Artificial Bone Marrow

Researchers Develop Artificial Bone Marrow:

 Hematopoietic Stem Cells

Hematopoietic Stem Cells

Blood cells such as erythrocytes or immune cells are continuously replaced by new supplied hematopoietic stem cells are found in a specialized bone marrow niche . Hematopoietic stem cells can be used for treatment of blood diseases such as leukemia. Patient affected cells are replaced by healthy blood stem cells from a donor eligible .

However, not all leukemia patients can be treated in this way, as the appropriate number of transplants is not enough. This problem could be solved by the reproduction of hematopoietic stem cells. These cells maintain their stem cell properties in their natural environment only , that is, in its bone marrow niche . Out of this niche market , properties are modified. Therefore, stem cell reproduction requires a similar stem cell niche in the bone marrow environment .

Stem cell niche, is a complex microscopic environment that has specific properties . The relevant areas are highly porous bone and spongelike . This not only accommodate dimensional environment of bone cells and hematopoietic stem cells, but also various other types of cells with which signal substances are exchanged. The space between the cells has a matrix ensuring a certain stability and provides cells with anchorage points. In the stem cell niche , cells with nutrients and oxygen are supplied.

Young Investigators Group “Stem Cell- Material Interactions ” led by Dr. Cornelia Lee- Thedieck composed of scientists from the Institute of Functional Interfaces GAME (IFG ), the Max Planck Institute for Intelligent Systems , Stuttgart, and the University of Tübingen. Artificially reproduces the main properties of natural bone marrow in the laboratory. With the aid of synthetic polymers , scientists created a porous structure simulating cancellous bone structure in the area of the bone marrow blood forming . Building blocks of proteins similar to anchor the cells are added to those in the matrix of the bone marrow. Scientists also insert other types of cells of the stem cell niche in the structure in order to ensure the exchange of substances .

Researchers then introduced hematopoietic stem cells isolated from cord blood in this artificial bone marrow. Subsequent breeding of the cells took several days . Analyzes with different methods revealed that the cells actually play in the newly developed artificial bone marrow . Compared with standard cell culture methods , more stem cells retain their specific properties in the artificial bone marrow.

The newly developed artificial bone marrow has significant properties of natural bone marrow , can now be used by scientists to study the interactions between the materials and the stem cells in the laboratory in detail . This will help you discover how the behavior of stem cells can be influenced and controlled by synthetic materials. This knowledge could contribute to producing an artificial stem cell niche for the specific reproduction of the mother and the treatment of leukemia cells ten or fifteen years from now .

Scientists Grow Human Brain

Scientists Grow Human Brain From Stem Cells:

Scientists Grow Human Brain From Stem Cells

Scientists Grow Human Brain From Stem Cells

Ear, eye, liver, windpipe, bladder and even a heart. The list of body parts grown from stem cells is getting longer and longer. Now add to it one of the most complex organs: the brain.

A team of European scientists has grown parts of a human brain in tissue culture from stem cells. Their work could help scientists understand the origins of schizophrenia or autism and lead to drugs to treat them, said Juergen Knoblich, deputy scientific director at the Institute of Molecular Biotechnology of the Austrian Academy of Sciences and one of the paper’s co-authors.

The advance could also eliminate the need for conducting experiments on animals, whose brains are not a perfect model for humans.

To grow the brain structures, called organoids, the scientists used stem cells, which can develop into any other kind of cell in the body. They put the stem cells into a special solution designed to promote the growth of neural cells. Bits of gel interspersed throughout the solution gave the cells a three-dimensional structure to grow upon. In eight to 10 days, the stem cells turned into brain cells. After 20 days to a month, the cells matured into a size between three and four millimeters, representing specific brain regions such as the cortex and the hindbrain.

Growing brain tissue this way marks a major advancement because the lab-grown brain cells self-organized and took on growth patterns seen in a developing, fetal brain.

Currently, the organoids are limited on how big they can get because they do not have a circulatory system to move around nutrients.

Knoblich’s team didn’t stop at growing the brain organoids, though. They went a step further and used the developing tissue to study microcephaly, a condition in which the brain stops growing. Microcephalic patients are born with smaller brains and impaired cognitive development. Studying microcephaly in mice doesn’t help because human and mouse brains are too different.

For this part of the study, the researchers used stem cells from a microcephalic patient and grew neurons in a culture. They found that normal brains have progenitor stem cells that make neurons and can do so repeatedly. In microcephalic brains, the progenitor cells differentiate into neurons earlier, said Madeline A. Lancaster, the study’s lead author. The brain doesn’t make as many neurons and a child is born with a much smaller brain volume.

Yoshiki Sasai, a stem-cell biologist at the Riken Center for Developmental Biology in Kobe, Japan, garnered headlines last year by growing the precursors to a human eye.

“The most important advancement is that they combined this self-organization culture with disease-specific cells to model a genetic disease of human brain malformation,” he said.

“Everything we have done with other organs starts with this stage,” said Dr. Anthony Atala, the director of the Wake Forest Institute for Regenerative Medicine, who has done years of research on using 3D printers to build organs. Atala was not involved in this study, but he noted that before he could build organs, he needed to grow the pieces in order to get the cells to differentiate in just the right way. So though it’s unlikely anyone will print brains the way he did a kidney, this kind of experiment is where organ regeneration starts.

Knoblich said the next step is studying other brain disorders, but it will take some time to grow enough brain tissue. One factor is maximum size and how far the brain can develop in the culture. Brain cells develop in layers, and there are several by the time a baby is born. The cortical cells Knoblich’s team grew only had one such layer. Another factor is getting blood vessels inside the tissue. That problem could be solved some time in the future, though he said he couldn’t predict when.

It is tempting to think one day there will be whole brains in vats, but that isn’t likely to happen.

“Aside from the severe ethical problem, I do not think this will be possible,” Knoblich said. To form actual functioning neural circuits, a brain needs sensory input. “Without any sensory input, the proper organization may not happen.”

Injecting neural stem cells bring back feeling for the paralysed

Stem cells bring back feeling for paralysed patients:

Stem cells bring back feeling for paralysed patients

Stem cells bring back feeling for paralysed patients

For the first time, people with broken spines have recovered feeling in previously paralysed areas after receiving injections of neural stem cells. Three people with paralysis received injections of 20 million neural stem cells directly into the injured region of their spinal cord. The cells, acquired from donated fetal brain tissue, were injected between four and eight months after the injuries happened. The patients also received a temporary course of immunosuppressive drugs to limit rejection of the cells. None of the three felt any sensation below their nipples before the treatment. Six months after therapy, two of them had sensations of touch and heat between their chest and belly button. The third patient has not seen any change. “The fact we’ve seen responses to light touch, heat and electrical impulses so far down in two of the patients is very unexpected,” says Stephen Huhn of StemCells, the company in Newark, California, developing and testing the treatment. “They’re really close to normal in those areas now in their sensitivity,” he adds. “We are very intrigued to see that patients have gained considerable sensory function,” says Armin Curt of Balgrist University Hospital in Zurich, Switzerland, where the patients were treated, and principal investigator in the trial. The data are preliminary, but “these sensory changes suggest that the cells may be positively impacting recovery”, says Curt, who presented the results today in London at the annual meeting of the International Spinal Cord Society. Persistent gains. The patients are the first three of 12 who will eventually receive the therapy. The remaining recipients will have less extensive paralysis. “The sensory gains, first detected at three months post-transplant, have now persisted and evolved at six months after transplantation,” says Huhn. “We clearly need to collect much more data to demonstrate efficacy, but our results so far provide a strong rationale to persevere with the clinical development of our stem cells for spinal injury,” he says. “We need to keep monitoring these patients to see if feeling continues to affect lower segments of their bodies,” says Huhn. “These are results after only six months, and we will follow these patients for many years.” Huhn says that the company has “compelling data” from animal studies that the donated cells can repair nerves within broken spines. There could be several reasons why the stem cells improve sensitivity, says Huhn. They might help to restore myelin insulation to damaged nerves, improving the communication of signals to and from the brain. Or they could be enhancing the function of existing nerves, replacing them entirely or reducing the inflammation that hampers repair. Abandoned trial. The announcement comes almost a year after the world’s only other trial to test stem cells for spinal injury was suspended. Geron of Menlo Park, California, had injected neural stem cells derived from embryonic stem cells into four people with spinal injuries when it announced that it was going to focus on cancer therapies instead. The company also abandoned its other stem-cell programmes combating diabetes, heart disease and arthritis. Huhn hopes that the results from the StemCells trial will revive the enthusiasm that evaporated following Geron’s bombshell. “It’s the first time we’ve seen a signal of some beneficial effect, so we’re moving in the right direction, and towards a proof of concept,” he says. The news was welcomed by other pioneers of neural stem-cell research. “It looks encouraging and has some parallels with what we’ve seen in our trial in stroke patients,” says Michael Hunt, CEO of ReNeuron, in Guildford, UK, which in 2010 became the first company in the world to treat strokes with stem cells. They appear to be making progress, and that’s good for the stem-cell field generally, and for neural stem-cell research in particular,” says Hunt. He says that seven people who have had strokes have now been treated, and that some have shown signs of functional improvement without adverse effects. “It’s early days, and we are proceeding cautiously before hopefully moving to more substantive trials,” says Hunt. “These initial data certainly indicate that stem-cell transplantation may help remediate some of the severe functional loss associated with spinal cord injury,” says George Bittner of the University of Texas at Austin, who has developed a polymer-based system for rapid treatment of damaged nerves. But, he says, a single mode of treatment is unlikely to be enough to restore function after spinal cord injuries. We will need “combinations of approaches including stem cells, polymer-based treatments, retraining and physical therapy”. Other researchers were intrigued but cautious. “It’s work in progress,” says Wagih El Masri, a spinal specialist at the Midlands Centre for Spinal Injuries in Oswestry, UK, who attended Curt’s presentation. “We need larger numbers of patients treated to confirm whether this interesting finding has any future.” He says that about 3 per cent of patients show similar improvements spontaneously at about 6 months, but seldom beyond that. Testing the therapy on patients who were injured more than six months before would help to confirm that the stem cells are responsible for the results.