Using 3D printer to develop treatment for spinal cord injury

3d-printed-device

3D printed device

Spinal cord injuries (SCIs) affect approximately 300,000 Americans, with about 18,000 new cases occurring per year. One of these patients, Jake Javier, who we have written about many times over the past several years, received ten million stem cells as part of a CIRM-funded clinical trial and a video about his first year at Cal Poly depicts how these injuries can impact someone’s life.

Currently, there is nothing that completely reverses SCI damage and most treatment is aimed at rehabilitation and empowering patients to lead as normal a life as possible under the circumstances. Improved treatment options are necessary both to improve patients’ overall quality of life, and to reduce associated healthcare costs.

Scientists at UC San Diego’s School of Medicine and Institute of Engineering in Medicine have made critical progress in providing SCI patients with hope towards a more comprehensive and longer lasting treatment option.

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Prof. Shaochen Chen and his 3D printer

In a study partially funded by CIRM and published in Nature Medicine, Dr. Mark Tuszynski’s and Dr. Shaochen Chen’s groups used a novel 3D printing method to grow a spinal cord in the lab.

Previous studies have seen some success in lab grown neurons or nerve cells, improving SCI in animal models. This new study, however, is innovative both for the speed at which the neurons are printed, and the extent of the neuronal network that is produced.

To achieve this goal, the scientists used a biological scaffold that directs the growth of the neurons so they grow to the correct length and generate a complete neuronal network. Excitingly, their 3D printing technology was so efficient that they were able to grow implants for an animal model in 1.6 seconds, and a human-sized implant in just ten minutes, showing that their technology is scalable for injuries of different sizes.

When they tested the spinal cord implants in rats, they found that not only did the implant repair the damaged spinal cord tissue, but it also provided sustained improvement in motor function up to six months after implantation.

Just as importantly, they also observed that blood vessels had infiltrated the implanted tissue. The absence of vascularized tissue is one of the main reasons engineered implants do not last long in the host, because blood vessels are necessary to provide nutrients and support tissue growth. In this case, the animal’s body solved the problem on its own.

In a press release, one of the co-first authors of the paper, Dr. Kobi Koffler, states the importance and novelty of this work:

“This marks another key step toward conducting clinical trials to repair spinal cord injuries in people. The scaffolding provides a stable, physical structure that supports consistent engraftment and survival of neural stem cells. It seems to shield grafted stem cells from the often toxic, inflammatory environment of a spinal cord injury and helps guide axons through the lesion site completely.”

In order to make this technology viable for human clinical trials, the scientists are testing their technology in larger animal models before moving into humans, as well as investigating how to improve the longevity of the neuronal network by introducing proteins into the scaffolds.

 

 

The most popular Stem Cellar posts of 2018

The blog

You never know when you write something if people are going to read it. Sometimes you wonder if anyone is going to read it. So, it’s always fun, and educational, to look back at the end of the year and see which pieces got the most eyeballs.

It isn’t always the ones you think will draw the biggest audiences. Sometimes it is diseases that are considered “rare” (those affecting fewer than 200,000 people) that get the most attention.

Maybe it’s because those diseases have such a powerful online community which shares news, any news, about their condition of interest with everyone they know. Whatever the reason, we are always delighted to share encouraging news about research we are funding or encouraging research that someone else is funding.

That was certainly the case with the top two stories this year. Both were related to ALS or Lou Gehrig’s disease.  It’s a particularly nasty condition. People diagnosed with ALS have a life expectancy of just 2 to 5 years. So it’s probably not a big surprise that stories suggesting stem cells could expand that life span got a big reception.

Whatever the reason, we’re just happy to share hopeful news with everyone who comes to our blog.

And so, without further ado, here is the list of the most popular Stem Cellar Blog Posts for 2018.

All of us in the Communications team at CIRM consider it an honor and privilege to be able to work here and to meet many of the people behind these stories; the researchers and the patients and patient advocates. They are an extraordinary group of individuals who help remind us why we do this work and why it is important. We love our work and we hope you enjoy it too. We plan to be every bit as active and engaged in 2019.

71 for Proposition 71

Proposition 71 is the state ballot initiative that created California’s Stem Cell Agency. This month, the Agency reached another milestone when the 71st clinical trial was initiated in the CIRM Alpha Stem Cell Clinics (ASCC) Network. The ASCC Network deploys specialized teams of doctors, nurses and laboratory technicians to conduct stem cell clinical trials at leading California Medical Centers.

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These teams work with academic and industry partners to support patient-centered for over 40 distinct diseases including:

  • Amyotrophic Lateral Sclerosis (ALS)
  • Brain Injury & Stroke
  • Cancer at Multiple Sites
  • Diabetes Type 1
  • Eye Disease / Blindness Heart Failure
  • HIV / AIDS
  • Kidney Failure
  • Severe Combined Immunodeficiency (SCID)
  • Sickle Cell Anemia
  • Spinal Cord Injury

These clinical trials have treated over 400 patients and counting. The Alpha Stem Cell Clinics are part of CIRM’s Strategic Infrastructure. The Strategic Infrastructure program which was developed to support the growth of stem cell / regenerative medicine in California. A comprehensive update of CIRM’s Infrastructure Program was provided to our Board, the ICOC.

CIRM’s infrastructure catalyzes stem cell / regenerative medicine by providing resources to all qualified researchers and organizations requiring specialized expertise. For example, the Alpha Clinics Network is supporting clinical trials from around the world.

Many of these trials are sponsored by commercial companies that have no CIRM funding. To date, the ASCC Network has over $27 million in contracts with outside sponsors. These contracts serve to leverage CIRMs investment and provide the Network’s medical centers with a diverse portfolio of clinical trials to address patients’’ unmet medical needs.

Alpha Clinics – Key Performance Metrics

  • 70+ Clinical Trials
  • 400+ Patients Treated
  • 40+ Disease Indications
  • Over $27 million in contracts with commercial sponsors

The CIRM Alpha Stem Cell Clinics and broader Infrastructure Programs are supporting stem cell research and regenerative medicine at every level, from laboratory research to product manufacturing to delivery to patients. This infrastructure has emerged to make California the world leader in regenerative medicine. It all started because California’s residents supported a ballot measure and today we have 71 clinical trials for 71.

 

 

Stem Cell Agency celebrates 50 clinical trials with patient #1

Yesterday the CIRM Board approved funding for our 50th clinical trial (you can read about that here) It was an historic moment for us and to celebrate we decided to go back in history and hear from the very first person to be treated in a CIRM-funded clinical trial. Rich Lajara was treated in the Geron clinical trial after experiencing a spinal cord injury, thus he became CIRM’s patient #1. It’s a badge he says he is honored to wear. This is the speech Rich made to our Board.

Rich Lajara

Hello and good afternoon everyone. It’s an honor to be here today as the 50th clinical trial has been officially funded by CIRM. It was feels like it was just yesterday that I was enrolled into the first funded clinical trial by CIRM and in turn became California’s’ 1st embryonic stem cell patient.

I became paralyzed from the waist down in September 2011. It was Labor Day and I was at a river with some close friends. There was this natural granite rock slide feature next to a waterfall, it was about 60 feet long; all you had to do was get a bucket of water to get the rocks wet and slide down into a natural pool. I ended up slipping and went down head first backwards but was too far over and I slid off a 15’ ledge where the waterfall was. I was pulled from the water and banged up pretty bad. Someone said “look at that deformity on his back” and tapped my leg and asked if I could feel that. I knew immediately I was paralyzed. I thought this was the end, little did I know this was just the beginning. I call it being in the wrong place at the right time.

So, after a few days in the hospital of course everyone, as well as myself, wanted a cure. We quickly learned one didn’t exist. A close family friend had been making phone calls and was able to connect with the Christopher & Dana Reeve Foundation and learned about a clinical trial with “stem cells”. One of my biggest question was how any people have done this? “Close to none”, I was told.

I was also told I most likely would have no direct benefit as this was a safety trial? So why do it at all? Obviously at that time I was willing to overlook the “most likely” part because I was willing to do anything to try and get my normal life back.

Looking back the big picture was laying the ground work for others like Kris or Jake (two people enrolled in a later version of this trial). At the time I had no clue that what I was doing would be such a big deal. The data collected from me would end up being priceless. It’s stories like Jake’s and Kris’ that make me proud and reinforce my decision to have participated in California’s first stem cell clinical trial funded by prop 71.

Like I said earlier it was just the beginning for me. A couple of years later I became a patient advocate working with Americans for Cures. I have been able to meet many people in the stem cell industry and love to see the glow in their face when they learn I was California’s first embryonic stem cell patient.

I can’t even fathom all the year’s of hard work and countless hours of research that had lead up to my long anticipated surgery, but when I see their glowing smile I know they knew what it took.

I also enjoy sharing my story and bridging the gap between myths and facts about stem cells, or talking to students and helping inspire the next generation that will be in the stem cell industry.  As a matter of fact, I have 13 year old sister, Maddie, dead set on being a neurosurgeon.

Fast forward to today. Life in a wheelchair is not exactly a roll in the park (no pun intended) but I have grown accustomed to the new normal. Aside from some neuropathic pain, life is back on track.

Not once did I feel sorry for myself, I was excited to be alive. Sure I have bad days but don’t we all.

In the last 14 years CIRM has funded 50 human clinical trials, published around 2750 new peer-reviewed scientific discoveries, and they’ve transformed California into the world leader in stem cell research. As I look around the posters on the wall, of the people whose lives have been transformed by the agency, I can’t help but be struck by just how much has been achieved in such a short period of time.

While my journey might not yet be over, Evie and 40 other children like her, (children born with SCID) will never remember what it was like to live with the horrible condition they were born with because they have been cured thanks to CIRM. There are hundreds of others whose lives have been transformed because of work the agency has funded.

CIRM has proven how much can be achieved if we invest in cutting-edge medical research.

As most of you here probably know CIRM’s funding from Proposition 71 is about to run out. If I had just one message I wanted people to leave with today it would be this. Everyone in this room knows how much CIRM has done in a little over a decade and how many lives have been changed because of its existence. We have the responsibility to make sure this work continues. We have a responsibility to make sure that the stories we’ve heard today are just the beginning.

I will do everything I can to make sure the agency gets refunded and I hope that all of you will join me in that fight. I’m excited for the world of stem cells, particularly in California, and can’t wait to see what’s on the horizon.

 

Has Regenerative Medicine Come of Age?

Signals logo

For the past few years the Signals blog site –  which offers an insiders’ perspectives on the world of regenerative medicine and stem cell research – has hosted what it calls a “Blog Carnival”. This is an event where bloggers from across the stem cell field are invited to submit a piece based on a common theme. This year’s theme is “Has Regenerative Medicine Come of Age?” Here’s my take on that question:

Many cultures have different traditions to mark when a child comes of age. A bar mitzvah is a Jewish custom marking a boy reaching his 13th birthday when he is considered accountable for his own actions. Among Latinos in the US a quinceañera is the name given to the coming-of-age celebration on a girl’s 15th birthday.

Regenerative Medicine (RM) doesn’t have anything quite so simple or obvious, and yet the signs are strong that if RM hasn’t quite come of age, it’s not far off.

For example, look at our experience at the California Institute for Regenerative Medicine (CIRM). When we were created by the voters of California in 2004 the world of stem cell research was still at a relatively immature phase. In fact, CIRM was created just six years after scientists first discovered a way to derive stem cells from human embryos and develop those cells in the laboratory. No surprise then that in the first few years of our existence we devoted a lot of funding to building world class research facilities and investing in basic research, to gain a deeper understanding of stem cells, what they could do and how we could use them to develop therapies.

Fast forward 14 years and we now have funded 49 projects in clinical trials – everything from stroke and cancer to spinal cord injury and HIV/AIDS – and our early funding also helped another 11 projects get into clinical trials. Clearly the field has advanced dramatically.

In addition the FDA last year approved the first two CAR-T therapies – Kymriah and Yescarta – another indication that progress is being made at many levels.

But there is still a lot of work to do. Many of the trials we are funding at the Stem Cell Agency are either Phase 1 or 2 trials. We have only a few Phase 3 trials on our books, a pattern reflected in the wider RM field. For some projects the results are very encouraging – Dr. Gary Steinberg’s work at Stanford treating people recovering from a stroke is tremendously promising. For others, the results are disappointing. We have cancelled some projects because it was clear they were not going to meet their goals. That is to be expected. These clinical trials are experiments that are testing, often for the first time ever in people, a whole new way of treating disease. Failure comes with the territory.

As the number of projects moving out of the lab and into clinical trials increases so too are the other signs of progress in RM. We recently held a workshop bringing together researchers and regulators from all over the world to explore the biggest problems in manufacturing, including how you go from making a small batch of stem cells for a few patients in an early phase clinical trial to mass producing them for thousands, if not millions of patients. We are also working with the National Institutes of Health and other stakeholders in discussing the idea of reimbursement, figuring out who pays for these therapies so they are available to the patients who need them.

And as the field advances so too do the issues we have to deal with. The discovery of the gene-editing tool CRISPR has opened up all sorts of possible new ways of developing treatments for deadly diseases. But it has also opened up a Pandora’s box of ethical issues that the field as a whole is working hard to respond to.

These are clear signs of a maturing field. Five years ago, we dreamed of having these kinds of conversations. Now they are a regular feature of any RM conference.

The simple fact that we can pose a question asking if RM has come of age is a sign all by itself that we are on the way.

Like little kids sitting in the back of a car, anxious to get to their destination, we are asking “Are we there yet?” And as every parent in the front seat of their car responds, “Not yet. But soon.”

Stem cell treatment for spinal cord injury offers improved chance of independent life for patients

kris-boesen

Kris Boesen, CIRM spinal cord injury clinical trial patient works to strengthen his upper body. (Photo/Greg Iger)

A spinal cord injury is devastating, changing a person’s life in a heartbeat. In the past there was little that doctors could do other than offer pain relief and physical therapy to try and regain as much muscle function as possible. That’s why the latest results from the CIRM-supported Asterias Biotherapeutics spinal cord injury trial are so encouraging.

Asterias is transplanting what they call AST-OPC1 cells into patients who have suffered injuries that left them paralyzed from the neck down.  AST-OPC1 are oligodendrocyte progenitor cells, which develop into cells that support and protect nerve cells in the central nervous system, the area damaged in spinal cord injury. It’s hoped the treatment will restore connections at the injury site, allowing patients to regain some movement and feeling.

The latest results seem to suggest they are doing just that.

In a news release, Asterias reports that of the 25 patients treated in this clinical trial none have experienced serious side effects. They also reported that magnetic resonance imaging (MRI) tests show that more than 95 percent of the patients have shown evidence of what’s called “tissue matrix” at the injury site. This is encouraging because it suggests the implanted cells are engrafting and helping prevent a cavitation, a serious process that often occurs in spinal cord injuries and can lead to permanent loss of muscle and sensory function plus chronic pain.

The study also shows that after six months:

  • 100 percent of the patients in Group 5 (who received 20 million cells) have recovered at least one motor level (for example increased ability to use their arms) on at least one side
  • Two patients in Group 5 recovered one motor level on both sides
  • Altogether four of the 25 patients have recovered two or more motor levels on at least one side.

Not surprisingly Ed Wirth, the Chief Medical Officer at Asterias, was pleased with the results:

“The results from the study remain encouraging as the six-month follow-up data continued to demonstrate a positive safety profile and show that the AST-OPC1 cells are successfully engrafting in patients.”

While none of the patients are able to walk, just regaining some use of their arms or hands can have a hugely important impact on their quality of life and their ability to lead an independent life. And, because lifetime costs of taking care of someone who is paralyzed from the neck or chest down can run as high as $5 million, anything that increases a patient’s independence can have a big impact on those costs.

The impact of this research is helping change the lives of the patients who received it. One of those patients is Jake Javier. We have blogged about Jake several times over the last two years and recently showed this video about his first year at Cal Poly and how Jake is turning what could have been a life-ending event into a life-affirming one.

 

Stem Cell Roundup: Jake Javier’s amazing spirit; TV report highlights clinic offering unproven stem cell therapies

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Jake Javier: Photo Michael Clemens, Sees the Day

In the Roundup we usually focus on studies that highlight advances in stem cell research but today we’re going to do something a little different. Instead of relying on print for our stories, we’re turning to video.

We begin with a piece about Jake Javier. Regular readers of our blog will remember that Jake is the young man who broke his neck the day before he graduated high school, leaving him paralyzed from the upper chest down.

After enrolling in the CIRM-funded Asterias clinical trial, and receiving a transplant of 10 million stem cells, Jake regained enough use of his arms and hands to be able to go to Cal Poly and start his life over.

This video highlights the struggles and challenges he faced in his first year, and his extraordinary spirit in overcoming them.

(thanks to Matt Yoon and his Creative Services team at Cal Poly for this video)

Going Undercover

The second video is from the NBC7 TV station in San Diego and highlights one of the big problems in regenerative medicine today, clinics offering unproven therapies. The investigative team at NBC7 went undercover at a stem cell clinic seminar where presenters talked about “the most significant breakthrough in natural medicine” for improving mobility and reducing pain. As the reporter discovered, the reality didn’t live up to the promise.

NBC7 Investigative Report

 

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.

Scientists repair spinal cord injuries in monkeys using human stem cells

Human neuronal stem cells extend axons (green). (Image UCSD)

An exciting development for spinal cord injury research was published this week in the journal Nature Medicine. Scientists from the University of San Diego School of Medicine transplanted human neural progenitor cells (NPCs) into rhesus monkeys that had spinal cord injuries. These cells, which are capable of turning into other cells in the brain, survived and robustly developed into nerve cells that improved the monkeys’ use of their hands and arms.

The scientists grafted 20 million human NPCs derived from embryonic stem cells into two-week-old spinal cord lesions in the monkeys. These stem cells were delivered with growth factors to improve their survival and growth. The monkeys were also treated with immunosuppressive drugs to prevent their immune system from rejecting the human cells.

After nine months, they discovered that the NPCs had developed into nerve cells within the injury site that extended past the injury into healthy tissue. These nerve extensions are called axons, which allow nerves to transmit electrical signals and instructions to other brain cells. During spinal cord injury, nerve cells and their axon extensions are damaged. Scientists have found it difficult to regenerate these damaged cells because of the inhibitory growth environment created at the injury site. You can compare it to the build-up of scar tissue after a heart attack. The heart has difficulty regenerating healthy heart muscle, which is instead replaced by fibrous scar tissue.

Excitingly, the UCSD team was able to overcome this hurdle in their current study. When they transplanted human NPCs with growth factors into the monkeys, they found that the cells were not affected by the inhibitory environment of the injury and were able to robustly develop into nerve cells and send out axon extensions.

Large numbers of human axons (green) emerge from a lesion/graft sites. Many axons travel along the interface (indicated by arrows) between spinal cord white matter (nerve fibers covered with myelin) and spinal cord gray matter (nerves without the whitish myelin sheathing). Image courtesy of Mark Tuszynski, UC San Diego School of Medicine.

The senior scientist on the study, Dr. Mark Tuszynski, explained how their findings in a large animal model are a huge step forward for the field in a UCSD Health news release:

“While there was real progress in research using small animal models, there were also enormous uncertainties that we felt could only be addressed by progressing to models more like humans before we conduct trials with people. We discovered that the grafting methods used with rodents didn’t work in larger, non-human primates. There were critical issues of scale, immunosuppression, timing and other features of methodology that had to be altered or invented. Had we attempted human transplantation without prior large animal testing, there would have been substantial risk of clinical trial failure, not because neural stem cells failed to reach their biological potential but because of things we did not know in terms of grafting and supporting the grafted cells.”

Dr. Tuszynski is a CIRM-grantee whose earlier research involved optimizing stem cell treatments for rodent models of spinal cord injury. We’ve blogged about that research previously on the Stem Cellar here and here.

Tuszynski recently was awarded a CIRM discovery stage research grant to develop a candidate human neural stem cell line that is optimized to repair the injured spinal cord and can be used in human clinical trials. He expressed cautious optimism about the future of this treatment for spinal cord injury patients emphasizing the need for patience and more research before arriving at clinical trials:

“We seem to have overcome some major barriers, including the inhibitory nature of adult myelin against axon growth. Our work has taught us that stem cells will take a long time to mature after transplantation to an injury site, and that patience will be required when moving to humans. Still, the growth we observe from these cells is remarkable — and unlike anything I thought possible even ten years ago. There is clearly significant potential here that we hope will benefit humans with spinal cord injury.”


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