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18 May 2019. San Francisco on Tuesday became the first U.S. city to ban the use of facial recognition technology by city agencies, which as our friends at Statista point out, reflects a nationwide unease with biometric system. A solid majority of Americans express at least some doubts about biometrics for accessing computers, this weekend’s infographic.
Last October, Statista conducted a survey about biometrics — measurement and analysis of people’s physical characteristics for identification, authentication, and access control — among people in the U.S. In addition to facial recognition, biometrics covers techniques such as fingerprints, iris matching, and voice recognition. The results show about 3 in 10 Americans (31%) have no arguments with biometrics for authentication, but the rest of the adult population has misgivings. The most frequently cited issues are worries about the use of their data and the ability to trick the technology, with 17 and 16 percent respectively.
The New York Times says Oakland, California and the town of Somerville, Massachusets near Boston are considering similar city-wide agency bans. A statewide bill is also being debated in Massachusetts, and legislation to restrict the use of facial recognition technology for commercial purposes was introduced in the U.S. Senate last month.
Thermoelectric armband with, right to left, heating and cooling patch, control circuits, and battery pack. (Univ of California, San Diego)
17 May 2019. An electronic wearable device worn as a patch is designed to act like a personal heating or cooling system in uncomfortable ambient temperatures. An engineering team from University of California in San Diego describes the personalized thermoelectric device in today’s issue of the journal Science Advances.
Most people today have few options for keeping comfortable when encountering uncomfortably high or low temperatures, other than adding or discarding layers of clothing, or adjusting central heating or air conditioning systems. Making adjustments in central heat or cooling to accommodate a few people can be wasteful, and in electric vehicles, adjusting cabin temperatures can affect the vehicle’s range. According data cited by the authors, climate control systems in vehicles can drain as much as 40 percent of an electric vehicle’s battery power.
Researchers from the lab of engineering professor Renkun Chen at UC-San Diego are seeking devices that provide more comfort options to people in changing ambient temperatures. Chen’s thermal energy materials and physics, or Temp lab studies nanoscale structured materials and devices that readily transfer heat and energy, helping provide individuals more personal comfort.
Many devices on the market today aiming to provide personal heating or cooling use fluids, fans, or complex electronics requiring considerable power, which are bulky, impractical, or not convenient in many instances. Chen and colleagues, however, propose a different approach: a wearable device with materials designed to transfer heat toward or away from the individual.
The team’s thermoelectric device uses a material known as bismuth telluride, known to efficiently transfer heat. The device places a series of short bismuth telluride pillars on thin copper electrodes between flexible, soft rubbery sheets. The sheets are made from commercial Ecoflex plastic, combined with powdered aluminum nitride, another material with high thermal conductivity. The device is powered by thin coin-type batteries connected by copper-wire springs, enclosed with flexible control circuits in a stretchable material.
A thermoelectric unit is configured as a 5-centimeter square patch, using 0.2 watts of power. When the device is turned on, it transfers heat from one side of the patch to the other, sending heat along the bismuth telluride pillars. “To do cooling,” says Chen in a university statement, “we have the current pump heat from the skin side to the layer facing outside. To do heating, we just reverse the current so heat pumps in the other direction.”
The researchers tested the thermoelectric device under simulated conditions in the lab, then configured into a wearable system, encasing the device in a mesh fabric and worn as an armband by a volunteer. The device kept the volunteer’s arm at a constant temperature of 90 degrees F (about 32 C), while the air temperature varied from 72 to 97 degrees. Physical activity by the volunteer causing the body temperature to rise triggered more cooling by the device. The unit’s heat transfers were also captured with infrared camera images.
The team estimates 144 of the units could be assembled into a vest or stitched into garments, supplemented with a lightweight battery pack that can operate for 6 hours. Wearing these themoelectric devices, say the authors, could return enormous savings in cooling large areas for relatively few people. “If there are just a handful of occupants in that room,” notes Chen “you are essentially consuming thousands of watts per person for cooling. A device like the patch could drastically cut down on cooling bills.”
The university filed for a provisional patent on the technology with Chen and first author Sahngki Hong as inventors. The project is financed in part by a grant from a university start-up fund.
Ramille Shah (2014 photo, Northwestern University)
17 May 2019. A Northwestern University bio-materials lab demonstrated the growth of new bone in skulls of lab animals on scaffolds made with three-dimensional printers. A team led by biomedical engineering and materials science professor Ramille Shah describes its techniques in this month’s issue of the journal Plastic and Reconstructive Surgery.
The Shah lab in Chicago studies materials for 3-D printing for medical uses, but also with applications across many industries. In this case, the researchers investigated a material to help regrow bone in people with injuries to their skulls, often from trauma, requiring reconstructive surgery. Up to now, the best solution in these cases is transfers of bone material from elsewhere in the patient’s body, such as rib or pelvis, which may not be readily available. And even if available, it means another surgery and associated risks for a patient already with a serious condition.
The team, with colleagues from University of Illinois Health and Shriner’s Hospital in Chicago, tested a 3-D printed scaffold from a material called hyperelastic bone. This material is made largely of hydroxyapatite, a calcium phosphate compound similar in composition and stability to human bone. About 10 percent of hyperelastic bone is the bio-compatible polymer polylactic-co-glycolic acid, or PLGA, approved by FDA for drug delivery and tissue engineering. Thus the material offers both the strength and stability of natural bone, as well as flexibility to fit into irregular-shaped openings like those repaired in reconstructive surgery.
In previous studies, the material is shown to promote bio-activity and the ability to integrate with surrounding tissue. For this project, the Shah lab printed hyperelastic bone samples, 5 layers thick, in a tight lattice formation on its 3-D bioplotter system. From these samples, the surgical team cut out scaffolds to fill holes made in skulls of lab rats. For comparison, the lab printed a similar PLGA material, but without the hydroxyapatite. The surgeons implanted the hyperelastic bone and PLGA scaffolds into the rats’ skulls, filling the holes.
The researchers compared bone regeneration from hyperelastic bone scaffolds to conventional bone transplants in the rats’ skulls, as well as the PLGA scaffolds. After 8 weeks, skull bone tissue regrew from hyperelastic bone scaffolds in 74 percent of the volume as conventional bone transplants. After 12 weeks, bone regrowth volume was 65 percent of bone transplants. Bone growth from the PLGA scaffolds was no more than 20 percent at either 8 or 12 weeks. Scanning electron microscope images show fibrous and cellular formations developing initially around the hyperelastic bone scaffolds, leading to growth of new bone.
“Hyperelastic bone,” says Shah in a statement from Wolters Kluwer, publisher of the journal, “has significant potential to be translated to craniofacial reconstructive surgery, where the need for cost-effective bone replacement grafts is enormous.”
Shah and co-author Adam Jakus are founders of the 3 year-old company Dimension Inx in Chicago, developers of advanced inks for 3-D printing and additive manufacturing, the industrial form of 3-D printing. Among the company’s offerings are hyperelastic bone described in the article. Shah and Jakus are Dimension Inx’s chief scientist and technology officer, respectively.
HydroSeq chip showing channels and chambers for capture and analysis of circulating tumor cells (Yoon Lab, University of Michigan)
16 May 2019. A lab-on-a-chip device shows in tests with cancer patient blood samples to detect and analyze circulating tumor cells providing precise therapy targets. A description of the device developed at University of Michigan and report of tests with blood samples appears in yesterday’s issue of the journal Nature Communications.
A team from Michigan’s engineering and medical schools is seeking simpler and faster diagnostics for cancer patients, to provide a detailed genetic picture of the cancer, and a roadmap for physicians to find therapies that meet the precise molecular nature of the patient. Up to now, techniques for this level of analysis could provide a detailed review of a few genes, or a limited picture of many genes in a sample.
In addition, advances in liquid biopsies, blood tests that detect and capture tumor cells circulating in the blood stream, make it feasible to closely monitor the progression of a patient’s cancer without tissue biopsies requiring surgery. But circulating tumor cells usually make up only a tiny proportion of blood samples making them difficult to isolate for diagnostics, with about 100 circulating tumor cells found among billions of white and red blood cells. As such, note the researchers led by Michigan engineering professor Euisik Yoon, there’s an unmet need for a high-throughput device that provides a comprehensive analysis of blood samples that capture and identify circulating tumor cells.
The technology proposed by Yoon and colleagues uses a microfluidics, or lab-on-a-chip device they call HydroSeq to separate circulating tumor cells in blood vessels and perform a genetic analysis of the captured cells. “Our chip,” says Yoon in a university statement, “allows us to capture pure circulating tumor cells and then extract genetic information without any contamination from red and white blood cells.”
HydroSeq is a matrix of fine channels and chambers with pneumatic valves to push through individual blood cells for scanning and identification of circulating tumor cells. In addition, the channels and chambers can be scaled-up to the thousands, enabling analysis of isolated circulating tumor cells from a high volume of blood cells.
Once captured and isolated, circulating tumor cells are analyzed by HydroSeq looking for characteristic ribonucleic acid or RNA transcribed from the DNA in the tumor. The analysis uses beads with unique identifiers to react with the circulating tumor cells and identify the RNA pointing to the tumor’s DNA.
The Michigan team tested HydroSeq with blood samples first with mixed human and mouse cells. The results show the device accurately separated and identified human from mouse cells, with no cross-contamination. The researchers then analyzed blood samples from 21 breast cancer patients. Hydro-Seq isolated 666 circulating tumor cells in the blood samples, and found expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal receptor 2 (HER2) genes, characteristic breast cancer biomarkers. The authors note that the analysis shows the molecular nature of the patients’ tumors did not always match the initial diagnosis, indicating a change in the composition of the tumors over time.
Co-author and medical school professor Monika Burness plans to try the chip in an upcoming clinical trial of an experimental cancer drug. “It’s a very powerful tool,” says Burness, “to monitor, at the cellular level, what a treatment does to tumors over time.” The university filed for a patent on HydroSeq, with several authors listed as inventors.
Co-author and medical school professor Randall Bly demonstrates using the ear fluid detection system (Dennis Wise, Univ of Washington)
16 May 2019. Computer scientists and medical researchers created a screening device for children’s ear infections with an app and algorithm on an ordinary smartphone. The team from University of Washington in Seattle describes the technology and tests of their device in yesterday’s issue of Science Translational Medicine (paid subscription required).
Several of the researchers, led by computer science professor Shyam Gollakota, also formed the start-up company Edus Health to commercialize the technology, for which the university filed for a provisional patent.
Gollakota and colleagues developed the system to help parents with infants and young children detect fluid build-up in the middle ear, behind the eardrum, a sign of ear infections. According to data cited by the authors, suspected ear infections are the leading reason for office visits to pediatricians. The problem covers two related ear conditions, acute otitis media where fluid builds up in the middle ear and becomes infected, and otitis media with effusion, a similar condition but without infection.
Acute otitis media is treatable with antibiotics, but if left untreated can lead to serious complications, including eardrum perforation. And while otitis media with effusion does not involve infections, this condition affecting up to 80 percent of children can interrupt their speech development, disrupt sleep, cause balance problems, and increase the likelihood of becoming infected.
Because these disorders happen to infants and young children, and the symptoms are often difficult to detect, parents have few options available other than taking the child to a doctor or outpatient clinic. Once at the doctor’s office, the tools for diagnosing these conditions are expensive and not always available. The authors note that doctors themselves are not happy with the current approach, and in conjunction with new clinical practice guidelines in 2016, American Academy of Otolaryngology recommended an easier method for parents to monitor fluid accumulations in children’s ears after the initial diagnosis.
Heeding that call, the Washington team devised a smartphone-based solution using a phone’s built-in speakers and microphone. The only other hardware added to the phone is a simple funnel cut from paper and attached to the speaker to direct test sounds into the child’s ears and reflected sounds back to the phone. The authors say this system can work with all iPhone versions, later Samsung Galaxy phones, and all other Android phones.
An app on the phone sends out continuous sounds like a bird chirping at a fixed frequency. The sounds sent from the phone then are reflected back from the ear canal, with the presence of fluid causing a characteristic audio pattern. That pattern is detected by an algorithm in the phone’s software, trained by tests with 53 children from 18 months to 17 years old.
The researchers tested the system with the same group at Seattle Children’s Hospital used for training the algorithm. Half of the children at the hospital were admitted for surgery to correct for recurring fluid build-up and ear infections, while the the remaining children had other conditions requiring hospitalization. Tests of the system with 98 ears on the 53 children show accurate detection of fluid 85 percent of the time, and found accurate detection of no fluid in 82 percent of cases, comparable to rates with standard and more expensive diagnostic equipment. Separate tests with children not involved in training the algorithm showed similar results.
The team also asked a group of parents to test the system with their children. The tests show parents could easily follow instructions to cut out and attach a paper filter, then use the smartphone and app to test for fluid in the middle ear. The results show in the 25 children’s ears tested, the parents accurately found the 6 ears with fluid and missed only 1 of the 19 ears that did not have fluid. The authors note that these usability tests with parents excluded children with more complex ear disorders.
The researchers believe the technology offers a useful device for parents and a way to reduce unnecessary office visits to pediatricians. “Designing an accurate screening tool on something as ubiquitous as a smartphone,” says Gollakota in a university statement, “can be game changing for parents as well as health care providers in resource limited regions.”
The following video demonstrates the smartphone-based system.
First smartphone app that can hear ear infections in children - YouTube
15 May 2019. Results from a clinical trial show patients recovered from their hernia surgeries with non-opioid pain medications, and stayed off opioids for 15 days. The topline findings from the study were released by Heron Therapeutics Inc. in San Diego, maker of the experimental pain drug being tested, but the results are not yet published in a peer-reviewed journal.
The company is developing the medication code-named HTX-011 designed for use by surgeons to reduce post-operative pain, and as a substitute for opioid pain relievers that continue to be abused at rates in the U.S. reaching emergency levels, along with heroin and fentanyl sold on the street. Overdose deaths from these drugs this year number more than 130 per day, according to National Institute on Drug Abuse. A report by the National Academies of Sciences, Engineering, and Medicine in July 2017 spells out the full scope of the crisis beyond overdose deaths, with some 2 million Americans age 12 and older addicted to prescription opioid drugs and another 600,000 addicted to heroin.
Heron Therapeutics’ main technology is a process for delivering drugs called Biochronomer used in HTX-011 that delivers a combination of compounds in a single injection. With Biochronomer, drug compounds are encased with biocompatible and degradable polymers that keep the drug compounds separate in the injection. But the polymers also enable their payloads to erode over time, allowing for long-term release of the drugs.
HTX-011 is designed to relieve post-surgical pain. The treatment combines the current local anesthetic bupivacaine with the anti-inflammatory drug meloxicam, delivered together with a needle-free syringe. HTX-011 is given once and allowed to coat affected tissue in the surgical site before suturing.
The late-stage clinical trial tested HTX-011 in patients receiving surgery to repair a hernia, weakness in the abdomen causing pain or protrusions in the groin. Heron says patients on average receive 30 opioid pain relievers following this kind of surgery. In the trial, 93 patients at a Houston, Texas hospital undergoing hernia surgery received HTX-011 before suturing. After surgery, patients were randomly assigned to receive only over-the-counter pain relievers, 300 or 600 milligrams of ibuprofen and 1 gram of acetaminophen. There were no other placebo or comparison groups.
Heron says a similar trial reported in January 2019 shows the vast majority of hernia patients (90%) treated with HTX-011 and given over-the-counter pain drugs did not need opioids in the 72 hours following surgery. In the new study, the hernia patients were tracked for 15 days following surgery, looking for use of opioid drugs for pain relief.
The results released by Heron show nearly all (95%) of the patients treated with HTX-011 and given over-the-counter pain pills did not need opioids to manage their post-surgical pain. Nearly as many patients (91%) did not receive an opioid prescription upon discharge, and none of those participants requested opioids in the days following release. Participants noted high satisfaction with their treatments on a standard medication-response questionnaire, and no adverse effects from the treatments were reported, according to the company.
Heron says HTX-011 has been tested in a number of clinical trials for different types of surgery including bunion removal — see the Science & Enterprise report from March 2018 — knee reconstruction, and breast augmentation, as well as hernia repair. FDA is now reviewing the company’s new drug application, after receiving fast-track and breakthrough designations for HTX-011 from the agency in 2017 and 2018 respectively.
Candas Stacey (left) and Kathi Lawrence provide feedback on robotic pets (Lisa Ventre, University of Cincinnati)
15 May 2019. A research team at University of Cincinnati is studying ways robotic pet animals can provide more help to older and infirm individuals. The Cincinnati designers and engineers are continuing work begun in 2017, funded by National Science Foundation, but working with Ageless Innovations LLC, a new corporate partner.
Pet dogs and cats have long been known to provide companionship as well as social and psychological support to people of all ages, particularly older persons who are less mobile, lonelier, and less able to care for themselves. These same factors, however, make it more difficult to care for a live animal pet, and assisted-living facilities in many cases restrict keeping pets for health reasons.
To meet this challenge, researchers at Brown University and toy maker Hasbro proposed developing robotic pet assistants configured as pet cats and dogs, with soft fur, soothing sounds, and sensors that respond to petting and hugs. Hasbro already started its Joy for All toy pet line in 2015, which the Brown University team offered to augment with more day-to-day helpful functions. As reported by Science & Enterprise in November 2017, National Science Foundation awarded about $1 million to the team for the 3-year project.
In May 2018, Hasbro spun-off the Joy for All robotic pet line to the start-up enterprise Ageless Innovations, in Pawtucket, Rhode Island that promised to continue developing its products. Claudia Rebola, an industrial design professor at Cincinnati and the department’s graduate studies coordinator, was part of the original project team while at Rhode Island School of Design. She is now leading the effort to advance the robotic pet technology, working with Ageless Innovations.
Rebola and a team of graduate students held focus group discussions with participants from retirement homes and lifelong learning centers in the region to get reactions to the first generation of robotic pets, which as she describes in a university statement, was also a way to “understanding the user, their needs and how to translate those needs into unique design opportunities for these pets.”
This initial feedback led to a redesign of the robotic dog, which more resembled a stuffed toy than a real animal. With contributions from a nearby faux-fur company, the robotic dog now looks more like a Yorkshire terrier, and is more flexible, like a lap dog.
The findings also pointed out opportunities to upgrade the care-giving help provided by the devices. Among these functions are detection of risky situations to prevent falls, detecting intruders, monitoring vital signs when hugged, tracking sleep patterns, and providing reminders of medications, doctors’ appointments, and recharging the devices. At the same time, the pet robots need to be unobtrusive, and more like partners than overseers.
Jeffrey Schlaudecker, a professor of geriatric medicine at Cincinnati, sees real benefits of robotic pets for his patients. “My patients affected with memory disorders can really benefit from the sensory aspects of a robotic pet,” says Schlaudecker. “Touch, sight and sound can all create a real consecutiveness.” He adds that the devices can also help some patients make transitions from their homes to less-familiar health facilities, which can be traumatic for people with cognitive impairment. “The presence of a known companion that can be transported easily anywhere,” he notes, “can be a great addition to smoothing these sometimes bumpy transitions.”
The following video tells more about the robotic pet project.
(Jack Dykinga, Agricultural Research Service, USDA)
14 May 2019. An analysis of genomes for all varieties of tomatoes, both wild and domesticated, found a rare gene variation that can make tomatoes tastier. A team led by the Boyce Thompson Institute at Cornell University and Agricultural Research Service, or ARS, of the U.S. Department of Agriculture in Ithaca, New York published its findings in yesterday’s issue of the journal Nature Genetics (paid subscription required).
Tomato growers, like other crop producers, often seek out varieties that grow faster, with larger fruit, and more resistance to pests and extreme weather conditions. But along the way, many of the tomatoes available in retail markets lost their characteristic and succulent taste, found today in only a few specialty varieties. Researchers led by Zhangjun Fei , a computational geneticist at Boyce Thompson Institute and James Giovannoni, a plant molecular biologist with ARS — also an adjunct professor at Boyce Thompson — believe they found a genetic variation for restoring that singular taste to tomatoes.
Tomato farming is a large agricultural enterprise, with worldwide production according to ARS of 182 million tons, generating some $60 billion in sales. Moreover, tomatoes are the second-most consumed vegetable in the U.S., after potatoes, with Americans eating 20.3 pounds of fresh tomatoes and 73.3 pounds of processed tomatoes per person per year.
Fei, Giovannoni, and colleagues analyzed the genomes of all 725 known tomato varieties, covering both domesticated tomatoes grown for today’s consumer markets, as well as wild varieties. This pan-genomic analysis revealed 4,873 genes not included in the accepted standard, or reference genome for tomatoes. Many of these genes were considered expendable as growers sought larger, heartier, and faster growing varieties. Over the years, this focus on productivity made the reference genome for tomatoes increasingly more constrained.
“During the domestication and improvement of the tomato,” says Fei in a Boyce Thompson statement, “people mostly focused on traits that would increase production, like fruit size and shelf-life,” so some genes involved in other important fruit quality traits and stress tolerance were lost during this process.”
One of the discoveries in their analysis is an allele, or genetic variation, called TomLoxC. This variation codes for acids that help produce aromas and flavors. Those acids act as catalysts, reacting with lipid, or fat-related compounds to evaporate quickly, producing aromas and influencing flavors. “We found it also produces flavor compounds from carotenoids,” says Giovannoni, “which are the pigments that make a tomato red. So it had an additional function beyond what we expected, and an outcome that is interesting to people who enjoy eating flavorful tomatoes.”
TomLoxC contributes still another feature with carotenoids, sending out signals that help protect against environmental stresses. And while present in 91 percent of wild tomato varieties, TomLoxC is found in only about 2 percent of older domestic varieties. Growers of domestic tomatoes, however, began including this gene in their breeding more recently, raising its presence to about 7 percent today in newer heirloom varieties.
“How many times do you hear someone say that tomatoes from the store just don’t quite measure up to heirloom varieties,” notes Fei. “This study gets to why that might be the case and shows that better tasting tomatoes appear to be on their way back.”
Fei and Giovannoni tell more about the study in the following video.
Science in Seconds - New genomic resource is sweet science for tomatoes - YouTube
14 May 2019. A new company formed offering full-scale facilities to develop cell and gene therapy products spun-off from academic research labs. ElevateBio in Cambridge, Massachusetts began operations yesterday, also raising $150 million in its first round of venture financing.
ElevateBio aims to provide scientists working in cell or gene therapies at academic, hospital, and institute labs with the business infrastructure to take research findings from the lab to marketable products or services. The company expects to provide researchers seeking to begin new enterprises with the product development, commercialization, and manufacturing expertise and facilities they need for this task.
A central feature of ElevateBio is its Basecamp, a central product development lab and manufacturing facility for gene and cell therapies to be shared among ElevateBio’s portfolio companies. “A foundational element of our scientific, clinical and financial strategy is ElevateBio Basecamp,” says CEO and founder David Hallal in a company statement, “which is our single R&D, process development and manufacturing company that supports our portfolio companies and a select group of strategic partners that will benefit from our expertise and facilities.”
ElevateBio Basecamp is being built in Waltham, Massachusetts, and expected to provide more than 100,000 square feet of lab and manufacturing space. The facility aims to provide automated protein engineering, virology, and immunology labs, as well as analytics and quality-control resources. In addition, says ElevateBio, Basecamp will provide manufacturing facilities that meet the industry’s Current Good Manufacturing Practice standards.
The company will use its Cambridge offices for Basecamp until the Waltham facility is completed, under the direction of chief scientist Mitchell Finer. “In the field of cell and gene therapies, as well as regenerative medicine products,” notes Finer, “the lack of high-quality process development and manufacturing capability is among the most significant barriers to moving these therapies forward.” Finer adds that, “Together, we are reducing inefficiencies that drain capital and delay new therapies, so that we can rapidly and successfully move novel candidates from concept to commercialization.”
ElevateBio is raising $150 million in its first venture funding round, led by the UBS Oncology Impact Fund and life science investment company F2 Ventures. The Swiss banking company UBS established the UBS Oncology Impact Fund in 2016 to invest in early-stage companies developing cancer treatments, and is managed by MPM Capital. ElevateBio also incubated at MPM Capital’s Cambridge offices. Joining the funding round are EcoR1 Capital, Redmile Group, and Samsara BioCapital.
Microbes in the human gut (Wyss Institute, Harvard University)
13 May 2019. A bio-engineering group created a chip device that simulates human intestine tissue in the lab, but under more realistic conditions than before. A team from the Wyss Institute for Biologically Inspired Engineering at Harvard University describes the device in today’s issue of the journal Nature Biomedical Engineering (paid subscription required).
This latest advance in organs-on-chips builds on the Wyss Institute’s work in the field, including earlier gut-on-a-chip devices. Organs-on-chips are small flexible polymer plastic devices with fine channels etched in the surface or drilled through, lined with live tissue and cells, and designed to simulate the workings of human organs. Three-dimensional tissues on the devices make it possible to predict the behavior of human organs better than animal models like mice, or cells grown in lab cultures. The devices are designed to simulate the flow, dynamics, and environment of complex systems in organs.
A drawback of gut-on-a-chip devices up to now is their inability to simulate the anaerobic, or low-oxygen, state found in parts of the human intestine, where certain microbes thrive. Moreover, this anaerobic environment coexists with oxygen-rich parts of the gut, calling for a device that can simultaneously support both states that interact with each other. This complex device is needed, say the authors to realistically study the workings of the microbiome, or microbial communities in the gut, an emerging focus of biomedical research.
“The major paradigm shift in medicine over the past decade has been the recognition of the huge role that the microbiome plays in health and disease,” says Donald Ingber, director of the Wyss Institute and senior author of the paper in an institute statement. “This new anaerobic intestine chip technology now provides a way to study clinically relevant human host-microbiome interactions at the cellular and molecular levels under highly controlled conditions in vitro,” referring to studies with instruments under lab conditions.
For their new intestine chip, the Wyss Institute researchers took their earlier gut-on-a-chip device and devised parallel channels, both with cells from human intestinal linings and supporting blood vessels. They derived these tissue samples from biopsies or stem cells grown into organoids, or small working tissue models. The team then placed the device in a chamber, enclosing one of the parallel channels, where the oxygen can be drawn out to simulate an anaerobic state, while still remaining connected and interacting with the other channels functioning in oxygen.
The team tested the device with microbes taken from mice and human stool samples. The microbes were injected into the intestinal lining tissue in the chip that developed a mucus layer, much like that found in the intestine. That mucus layer provides a protective seal in the new intestine chip similar to the one found in healthy gut tissue. In addition, the device supported the growth of more than 200 different types of gut bacteria, similar to those found in human stools.
The researchers believe the new, more realistic gut-on-a-chip offers opportunities for personalized drug testing with an individual’s unique gut tissue. “We can culture region-specific intestinal tissue and microbiomes from the same individual to find associations that cause sensitivity or tolerance to specific pathogenic, inflammatory, and systemic diseases,” says postdoctoral researcher and co-first author Francesca Gazzaniga. “With the anaerobic intestine chip, we can also test the direct effects of drugs on the human microbiome before giving them to people.”
Ingber is scientific founder of the company Emulate Inc. developing commercial applications for organs-on-chips, including intestine chips, and chairs its scientific advisory board. As reported by Science & Enterprise in December 2018, Emulate Inc. is designing special versions of its intestine chip as part of an experiment on the International Space Station to test effects of weightlessness on immune functions and bacterial infections in the gastrointestinal tract.