Regenerative medicine has come a long way, baby
The field of regenerative medicine had a shaky start. In 2002, when news spread about the first cloned animal, Dolly the sheep, a raucous debate ensued. Scary headlines and organized opposition groups put pressure on government leaders, who responded by tightening restrictions on this type of research.
Fast forward to today, and regenerative medicine, which focuses on making unhealthy tissues and organs healthy again, is rewriting the code to healing many disorders, though it’s still young enough to be considered nascent. What started as one of the most controversial areas in medicine is now promising to transform it.
Progress in the lab has addressed previous concerns. Back in the early 2000s, some of the most fervent controversy centered around somatic cell nuclear transfer (SCNT), the process used by scientists to produce Dolly. There was fear that this technique could be used in humans, with possibly adverse effects, considering the many medical problems of the animals who had been cloned.
But today, scientists have discovered better approaches with fewer risks. Pioneers in the field are embracing new possibilities for cellular reprogramming, 3D organ printing, AI collaboration, and even growing organs in space. It could bring a new era of personalized medicine for longer, healthier lives - while potentially sparking new controversies.
Engineering tissues from amniotic fluids
Work in regenerative medicine seeks to reverse damage to organs and tissues by culling, modifying and replacing cells in the human body. Scientists in this field reach deep into the mechanisms of diseases and the breakdowns of cells, the little workhorses that perform all life-giving processes. If cells can’t do their jobs, they take whole organs and systems down with them. Regenerative medicine seeks to harness the power of healthy cells derived from stem cells to do the work that can literally restore patients to a state of health—by giving them healthy, functioning tissues and organs.
Modern-day regenerative medicine takes its origin from the 1998 isolation of human embryonic stem cells, first achieved by John Gearhart at Johns Hopkins University. Gearhart isolated the pluripotent cells that can differentiate into virtually every kind of cell in the human body. There was a raging controversy about the use of these cells in research because at that time they came exclusively from early-stage embryos or fetal tissue.
Back then, the highly controversial SCNT cells were the only way to produce genetically matched stem cells to treat patients. Since then, the picture has changed radically because other sources of highly versatile stem cells have been developed. Today, scientists can derive stem cells from amniotic fluid or reprogram patients’ skin cells back to an immature state, so they can differentiate into whatever types of cells the patient needs.
In the context of medical history, the field of regenerative medicine is progressing at a dizzying speed. But for those living with aggressive or chronic illnesses, it can seem that the wheels of medical progress grind slowly.
The ethical debate has been dialed back and, in the last few decades, the field has produced important innovations, spurring the development of whole new FDA processes and categories, says Anthony Atala, a bioengineer and director of the Wake Forest Institute for Regenerative Medicine. Atala and a large team of researchers have pioneered many of the first applications of 3D printed tissues and organs using cells developed from patients or those obtained from amniotic fluid or placentas.
His lab, considered to be the largest devoted to translational regenerative medicine, is currently working with 40 different engineered human tissues. Sixteen of them have been transplanted into patients. That includes skin, bladders, urethras, muscles, kidneys and vaginal organs, to name just a few.
These achievements are made possible by converging disciplines and technologies, such as cell therapies, bioengineering, gene editing, nanotechnology and 3D printing, to create living tissues and organs for human transplants. Atala is currently overseeing clinical trials to test the safety of tissues and organs engineered in the Wake Forest lab, a significant step toward FDA approval.
In the context of medical history, the field of regenerative medicine is progressing at a dizzying speed. But for those living with aggressive or chronic illnesses, it can seem that the wheels of medical progress grind slowly.
“It’s never fast enough,” Atala says. “We want to get new treatments into the clinic faster, but the reality is that you have to dot all your i’s and cross all your t’s—and rightly so, for the sake of patient safety. People want predictions, but you can never predict how much work it will take to go from conceptualization to utilization.”
As a surgeon, he also treats patients and is able to follow transplant recipients. “At the end of the day, the goal is to get these technologies into patients, and working with the patients is a very rewarding experience,” he says. Will the 3D printed organs ever outrun the shortage of donated organs? “That’s the hope,” Atala says, “but this technology won’t eliminate the need for them in our lifetime.”
New methods are out of this world
Jeanne Loring, another pioneer in the field and director of the Center for Regenerative Medicine at Scripps Research Institute in San Diego, says that investment in regenerative medicine is not only paying off, but is leading to truly personalized medicine, one of the holy grails of modern science.
This is because a patient’s own skin cells can be reprogrammed to become replacements for various malfunctioning cells causing incurable diseases, such as diabetes, heart disease, macular degeneration and Parkinson’s. If the cells are obtained from a source other than the patient, they can be rejected by the immune system. This means that patients need lifelong immunosuppression, which isn’t ideal. “With Covid,” says Loring, “I became acutely aware of the dangers of immunosuppression.” Using the patient’s own cells eliminates that problem.
Microgravity conditions make it easier for the cells to form three-dimensional structures, which could more easily lead to the growing of whole organs. In fact, Loring's own cells have been sent to the ISS for study.
Loring has a special interest in neurons, or brain cells that can be developed by manipulating cells found in the skin. She is looking to eventually treat Parkinson’s disease using them. The manipulated cells produce dopamine, the critical hormone or neurotransmitter lacking in the brains of patients. A company she founded plans to start a Phase I clinical trial using cell therapies for Parkinson’s soon, she says.
This is the culmination of many years of basic research on her part, some of it on her own cells. In 2007, Loring had her own cells reprogrammed, so there’s a cell line that carries her DNA. “They’re just like embryonic stem cells, but personal,” she said.
Loring has another special interest—sending immature cells into space to be studied at the International Space Station. There, microgravity conditions make it easier for the cells to form three-dimensional structures, which could more easily lead to the growing of whole organs. In fact, her own cells have been sent to the ISS for study. “My colleagues and I have completed four missions at the space station,” she says. “The last cells came down last August. They were my own cells reprogrammed into pluripotent cells in 2009. No one else can say that,” she adds.
Future controversies and tipping points
Although the original SCNT debate has calmed down, more controversies may arise, Loring thinks.
One of them could concern growing synthetic embryos. The embryos are ultimately derived from embryonic stem cells, and it’s not clear to what stage these embryos can or will be grown in an artificial uterus—another recent invention. The science, so far done only in animals, is still new and has not been widely publicized but, eventually, “People will notice the production of synthetic embryos and growing them in an artificial uterus,” Loring says. It’s likely to incite many of the same reactions as the use of embryonic stem cells.
Bernard Siegel, the founder and director of the Regenerative Medicine Foundation and executive director of the newly formed Healthspan Action Coalition (HSAC), believes that stem cell science is rapidly approaching tipping point and changing all of medical science. (For disclosure, I do consulting work for HSAC). Siegel says that regenerative medicine has become a new pillar of medicine that has recently been fast-tracked by new technology.
Artificial intelligence is speeding up discoveries and the convergence of key disciplines, as demonstrated in Atala’s lab, which is creating complex new medical products that replace the body’s natural parts. Just as importantly, those parts are genetically matched and pose no risk of rejection.
These new technologies must be regulated, which can be a challenge, Siegel notes. “Cell therapies represent a challenge to the existing regulatory structure, including payment, reimbursement and infrastructure issues that 20 years ago, didn’t exist.” Now the FDA and other agencies are faced with this revolution, and they’re just beginning to adapt.
Siegel cited the 2021 FDA Modernization Act as a major step. The Act allows drug developers to use alternatives to animal testing in investigating the safety and efficacy of new compounds, loosening the agency’s requirement for extensive animal testing before a new drug can move into clinical trials. The Act is a recognition of the profound effect that cultured human cells are having on research. Being able to test drugs using actual human cells promises to be far safer and more accurate in predicting how they will act in the human body, and could accelerate drug development.
Siegel, a longtime veteran and founding father of several health advocacy organizations, believes this work helped bring cell therapies to people sooner rather than later. His new focus, through the HSAC, is to leverage regenerative medicine into extending not just the lifespan but the worldwide human healthspan, the period of life lived with health and vigor. “When you look at the HSAC as a tree,” asks Siegel, “what are the roots of that tree? Stem cell science and the huge ecosystem it has created.” The study of human aging is another root to the tree that has potential to lengthen healthspans.
The revolutionary science underlying the extension of the healthspan needs to be available to the whole world, Siegel says. “We need to take all these roots and come up with a way to improve the life of all mankind,” he says. “Everyone should be able to take advantage of this promising new world.”
Deaf Scientists Just Created Over 1000 New Signs to Dramatically Improve Ability to Communicate
For the deaf, talent and hard work may not be enough to succeed in the sciences. According to the National Science Foundation, deaf Americans are vastly underrepresented in the STEM fields, a discrepancy that has profound economic implications.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available.
Deaf and hard-of-hearing professionals in the sciences earn 31 percent more than those employed in other careers, according to a 2010 study by the National Technical Institute for the Deaf (NTID) in Rochester, N.Y., the largest technical college for deaf and hard-of-hearing students. But at the same time, in 2017, U.S. students with hearing disabilities earned only 1.1 percent of the 39,435 doctoral degrees awarded in science and engineering.
One reason so few deaf students gravitate to science careers and may struggle to complete doctoral programs is the communication chasm between deaf and hard-of-hearing scientists and their hearing colleagues.
Lorne Farovitch is a doctoral candidate in biomedical science at the University of Rochester of New York. Born deaf and raised by two deaf parents, he communicated solely in American Sign Language (ASL) until reaching graduate school. There, he became frustrated at the large chunk of his workdays spent communicating with hearing lab mates and professors, time he would have preferred spending on his scientific work.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available, says Farovitch. Names, words, or phrases that don't exist in ASL must be finger spelled — the signer must form a distinct hand shape to correspond with each letter of the English alphabet, a tedious and time-consuming process. For instance, it requires 12 hand motions to spell out the word M-I-T-O-C-H-O-N-D-R-I-A. Imagine repeating those motions countless times a day.
To bust through this linguistic quagmire, Farovitch, along with a team of deaf STEM professionals, linguists, and interpreters, have been cooking up signs for terms like Anaplasma phagocytophilum, the tick-borne bacterium Farovitch studies. The sign creators are then videotaped performing the new signs. Those videos are posted on two crowd-sourcing sites, ASLcore.org and ASL Clear.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word.
"If others don't pick it up and use it, a sign goes extinct," says Farovitch. Thus far, more than 1,000 STEM terms have been developed on ASL Clear and 500 vetted and approved by the deaf STEM community, according to Jeanne Reis, project director of the ASL Clear Project, based at The Learning Center for the Deaf in Framingham, Mass.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word. The signs are generally intuitive and wonderfully creative. To express "DNA" Farovitch uses two fingers of each hand touching the tips of the opposite hand; then he draws both the hands away to suggest the double helix form of the hereditary material present in most organisms.
"If you can show it, you can understand the concept better,'' says the Canadian-born scientist. "I feel I can explain science better now."
The hope is that as ASL science vocabulary expands more, deaf and hard-of-hearing students will be encouraged to pursue the STEM fields. "ASL is not just a tool; it's a language. It's a vital part of our lives," Farovitch explains through his interpreter.
The deaf community is diverse—within and beyond the sciences. Sarah Latchney, PhD, an environmental toxicologist, is among the approximately 90 percent of deaf people born to hearing parents. Hers made sure she learned ASL at an early age but they also sent Latchney to a speech therapist to learn to speak and read lips. Latchney is so adept at both that she can communicate one-on-one with a hearing person without an interpreter.
Like Favoritch, Latchney has developed "conceptually accurate" ASL signs but she has no plans to post them on the crowd-sourcing sites. "I don't want to fix [my signs]; it works for me," she explains.
Young scientists like Farovitch and Latchney stress the need for interpreters who are knowledgeable about science. "When I give a presentation I'm a nervous wreck that I'll have an interpreter who may not have a science background," Latchney explains. "Many times what I've [signed] has been misinterpreted; either my interpreter didn't understand the question or didn't frame it correctly."
To enlarge the pool of science-savvy interpreters, the University of Rochester will offer a new masters degree program: ASL Interpreting in Medicine and Science (AIMS), which will train interpreters who have a strong background in the biological sciences.
Since the Americans with Disabilities Act was enacted in 1990, opportunities in higher education for deaf and hard-of-hearing students have opened up in the form of federally funded financial aid and the creation of student disability services on many college campuses. Still, only 18 percent of deaf adults have graduated from college, compared to 33 percent of the general population, according to a survey by the U.S. Census Bureau in 2015.
The University of Rochester and the Rochester Institute of Technology, home to NTID, have jointly created two programs to increase the representation of deaf and hard-of-hearing professionals in the sciences. The Rochester Bridges to the Doctorate Program, which Farovitch is enrolled in, prepares deaf scholars for biomedical PhD programs. The Rochester Postdoctoral Partnership readies deaf postdoctoral scientists to successfully attain academic research and teaching careers. Both programs are funded by the National Institutes of Science. In the last five years, the University of Rochester has gone from zero deaf postdoctoral and graduate students to nine.
"Deafness is not a problem, it's just a difference."
It makes sense for these two private universities to support strong programs for the deaf: Rochester has the highest per capita population of deaf or hard-of-hearing adults younger than 65 in the nation, according to the U.S. Census. According to the U.S. Department of Education, there are about 136,000 post-secondary level students who are deaf or hard of hearing.
"Deafness is not a problem, it's just a difference," says Farovitch. "We just need a different way to communicate. It doesn't mean we require more work."
Pregnant and Breastfeeding Women Might Have a New Reason to Ditch Artificial Sweeteners
Women considering pregnancy might have another reason to drop artificial sweeteners from their diet, if a new study of mice proves to apply to humans as well. It highlights "yet another potential health impact of zero-calorie sweeteners," according to lead author Stephanie Olivier-Van Stichelen.
The discovery was serendipitous, not part of the original study.
It found that commonly used artificial sweeteners consumed by female mice transfer to pups in the womb and later through milk, harming their development. The sweeteners affected the composition of bacteria in the gut of the pups, making them more vulnerable to developing diabetes, and greatly reduced the liver's capacity to neutralize toxins.
The discovery was serendipitous, not part of the original study, says John Hanover, the senior author and a cell biologist at the NIH National Institute of Diabetes and Digestive and Kidney Diseases. The main study looked at how a high sugar diet in the mother turns genes on and off in the developing offspring.
It compared them with mothers fed a low sugar diet, replacing sugar with a mix of sucralose and acesulfame-K (AK), two non-nutrient artificial sugars that are already used extensively in our food products and thought to be safe.
While the artificial sweeteners had little effect on the mothers, the trace amounts that were transferred through the placenta and milk had a profound effect on the pups. Hanover believes the molecules are changing gene expression during a crucial, short period of development.
"Somewhat to our surprise, we saw in the pups a really dramatic change in the microbiome" of those whose mothers were fed the artificial sweeteners, Hanover told leapsmag. "It looked like the neonates were much, much more sensitive than their mothers to the sucralose and AK." The unexpected discovery led them to publish a separate paper.
"The protective microbe Akkermansia was largely missing, and we saw a pretty dramatic shift in the ratio of two bacteria that are normally associated with metabolic disease," a precursor to diabetes, he explains. Akkermansia is a bacteria that feeds on mucus in the gut and helps remodel the tissue to an adult state over the first several months of life in a mouse. A similar process takes several years in humans, as the infant is weaned off of breast milk as the primary food source.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week.
Another problem the researchers saw in the animals was "a particularly striking change in the metabolism of the detoxification systems" in the liver, says Hanover. A healthy liver is dark red, but a high dose of the artificial sweeteners turned it white, "which is a sign of massive problems."
The study was conducted in mice and Hanover cautions the findings may not apply to humans. "But in general, the microbiome changes that one sees in the rodent model mimics what we see in humans...[and] the genes that are turned on in the mouse and the human are very similar."
Hanover acknowledges the quantity of artificial sweeteners used in the study is on the high end of human consumption, roughly the equivalent of 20 cans of diet soda a day. But the sweeteners are so ubiquitous in consumer products, from foods to lipstick, and often not even mentioned on the label, that it is difficult to measure just how much a person consumes every day.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week. Until further studies provide a clearer picture, women who want to err on the side of caution can choose to reduce if not eliminate their exposure to artificial sweeteners during pregnancy and breastfeeding.