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Therapy shown to relieve extreme pain in mice; now moving towards human trials — ScienceDaily

Researchers at the University of Sydney have used human stem cells to make pain-killing neurons that provide lasting relief in mice, without side effects, in a single treatment.

The next step is to perform extensive safety tests in rodents and pigs, and then move to human patients suffering chronic pain within the next five years.

If the tests are successful in humans, it could be a major breakthrough in the development of new non-opioid, non-addictive pain management strategies for patients, the researchers said.

“We are already moving towards testing in humans,” said Associate Professor Greg Neely, a leader in pain research at the Charles Perkins Centre and the School of Life and Environmental Sciences.

“Nerve injury can lead to devastating neuropathic pain and for the majority of patients there are no effective therapies. This breakthrough means for some of these patients, we could make pain-killing transplants from their own cells, and the cells can then reverse the underlying cause of pain.”

Published today in the peer-reviewed journal Pain, the team used human induced pluripotent stem cells (iPSC) derived from bone marrow to make pain-killing cells in the lab, then put them into the spinal cord of mice with serious neuropathic pain. The development of iPSC won a Nobel Prize in 2012.

“Remarkably, the stem-cell neurons promoted lasting pain relief without side effects,” co-senior author Dr Leslie Caron said. “It means transplant therapy could be an effective and long-lasting treatment for neuropathic pain. It is very exciting.”

John Manion, a PhD student and lead author of the paper said: “Because we can pick where we put our pain-killing neurons, we can target only the parts of the body that are in pain. This means our approach can have fewer side effects.”

The stem cells used were derived from adult blood samples.

The total cost of chronic pain in Australia in 2018 was estimated to be $139.3 billion.

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Researchers discover new stem cells that can generate new bone — ScienceDaily

A population of stem cells with the ability to generate new bone has been newly discovered by a group of researchers at the UConn School of Dental Medicine.

In the journal STEM CELLS, lead investigator Dr. Ivo Kalajzic, professor of reconstructive sciences, postdoctoral fellows Dr. Sierra Root and Dr. Natalie Wee, and collaborators at Harvard, Maine Medical Research Center, and the University of Auckland present a new population of cells that reside along the vascular channels that stretch across the bone and connect the inner and outer parts of the bone.

“This is a new discovery of perivascular cells residing within the bone itself that can generate new bone forming cells,” said Kalajzic. “These cells likely regulate bone formation or participate in bone mass maintenance and repair.”

Stem cells for bone have long been thought to be present within bone marrow and the outer surface of bone, serving as reserve cells that constantly generate new bone or participate in bone repair. Recent studies have described the existence of a network of vascular channels that helped distribute blood cells out of the bone marrow, but no research has proved the existence of cells within these channels that have the ability to form new bones.

In this study, Kalajzic and his team are the first to report the existence of these progenitor cells within cortical bone that can generate new bone-forming cells — osteoblasts — that can be used to help remodel a bone.

To reach this conclusion, the researchers observed the stem cells within an ex vivo bone transplantation model. These cells migrated out of the transplant, and began to reconstruct the bone marrow cavity and form new bone.

While this study shows there is a population of cells that can help aid bone formation, more research needs to be done to determine the cells’ potential to regulate bone formation and resorption.

This study was funded by the Regenerative Medicine Research Fund (RMRF; 16-RMB-UCHC-10) by CT Innovations and by National Institute of Arthritis and Musculoskeletal and Skin.

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Treatment uses person’s own stem cells instead of donor cells — ScienceDaily

UCLA researchers are part of an international team that reported the use of a stem cell gene therapy to treat nine people with the rare, inherited blood disease known as X-linked chronic granulomatous disease, or X-CGD. Six of those patients are now in remission and have stopped other treatments. Before now, people with X-CGD — which causes recurrent infections, prolonged hospitalizations for treatment, and a shortened lifespan — had to rely on bone marrow donations for a chance at remission.

“With this gene therapy, you can use a patient’s own stem cells instead of donor cells for a transplant,” said Dr. Donald Kohn, a member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA and a senior author of the new paper, published today in the journal Nature Medicine. “This means the cells are perfectly matched to the patient and it should be a much safer transplant, without the risks of rejection.”

People with chronic granulomatous disease, or CGD, have a genetic mutation in one of five genes that help white blood cells attack and destroy bacteria and fungus using a burst of chemicals. Without this defensive chemical burst, patients with the disease are much more susceptible to infections than most people. The infections can be severe to life-threatening, including infections of the skin or bone and abscesses in organs such as lungs, liver or brain. The most common form of CGD is a subtype called X-CGD, which affects only males and is caused by a mutation in a gene found on the X-chromosome.

Other than treating infections as they occur and taking rotating courses of preventive antibiotics, the only treatment option for people with CGD is to receive a bone marrow transplant from a healthy matched donor. Bone marrow contains stem cells called hematopoietic, or blood-forming, stem cells, which produce white blood cells. Bone marrow from a healthy donor can produce functioning white blood cells that effectively ward off infection. But it can be difficult to identify a healthy matched bone marrow donor and the recovery from the transplant can have complications such as graft versus host disease, and risks of infection and transplant rejection.

“Patients can certainly get better with these bone marrow transplants, but it requires finding a matched donor and even with a match, there are risks,” Kohn said. Patients must take anti-rejection drugs for six to 12 months so that their bodies don’t attack the foreign bone marrow.

In the new approach, Kohn teamed up with collaborators at the United Kingdom’s National Health Service, France-based Genethon, the U.S. National Institute of Allergy and Infectious Diseases at the National Institutes of Health, and Boston Children’s Hospital. The researchers removed hematopoietic stem cells from X-CGD patients and modified the cells in the laboratory to correct the genetic mutation. Then, the patients’ own genetically modified stem cells — now healthy and able to produce white blood cells that can make the immune-boosting burst of chemicals — were transplanted back into their own bodies. While the approach is new in X-CGD, Kohn previously pioneered a similar stem cell gene therapy to effectively cure a form of severe combined immune deficiency (also known as bubble baby disease) in more than 50 babies.

The viral delivery system for the X-CGD gene therapy was developed and fine-tuned by Professor Adrian Thrasher’s team at Great Ormond Street Hospital, or GOSH, in London, who collaborated with Kohn. The patients ranged in age from 2 to 27 years old; four were treated at GOSH and five were treated in the U.S., including one patient at UCLA Health.

Two people in the new study died within three months of receiving the treatment due to severe infections that they had already been battling before gene therapy. The seven surviving patients were followed for 12 to 36 months after receiving the stem cell gene therapy. All remained free of new CGD-related infections, and six of the seven have been able to discontinue their usual preventive antibiotics.

“None of the patients had complications that you might normally see from donor cells and the results were as good as you’d get from a donor transplant — or better,” Kohn said.

An additional four patients have been treated since the new paper was written; all are currently free of new CGD-related infections and no complications have arisen.

Orchard Therapeutics, a biotechnology company of which Kohn is a scientific co-founder, acquired the rights to the X-CGD investigational gene therapy from Genethon. Orchard will work with regulators in the U.S. and Europe to carry out a larger clinical trial to further study this innovative treatment. The aim is to apply for regulatory approval to make the treatment commercially available, Kohn said.

Kohn and his colleagues plan to develop similar treatments for the other forms of CGD — caused by four other genetic mutations that affect the same immune function as X-CGD.

“Beyond CGD, there are also other diseases caused by proteins missing in white blood cells that could be treated in similar ways,” Kohn said.

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After a bone injury, shape-shifting cells rush to the rescue — ScienceDaily

Conventional thinking is that bone regeneration is left to a small number of mighty cells called skeletal stem cells, which reside within larger groups of bone marrow stromal cells.

But new findings from the University of Michigan recasts that thinking.

In a recent study, Noriaki Ono, assistant professor at the U-M School of Dentistry, and colleagues report that mature bone marrow stromal cells metamorphosed to perform in ways similar to their bone-healing stem cell cousins — but only after an injury.

Bone fracture is an emergency for humans and all vertebrates, so the sooner cells start the business of healing damaged bone — and the more cells there are to do it — the better.

“Our study shows that other cells besides skeletal stem cells can do this job as well,” Ono said.

In the mouse study, inert Cxcl12 cells in bone marrow responded to post-injury cellular cues by converting into regenerative cells, much like skeletal stem cells. Normally, the main job of these Cxcl12-expressing cells, widely known as CAR cells, is to secrete cytokines, which help regulate neighboring blood cells. They were recruited for healing only after an injury.

“The surprise in our study is that these cells essentially did nothing in terms of making bones, when bones grow longer,” Ono said. “It’s only when bones are injured that these cells start rushing to repair the defect.”

This is important because the remarkable regenerative potential of bones is generally attributed to rare skeletal stem cells, Ono says. These new findings raise the possibility that these mighty skeletal stem cells could be generated through the transformation of the more available mature stromal cells.

These mature stromal cells are malleable and readily available throughout life, and could potentially provide an excellent cellular source for bone and tissue regeneration, Ono says.

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New injection technique may boost spinal cord injury repair efforts — ScienceDaily

Writing in the journal Stem Cells Translational Medicine, an international research team, led by physician-scientists at University of California San Diego School of Medicine, describe a new method for delivering neural precursor cells (NSCs) to spinal cord injuries in rats, reducing the risk of further injury and boosting the propagation of potentially reparative cells.

The findings are published in the Jan. 29, 2020 print issue.

NSCs hold great potential for treating a variety of neurodegenerative diseases and injuries to the spinal cord. The stem cells possess the ability to differentiate into multiple types of neural cell, depending upon their environment. As a result, there is great interest and much effort to use these cells to repair spinal cord injuries and effectively restore related functions.

But current spinal cell delivery techniques, said Martin Marsala, MD, professor in the Department of Anesthesiology at UC San Diego School of Medicine, involve direct needle injection into the spinal parenchyma — the primary cord of nerve fibers running through the vertebral column. “As such, there is an inherent risk of (further) spinal tissue injury or intraparechymal bleeding,” said Marsala.

The new technique is less invasive, depositing injected cells into the spinal subpial space — a space between the pial membrane and the superficial layers of the spinal cord.

“This injection technique allows the delivery of high cell numbers from a single injection,” said Marsala. “Cells with proliferative properties, such as glial progenitors, then migrate into the spinal parenchyma and populate over time in multiple spinal segments as well as the brain stem. Injected cells acquire the functional properties consistent with surrounding host cells.”

Marsala, senior author Joseph Ciacci, MD, a neurosurgeon at UC San Diego Health, and colleagues suggest that subpially-injected cells are likely to accelerate and improve treatment potency in cell-replacement therapies for several spinal neurodegenerative disorders in which a broad repopulation by glial cells, such as oligodendrocytes or astrocytes, is desired.

“This may include spinal traumatic injury, amyotrophic lateral sclerosis and multiple sclerosis,” said Ciacci.

The researchers plan to test the cell delivery system in larger preclinical animal models of spinal traumatic injury that more closely mimic human anatomy and size. “The goal is to define the optimal cell dosing and timing of cell delivery after spinal injury, which is associated with the best treatment effect,” said Marsala.

Co-authors include: Kota Kamizato and Takahiro Tadokoro, UC San Diego and University of Ryukyus, Japan; Michael Navarro and Silvia Marsala, UC San Diego; Stefan Juhas, Jana Juhasova, Hana Studenovska and Vladimir Proks, Czech Academy of Sciences; Tom Hazel and Karl Johe, Neuralstem, Inc.; and Shawn Driscoll, Thomas Glenn and Samuel Pfaff, Salk Institute.

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Materials provided by University of California – San Diego. Original written by Scott LaFee. Note: Content may be edited for style and length.

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Egg stem cells do not exist, new study shows — ScienceDaily

Researchers at Karolinska Institutet in Sweden have analysed all cell types in the human ovary and found that the hotly debated so-called egg stem cells do not exist. The results, published in Nature Communications, open the way for research on improved methods of treating involuntary childlessness.

The researchers used single-cell analysis to study more than 24,000 cells collected from ovarian cortex samples of 21 patients. They also analysed cells collected from the ovarian medulla, allowing them to present a complete cell map of the human ovary.

One of the aims of the study was to establish the existence or non-existence of egg stem cells.

“The question is controversial since some research has reported that such cells do exist, while other studies indicate the opposite,” says Fredrik Lanner, researcher in obstetrics and gynaecology at the Department of Clinical Science, Intervention and Technology at Karolinska Institutet, and one of the study’s authors.

The question of whether egg stem cells exist affects issues related to fertility treatment, since stem cells have properties that differ from other cells.

“Involuntary childlessness and female fertility are huge fields of research,” says co-author Pauliina Damdimopoulou, researcher in obstetrics and gynaecology at the same department. “This has been a controversial issue involving the testing of experimental fertility treatments.”

The new study substantiates previously reported findings from animal studies — that egg stem cells do not exist. Instead, these are so-called perivascular cells.

The new comprehensive map of ovarian cells can contribute to the development of improved methods of treating female infertility, says Damdimopoulou.

“The lack of knowledge about what a normal ovary looks like has held back developments,” she says. “This study now lays the ground on which to produce new methods that focus on the egg cells that already exist in the ovary. This could involve letting egg cells mature in test tubes or perhaps developing artificial ovaries in a lab.”

The results of the new study show that the main cell types in the ovary are egg cells, granulosa cells, immune cells, endothelial cells, perivascular cells and stromal cells.

The study was financed with the support of several bodies, including the Swedish Research Council, the Swedish Childhood Cancer Foundation, Horizon2020 (FREIA project), the Ragnar Söderberg Foundation, the Ming Wai Lau Centre for Reparative Medicine, the Centre for Innovative Medicine and Wallenberg Academy Fellows.

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Cells carrying Parkinson’s mutation could lead to new model for studying disease — ScienceDaily

Parkinson’s disease researchers have used gene-editing tools to introduce the disorder’s most common genetic mutation into marmoset monkey stem cells and to successfully tamp down cellular chemistry that often goes awry in Parkinson’s patients.

The edited cells are a step toward studying the degenerative neurological disorder in a primate model, which has proven elusive. Parkinson’s, which affects more than 10 million people worldwide, progressively degrades the nervous system, causing characteristic tremors, dangerous loss of muscle control, cardiac and gastrointestinal dysfunction and other issues.

“We know now how to insert a single mutation, a point mutation, into the marmoset stem cell,” says Marina Emborg, professor of medical physics and leader of University of Wisconsin-Madison scientists who published their findings Feb. 26 in the journal Scientific Reports. “This is an exquisite model of Parkinson’s. For testing therapies, this is the perfect platform.”

The researchers used a version of the gene-editing technology CRISPR to change a single nucleotide — one molecule among more than 2.8 billion pairs of them found in a common marmoset’s DNA — in the cells’ genetic code and give them a mutation called G2019S.

In human Parkinson’s patients, the mutation causes abnormal over-activity of an enzyme, a kinase called LRRK2, involved in a cell’s metabolism. Other gene-editing studies have employed methods in which the cells produced both normal and mutated enzymes at the same time. The new study is the first to result in cells that make only enzymes with the G2019S mutation, which makes it easier to study what role this mutation plays in the disease.

“The metabolism inside our stem cells with the mutation was not as efficient as a normal cell, just as we see in Parkinson’s,” says Emborg, whose work is supported by the National Institutes of Health. “Our cells had a shorter life in a dish. And when they were exposed to oxidative stress, they were less resilient to that.”

The mutated cells shared another shortcoming of Parkinson’s: lackluster connections to other cells. Stem cells are an especially powerful research tool because they can develop into many different types of cells found throughout the body. When the researchers spurred their mutated stem cells to differentiate into neurons, they developed fewer branches to connect and communicate with neighboring neurons.

“We can see the impact of these mutations on the cells in the dish, and that gives us a glimpse of what we could see if we used the same genetic principles to introduce the mutation into a marmoset,” says Jenna Kropp Schmidt, a Wisconsin National Primate Research Center scientist and co-author of the study. “A precisely genetically-modified monkey would allow us to monitor disease progression and test new therapeutics to affect the course of the disease.”

The concept has applications in research beyond Parkinson’s.

“We can use some of the same genetic techniques and apply it to create other primate models of human diseases,” Schmidt says.

The researchers also used marmoset stem cells to test a genetic treatment for Parkinson’s. They shortened part of a gene to block LRRK2 production, which made positive changes in cellular metabolism.

“We found no differences in viability between the cells with the truncated kinase and normal cells, which is a big thing. And when we made neurons from these cells, we actually found an increased number of branches,” Emborg says. “This kinase gene target is a good candidate to explore as a potential Parkinson’s therapy.”

This research was supported by grants from the National Institutes of Health (R24OD019803, P51OD011106 and UL1TR000427).

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Materials provided by University of Wisconsin-Madison. Original written by Chris Barncard. Note: Content may be edited for style and length.

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Inhalation therapy shows promise against pulmonary fibrosis in mice, rats — ScienceDaily

A new study from North Carolina State University shows that lung stem cell secretions — specifically exosomes and secretomes — delivered via nebulizer, can help repair lung injuries due to multiple types of pulmonary fibrosis in mice and rats. The work could lead to more effective, less invasive treatment for human pulmonary fibrosis sufferers.

Pulmonary fibrosis is a fatal disease that thickens and scars healthy lung tissue, creating inflammation and replacing the lining of the lung cells with fibrotic tissue. In the last five years, Ke Cheng and his lab developed spheroid-produced lung stem cells (LSCs) as a potential therapeutic for pulmonary fibrosis. Cheng is the Randall B. Terry Jr. Distinguished Professor in Regenerative Medicine at NC State, a professor in the NC State/UNC-Chapel Hill Joint Department of Biomedical Engineering, and corresponding author of the research.

“The mixture of cells in LSCs recreates the stem cells’ natural microenvironment — known as the stem cell niche — where cells secrete exosomes to communicate with each other just as they would inside your body,” Cheng says. “LSCs secrete many beneficial proteins and growth factors known collectively as ‘secretome’ — exosomes and soluble proteins which can reproduce the regenerative microenvironment of the cells themselves. In this work we took it one step further and tested the secretome and exosomes from our spheroid-produced stem cells against two models of pulmonary fibrosis.”

Cheng and his colleagues tested lung spheroid cell secretome (LSC-Sec) and lung spheroid cell exosomes (LSC-Exo) against commonly used mesenchymal stem cells (MSCs) in mouse and rat models of chemically induced and silica- or particle-induced pulmonary fibrosis. The stem cell-derived therapeutics were delivered through a “stem cell sauna,” a nebulizer that allowed the therapeutic proteins, small molecules and exosomes to be inhaled directly into the lungs.

In the mouse model of chemically induced fibrosis, the researchers found that although inhalation treatment with either LSC-Sec or MSC-Sec led to improvements compared to the saline-treated control, LSC-Sec treatment resulted in nearly 50% reduction of fibrosis compared to 32.4% reduction with MSC-Sec treatment.

In the mouse model of silica-induced pulmonary fibrosis, LSC-Sec treatment resulted in 26% reduction of fibrosis compared to 16.9% reduction with MSC-Sec treatment.

The researchers also looked at rat models of both types of pulmonary fibrosis, and tested both LSC-exosome and LSC-Sec treatments against MSC-Exo with similar results. Additionally, they found that while LSC-exosome inhalation treatment alone can elicit a therapeutic effect similar to LSC-Sec treatment, the full secretome was still the most therapeutic.

“This work shows that lung spheroid cell secretome and exosomes are more effective than their mesenchymal stem cells counterparts in decreasing fibrotic tissue and inflammation in damaged lung tissue,” Cheng says. “Hopefully we are taking our first steps toward an efficient, non-invasive and cost-effective way to repair damaged lungs.

“Given the therapy’s effectiveness in multiple models of lung fibrosis and inflammation, we are planning to expand the test into more pulmonary diseases, including chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), and pulmonary hypertension (PH).”

“The finding that products released by lung stem cells can be just as efficacious, if not more so, than the stem cells themselves in treating pulmonary fibrosis can be a major finding that can have implications in many other diseases where stem cell therapy is being developed,” says Kenneth Adler, Alumni Distinguished Graduate Professor at NC State and a co-author of the paper.

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A molecular atlas of skin cells — ScienceDaily

Our skin protects us from physical injury, radiation and microbes, and at the same time produces hair and facilitates perspiration. Details of how skin cells manage such disparate tasks have so far remained elusive. Now, researchers at Karolinska Institutet in Sweden have systematically mapped skin cells and their genetic programs, creating a detailed molecular atlas of the skin in its complexity. The study is published today in the scientific journal Cell Stem Cell.

Mammalian skin has several important tasks to perform. It provides a waterproof protective barrier against the outside world, produces hair and harbours sweat glands. This tissue complexity requires many types of cells, such as fibroblasts, immune cells, nerve cells and pigment cells. To systematically study the skin, researchers at Karolinska Institutet have mapped the genes that are active in thousands of individual cells using a technique called single-cell RNA sequencing. Examining tissue from the skin and its hair-producing hair follicles at different stages of hair growth, the researchers uncovered how cells are coordinated during the phases of hair growth and rest.

“We found over 50 different kinds of cells in the skin, including new variations of cell types that have not been described before,” says Maria Kasper, research group leader at the Department of Biosciences and Nutrition, Karolinska Institutet. “We’ve also seen that most types of skin cells are affected by different phases of hair growth.”

As part of the study, the researchers described exactly where in the skin these cells are located and which genes they express. The authors have made this information available in an open-access online atlas, which helps others interested in specific genes to quickly find out if and where they are expressed. Conversely, researchers interested in specific cells can find out how gene expression changes during their task specification. The researchers behind this atlas believe that this information will be useful to other scientists studying for example skin diseases, wound healing or skin cancer.

By using their own atlas the authors have made several discoveries. For example, they have found that the outermost layer of the hair follicle consists of several types of cells organised in a specific way. They could also see how the hair progenitors, a type of stem cell that has started its specialisation towards specific hair follicle parts, goes through different molecular stages.

“This gives us vital knowledge on the flexibility of the skin, what the skin does to maintain its function and structure in different situations,” says Simon Joost, first author and recent graduate from Maria Kasper’s research group. “This knowledge may help us understand the flexibility of other organs, how they renew themselves and respond to different needs.”

The study was financed with grants from the Swedish Research Council, the Swedish Cancer Society, the Swedish Foundation for Strategic Research, the Ragnar Söderberg Foundation, the LEO Foundation, the Center for Innovative Medicine (CIMED), the Göran Gustafsson Foundation, the Wenner-Gren Foundation and Karolinska Institutet PhD (KID) funding.

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Molecular motors direct the fate of stem cells — ScienceDaily

Scientists at the University of Groningen and the University Medical Center Groningen used molecular motors to manipulate the protein matrix on which bone marrow-derived mesenchymal stem cells are grown. Rotating motors altered the protein structure, which resulted in a bias of the stem cells to differentiate into bone cells (osteoblasts). Without rotation, the stem cells tended to remain multipotent. These results, which could be used in tissue engineering, were published in Science Advances on 29 January.

‘Cells are sensitive to the structure of the surface that they attach to,’ explains Patrick van Rijn, associate professor in Materiobiology and Nanobiomaterials. ‘And movement is an important driver in biology, especially continuous movement.’ That is why Van Rijn and Feringa and their colleagues decided to use molecular motors to manipulate the protein matrix on which stem cells are grown. The light-driven motor molecules were designed by the 2016 Nobel Laureate in Chemistry Ben Feringa.

Structural changes

The scientists linked molecular motors to a glass surface. Subsequently, the surface was coated with protein and either exposed to UV irradiation to power the motors or not exposed to it at all. After about an hour, the motor movement was stopped and cells were seeded onto the protein layer and left to attach. Finally, differentiation factors were added. These experiments showed that cells grown on protein that was submitted to the rotary motion of the molecular motors tended to specialize into bone cells more often, while cells seeded on protein that was not disturbed were more inclined to maintain their stem-cell properties.

Observations of the protein layer using atomic force microscopy and simulations of the interaction between the motor molecules and proteins, performed by Prof. Marrink’s research group, showed that the movement induced subtle structural changes in the protein matrix. ‘The movement of motor molecules interferes with the alpha-helices in the proteins, which causes structural changes,’ explains Van Rijn. He compares it to the difference in texture between an unwhipped egg white and a whipped one.

Cell fate

The change in the surface structure of the adhered protein affects how the cells attach, for example how much they stretch out. This sets off a signaling cascade that eventually leads to altered behavior, such as the differentiation into bone cells. Thus, molecular movement leads to nanoscopic changes in surface structure, which in turn leads to differences in cell attachment, cell morphology and eventually, cell differentiation. ‘It’s like a domino effect, where smaller stones consecutively topple slightly larger ones so that a large effect can be achieved with a small trigger.’

‘Changing the properties of a surface to affect cell fate has been used before,’ says Van Rijn. However, this was done primarily with switches, so there was just a change from one state to another. ‘In our study, we had continuous movement, which is much more in line with the continuous motion found in biological transport and communication systems. The fact that the motors are driven by light is important,’ Van Rijn adds. ‘Light can be carefully controlled in space and time. This would allow us to create complex geometries in the growth matrix, which then result in different properties for the cells.’ Therefore, light-controlled molecular motors could be a useful tool in tissue engineering.

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