Scientists are making machines, wearable and implantable, to act as kidneys
Like all those whose kidneys have failed, Scott Burton’s life revolves around dialysis. For nearly two decades, Burton has been hooked up (or, since 2020, has hooked himself up at home) to a dialysis machine that performs the job his kidneys normally would. The process is arduous, time-consuming, and expensive. Except for a brief window before his body rejected a kidney transplant, Burton has depended on machines to take the place of his kidneys since he was 12-years-old. His whole life, the 39-year-old says, revolves around dialysis.
“Whenever I try to plan anything, I also have to plan my dialysis,” says Burton says, who works as a freelance videographer and editor. “It’s a full-time job in itself.”
Many of those on dialysis are in line for a kidney transplant that would allow them to trade thrice-weekly dialysis and strict dietary limits for a lifetime of immunosuppressants. Burton’s previous transplant means that his body will likely reject another donated kidney unless it matches perfectly—something he’s not counting on. It’s why he’s enthusiastic about the development of artificial kidneys, small wearable or implantable devices that would do the job of a healthy kidney while giving users like Burton more flexibility for traveling, working, and more.
Still, the devices aren’t ready for testing in humans—yet. But recent advancements in engineering mean that the first preclinical trials for an artificial kidney could happen soon, according to Jonathan Himmelfarb, a nephrologist at the University of Washington.
“It would liberate people with kidney failure,” Himmelfarb says.
An engineering marvel
Compared to the heart or the brain, the kidney doesn’t get as much respect from the medical profession, but its job is far more complex. “It does hundreds of different things,” says UCLA’s Ira Kurtz.
Kurtz would know. He’s worked as a nephrologist for 37 years, devoting his career to helping those with kidney disease. While his colleagues in cardiology and endocrinology have seen major advances in the development of artificial hearts and insulin pumps, little has changed for patients on hemodialysis. The machines remain bulky and require large volumes of a liquid called dialysate to remove toxins from a patient’s blood, along with gallons of purified water. A kidney transplant is the next best thing to someone’s own, functioning organ, but with over 600,000 Americans on dialysis and only about 100,000 kidney transplants each year, most of those in kidney failure are stuck on dialysis.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. Each of the 45 different cell types in the kidney do something different.
Part of the lack of progress in artificial kidney design is the sheer complexity of the kidney’s job. To build an artificial heart, Kurtz says, you basically need to engineer a pump. An artificial pancreas needs to balance blood sugar levels with insulin secretion. While neither of these tasks is simple, they are fairly straightforward. The kidney, on the other hand, does more than get rid of waste products like urea and other toxins. Each of the 45 different cell types in the kidney do something different, helping to regulate electrolytes like sodium, potassium, and phosphorous; maintaining blood pressure and water balance; guiding the body’s hormonal and inflammatory responses; and aiding in the formation of red blood cells.
There's been little progress for patients during Ira Kurtz's 37 years as a nephrologist. Artificial kidneys would change that.
UCLA
Dialysis primarily filters waste, and does so well enough to keep someone alive, but it isn’t a true artificial kidney because it doesn’t perform the kidney’s other jobs, according to Kurtz, such as sensing levels of toxins, wastes, and electrolytes in the blood. Due to the size and water requirements of existing dialysis machines, the equipment isn’t portable. Physicians write a prescription for a certain duration of dialysis and assess how well it’s working with semi-regular blood tests. The process of dialysis itself, however, is conducted blind. Doctors can’t tell how much dialysis a patient needs based on kidney values at the time of treatment, says Meera Harhay, a nephrologist at Drexel University in Philadelphia.
But it’s the impact of dialysis on their day-to-day lives that creates the most problems for patients. Only one-quarter of those on dialysis are able to remain employed (compared to 85% of similar-aged adults), and many report a low quality of life. Having more flexibility in life would make a major different to her patients, Harhay says.
“Almost half their week is taken up by the burden of their treatment. It really eats away at their freedom and their ability to do things that add value to their life,” she says.
Art imitates life
The challenge for artificial kidney designers was how to compress the kidney’s natural functions into a portable, wearable, or implantable device that wouldn’t need constant access to gallons of purified and sterilized water. The other universal challenge they faced was ensuring that any part of the artificial kidney that would come in contact with blood was kept germ-free to prevent infection.
As part of the 2021 KidneyX Prize, a partnership between the U.S. Department of Health and Human Services and the American Society of Nephrology, inventors were challenged to create prototypes for artificial kidneys. Himmelfarb’s team at the University of Washington’s Center for Dialysis Innovation won the prize by focusing on miniaturizing existing technologies to create a portable dialysis machine. The backpack sized AKTIV device (Ambulatory Kidney to Increase Vitality) will recycle dialysate in a closed loop system that removes urea from blood and uses light-based chemical reactions to convert the urea to nitrogen and carbon dioxide, which allows the dialysate to be recirculated.
Himmelfarb says that the AKTIV can be used when at home, work, or traveling, which will give users more flexibility and freedom. “If you had a 30-pound device that you could put in the overhead bins when traveling, you could go visit your grandkids,” he says.
Kurtz’s team at UCLA partnered with the U.S. Kidney Research Corporation and Arkansas University to develop a dialysate-free desktop device (about the size of a small printer) as the first phase of a progression that will he hopes will lead to something small and implantable. Part of the reason for the artificial kidney’s size, Kurtz says, is the number of functions his team are cramming into it. Not only will it filter urea from blood, but it will also use electricity to help regulate electrolyte levels in a process called electrodeionization. Kurtz emphasizes that these additional functions are what makes his design a true artificial kidney instead of just a small dialysis machine.
One version of an artificial kidney.
UCLA
“It doesn't have just a static function. It has a bank of sensors that measure chemicals in the blood and feeds that information back to the device,” Kurtz says.
Other startups are getting in on the game. Nephria Bio, a spinout from the South Korean-based EOFlow, is working to develop a wearable dialysis device, akin to an insulin pump, that uses miniature cartridges with nanomaterial filters to clean blood (Harhay is a scientific advisor to Nephria). Ian Welsford, Nephria’s co-founder and CTO, says that the device’s design means that it can also be used to treat acute kidney injuries in resource-limited settings. These potentials have garnered interest and investment in artificial kidneys from the U.S. Department of Defense.
For his part, Burton is most interested in an implantable device, as that would give him the most freedom. Even having a regular outpatient procedure to change batteries or filters would be a minor inconvenience to him.
“Being plugged into a machine, that’s not mimicking life,” he says.
This article was first published by Leaps.org on May 5, 2022.
Researchers advance drugs that treat pain without addiction
Opioids are one of the most common ways to treat pain. They can be effective but are also highly addictive, an issue that has fueled the ongoing opioid crisis. In 2020, an estimated 2.3 million Americans were dependent on prescription opioids.
Opioids bind to receptors at the end of nerve cells in the brain and body to prevent pain signals. In the process, they trigger endorphins, so the brain constantly craves more. There is a huge risk of addiction in patients using opioids for chronic long-term pain. Even patients using the drugs for acute short-term pain can become dependent on them.
Scientists have been looking for non-addictive drugs to target pain for over 30 years, but their attempts have been largely ineffective. “We desperately need alternatives for pain management,” says Stephen E. Nadeau, a professor of neurology at the University of Florida.
A “dimmer switch” for pain
Paul Blum is a professor of biological sciences at the University of Nebraska. He and his team at Neurocarrus have created a drug called N-001 for acute short-term pain. N-001 is made up of specially engineered bacterial proteins that target the body’s sensory neurons, which send pain signals to the brain. The proteins in N-001 turn down pain signals, but they’re too large to cross the blood-brain barrier, so they don’t trigger the release of endorphins. There is no chance of addiction.
When sensory neurons detect pain, they become overactive and send pain signals to the brain. “We wanted a way to tone down sensory neurons but not turn them off completely,” Blum reveals. The proteins in N-001 act “like a dimmer switch, and that's key because pain is sensation overstimulated.”
Blum spent six years developing the drug. He finally managed to identify two proteins that form what’s called a C2C complex that changes the structure of a subunit of axons, the parts of neurons that transmit electrical signals of pain. Changing the structure reduces pain signaling.
“It will be a long path to get to a successful clinical trial in humans," says Stephen E. Nadeau, professor of neurology at the University of Florida. "But it presents a very novel approach to pain reduction.”
Blum is currently focusing on pain after knee and ankle surgery. Typically, patients are treated with anesthetics for a short time after surgery. But anesthetics usually only last for 4 to 6 hours, and long-term use is toxic. For some, the pain subsides. Others continue to suffer after the anesthetics have worn off and start taking opioids.
N-001 numbs sensation. It lasts for up to 7 days, much longer than any anesthetic. “Our goal is to prolong the time before patients have to start opioids,” Blum says. “The hope is that they can switch from an anesthetic to our drug and thereby decrease the likelihood they're going to take the opioid in the first place.”
Their latest animal trial showed promising results. In mice, N-001 reduced pain-like behaviour by 90 percent compared to the control group. One dose became effective in two hours and lasted a week. A high dose had pain-relieving effects similar to an opioid.
Professor Stephen P. Cohen, director of pain operations at John Hopkins, believes the Neurocarrus approach has potential but highlights the need to go beyond animal testing. “While I think it's promising, it's an uphill battle,” he says. “They have shown some efficacy comparable to opioids, but animal studies don't translate well to people.”
Nadeau, the University of Florida neurologist, agrees. “It will be a long path to get to a successful clinical trial in humans. But it presents a very novel approach to pain reduction.”
Blum is now awaiting approval for phase I clinical trials for acute pain. He also hopes to start testing the drug's effect on chronic pain.
Learning from people who feel no pain
Like Blum, a pharmaceutical company called Vertex is focusing on treating acute pain after surgery. But they’re doing this in a different way, by targeting a sodium channel that plays a critical role in transmitting pain signals.
In 2004, Stephen Waxman, a neurology professor at Yale, led a search for genetic pain anomalies and found that biologically related people who felt no pain despite fractures, burns and even childbirth had mutations in the Nav1.7 sodium channel. Further studies in other families who experienced no pain showed similar mutations in the Nav1.8 sodium channel.
Scientists set out to modify these channels. Many unsuccessful efforts followed, but Vertex has now developed VX-548, a medicine to inhibit Nav1.8. Typically, sodium ions flow through sodium channels to generate rapid changes in voltage which create electrical pulses. When pain is detected, these pulses in the Nav1.8 channel transmit pain signals. VX-548 uses small molecules to inhibit the channel from opening. This blocks the flow of sodium ions and the pain signal. Because Nav1.8 operates only in peripheral nerves, located outside the brain, VX-548 can relieve pain without any risk of addiction.
"Frankly we need drugs for chronic pain more than acute pain," says Waxman.
The team just finished phase II clinical trials for patients following abdominoplasty surgery and bunionectomy surgery.
After abdominoplasty surgery, 76 patients were treated with a high dose of VX-548. Researchers then measured its effectiveness in reducing pain over 48 hours, using the SPID48 scale, in which higher scores are desirable. The score for Vertex’s drug was 110.5 compared to 72.7 in the placebo group, whereas the score for patients taking an opioid was 85.2. The study involving bunionectomy surgery showed positive results as well.
Waxman, who has been at the forefront of studies into Nav1.7 and Nav1.8, believes that Vertex's results are promising, though he highlights the need for further clinical trials.
“Blocking Nav1.8 is an attractive target,” he says. “[Vertex is] studying pain that is relatively simple and uniform, and that's key to having a drug trial that is informative. But the study needs to be replicated and frankly we need drugs for chronic pain more than acute pain. If this is borne out by additional studies, it's one important step in a journey.”
Vertex will be launching phase III trials later this year.
Finding just the right amount of Nerve Growth Factor
Whereas Neurocarrus and Vertex are targeting short-term pain, a company called Levicept is concentrating on relieving chronic osteoarthritis pain. Around 32.5 million Americans suffer from osteoarthritis. Patients commonly take NSAIDs, or non-steroidal anti-inflammatory drugs, but they cannot be taken long-term. Some take opioids but they aren't very effective.
Levicept’s drug, Levi-04, is designed to modify a signaling pathway associated with pain. Nerve Growth Factor (NGF) is a neurotrophin: it’s involved in nerve growth and function. NGF signals by attaching to receptors. In pain there are excess neurotrophins attaching to receptors and activating pain signals.
“What Levi-04 does is it returns the natural equilibrium of neurotrophins,” says Simon Westbrook, the CEO and founder of Levicept. It stabilizes excess neurotrophins so that the NGF pathway does not signal pain. Levi-04 isn't addictive since it works within joints and in nerves outside the brain.
Westbrook was initially involved in creating an anti-NGF molecule for Pfizer called Tanezumab. At first, Tanezumab seemed effective in clinical trials and other companies even started developing their own versions. However, a problem emerged. Tanezumab caused rapidly progressive osteoarthritis, or RPOA, in some patients because it completely removed NGF from the system. NGF is not just involved in pain signalling, it’s also involved in bone growth and maintenance.
Levicept has found a way to modify the NGF pathway without completely removing NGF. They have now finished a small-scale phase I trial mainly designed to test safety rather than efficacy. “We demonstrated that Levi-04 is safe and that it bound to its target, NGF,” says Westbrook. It has not caused RPOA.
Professor Philip Conaghan, director of the Leeds Institute of Rheumatic and Musculoskeletal Medicine, believes that Levi-04 has potential but urges the need for caution. “At this early stage of development, their molecule looks promising for osteoarthritis pain,” he says. “They will have to watch out for RPOA which is a potential problem.”
Westbrook starts phase II trials with 500 patients this summer to check for potential side effects and test the drug’s efficacy.
There is a real push to find an effective alternative to opioids. “We have a lot of work to do,” says Professor Waxman. “But I am confident that we will be able to develop new, much more effective pain therapies.”
In the 1990s, a mysterious virus spread throughout the Massachusetts Institute of Technology Artificial Intelligence Lab—or that’s what the scientists who worked there thought. More of them rubbed their aching forearms and massaged their cricked necks as new computers were introduced to the AI Lab on a floor-by-floor basis. They realized their musculoskeletal issues coincided with the arrival of these new computers—some of which were mounted high up on lab benches in awkward positions—and the hours spent typing on them.
Today, these injuries have become more common in a society awash with smart devices, sleek computers, and other gadgets. And we don’t just get hurt from typing on desktop computers; we’re massaging our sore wrists from hours of texting and Facetiming on phones, especially as they get bigger in size.
In 2007, the first iPhone measured 3.5-inches diagonally, a measurement known as the display size. That’s been nearly doubled by the newest iPhone 13 Pro, which has a 6.7-inch display. Other phones, too, like the Google Pixel 6 and the Samsung Galaxy S22, have bigger screens than their predecessors. Physical therapists and orthopedic surgeons have had to come up with names for a variety of new conditions: selfie elbow, tech neck, texting thumb. Orthopedic surgeon Sonya Sloan says she sees selfie elbow in younger kids and in women more often than men. She hears complaints related to technology once or twice a day.
The addictive quality of smartphones and social media means that people spend more time on their devices, which exacerbates injuries. According to Statista, 68 percent of those surveyed spent over three hours a day on their phone, and almost half spent five to six hours a day. Another report showed that people dedicate a third of their day to checking their phones, while the Media Effects Research Laboratory at Pennsylvania State University has found that bigger screens, ideal for entertainment purposes, immerse their users more than smaller screens. Oversized screens also provide easier navigation and more space for those with bigger hands or trouble seeing.
But others with conditions like arthritis can benefit from smaller phones. In March of 2016, Apple released the iPhone SE with a display size of 4.7 inches—an inch smaller than the iPhone 7, released that September. Apple has since come out with two more versions of the diminutive iPhone SE, one in 2020 and another in 2022.
These devices are now an inextricable part of our lives. So where does the burden of responsibility lie? Is it with consumers to adjust body positioning, get ergonomic workstations, and change habits to abate tech-related pain? Or should tech companies be held accountable?
Kavin Senapathy, a freelance science journalist, has the Google Pixel 6. She was drawn to the phone because Google marketed the Pixel 6’s camera as better at capturing different skin tones. But this phone boasts one of the largest display sizes on the market: 6.4 inches.
Senapathy was diagnosed with carpal and cubital tunnel syndromes in 2017 and fibromyalgia in 2019. She has had to create a curated ergonomic workplace setup, otherwise her wrists and hands get weak and tingly, and she’s had to adjust how she holds her phone to prevent pain flares.
Recently, Senapathy underwent an electromyography, or an EMG, in which doctors insert electrodes into muscles to measure their electrical activity. The electrical response of the muscles tells doctors whether the nerve cells and muscles are successfully communicating. Depending on her results, steroid shots and even surgery might be required. Senapathy wants to stick with her Pixel 6, but the pain she’s experiencing may push her to buy a smaller phone. Unfortunately, options for these modestly sized phones are more limited.
These devices are now an inextricable part of our lives. So where does the burden of responsibility lie? Is it with consumers like Senapathy to adjust body positioning, get ergonomic workstations, and change habits to abate tech-related pain? Or should tech companies be held accountable for creating addictive devices that lead to musculoskeletal injury?
Kavin Senapathy, a freelance journalist, bought the Google Pixel 6 because of its high-quality camera, but she’s had to adjust how she holds the oversized phone to prevent pain flares.
Kavin Senapathy
A one-size-fits-all mentality for smartphones will continue to lead to injuries because every user has different wants and needs. S. Shyam Sundar, the founder of Penn State’s lab on media effects and a communications professor, says the needs for mobility and portability conflict with the desire for greater visibility. “The best thing a company can do is offer different sizes,” he says.
Joanna Bryson, an AI ethics expert and professor at The Hertie School of Governance in Berlin, Germany, echoed these sentiments. “A lot of the lack of choice we see comes from the fact that the markets have consolidated so much,” she says. “We want to make sure there’s sufficient diversity [of products].”
Consumers can still maintain some control despite the ubiquity of tech. Sloan, the orthopedic surgeon, has to pester her son to change his body positioning when using his tablet. Our heads get heavier as they bend forward: at rest, they weigh 12 pounds, but bent 60 degrees, they weigh 60. “I have to tell him, ‘Raise your head, son!’” she says. It’s important, Sloan explains, to consider that growth and development will affect ligaments and bones in the neck, potentially making kids even more vulnerable to injuries from misusing gadgets. She recommends that parents limit their kids’ tech time to alleviate strain. She also suggested that tech companies implement a timer to remind us to change our body positioning.
In 2017, Nan-Wei Gong, a former contractor for Google, founded Figur8, which uses wearable trackers to measure muscle function and joint movement. It’s like physical therapy with biofeedback. “Each unique injury has a different biomarker,” says Gong. “With Figur8, you are comparing yourself to yourself.” This allows an individual to self-monitor for wear and tear and strengthen an injury in a way that’s efficient and designed for their body. Gong noticed that the work-from-home model during the COVID-19 pandemic created a new set of ergonomic problems that resulted in injuries. Figur8 provides real-time data for these injuries because “behavioral change requires feedback.”
Gong worked on a project called Jacquard while at Google. Textile experts weave conductive thread into their fabric, and the result is a patch of the fabric—like the cuff of a Levi’s jacket—that responds to commands on your smartphone. One swipe can call your partner or check the weather. It was designed with cyclists in mind who can’t easily check their phones, and it’s part of a growing movement in the tech industry to deliver creative, hands-free design. Gong thinks that engineers at large corporations like Google have accessibility in mind; it’s part of what drives their decisions for new products.
Display sizes of iPhones have become larger over time.
Sourced from Screenrant https://screenrant.com/iphone-apple-release-chronological-order-smartphone/ and Apple Tech Specs: https://www.apple.com/iphone-se/specs/
Back in Germany, Joanna Bryson reminds us that products like smartphones should adhere to best practices. These rules may be especially important for phones and other products with AI that are addictive. Disclosure, accountability, and regulation are important for AI, she says. “The correct balance will keep changing. But we have responsibilities and obligations to each other.” She was on an AI Ethics Council at Google, but the committee was disbanded after only one week due to issues with one of their members.
Bryson was upset about the Council’s dissolution but has faith that other regulatory bodies will prevail. OECD.AI, and international nonprofit, has drafted policies to regulate AI, which countries can sign and implement. “As of July 2021, 46 governments have adhered to the AI principles,” their website reads.
Sundar, the media effects professor, also directs Penn State’s Center for Socially Responsible AI. He says that inclusivity is a crucial aspect of social responsibility and how devices using AI are designed. “We have to go beyond first designing technologies and then making them accessible,” he says. “Instead, we should be considering the issues potentially faced by all different kinds of users before even designing them.”