Researchers 3D print a heart pump using stem cells

This image used on the cover of the American Heart Association’s Circulation Research journal is a 3D rendering of the printed heart pump developed at the University of Minnesota. The discovery could have major implications for studying heart disease. 
Credit: Kupfer, Lin, et al., University of Minnesota

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death for men, women, and people of most racial and ethnic groups in the United States. About 647,000 Americans die from heart disease each year, which is roughly one out of every four deaths total in the US.

In order to better study heart disease, Dr. Brenda Ogle and her team at the University of Minnesota have successfully 3D printed a functioning centimeter-scale human heart pump.

Previously, researchers have attempted to 3D print heart muscle cells within a 3D structure called an extracellular matrix. The heart muscle cells were made from induced pluripotent stem cells (iPSCs), a type of stem cell that can turn into virtually any kind of cell. Unfortunately, the cell density needed for the heart cells to function was never reached.

In this study. Dr. Ogle and her team made some slight changes to the process that had failed previously. First, they optimized a specialized ink made from extracellular matrix proteins. They then mixed the newly created ink with human iPSCs and used this new mixture to 3D print the chambered structure. The iPSCS were expanded to high cell densities in the structure first, and then were differentiated into heart muscle cells. The heart muscle model is about 1.5 centimeters long and was specifically designed to fit into the abdominal cavity of a mouse for future studies.

A video of this process can be seen below:

The team of researchers found that for the first time ever they could achieve the goal of high cell density to allow the cells to beat together, just like a human heart. Furthermore, this study shows how heart muscle cells can organize and work together. The iPSCs differentiating into heart muscle cells right next to each other is comparable to how stem cells grow in the body and then undergo specification to heart muscle cells.

A video of the heart pump contractions can be seen below as well:

In a press release from the University of Minnesota, Dr. Ogle elaborates on the implications of this study.

“We now have a model to track and trace what is happening at the cell and molecular level in pump structure that begins to approximate the human heart. We can introduce disease and damage into the model and then study the effects of medicines and other therapeutics.”

The full results of this study were published in Circulation Research.

How a tiny patch of skin helped researchers save the life of a young boy battling a deadly disease

 

EB boy

After receiving his new skin, the boy plays on the grounds of the hospital in Bochum, Germany. Credit: RUB

By any standards epidermolysis bullosa (EB) is a nasty disease. It’s a genetic condition that causes the skin to blister, break and tear off. At best, it’s painful and disfiguring. At worst, it can be fatal. Now researchers in Italy have come up with an approach that could offer hope for people battling the condition.

EB is caused by genetic mutations that leave the top layer of skin unable to anchor to inner layers. People born with EB are often called “Butterfly Children” because, as the analogy goes, their skin is as fragile as the wings of a butterfly. There are no cures and the only treatment involves constantly dressing the skin, sometimes several times a day. With each change of dressing, layers of skin can be peeled away, causing pain.

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Hands of a person with EB

Life and death for one boy

For Hassan, a seven-year old boy admitted to the Burn Unit of the Children’s Hospital in Bochum, Germany, the condition was particularly severe. Since birth Hassan had repeatedly developed blisters all over his body, but several weeks before being admitted to the hospital his condition took an even more serious turn. He had lost skin on around 80 percent of his body and he was battling severe infections. His life hung in the balance.

Hassan’s form of EB was caused by a mutation in a single gene, called LAMB3. Fortunately, a team of researchers at the University of Modena and Reggio Emilia in Italy had been doing work in this area and had a potential treatment.

To repair the damage the researchers took a leaf out of the way severe burns are treated, using layers of skin to replace the damaged surface. In this case the team took a tiny piece of skin, about half an inch square, from Hassan and, in the laboratory, used a retrovirus to deliver a corrected version of the defective gene into the skin cells.

 

They then used the stem cells in the skin to grow sizable sheets of new skin, ranging in size from about 20 to 60 square inches, and used that to replace the damaged skin.

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In the study, published in the journal Nature, the researchers say the technique worked quickly:

“Upon removal of the non-adhering gauze (ten days after grafting) epidermal engraftment was evident. One month after grafting, epidermal regeneration was stable and complete. Thus approximately 80% of the patient’s TBSA (total body surface area) was restored by the transgenic epidermis.”

The engrafted skin not only covered all the damaged areas, it also proved remarkably durable. In the two years since the surgery the skin has remained, in the words of the researchers, “stable and robust, and does not blister, itch, or require ointment or medications.”

In an interview in Science, Jakub Tolar, an expert on EB at the University of Minnesota, talked about the significance of this study:

“It is very unusual that we would see a publication with a single case study anymore, but this one is a little different. This is one of these [studies] that can determine where the future of the field is going to go.”

Because the treatment focused on one particular genetic mutation it won’t be a cure for all EB patients, but it could provide vital information to help many people with the disease. The researchers identified a particular category of cells that seemed to play a key role in helping repair the skin. These cells, called holoclones, could be an important target for future research.

The researchers also said that if a child is diagnosed with EB at birth then skin cells can be taken and turned into a ready-made supply of the sheets that can be used to treat skin lesions when they develop. This would enable doctors to treat problems before they become serious, rather than have to try and repair the damage later.

As for Hassan, he is now back in school, leading a normal life and is even able to play soccer.

 

 

A call to put the ‘public’ back in publication, and make stem cell research findings available to everyone

Opening the door

Opening the door to scientific knowledge

Thomas Gray probably wasn’t thinking about stem cell research when, in 1750 in his poem “Elegy in a Country Churchyard”, he wrote: “Full many a flower is born to blush unseen”. But a new study says that’s precisely what seems to happen to the findings of many stem cell clinical trials. They take place, but no details of their findings are ever made public. They blush, if they blush at all, unseen.

The study, in the journal Stem Cell Reports, says that only around 45 percent of stem cell clinical trials ever have their results published in peer-reviewed journals. Which means the results of around 55 percent of stem cell clinical trials are never shared with either the public or the scientific community.

Now, this finding apparently is not confined to stem cell research. Previous studies have shown a similar lack of publication of the results of more conventional therapies. Nonetheless, it’s a little disappointing – to say the least – to find out that so much knowledge and potentially valuable data is being lost due to lack of publication.

Definitely not full disclosure

Researchers at the University of Alberta in Canada used the US National Institute of Health’s (NIH) clinicaltrials.gov website as their starting point. They identified 1,052 stem cell clinical trials on the site. Only 393 trials were completed and of these, just 179 (45.4 percent) published their findings in a peer-reviewed journal.

In an interview in The Scientist, Tania Bubela, the lead researcher, says they chose to focus on stem cell clinical trials because of extensive media interest and the high public expectations for the field:

“When you have a field that is accused of over promising in some areas, it is beholden of the researchers in that field to publish the results of their trials so that the public and policy makers can realistically estimate the potential benefits.”

Now, it could be argued that publishing in a peer-reviewed journal is a rather high bar, that many researchers may have submitted articles but were rejected. However, there are other avenues for researchers to publish their findings, such as posting results on the clinicaltrials.gov database. Only 37 teams (3.5 percent) did that.

Why do it?

In the same article in The Scientist, Leigh Turner, a bioethicist at the University of Minnesota, raises the obvious question:

“The study shows a gap between studies that have taken place and actual publication of the data, so a substantial number of trials testing cell-based interventions are not entering the public domain. The underlying question is, what is the ethical and scientific basis to exposing human research subjects to risk if there is not going to be any meaningful contribution to knowledge at the end of the process?”

In short, why do it if you are not going to let anyone know what you did and what you found?

It’s a particularly relevant question when you consider that much of this research was supported with taxpayer dollars from the NIH and other institutions. So, if the public is paying for this research, doesn’t the public have a right to know what was learned?

Right to know

At CIRM we certainly think so. We expect and encourage all the researchers we fund to publish their findings. There are numerous ways and places to do that. For example, we expect each grantee to post a lay summary of their progress which we publish on our website. Stanford’s Dr. Joseph Wu’s progress reports for his work on heart disease shows you what those look like.

We also require researchers conducting clinical trials that we are funding to submit and post their trial results on the clinicaltrials.gov website.

The International Society for Stem Cell Research (ISSCR), agrees and recently updated its Guidelines for Stem Cell Research and Clinical Translation calling on researchers to publish, as fully as possible, their clinical trial results.

That is true regardless of whether or not the clinical trial showed it was both safe and effective, or whether it showed it was unsafe and ineffective. We can learn as much from failure as we can from success. But to do that we need to know what the results are.

Publishing only positive findings skews the scientific literature, and public perception of this work. Ignoring the negative could mean that other scientists waste a lot of time and money trying to do something that has already demonstrated it won’t work.

Publication should be a requirement for all research, particularly publicly funded research. It’s time to put the word “public” back in publication.