A group of researchers in Spain has developed a silk biomaterial that can increase the survival of transplanted stem cells into the brain, improving recovery after a stroke or brain injury. The nervous system has limited capacity to recover after an injury, such as those produced by a stroke or brain trauma, says Labiotech.eu.
Stem-cell transplants are a promising therapy to promote regeneration of the brain by reducing the extent of the damage and promoting the remodeling of the brain. However, most of the cells don’t survive the procedure due to the inflammatory environment created in the brain after an injury. A study has shown that encapsulating stem cells into a biomaterial containing silk proteins could protect the cells and make them last significantly longer when treating stroke in mice.
“In many cell therapy studies, most of the mesenchymal stem cells implanted don’t survive beyond 1-2 weeks after the implantation,” Daniel Gonzalez-Nieto, researcher at the Polytechnic University of Madrid (UPM), said. “In this study we found that our biomaterial increases the survival of these cells in the brain to over 4 weeks.” With more cells surviving the procedure, the mice recovered better. “The changes were extraordinary, the treatment improved the sensory and movement ability of the animals that had suffered a stroke,” said Gonzalez-Nieto.
The encapsulated stem cells were able to reduce the size of the lesion and promote the remodeling of the brain areas adjacent to the injury, making the neurons take over control of the functions that were lost after the stroke.
“This remodeling around the lesion has been observed in patients that improve after a stroke or some type of brain trauma,” explained Gonzalez-Nieto. “These patients are a minority and they get better because the damaged area is smaller and respond relatively better to physical rehabilitation.”
The biomaterial consists of a hydrogel containing silk fibroin, a protein that the researchers extracted from the silk of the cocoons of the silkworm. According to Gonzalez-Nieto, the material has been used for decades in medical practice for applications such as wound stitching.
Compared to other biomaterials, silk fibroin does not generate any immune response against it. In addition, silk fibroin doesn’t produce any toxic by-products when it degrades, as is the case with hyaluronic acid, a biomaterial commonly used in research to encapsulate cells and drugs.
So, what just happened? Something extraordinary, albeit the news got short shrift in the mainstream medical and scientific media.
Essentially, Spanish researchers from the Polytechnic University of Madrid developed a silk biomaterial that can increase the survival of transplanted stem cells into the brain, improving recovery after a stroke or brain injury, according to Labiotech.
While stem-cell transplants are promising for regeneration of the brain, most cells don’t survive due to the inflammation that occurs after an injury. The researchers found that by encapsulating the stem cells with a silk protein based biomaterial, the cells were protected and had a higher chance of survival.
“In many cell therapy studies, most of the mesenchymal stem cells implanted don’t survive beyond 1-2 weeks after the implantation,” Daniel Gonzalez-Nieto, researcher at the Polytechnic University of Madrid, told Labiotech. “In this study we found that our biomaterial increases the survival of these cells in the brain to over 4 weeks.”
I call that SUCCESS!
While cancer miracle “cures,” such as the checkpoint inhibitor Keytruda from Merck & Co. and CAR T-cell therapy Kymriah from Bristol-Myers Squibb Co. are grabbing all the headlines, tissue engineering has been flying under the radar but is emerging as a promising approach to repair or replace the functions of diseased or damaged tissues/organs.
The essential strategy of tissue engineering is to closely repeat the microenvironmental cues in vitro (in English: studies performed with microorganisms, cells, or biological molecules outside their normal biological context) so that the regenerated tissues are sufficiently mature and functional for clinical applications.
Until the myth of the fountain of youth proves true, regenerative medicine is the best hope we’ve got for fixing failed body parts and, as a result, living longer, says Ephrat Livni for Quartz. As implied several times in this piece, even if there were such a fountain, scientists wouldn’t be able to bottle forever. They are, thankfully, working on engineering human cells, tissues, and organs that can repair themselves.
Basically, they’re trying to heal body parts using cells or tissue grown from stem cells, and by prompting regeneration with biologically active drugs that would essentially restart parts by forcing new growth, among other approaches. But it’s still a speculative venture, say Goldman Sachs analysts in an report on venture capital going into this “novel frontier.”
Perfecting processes for regenerating body parts is no stroll in the park, technically speaking. Plus, there are ethical questions to resolve and regulatory hurdles to overcome. In other words, it’ll take a while before new parts are available. Nonetheless, investors are interested in the field, and especially in companies working with stem cells, Livni notes. Goldman analysts believe regenerative medicine is attractive because of “its vast potential” to eventually cure common and rare diseases in almost any tissue or organ, including the heart, liver, and lungs.
Thus, capital is now flowing into regenerative medicine at a rate of hundreds of millions of dollars annually. In 2010, the field attracted about $200 million in venture capital and in 2016, that figure had quadrupled. Stem-cell technology attracts the vast majority of investment; $700 million of the $800 million dedicated to regenerative medicine in 2016 went to stem-cell projects. But analysts noted that the number of deals hasn’t increased accordingly. Between 2010 and 2016 deals remained in a range of 30 to 40 while investment rose fairly steadily. This suggests that a few companies attracted larger investments per deal over time from venture capital firms.
Scientists also seek funding from public sources. At the University of Washington’s Institute for Stem Cell and Regenerative Medicine, for example, researchers are manipulating stem cells to heal and restore the function in hearts, eyes, kidneys and other tissues, according to Charles Murray, the institute’s interim director. In an April 9, 2017 editorial in the Seattle Times, he writes, “This year, we also seek a first-time investment from our state legislature.”
The global regenerative medicine market will hit over $53 billion by 2021, according to a report by MarketWatch.
According to the report, “Due to the dominance of the bone and joint reconstruction market, the US currently has the biggest space, followed by Europe. However, due to recent positive legislation in Japan and Europe, the stem-cell arena will grow more substantially in these regions over the next five years. By 2021, it is possible that Europe will surpass the US market with respect to stem-cell applications, and this will become more likely if the Trump Administration restricts legislation and funding.”
The regenerative medicine market has massive scope and can be applied to a wide range of diseases and indications including neurological, autoimmune, cardiovascular, diabetes, musculoskeletal, ocular, orthopedic and wound healing. To that end, the expanse of market opportunities is large as is the global patient population.
The following are denominated “key companies” in the global tissue engineering market as cited in the MarketWatch report. Publicly traded companies are denominated parenthetically by their symbol on the New York Stock Exchange:
- Arteriocyte Medical Systems Inc.
- Athersys Inc. (ATHX)
- Wright Medical Group N.V. (WMGI)
- Cerapedics Inc. Co.
- Don AG
- Cook Medical Inc.
- Cryolife Inc. (CRY)
- Genzyme Corp.
- Kinetic Concepts Inc.
- Mesoblast Ltd. (MESO)
- Nuo Therapeutics Inc. (AURX; previously known as Cytomedix Inc.)
- Ocata Therapeutics Inc. (unit of Astellas Pharma Inc.)
- Organogenesis Inc. (unit of Advanced Biohealing)
- Orthopeutics L.P.
- US Stem Cell Inc. (USRM; previously known as Bioheart Inc.)
- Vericel Corp. (VCEL; previously known as Aastrom Biosciences Inc.) and
- Cytori Therapeutics Inc. (CYTX)
While the cancer wonder drugs do indeed deserve headlines, I’ll be keeping a sharp eye on this promising field of tissue engineering, with special focus on the companies mentioned herein. Sorry, Keytruda. You can’t expect to grab all the press.