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soft total artifical heart

For the first time scientists successfully create a complete heart by 3D printing

A team of researchers at the Tel Aviv University has managed to successfully 3D print a small heart by using human tissues which includes blood vessels, biological molecules and collagens. This is considered to be a remarkable achievement as the scientists hope that with the help of this, they can make organ donation to be a thing of the past.

This achievement was reported by head researchers from TAU’s Faculty of Life Sciences, Professor Tal Dvir, Dr. Assaf Shapira and his doctoral student Nadav Noor in the Advanced Science journal.

The 3D printed heart is the size of a rabbit’s and it is not fully functional yet. However, the team has pointed out that the technology involved in 3D printing the heart for a human body is essentially the same. There are several steps of improvement left in the heart as the cells need to possess the pumping ability, a crucial working of the heart. Currently, the group of cells can contract but they need to work together. The scientists believe that they can succeed in increasing the efficiency of the method.

So the next step in the line is to make the printed heart grow and mature in the laboratory and make it learn how to function like an actual heart. Only after then can scientists take the decision to use it for transplant in animals for testing their functionality. This is a very time-consuming process and it may take years before this technology can create actual functioning organs that are ready to transplant. Nevertheless, this is a significant progress, as three-dimensional printing has managed to print tissues but not the blood vessels, which is very important for its working.

Dr. Dvir said that this is the first time, a team has successfully managed to engineer and print an entire heart with all the components inside it, the cells, blood vessels, chambers.

Scientists have previously printed cartilage and aortal tissues, but the main challenge was not accomplished, which is to create tissues with complete vascularization, blood vessels, capillaries. In the absence of these, the organs would not survive.

The scientists began the process with fatty tissues extracted from the human body and then they separated the cellular components from the non-cellular components. After that, they programmed these cells to undifferentiated stem cells which can be nudged to form cardiac cells or endothelial cells. The non-cellular materials such as the proteins galore were processed to form a personalized hydrogel which served as printing ink.

Organ printing basically involves three stages. The first stage is called the pre-print stage, which involves scanning the organ. The second stage is printing the organ and the third stage is maturing the organ in a proper environment.

brain organoids in a petri dish

Researchers created lab grown brain that independently connected to spinal cord

There are many diseases wherein one needs a donor to donate an organ, it is very difficult to get donors these days and even if you get one, it should be a perfect match. However, there are various complications that are bound to happen during the transplant. Hence, scientists are finding alternate solutions to transplant and that is nothing but growing an organ artificially and then letting it grow in the body.

It is very difficult to grow something in a laboratory as there are many factors that one has to consider, right from is it getting the proper environment to producing and also giving it the proper nutrition it requires.

After a lot of research, scientists in UK have cultivated an artificial brain in a dish and the behaviour of the brain is similar to the brain developed in humans. Scientists say that the size of the brain grown in the laboratory is similar to the size of human fetal brain at 12 to 13 weeks during which the ‘brain organoid is not complex since it doesn’t have any thoughts, feelings or consciousness – but that doesn’t make it entirely inert. It is composed of two million organized neurons.

The scientists when placed this piece of brain next to a piece of mouses’ spinal cord and a piece of mouses’ muscle tissue, this pea-sized blob of human brain cells sent out long, probing tendrils to check out its new neighbours. After which, they spontaneously connected itself to nearby spinal cord and tissue. This was observed with the help of long term live microscopy.

These probings aren’t the only skills. This brain was also the first sample to initiate muscle movement. The researchers also noticed the visible and controlled muscle contraction.

Lab Grown Brain

An image of the cerebral organoids grown from stem cells by Cambridge researchers.
Photograph: MRC Laboratory of Molecular Biology

Madeline Lancaster neuroscientist from the Medical Research Council Laboratory of Molecular Biology told The Guardian, “We like to think of them as mini-brains on the move.”

The authors mentioned, “After 2-3 weeks in co-culture, dense axon tracts could be seen innervating the mouse spinal cord and synapses were visible between human projecting axons and neurons of the mouse spinal cord. Live imaging of the mouse muscle tissue revealed sporadic concerted muscle contractions with irregular periodicity.”

Today, most brain organoids are grown from human stem cells, which spontaneously organize themselves into the structures and layers needed for early brain development. The problem is, once this cluster gets to a certain size, the middle becomes deprived of nutrients and oxygen and it stops becoming useful. Therefore the researchers sliced up the organoids and placed them on a porous membrane, the researchers made sure that their mini-brains could simultaneously use the air above and absorb the nutrients below, staying healthy after a year in their dishes.

The authors are hopeful that the success of their new approach will allow us to model brain diseases in greater detail than ever before.

The authors write, “For instance, it opens the door to the study of neurodevelopmental conditions of the corpus callosum, neuronal circuit imbalances seen in epilepsy, and other defects where connectivity is thought to play a role, such as in autism and schizophrenia.”

Published Research: https://www.nature.com/articles/s41593-019-0350-2