Young Blood Old Brain, Night Vision and removing Memory from Stem Cells

August 24

This week we investigate a new attempt to make our brains younger. We examine a heat signature based night vision that is much clearer than current systems and we discover a way to wipe the memory from cells that are being turned back into stem cells. Finally we look at how the Japanese Art of Kirigami is enabling the building of stronger lighter structures.

Young Blood, Old Brain

There have been many attempts at recreating youth by injecting or transfusing young blood into older bodies. We now may be a step closer to helping our aging brains. Platelet factor 4 (PF4) has long been known for it role in promoting blood clotting and sealing broken blood vessels. A team at the University of California, San Francisco has been wondering if this signaling molecule could be used to treat age related cognitive disorders such as Alzheimer's.

Roughly a decade ago it was discovered that blood from young mice could restore youthful properties such as learning in older mice. The team from UCSF started working on the components of blood that cause this rejuvenation. They speculated the PF4 might just be one of the components responsible for this affect. Young mice have a greater levels of PF4 in their blood.

The team started by injecting only PF4 into older mice and they found that the ratios of various types of immune cells shifted to become similar to the levels in younger mice. PF4 is not able to cross the blood brain barrier however its effect on the immune system also led to changes in the brain. Inflammation decreased in the hippocampus and there was an increase in the levels of molecules responsible for synaptic plasticity (the ability to alter the strength of connections between nerve cells). Aged mice with PF4 injected also did better in cognitive tests.

Other researchers are also studying PF4. A team from the University of Queensland has very recently found that PF4 is involved in the formation of new neurons. Several biotech companies including Elevian and Alkahest are developing therapies that promote regeneration and healthy aging. If (again a big if) decreases in the levels of PF4 are found to precede the development of Alzheimer's this will be a very useful biomarker for people who will benefit from early treatments. The most promising current treatments for Alzheimer's require early intervention.

Wiping cell memory

In 2007, Japanese researcher Shima Yamanaka won the Nobel Prize for discovering the way to turn ordinary cells back into stem cells. The advantage of stem cells is that they can become any cell in the body. One problem however is that these cells still retain an epigenetic memory of their original function.

Teams from the University of Western Australia, Monash University from Melbourne and other institutions from around the world have developed a new method to reprogram human cells to better mimic embryonic stem cells.

Called transient-native-treatment (TNT) reprogramming it mimics the reset of a cells’s epigenome that happens very early in embryonic development. The epigenome reset is introduced at the point of the emergence of the aberrations caused by the memory of previous use, to allow the cells to completely reset.

This new treatment solves a problem with conventionally generated stem cells that if not addressed could have severe implications for a wide range of cell therapies that are underdevelopment. It may also open the way for other significant biomedical and therapeutic uses of stem cells.

Night Vision

Many nocturnal predators can see in pitch black darkness. They can survey their surroundings and identify prey. Humans struggle to process depth, texture and even objects in dim lighting. Machines suffer a similar problem. Automated vehicles struggle to drive in heavy rain, fog and smoky conditions and on roads without streetlights.

A team at Purdue University have combined thermal imaging, physics and machine learning to develop a visual AI driven system that can see in the dark as if it was daylight. The technology called Heat assisted detection and ranging (HADAR) was able to overcome the biggest stumbling block encountered by previous efforts, ghosting.

Ghosting results in smeared images that are not clear enough for navigation. Even the most sophisticated thermal cameras suffer from ghosting. All materials send out heat signals. The entire environment also sends out heat radiation. When trying to capture an image based upon thermal signals, ambient heat blends with other heat signals resulting in hazy images.

Thermal images can be thought of as several useful data streams jumbled together. They include the temperature of an object and information about texture and depth. The team developed an algorithm that isolates each of these data streams into different buckets, i.e. texture, temperature and heat emitted. The algorithm was trained on which objects generate what signals across the light spectrum.

This model allowed the cameras to see in pitch darkness and to dampen the ghosting effects. This gave clearer and more detailed images. The main drawback of this system is the price. The current cost is over US$1 million for the cameras and military grade imagers. Processing speed can also be a drawback as the system currently process 1 image a second whereas for autonomous cars 30 to 60 frames per second are needed.

Despite these remaining hurdles the team is hopeful that a commercial product will be in market within 3 years.

Using Kirigami to make Strong Lightweight Structures

Materials that are comprised of many cells packed together are cellular solids e.g. honeycomb. The shape of the cells determines the mechanical properties including stiffness and strength. Our bones are stiff and strong but still relatively light.

We have used these concepts to develop other types of cellular solids. For example shock absorbing packing foam and heat regulating radiators. MIT researchers were inspired by the Japanese art of folding and cutting paper, Kirigami, to develop a new type of material known as a plate lattice.

The materials were created with custom shapes and specifically tailored mechanical properties. The result is a material that is like steel cork. It is lighter than cork but with high strength and stiffness.

The team developed a modular construction process in which many smaller components are formed, folded and assembled into 3D shapes. The ultra lightweight and ultra strong structures can, under specified loads, morph and hold their shape. The shapes are lightweight, strong, stiff and easy to mass produce at larger scales they could be useful in architecture, aviation, automotive and aerospace.

Paying it Forward

If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.

If you have any questions or comments please comment below.

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Till next week.