney Organoid

 

Now scientists want to use these micro-kidneys for the “high throughput screening of chemicals in order to test pharmaceutical compounds and  identify potentially dangerous pollutants. A particular area of concern is polysystic kidney disease where they discovered by creating mirocysts and exposing the organoids to various chemicals that the use of Blebastatin in particular increases the size of cysts.

High-content imaging analysis reveals both dose-dependent and threshold effects during organoid differentiation.

Immunofluorescence and single-cell RNA sequencing identify previously undetected parietal, interstitial, and partially differentiated compartments within organoids and define conditions that greatly expand the vascular endothelium. Chemical modulation of toxicity and disease phenotypes can be quantified

 

 

Sources

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