Making Better Induced Pluripotent Stem Cells


On July 2nd of this year, a paper appeared in the journal Nature that performed complete genomic analyses of embryonic stem cells derived from embryos or cloned embryos, and induced pluripotent stem cells (iPSCs), which are made from reprogrammed adult cells.  They found that both embryonic stem cells made from cloned embryos and iPSCs derived from the same types of adult cells contained comparable numbers of newly introduced mutations.  However, when it came to the epigenetic modification of the genome (the small chemical tags attached to specific bases of DNA that gives the cell hints as to which genes to turn off), the epigenetic pattern of the embryonic stem cells made from cloned embryos more closely resembled that from embryonic stem cells.  The iPSCs still had some similarities with the adult cells from which they were derived whereas the embryonic stem cells made from cloned embryos were more completely reprogrammed.  From this the authors claimed that making embryonic stem cells by means of cloning is ideal for cell replacement therapies.

There is a big problem with this conclusion:  This was tried in animals and it did not work because of immunological rejection of the products from the stem cells.  For more information on this, see my book, The Stem Cell Epistles, chapter 18.

Despite this “bad news” for iPSCs, two recent papers have actually provided some good news for stem cells that can heal without destroying embryos.  The first paper comes from Timothy Nelson’s laboratory at the Mayo Clinic in Rochester, Minnesota.  Differentiation of iPSCs is, in some cases, rather efficient and the isolation procedure do a very good job of isolated the differentiated cells from potentially tumor-causing cells.  However, in other cases, the differentiation is inefficient and the isolation procedures are also rather poor, which leaves a large enough population of undifferentiated tumor-causing cells.

Nelson’ group has discovered that treating iPSCs and their derivatives with anti-cancer drugs like etoposide (a topoisomerase II inhibitor for those who are interested) increases engraftment efficiency and decreases the incidence of tumors.  My only problem with Nelson’s paper is that he and his colleagues used lentiviral vectors to make their iPSCs.  These vectors tend to produce iPSCs that are rather good at causing tumors.  I would have rather that he tried making iPSCs with other methods that do not leave permanent transgenes in the cells.  Nelson and his group transplanted their iPSC-derived cells into the hearts of mice where they could use high-resolution imaging to determine the number of cells that integrated into the heart and the presence of cell masses that were indicative of tumors.  None of the ectoposide-treated cell transplants caused tumors whereas 4 of the 5 transplants not treated with ectoposide caused tumors.  This paper appeared in Stem Cells and Development.

The second “good news” paper for iPSCs comes from Junji Takeda at the University of Osaka and Ken Igawa from the Tokyo Medical and Dental University, Japan.   In their paper from Stem Cells Translational Medicine, the Japanese groups collaborated to make iPSCs from skin based fibroblasts and then differentiate them into skin cells (keratinocytes).  However, they made the iPSCs in two different ways.  The first protocol utilized the piggyBac transposon system to make iPSCs.  The piggyBac system comes from moths, but it is highly active in mammalian cells.  It can deliver the genes to the cells, but the segment of DNA is then easily excised from the host cells without causing any mutations.  This system, therefore, will generate iPSCs that do not have any transcends in them.  The second protocol used a system based on cytomegalovirus that leaves the transgenes in the cells but gradually inactivates their expression.

When these two types of iPSCs were compared, they seems to be essentially identical when grown in culture.  Thus in the pluripotent state, the cells were equivalent for the most part.  But once the iPSC lines were differentiated into skin cells, the transgene-free iPSCs formed skin cells that looked, behaved and had the same gene expression profile as normal human skin cells.  The transgene-containing iPSCs differentiated into skin cells, but they did not look quite like skin cells, did not have the same gene expression profile as normal human skin cells, and did not behave like normal human skin cells.

The moral of this story is that not all iPSC lines are created equally and the way you derive them is as important as the cell type from which they were derived.  Also, even incomplete differentiation does not need to be an obstacle for iPSCs, since the cancer-causing cells can be removed by means of specific drugs.  Finally, not all that glitters is gold.  Cloned embryos may give you stem cells that look more like embryonic stem cells, but so what.  These might still suffer from many of the same set backs.  Add to that the ethical problems with getting women to give up their eggs for research and cures (see Jennifer Lahl’s movie Eggsploitation for more disturbing information about that), and you have a losing combination.

StemCells, Inc., Sued by Former Employee Who Says Their Stem Cell Treatment is Unsafe


A California stem cell company, StemCells, Inc., that is developing cell-based therapies for several different neurological and eye conditions, is being sued by a former employee (whistleblower) who claims that the company did not follow proper protocols in the preparation of their treatments. Rob Williams, who was once a senior manager at StemCells, Inc., has alleged that the company fired him after he brought these problems to the attention of senior management.

According to the Courthouse New Service, Williams in the lawsuit stated that he “noted poor sterile technique, failure to adhere to current Good Manufacturing Practices in the company’s manufacturing process, and substantial deficiencies in the company’s Manual Aseptic Processing of HuCNS-SC (Human Central Nervous System Stem Cells) cell lines—failure and deficiencies that put patients at risk of infection or death during ongoing clinical trials.”

Ken Stratton, who serves as the general counsel for StemCells, Inc., has told the California Stem Cell Report that Williams’s employment “was terminated for performance deficiencies, and [the company] finds no merit to the allegations.” Stratton also said that “the elements of manufacturing practices that concerned Mr. Williams were immediately and carefully reviewed by the company.”

It might be worth noting that this lawsuit coincides with the departure this past April or May of StemCells, Inc.’s Executive VP of Manufacturing Operations and Regulatory Affairs, Stewart Craig, who took a position at Sangamo Biosciences.

Unfortunately for StemCells, Inc., this particular lawsuit comes soon after a second bit of bad press. Embryologist Alan Trounson led the California Institute for Regenerative Medicine (CIRM) until June of this year, but has joined the board of StemCells, Inc., shortly after leaving the state stem cell research funding agency. According to an opinion article written by Ron Leuty, who is a reporter for the San Francisco Business Times, Trounson has recused himself from discussions regarding a loan StemCells, Inc., received from CIRM in 2012 because of his close relationship with the company’s founder. “But the speed of his appointment to the StemCells board has raised questions” about a possible conflict of interest, Leuty wrote.

CIRM has been marred by conflicts of interest accusations since California voters in 2004 birthed CIRM through Proposition 71 and the subsequent sale of $3 billion in state bonds. Now it has one more strike against it.

Leuty called the situation an embarrassment for CIRM. “If the public perceives that individuals—researchers or CIRM employees or company executives—are feeding at the trough of the semiautonomous public agency, it isn’t going to help CIRM get more cash from that very same public that foots the bill.”

Patient-Specific Stem Cells Made More Easily?


A Michigan State University research team uncovered the function of an already characterized gene that could be linchpin in the derivation of patient-specific stem cells that might be able to save millions of lives by differentiating into practically any cell in the body.

The gene is known as ASF1A, and even though it was not discovered by the team, ASF1A is one of the genes responsible for the mechanism of cellular reprogramming. Cellular reprogramming de-differentiates adult cells into less mature stem cells that have the capacity to differentiate into any cell type in the adult body.

This work was published in the journal Science. In this paper, the MSU team analyzed more than 5,000 genes from a human egg (oocyte) and determines that ASF1A in combination with another gene known as OCT4 and another molecule were primarily responsible for reprogramming.

Human oocytes

Human oocytes

“This has the potential to be a major breakthrough in the way we look at how stem cells are developed,” said Elena Gonzalez-Munoz, a former MSU post-doctoral researcher and first author of the paper. “Researchers are just now figuring out how adult somatic cells such as skin cells can be turned into embryonic stem cells. Hopefully this will be the way to understand more about how that mechanism works.”

An MSU team identified the thousands of genes expressed in oocytes in 2006. From this list of genes, the genes responsible for cellular reprogramming were then identified.

In 2007, a Japanese research team led by Shinya Yamanaka found that by introducing four other genes into adult cells, they could derive embryonic-like stem cells without the use of a human egg. These cells are called induced pluripotent stem cells, or iPSCs. “This is important because the iPSCs are derived directly from adult tissue and can be a perfect genetic match for a patient,” said Jose Cibelli, an MSU professor of animal science and a member of the team.

Apparently, ASF1A and OCT4 work in together in combination with a hormone-like substance that also is produced in the oocyte called GDF9 to facilitate the reprogramming process. “We believe that ASF1A and GDF9 are two players among many others that remain to be discovered which are part of the cellular-reprogramming process,” Cibelli said.

“We hope that in the near future, with what we have learned here, we will be able to test new hypotheses that will reveal more secrets the oocyte is hiding from us,” he said. “In turn, we will be able to develop new and safer cell-therapy strategies.”

Potential Marker Found for Stem Cell Population in the Inner Ear


Hearing loss is common as we get older. Presbycusis or age-related hearing loss results from the progressive death of sensory cells in the cochlea. Wouldn’t it be great if a stem cell population in the inner ear replaced these dying auditory sensory cells?

As it turns out, a stem cell population might exist in the mammalian inner ear and researchers from the UC Davis Comprehensive Cancer Center have identified a polysialylated glycoprotein that regulates neurodevelopment and is on the surface of cells in the adult inner ear. This glycoprotein acts as a marker of early cells in the inner ear and allows researchers to identify immature cells in the inner ear. This discovery was published in the journal Biochemical and Biophysical Research Communications and potentially opens the door to developing stem cell replacement treatments in the inner ear to treat certain hearing disorders.

“Hearing loss is a complex process and is usually regarded as irreversible,” said Frederic A. Troy II, principal investigator of the study from the UC Davis Comprehensive Cancer Center. “Finding this molecule in the inner ear that is known to be associated with early development may change that view.”

The existence of a marker for immature stem cells could make it possible to isolate neural stem cells from the adult inner ear in those people who suffer from hearing loss, culture and expand these cells in the laboratory, and then re-introduce them back into the inner ear as functioning neurons. These implanted cells might recolonize and establish themselves and improve hearing.

During development, certain glycoproteins (carbohydrate-protein linked molecules) are expressed on cell surfaces and serve critical functions essential to the normal growth and organization of the nervous system. One member of the class of cell-surface glycoproteins is an unusual molecule called polysialic acid or polySia. The large size of polySia allows it to fill spaces between cells and its strong electric charge repels other molecules. Therefore, polySia prevents cells from adhering or attaching to one another and thereby promotes cell movement to other areas.

Polysialic_acid_cell_interactions

Neural cell adhesion molecules (NCAMs) are also expressed on neuronal cell surfaces. As their name suggests, NCAMs help cells stick together and stay put. However, when NCAMs become modified with polysialic acid (or becomes “polysialylated”), the cells no longer adhere to other cells and are induced to migrate to new areas. Re-expression of the “anti-adhesive” polySia glycan on the surface of many adult human cancer cells facilitates their detachment, which enhances their metastatic spread.

Neural stem cells with these polySia-NCAMs on their cell surfaces play very important roles during embryonic development because these cells are able to travel throughout the body and differentiate into specialized cells. During adulthood, neural stem cells with polySia-NCAMs may migrate to injured areas and promote healing.

“The landscape of the cell surface of developing cells is decorated with a bewildering array of informational-rich sugar-protein molecules of which polysialylated NCAMs are of chief importance,” explained Troy. “During the life of a cell, these surface molecules are critical to cellular proliferation, self-renewal, differentiation and survival—essential processes for normal embryonic development and tissue regeneration in adults.”

It was already well-known that polySia-NCAM-expressing cells exist in the central nervous system, but Troy’s study is the first to document that they are also in the peripheral nervous system, and specifically in the spiral ganglia, those cluster of nerve cells in the inner ear that are essential to hearing.

Working with adult cells isolated from the inner ear spiral ganglia of guinea pigs, Troy and his team showed that these spiral ganglia cells expressed both polySia and NCAM. The polySia component was abundantly present on neural stem cells but was markedly reduced on mature cells. This implies that the polySia-NCAM complex is present on immature cells and can serve as a biomarker to identify these immature cells.

“Finding polySia-NCAM—a functional biomarker that modulates neuronal differentiation—on adult inner ear neural stem cells after differentiation gives researchers a ‘handle’ to identify and isolate these cells from among the many cells taken from a patient,” said Jan Nolta, director of the UC Davis Stem Cell Program and the university’s Institute for Regenerative Cures. “This discovery will enhance research into spiral ganglion neurons and may bring treatments closer to patients with hearing deficits.”

Lead author Park Kyoung Ho, a professor at Catholic University College of Medicine in Seoul, Korea, initiated the research for this article while on sabbatical leave in Troy’s laboratory at UC Davis. With his colleague and co-author, Yeo Sang Won, he is now planning clinical trials, based on the findings, in Korea with individuals who suffer from hearing disorders.

Stem Cells Aid Muscle Strengthing and Repair After Resistance Exercise


University of Illinois professor of Kinesiology and Community Health, Marni Boppart and her colleagues have published experiments that demonstrate that mesenchymal stem cells (MSCs) rejuvenate skeletal muscle after resistance exercise. These new findings, which were published in the journal Medicine and Science in Sports and Exercise, might be the impetus for new medical interventions to combat age-related declines in muscle structure and function.

Marni Boppart

Marni Boppart

Injecting MSCs into mouse leg muscles before several bouts of exercise that mimic resistance training in humans and result in mild muscle damage caused increases in the rate of muscle repair and enhanced the growth and strength of those muscles in exercising mice.

“We have an interest in understanding how muscle responds to exercise, and which cellular components contribute to the increase in repair and growth with exercise,” Boppart said. “But the primary goal of our lab really is to have some understanding of how we can rejuvenate the aged muscle to prevent the physical disability that occurs with age, and to increase quality of life in general as well.”

MSCs are found throughout the body, but several studies have established that MSCs from different tissue sources have distinct biological properties. Typically, MSCs can readily differentiate into bone, fat, and cartilage cells, but coaxing MSCs to form skeletal muscle has proven to be very difficult. MSCs usually form part of the stroma, which is the connective tissue that supports organs and other tissues.

Because of their inability to readily differentiate into skeletal muscle, MSCs probably potentiate muscle repair by “paracrine” mechanisms. Paracrine mechanisms refer to molecules secreted by cells that induce responses in nearby cells. Not surprisingly, MSCs excrete a wide variety of growth factors, cytokines, and other molecules that, according to this new study, stimulate the growth of muscle precursor cells, otherwise known as “satellite cells.” The growth of satellite cells expands muscle tissue and contributes to repair following muscle injury. Once activated, satellite cells fuse with damaged muscle fibers and form new fibers to reconstruct the muscle and enhance strength and restore muscle function.

“Satellite cells are a primary target for the rejuvenation of aged muscle, since activation becomes increasingly impaired and recovery from injury is delayed over the lifespan,” Boppart said. “MSC transplantation may provide a viable solution to reawaken the aged satellite cell.”

Unfortunately, satellite cells, even though they can be isolated from muscle biopsies and grown in culture, will probably not be used therapeutically to enhance repair or strength in young or aged muscle “because they cause an immune response and rejection within the tissue,” Boppart said. But MSCs are “immunoprivileged,” which simply means that they can be transplanted from one individual to another without sparking an immune response.

“Skeletal muscle is a very complex organ that is highly innervated and vascularized, and unfortunately all of these different tissues become dysfunctional with age,” Boppart said. “Therefore, development of an intervention that can heal multiple tissues is ideally required to reverse age-related declines in muscle mass and function. MSCs, because of their ability to repair a variety of different tissue types, are perfectly suited for this task.”

Mesenchymal Stem Cells Make Tendons on Fabricated Collagen


Ozan Akkus and his colleagues from the Department of Mechanical and Aerospace Engineering at Case Western Reserve University in Cleveland, Ohio has succeeded in making fibers made completely from the protein collagen. Why is this a big deal? Because it is so bloody hard to do.

In a paper published the journal Advanced Functional Materials, Akkus and others describe the generation of their three-dimensional collagen threads. This is the first time anyone has described the formation of such threads made purely from collagen.

Collagen is a very widely distributed protein in our bodies. It is the major structural component of tendons, and most connective tissues, and as a whole, collagen composes approximately one-third of all the protein in our bodies. There are almost 30 different types of collagen; some collagens for stiff fibers and others form flat networks that act as cushions upon which cells and other tissues can sit.

Collagen biosynthesis is very complicated and occurs in several steps. First, the collagen genes are transcribed into messenger RNAs that are translated by ribosomes into collagen protein. However, collagen proteins are made in a longer, inactive form that must undergo several types of modifications before it is usable.

Collagen synthesis begins in a compartment of the cell known as the endoplasmic reticulum, which is a series of folded membranes associated with the nuclear membrane. Within the endoplasmic reticulum, the end piece of the collagen protein, known as the signal peptide, is removed by enzymes called signal peptidases that clip such caps off proteins. Now particular amino acids within the collagen protein chains are chemically modified. The significance of these modifications will become clear later, but two amino acids, lysine and proline, and -OH or hydroxyl groups added to them. This process is called “hydroxylation,” and vitamin C is an important co-factor for this reaction. Some of the hydroxylysine residues have sugars attached to them, and three collagen protein chains now self-associate to form a “triple ɣ helical structure.” This “procollagen” as it is called, is shipped to another compartment in the cell known as the Golgi apparatus. Within the Golgi apparatus, the procollagen it is prepared to be secreted to the cell exterior. Once secreted, collagen modification continues. Other proteins of the collagen protein chains called “registration peptides” are clipped off by procollagen peptidase to form “tropocollagen.” Multiple tropocollagen molecules are then lashed together by means of the enzyme lysyl oxidase, which links hydroxylysine and lysine residues together in order to form the collagen fibrils. Multiple collagen fibrils form a proper collagen fiber. Variations on a theme are also available, since collagen can also, alternatively, attached to cell membranes by means of several types of proteins, including fibronectin and integrin.

collagen1

Now, if the cells has to go through all that just to make a collagen fiber, how tough do you think it is to make collagen fiber in a culture dish? Answer – way hard. In order to make collagen threads, Akkus and his team had to use a novel method for mature collagen production, and then they compacted the collagen molecules by means of the mobility of these molecules in an electrical field. This “electrophoretic compaction” method also served to properly align the collagen molecules until they formed proper collagen threads. Biomechanical analyses of these fabricated collagen threads showed that they had the mechanical properties of a genuine tendon. Akkus’ group when one step further and showed that a device they designed with movable electrodes could fabricate continuous collagen threads (). Thus, Akkus and his crew showed that they could make as many collagen threads as they needed and that these threads worked like tendons (see here for video). Are these guys good or what?

A. Schematic of basic electro-chemical cell layout for collagen alignment; B. Polarized image confirming the alignment of ELAC; C. Human mesenchymal stem cells on ELAC threads at day 1 and day 14. Cell form a confluent layer on day 14. Scale bar: 0.5 mm.

A. Schematic of basic electro-chemical cell layout for collagen alignment; B. Polarized image confirming the alignment of ELAC; C. Human mesenchymal stem cells on ELAC threads at day 1 and day 14. Cell form a confluent layer on day 14. Scale bar: 0.5 mm.

Nest, Akkus and his gang seeded collagen threads with mesenchymal stem cells (MSCs) from bone marrow. Remarkably, these collagen thread-grown mesenchymal stem cells differentiated into tenocytes, which are the cells that made tendons. Normally, MSCs do not readily form tenocytes in the laboratory, and they do not easily make tendons. However, in this case, the MSCs not only differentiated into tenocytes and made tenocyte-specific proteins and genes, but they do so without the addition of exogenous growth factors; the collagen threads were all the cells needed.

The seeded MSCs made Collagen I, which is the most abundant collagen of the human body, and is present in scar tissue, tendons, skin, artery walls, corneas, the endomysium surrounding muscle fibers, fibrocartilage, and the organic part of bones and teeth. Other tendon-specific proteins that were made included tenomodulin, and COMP (Cartilage oligomeric matrix protein). Furthermore, the electrically-aligned collagen does a better job of inducing the tenocyte fate in MSCs than collagen that is randomly oriented.

These remarkable and fascinating results demonstrate scaffolds made of densely compacted collagen threads stimulates tendon formation by Mesenchymal stem cells. Thus electrically aligned collagen as a very promising candidate for functional repair of injured tendons and ligaments. Now it is time to show that this can work in a living creature. Let the preclinical trials commence!!

Stem Cell Treatment Saves Man’s Leg From Amputation


Clive Randell loves motorcycles, but an unfortunate accident in 2011 seriously injured his leg and potentially prevented him from ever riding his beloved Harley-Davidson motorcycle again. His leg had several open fractures and one particular fracture that left some bone that protruded through his skin. He had extensive skin loss, and his doctors told me several times that his leg would have to be amputated. Things looked grim to say the least.

However, new stem cell procedure that repairs severely fractured bones has healed his bad leg and saved Clive from amputation. In fact, now Clive can ride his motorbike again. This new, pioneering stem cell procedure could give a new hope for victims of severe accidents who face limb amputation.

This new procedure uses stem cells extracted from the patient’s bone marrow from the patient’s pelvis and then mixes these cells with a specially created gel matrix to provide the cells with the right environment in order for them to form bone. This stem cell/matrix was then injected into the damaged bone with some hardware, such as a rod, which is inserted into the bone for support. Over time, the stem cells regenerate bone at the fracture site, traversing the fracture with new bone and completely healing the damaged bone.

Bone healing procedure

The intrepid physician who used this new procedure to heal Mr. Randall is Professor Anan Shetty, who serves as the Deputy Director of Minimally Invasive Surgery at Kent’s Canterbury Christ Church University. The motivation behind Dr. Shetty’s research is easy to understand. In the United Kingdom alone there are 350,000 serious fractures every year. Five to ten percent of these fractures are too extensive to heal and demand multiple surgeries, bone grafts, and other procedures that sometimes end in limb amputation if they fail to produce satisfactory results.

The fractured bone lacks an established blood supply, which means that it is very tough going for any implanted stem cells. Implanted stem cells have no way to receive signals to regenerate damaged cells. This new treatment circumvents this problem by using the bioengineered gel that contains the ingredients to that tells the stem cells what to do.

According to Professor Shetty, “Experiments have shown that collagen [gels] can trigger the transformation of stem cells into bone forming cells.” Dr. Shetty continued: “These “miracle” cells are abundant in bone marrow, so may be harvested, concentrated and applied with a collagen ‘scaffold’ into an area of poor healing.”

According to Clive Randall, “I may never dance the tango, but, thanks to Professor Shetty, I will be able to get as near to normal as possible.”

This bone-healing operation is performed under a general anaesthesia and only takes 30 minutes, after which the patient can walk out of the hospital and go home on the same day as the procedure. To date, six patients in the UK, four in India and 20 in South Korea have undergone this procedure.

Bone marrow for this procedure is drawn from the crest of the ilium of the patient’s pelvis by means of a stiff, hollow needle. Bone marrow contains a mixture of differ types of stem cells (including hematopoietic stem cells, mesenchymal stem cells, and endothelial progenitor cells), and red blood cells. The bone marrow extract is then concentrated through centrifugation, but the red blood cells are usually removed. The concentrated bone marrow stem cell preparation is then mixed with collagen and this mixture is ready for implantation by injection.

For the surgical procedure, the surgeon stabilizes the fracture with a plate or long metal rod that is inserted through the central medullary canal or the bone. These stabilizing tools can be inserted with a small incision. The stem cell and collagen suspension is then injected into the fracture site and around the bone, guided by either live fluoroscopy or X-ray.

After the surgery, the patient is actually allowed put some weight on the affected limb, and is instructed to progressively increase the load he or she applies through his leg. Interestingly, Prof Shetty’s pioneering procedure cuts the healing time associated with these types of procedures in half, and at a cost of about $3,500 to $5,200, costs a fraction of the hundreds of thousands of dollars usually involved in amputation, rehabilitation and fitting the patient for prosthetics.

Professor Norimasa Nakamura, president elect of the International Cartilage Repair Society and one of the world’s leading authorities on stem cell treatment, has welcomed Prof Shetty’s work, saying: “It will revolutionize the whole field of bone fracture repairs. The patient has a more effective treatment and the health provider saves money. It’s a win-win situation.”

After his accident, Clive Randall, who worked as a high-altitude window cleaner who lived in Orpington, Kent, had a cage screwed to his damaged leg. He also underwent three bone grafts and several other procedures within 18 months after his accident. The accident also drastically changed his life. Even though the driver of the car was successfully prosecuted, he lost his job, girlfriend, and most of his money. He also had to take a deal of pain medication and became greatly depresses; at one time, understandably, he contemplated suicide. In a kind of “Hail Mary,” Clive turned to the internet and typed “I want to save my leg.”

He found Prof Shetty’s name, and the rest is history, but he is still in a state of disbelief over the reversal in his fortunes since having the operation in 2012. He said, “Six hours after the operation, Professor Shetty told me to get up and go for a walk. After being in and out of hospitals, I really couldn’t believe it. I’d suffered 15 months of being told there was a good chance I was going to lose my leg, yet eight weeks after the procedure I was told to start putting weight on it and to walk as much as I could. It still hurts to walk long distances, but that will improve. My foot is turned out a little bit to the side and I have a limp, but that’s a small price to pay to keep my leg. My hope is this procedure will eventually be available to everyone, since it can help so many people, particularly the military. The old way of mending broken bones is so painful and stops you getting on with your life. Professor Shetty’s stem cell surgery is quick and almost painless, so it’s important more people hear about it.”

There you have it from the patient himself.  Now only if the power-hungry, control-driven FDA would get off their duffs and look into bringing this procedure to the US?