Stem cell clinics make big claims but offer little evidence they can treat osteoarthritic knees

osteoarthritis knee

If someone says they have a success rate of close to 100 percent in treating a major health problem but offer little evidence to back that up, you might be excused for being more than a tad skeptical. And a new study says you would be right.

The health problem in question is osteoarthritis (OA) of the knee, something that affects almost 10 million Americans. It’s caused by the wearing down of the protective cartilage in the knee. That cartilage acts as a kind of shock absorber, so when it’s gone you have bone rubbing against bone. That’s not just painful but also debilitating, making it hard to lead an active life.

There is a lot of research taking place – including a clinical trial that CIRM is funding – that focuses on using stem cells to create new cartilage, but so far nothing has been approved by the US Food and Drug Administration for wider use. The reason for that is simple. No approach has yet proven it is both safe and effective.

No evidence? No worries

But that doesn’t stop many clinics around the US, and around the world, from claiming they have treatments that work and charging patients a hefty sum to get them.

In a study presented at the Annual Meeting of the American Academy of Orthopaedic Surgeons, researchers contacted 317 clinics in the US that directly market stem cell therapies to consumers. They asked the clinics for information on the cost of the procedure and their success rate.

  • Only 65 clinics responded
  • Lowest price was $1,150
  • Highest price was $12,000,
  • Average price of $5,156.

Only 36 clinics responded with information about success rates.

  • 10 claimed between 90 and 100 percent success
  • 15 claimed 80 to 90 percent success
  • 10 claimed 70 to 80 percent
  • One said just 55 percent.

None offered any evidence based on a clinical trial that supported those claims, and there was no connection between how much they charged and how successful they claimed to be.

In a news release about the study – which appears in the Journal of Knee Surgery – George Muschler, one of the lead authors, said that orthopedic surgeons have a duty to give patients the best information available about all treatment options.

“Recent systematic reviews of cellular therapies for the treatment of knee OA (over 400 papers screened) have found poor levels of evidence for the efficacy of these treatments to date. Current evidence does not justify the rapid rate of growth for these therapies.”

Nicolas Piuzzi, the other lead author on the study, says if the evidence doesn’t justify the growth in the number of clinics offering these therapies, it certainly doesn’t justify the prices they charge.

“The claim of “stem cell” therapy carries a high level of expectations for the potential benefits, but research is still many years away from providing clear evidence of effective treatment to patients. As clinicians and researchers, we have ethical, scientific, legal and regulatory concerns. Patients need to be aware of the status of research within the field. If they receive information from anyone offering a treatment claim of an 80 to 100 percent successful recovery, they should be concerned in observance of published peer-reviewed evidence.”

CIRM-funded clinical trial takes a combination approach to treating deadly blood cancers

Stained blood smear shows enlarged chronic lymphocytic leukemia cells among normal red blood cells. (UCSD Health)

A diagnosis of cancer often means a tough road ahead, with surgery, chemotherapy and radiation used to try and kill the tumor. Even then, sometimes cancer cells manage to survive and return later, spreading throughout the body. Now researchers at UC San Diego and Oncternal Therapeutics are teaming up with a combination approach they hope will destroy hard-to-kill blood cancers like leukemia.

The combination uses a monoclonal antibody called cirmtuzumab (so called because CIRM funding helped develop it) and a more traditional anti-cancer therapy called ibrutinib. Here’s how it is hoped this approach will work.

Ibrutinib is already approved by the US Food and Drug Administration (FDA) to treat blood cancers such as leukemia and lymphoma. But while it can help, it doesn’t always completely eradicate all the cancer cells. Some cancer stem cells are able to lie dormant during treatment and then start proliferating and spreading the cancer later. That’s why the team are pairing ibrutinib with cirmtuzumab.

In a news release announcing the start of the trial, UCSD’s Dr. Thomas Kipps,  said they hope this one-two punch combination will be more effective.

Thomas Kipps, UCSD

“As a result {of the failure to kill all the cancer cells}, patients typically need to take ibrutinib indefinitely, or until they develop intolerance or resistance to this drug. Cirmtuzumab targets leukemia and cancer stem cells, which are like the seeds of cancer. They are hard to find and difficult to destroy. By blocking signaling pathways that promote neoplastic-cell growth and survival, cirmtuzumab may have complementary activity with ibrutinib in killing leukemia cells, allowing patients potentially to achieve complete remissions that permit patients to stop therapy altogether.”

Because this is an early stage clinical trial, the goal is to first make sure the approach is safe, and second to identify the best dose and treatment schedule for patients.

The researchers hope to recruit 117 patients around the US. Some will get the cirmtuzumab and ibrutinib combination, some will get ibrutinib alone to see if one approach is more effective than the other.

CIRM has a triple investment in this research. Not only did our funding help develop cirmtuzumab, but CIRM is also funding this clinical trial and one of the trial sites is at UCSD, one of the CIRM Alpha Stem Cell Clinics.

CIRM’s Dr. Ingrid Caras says this highlights our commitment to our mission of accelerating stem cell therapies to patients with unmet medical needs.

“Our partnership with UC San Diego and the Alpha Stem Cell Clinics has enabled this trial to more quickly engage potential patient-participants. Being among the first to try new therapies requires courage and CIRM is grateful to the patients who are volunteering to be part of this clinical trial.”

Related Links:

A shot in the arm for people with bad knees


Almost every day I get an email or phone call from someone asking if we have a stem cell therapy for bad knees. The inquiries are from people who’ve been told they need surgery to replace joints damaged by age and arthritis. They’re not alone. Every year around 600,000 Americans get a knee replacement. That number is expected to rise to three million by 2030.

Up till now my answer to those calls and emails has been ‘I’m sorry, we don’t have anything’. But a new CIRM-funded study from USC stem cell scientist Denis Evseenko says that may not always be the case.


The ability to regenerate joint cartilage cells instead of surgically replacing joints would be a big boon for future patients. (Photo/Nancy Liu, Denis Evseenko Lab, USC Stem Cell)

Evseenko and his team have discovered a molecule they have called Regulator of Cartilage Growth and Differentiation or RCGD 423. This cunning molecule works in two different ways. One is to reduce the inflammation that many people with arthritis have in their joints. The second is to help stimulate the regeneration of the cartilage destroyed by arthritis.

When they tested RCGD 423 in rats with damaged cartilage, the rats cartilage improved. The study is published in the Annals of Rheumatic Diseases.

In an article in USC News, Evseenko, says there is a lot of work to do but that this approach could ultimately help people with osteoarthritis or juvenile arthritis.

“The goal is to make an injectable therapy for an early to moderate level of arthritis. It’s not going to cure arthritis, but it will delay the progression of arthritis to the damaging stages when patients need joint replacements, which account for a million surgeries a year in the U.S.”

Breaking the isolation of rare diseases

Rare disease day

Rare Disease Day in Sacramento, California

How can something that affects 30 million Americans, one in ten people in the US, be called rare? But that’s the case with people who have a rare disease. There are around 7,000 different diseases that are categorized as rare because they affect fewer than 200,000 people. Less than five percent of these diseases have a treatment.

That’s why last Wednesday, in cities across the US, members of the rare disease community gathered to call for more support, more research, and more help for families battling these diseases. Their slogan tells their story, ‘Alone we are rare; Together we are strong.’

At the Rare Disease Day rally in Sacramento, California, I met Kerry Rivas. Kerry’s son Donovan has a life-threatening condition called Shprintzen-Goldberg Syndrome. Talk about rare. There are only 70 documented cases of the syndrome worldwide. Just getting a diagnosis for Donovan took years.

DonovanDonovan suffers from a lot of problems but the most serious affect his heart, lungs and spinal cord. Getting him the care he needs is time consuming and expensive and has forced Kerry and her family to make some big sacrifices. Even so they work hard to try and see that Donovan is able to lead as normal a life as is possible.

While the disease Kerry’s son has is rarer than most, everyone at Rare Disease Day had a similar story, and an equal commitment to doing all they can to be an effective advocate. And their voices are being heard.

To honor the occasion the US Food and Drug Administration (FDA) announced it was partnering with the National Organization of Rare Diseases (NORD) to hold listening sessions involving patients and FDA medical reviewers.

In a news release Peter L. Saltonstall, President and CEO of NORD, said:

“These listening sessions will provide FDA review division staff with better insight into what is important to patients in managing their diseases and improving their quality of life. It is important for FDA to understand, from the patient perspective, disease burden, management of symptoms, daily impact on quality of life, and patients’ risk tolerance. Patients and caregivers bring a pragmatic, realistic perspective about what they are willing to deal with in terms of potential risks and benefits for new therapies.”

FDA Commissioner Dr. Scott Gottlieb said his agency is committed to doing everything possible to help the rare disease community:

“Despite our successes, there are still no treatments for the vast proportion of rare diseases or conditions. FDA is committed to do what we can to stimulate the development of more products by improving the consistency and efficiency of our reviews, streamlining our processes and supporting rare disease research.”

At CIRM we are also committed to doing all we can to help the cause. Many of the diseases we are currently funding in clinical trials are rare diseases like ALS or Lou Gehrig’s disease, SCID, spinal cord injury and sickle cell disease.

Many pharmaceutical companies are shy about funding research targeting these diseases because the number of patients involved is small, so the chances of recouping their investment or even making a profit is small.

At CIRM we don’t have to worry about those considerations. Our focus is solely on helping those in need. People like Donovan Rivas.

Friday Roundup: A better kind of blood stem cell transplant; Encouraging news from spinal cord injury trial; Finding an “elusive” cell that could help diabetics

Cool Instagram image of the week:

Pancreatic Progenitors

Diabetes Research Institute scientists have confirmed that the unique stem cells reside within large ducts of the human pancreas. Two such ducts (green) surrounded by three islets (white) are shown. [Diabetes Research Institute Foundation]

Chemo- and radiation-free blood stem cell transplant showing promise

Bubble baby disease, also known as severe combined immunodeficiency (SCID), is an inherited disorder that leaves newborns without an effective immune system. Currently, the only approved treatment for SCID is a blood stem cell transplant, in which the patient’s defective immune system cells are eliminated by chemotherapy or radiation to clear out space for cells from a healthy, matched donor. Even though the disease can be fatal, physicians loathe to perform a stem cell transplant on bubble baby patients:

Shizuru“Physicians often choose not to give chemotherapy or radiation to young children with SCID because there are lifelong effects: neurological impairment, growth delays, infertility, risk of cancer, etc.,” says Judith Shizuru, MD, PhD, professor of medicine at Stanford University.

To avoid these complications, Dr. Shizuru is currently running a CIRM-funded clinical trial testing a gentler approach to prepare patients for blood stem cell transplants. She presented promising, preliminary results of the trial on Tuesday at the annual meeting of Stanford’s Center for Definitive and Curative Medicine.

Trial participants are receiving a protein antibody called CD117 before their stem cell transplant. Previous studies in animals showed that this antibody binds to the surface of blood stem cells and blocks the action of a factor which is required for stem cell survival. This property of CD117 provides a means to get rid of blood stem cells without radiation or chemotherapy.

Early results in two participants indicate that, 6 and 9 months after receiving the CD117 blood stem cell transplants, the donor cells have successfully established themselves in the patients and begun making immune cells.

Spinal cord injury trial reports more promising results:

AsteriasRegular readers of our blog will already know about our funding for the clinical trial being run by Asterias Biotherapeutics to treat spinal cord injuries. The latest news from the company is very encouraging, in terms of both the safety and effectiveness of the treatment.

Asterias is transplanting stem cells into patients who have suffered recent injuries that have left them paralyzed from the neck down. It’s hoped the treatment will restore connections at the injury site, allowing patients to regain some movement and feeling in their hands and arms.

This week the company announced that of the 25 patients they have treated there have been no serious side effects. In addition:

  • Magnetic Resonance Imaging (MRI) scans show that in more than 90 percent of the patients the cells appear to show signs of engraftment
  • At least 75 percent of those treated have recovered at least one motor level, and almost 20 percent have recovered two levels

In a news release, Michael Mulroy, Asterias’ President and CEO, said:

“The positive safety profile to date, the evidence supporting engraftment of the cells post-implantation, and the improvements we are seeing in upper extremity motor function highlight the promising findings coming from this Phase 1/2a clinical trial, which will guide us as we work to design future studies.”

There you are! Finding the “elusive” human pancreatic progenitor cells – the story behind our cool Instagram image of the week.

Don’t you hate it when you lose something and can’t find it? Well imagine the frustration of scientists who were looking for a group of cells they were sure existed but for decades they couldn’t locate them. Particularly as those cells might help in developing new treatments for diabetes.

Diabetes-Research-Institute_University-of-Miami-Miller-School-of-MedicineWell, rest easy, because scientists at the Diabetes Research Institute at the University of Miami finally found them.

In a study, published in Genetic Engineering and Biotechnology News, the researchers show how they found these progenitor cells in the human pancreas, tucked away in the glands and ducts of the organ.

In type 1 diabetes, the insulin-producing cells in the pancreas are destroyed. Finding these progenitor cells, which have the ability to turn into the kinds of cells that produce insulin, means researchers could develop new ways to regenerate the pancreas’ ability to function normally.

That’s a long way away but this discovery could be an important first step along that path.

Stem Cell Roundup: Improving muscle function in muscular dystrophy; Building a better brain; Boosting efficiency in making iPSC’s

Here are the stem cell stories that caught our eye this week.

Photos of the week

TGIF! We’re so excited that the weekend is here that we are sharing not one but TWO amazing stem cell photos of the week.

RMI IntestinalChip

Image caption: Cells of a human intestinal lining, after being placed in an Intestine-Chip, form intestinal folds as they do in the human body. (Photo credit: Cedars-Sinai Board of Governors Regenerative Medicine Institute)

Photo #1 is borrowed from a blog we wrote earlier this week about a new stem cell-based path to personalized medicine. Scientists at Cedars-Sinai are collaborating with a company called Emulate to create intestines-on-a-chip using human stem cells. Their goal is to create 3D-organoids that represent the human gut, grow them on chips, and use these gut-chips to screen for precision medicines that could help patients with intestinal diseases. You can read more about this gut-tastic research here.

Young mouse heart 800x533

Image caption: UCLA scientists used four different fluorescent-colored proteins to determine the origin of cardiomyocytes in mice. (Image credit: UCLA Broad Stem Cell Research Center/Nature Communications)

Photo #2 is another beautiful fluorescent image, this time of a cross-section of a mouse heart. CIRM-funded scientists from UCLA Broad Stem Cell Research Center are tracking the fate of stem cells in the developing mouse heart in hopes of finding new insights that could lead to stem cell-based therapies for heart attack victims. Their research was published this week in the journal Nature Communications and you can read more about it in a UCLA news release.

Stem cell injection improves muscle function in muscular dystrophy mice

Another study by CIRM-funded Cedars-Sinai scientists came out this week in Stem Cell Reports. They discovered that they could improve muscle function in mice with muscular dystrophy by injecting cardiac progenitor cells into their hearts. The injected cells not only improved heart function in these mice, but also improved muscle function throughout their bodies. The effects were due to the release of microscopic vesicles called exosomes by the injected cells. These cells are currently being used in a CIRM-funded clinical trial by Capricor therapeutics for patients with Duchenne muscular dystrophy.

How to build a better brain (blob)

For years stem cell researchers have been looking for ways to create “mini brains”, to better understand how our own brains work and develop new ways to repair damage. So far, the best they have done is to create blobs, clusters of cells that resemble some parts of the brain. But now researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have come up with a new method they think can advance the field.

Their approach is explained in a fascinating article in the journal Science News, where lead researcher Bennet Novitch says finding the right method is like being a chef:

“It’s like making a cake: You have many different ways in which you can do it. There are all sorts of little tricks that people have come up with to overcome some of the common challenges.”

Brain cake. Yum.

A more efficient way to make iPS cells


Shinya Yamanaka. (Image source: Ko Sasaki, New York Times)

In 2006 Shinya Yamanaka discovered a way to take ordinary adult cells and reprogram them into embryonic-like stem cells that have the ability to turn into any other cell in the body. He called these cells induced pluripotent stem cells or iPSC’s. Since then researchers have been using these iPSC’s to try and develop new treatments for deadly diseases.

There’s been a big problem, however. Making these cells is really tricky and current methods are really inefficient. Out of a batch of, say, 1,000 cells sometimes only one or two are turned into iPSCs. Obviously, this slows down the pace of research.

Now researchers in Colorado have found a way they say dramatically improves on that. The team says it has to do with controlling the precise levels of reprogramming factors and microRNA and…. Well, you can read how they did it in a news release on Eurekalert.




A Noble pursuit; finding the best science to help the most people


Mark Noble. Photo by Todd Dubnicoff

Mark Noble, Ph.D., is a pioneer in stem cell research and the Director of the University of Rochester Stem Cell and Regenerative Medicine Institute in New York. He is also a member of CIRM’s Grants Working Group (GWG), the panel of independent scientific experts we use to review research applications for funding and decide which are the most promising.

Mark has been a part of the GWG since 2011. When asked how he came to join the GWG he joked: “I saw an ad on Craigslist and thought it sounded fun.”  But he is not joking when he says it is a labor of love.

“My view is that CIRM is one of the greatest experiments in how to develop a new branch of science and medicine. If you look at ventures, like the establishment of the National Institutes of Health, what you see is that when there is a concentrated effort to achieve an enormous goal, amazing things can happen. And if your goal is to create a new field of medicine you have to take a truly expansive view.”

Mark has been on many other review panels but says they don’t compare to CIRM’s.

“These are the most exciting review panels in which I take part. I don’t know of any comparable panels that bring together experts working across such a wide range of disciplines and diseases.   It’s particularly interesting to be involved in reviews at this stage because we get to look at the fruits of CIRM’s long investment, and at projects that are now in, or well on the way towards, clinical trials.

It’s a wonderful scientific education because you come to these meetings and someone is submitting an application on diabetes and someone else has submitted an application on repairing the damage to the heart or spinal cord injury or they have a device that will allow you to transplant cells better. There are people in the room that are able to talk knowledgeably about each of these areas and understand how the proposed project might work in terms of actual financial development, and how it might work in the corporate sphere and how it fits in to unmet medical needs.  I don’t know of any comparable review panels like this that have such a broad remit and bring together such a breadth of expertise. Every review panel you come to you are getting a scientific education on all these different areas, which is great.”

Another aspect of CIRM’s work that Mark admires is its ability to look past the financial aspects of research, to focus on the bigger goal:

“I like that CIRM recognizes the larger problem, that a therapy that is curative but costs a million dollars a patient is not going to be implemented worldwide. Well, CIRM is not here to make money. CIRM is here to find cures for unmet medical needs, which means that if someone comes in with a great application on a drug that is going to cure some awful disease and it’s not going to be worth a fortune, that is not the main concern. The main concern is that you might be able to cure this disease and yeah, we’ll put up money to help you so that you might be able to get into clinical trials, to get enough information to find out if it works. And to have the vision to go all the way from, ‘ok, you guys, we want you to enter this field, we want you to be interested in therapeutic development, we are going to help you structure the clinical trials, we are going to provide all the Alpha Stem Cell Clinics that can talk to each other to make the clinical trials happen.

The goal of CIRM is to change medicine and these are the approaches that have worked really well in doing this. The CIRM view clearly is:

‘There are 100 horses in this race and every single one that crosses the finish line is a success story.’ That’s what is necessary, because there are so many diseases and injuries for which new approaches are needed.”

Mark says working with CIRM has helped him spread the word back home in New York state:

“I have been very involved in working with the New York state legislature over the years to promote funding for stem cell biology and spinal cord injury research so having the CIRM experience has really helped me to understand what it is that another place can try and accomplish. A lot of the ideas that have been worked out at CIRM have been extremely helpful for statewide scientific enterprises in New York, where we have had people involved in different areas of the state effort talk to people at CIRM to find out what best practice is.”

Mark says he feels as if he has a front row seat to history.

“Seeing the stem cell field grow to its present stage and enhancing the opportunity to address multiple unmet medical needs, is a thrilling adventure. Working with CIRM to help create a better future is a privilege.”


Seeing is believing. Proof a CIRM-funded therapy is making a difference


Thelma, participant in the CAMELLIA clinical trial

You have almost certainly never heard of Thelma, or met her, or know anything about her. She’s a lady living in England who, if it wasn’t for a CIRM-funded therapy, might not be living at all. She’s proof that what we do, is helping people.

Thelma is featured in a video about a treatment for acute myeloid leukemia, one of the most severe forms of blood cancer. Thelma took part in a clinical trial, called CAMELLIA, at Oxford Cancer Centre in Oxford, UK. The clinical trial uses a therapy that blocks a protein called CD47 that is found on the surface of cancer cells, including cancer stem cells which can evade traditional therapies. The video was shot to thank the charity Bloodwise for raising the funds to pay for the trial.

Prof. Paresh Vyas of Oxford University, who was part of the clinical trial team that treated Thelma, says patients with this condition face long odds.

“Patients with acute myeloid leukemia have the most aggressive blood cancer. We really haven’t had good treatments for this condition for the last 40 years.”

While this video was shot in England, featuring English nurses and doctors and patients, the therapy itself was developed here in California, first at Stanford University under the guidance of Irv Weissman and, more recently, at Forty Seven Inc. That company is now about to test their approach in a CIRM-funded clinical trial here in the US.

This is an example of how CIRM doesn’t just fund research, we invest in it. We help support it at every stage, from the earliest research through to clinical trials. Without our early support this work may not have made it this far.

The Forty Seven Inc. therapy uses the patient’s own immune system to help fight back against cancer stem cells. It’s looking very promising. But you don’t have to take our word for it. Take Thelma’s.

California gets first royalty check from Stem Cell Agency investments

COH image

CIRM recently shared in a little piece of history. The first royalty check, based on CIRM’s investment in stem cell research, was sent to the California State Treasurer’s office from City of Hope. It’s the first of what we hope will be many such checks, helping repay, not just the investment the state made in the field, but also the trust the voters of California showed when they created CIRM.

The check, for $190,345.87, was for a grant we gave City of Hope back in 2012 to develop a therapy for glioblastoma, one of the deadliest forms of brain cancer. That has led to two clinical trials and a number of offshoot inventions that were subsequently licensed to a company called Mustang Bio.

Christine Brown, who is now the principal investigator on the project, is quoted in a front page article in the San Francisco Chronicle, on the significance of the check for California:

“This is an initial payment for the recognition of the potential of this therapy. If it’s ultimately approved by the FDA as a commercial product, this could be a continued revenue source.”

In the same article, John Zaia, Director of the City of Hope Alpha Stem Cell Clinic, says this also reflects the unique nature of CIRM:

“I think this illustrates that a state agency can actually fund research in the private community and get a return on its investment. It’s something that’s not done in general by other funding agencies such as the National Institutes of Health, and this is a proof of concept that it can work.”

Maria Millan, CIRM’s President & CEO, says the amount of the payment is not the most significant part of this milestone – after all CIRM has invested more than $2.5 billion in stem cell research since 2004. She says the fact that we are starting to see a return on the investment is important and reflects some of the many benefits CIRM brings to the state.

“It’s a part of the entire picture of the return to California. In terms of what it means to the health of Californians, and access to these transformative treatments, as well as the fact that we are growing an industry.”


Creating a platform to help transplanted stem cells survive after a heart attack


Developing new tools to repair damaged hearts

Repairing, even reversing, the damage caused by a heart attack is the Holy Grail of stem cell researchers. For years the Grail seemed out of reach because the cells that researchers transplanted into heart attack patients didn’t stick around long enough to do much good. Now researchers at Stanford may have found a way around that problem.

In a heart attack, a blockage cuts off the oxygen supply to muscle cells. Like any part of our body starved off oxygen the muscle cells start to die, and as they do the body responds by creating a layer of scars, effectively walling off the dead tissue from the surviving healthy tissue.  But that scar tissue makes it harder for the heart to effectively and efficiently pump blood around the body. That reduced blood flow has a big impact on a person’s ability to return to a normal life.

In the past, efforts to transplant stem cells into the heart had limited success. Researchers tried pairing the cells with factors called peptides to help boost their odds of surviving. That worked a little better but most of the peptides were also short-lived and weren’t able to make a big difference in the ability of transplanted cells to stick around long enough to help the heart heal.

Slow and steady approach

Now, in a CIRM-funded study published in the journal Nature Biomedical Engineering, a team at Stanford – led by Dr. Joseph Wu – believe they have managed to create a new way of delivering these cells, one that combines them with a slow-release delivery mechanism to increase their chances of success.

The team began by working with a subset of bone marrow cells that had been shown in previous studies to have what are called “pro-survival factors.” Then, working in mice, they identified three peptides that lived longer than other peptides. That was step one.

Step two involved creating a matrix, a kind of supporting scaffold, that would enable the researchers to link the three peptides and combine them with a delivery system they hoped would produce a slow release of pro-survival factors.

Step three was seeing if it worked. Using fluorescent markers, they were able to show, in laboratory tests, that unlinked peptides were rapidly released over two or three days. However, the linked peptides had a much slower release, lasting more than 15 days.

Out of the lab and into animals

While these petri dish experiments looked promising the big question was could this approach work in an animal model and, ultimately, in people. So, the team focused on cardiac progenitor cells (CPCs) which have shown potential to help repair damaged hearts, but which also have a low survival rate when transplanted into hearts that have experienced a heart attack.

The team delivered CPCs to the hearts of mice and found the cells without the pro-survival matrix didn’t last long – 80 percent of the cells were gone four days after they were injected, 90 percent were gone by day ten. In contrast the cells on the peptide-infused matrix were found in large numbers up to eight weeks after injection. And the cells didn’t just survive, they also engrafted and activated the heart’s own survival pathways.

Impact on heart

The team then tested to see if the treatment was helping improve heart function. They did echocardiograms and magnetic resonance imaging up to 8 weeks after the transplant surgery and found that the mice treated with the matrix combination had a statistically improved left ventricular function compared to the other mice.

Jayakumar Rajadas, one of the authors on the paper told CIRM that, because the matrix was partly made out of collagen, a substance the FDA has already approved for use in people, this could help in applying for approval to test it in people in the future:

“This paper is the first comprehensive report to demonstrate an FDA-compliant biomaterial to improve stem cell engraftment in the ischemic heart. Importantly, the biomaterial is collagen-based and can be readily tested in humans once regulatory approval is obtained.”