Scientists believe the biodegradable device could someday help detect multiple saliva biomarkers. If true, it might provide a new type of test for clinical laboratories
When it comes to tongue depressors, it turns out you can teach an old dog new tricks. Researchers from National and Kapodistrian University of Athens Greece (NKUA) have taken this simple wooden medical tool and developed a high-tech biosensing device that may someday be useful at the point-of-care in hospitals and as a new type of test for clinical laboratories.
Using diode laser engraving, the researchers developed an “eco-friendly disposable sensor that can measure glucose levels and other biomarkers in saliva,” according to LabMedica.
This proof-of-principle biosensing device demonstrates the feasibility of “simultaneous determination of glucose and nitrite in artificial saliva,” according to the NKUA scientists who hope it will help doctors diagnose a variety of conditions.
In their published paper, the scientists at the University of Athens wrote that their wooden electrochemical biosensing tongue depressor (above) “is an easy-to-fabricate disposable point-of-care chip with a wide scope of applicability to other bioassays,” and that “it paves the way for the low-cost and straightforward production of wooden electrochemical platforms.” Might this and other similar biosensing devices eventually find their way to clinical laboratories for use in identifying and tracking certain biomarkers for disease? (Photo copyright: University of Athens.)
How to Make a High-Tech Tongue Depressor
Though wood is affordable and accessible, it doesn’t conduct electricity very well. The researchers’ first attempt to solve this problem was to use the wood as “a passive substrate” to which they coated “metals and carbon-based inks,” LabMedica reported. After that they tried using high-powered lasers to “char specific regions on the wood, turning those spots into conductive graphite.” But that process was complicated, expensive, and a fire hazard.
The researchers eventually turned to “low-power diode lasers” which have been used successfully “to make polyimide-based sensors but have not previously been applied to wooden electronics and electrochemical sensors,” LabMedica noted.
In their Analytical Chemistry paper, the researchers wrote, “A low-cost laser engraver, equipped with a low-power (0.5 W) diode laser, programmably irradiates the surface of the WTD [wooden tongue depressor], forming two mini electrochemical cells (e-cells). The two e-cells consist of four graphite electrodes: two working electrodes, a common counter, and a common reference electrode. The two e-cells are spatially separated via programmable pen-plotting, using a commercial hydrophobic marker pen.”
In other words, the researchers “used a portable, low-cost laser engraver to create a pattern of conductive graphite electrodes on a wooden tongue depressor, without the need for special conditions. Those electrodes formed two electrochemical cells separated by lines drawn with a water-repellent permanent marker,” states a press release from the American Chemical Society.
“The biosensor was then used to quickly and simultaneously measure nitrite and glucose concentrations in artificial saliva. Nitrite can indicate oral diseases like periodontitis, while glucose can serve as a diagnostic for diabetes. The researchers suggest that these low-cost devices could be adapted to detect other saliva biomarkers and could be easily and rapidly produced on-site at medical facilities,” LabMedica reported.
Benefits of Using Wood
One of the major benefits of using wood for their biosensing device is how environmentally friendly it is. “Since wood is a renewable, biodegradable naturally occurring material, the development of conductive patterns on wood substrates is a new and innovative chapter in sustainable electronics and sensors,” the researchers wrote in Analytical Chemistry.
Additionally, the tongue depressor features “An easy-to-fabricate disposable point-of-care chip with a wide scope of applicability to other bioassays, while it paves the way for the low-cost and straightforward production of wooden electrochemical platforms,” the researchers added.
This adds to a growing trend of developing bioassay products that keep the health of our planet in mind.
“This new BC test is non-toxic, naturally biodegradable and both inexpensive and scalable to mass production, currently costing less than $4.00 per test to produce. Its cellulose fibers do not require the chemicals used to manufacture paper, and the test is almost entirely biodegradable,” a UPenn blog post noted.
New Future Tool Use in Clinical Diagnostics
Who could have predicted that the lowly wooden tongue depressor would go high tech with technology that uses lasers to convert it to an electrochemical multiplex biosensing device for oral fluid analysis? This is yet another example of technologies cleverly applied to classic devices that enable them to deliver useful diagnostic information about patients.
And while a biosensing tongue depressor is certainly a diagnostic tool that may be useful for nurses and physicians in clinic and hospital settings, with further technology advancements, it could someday be used to collect specimens that measure more than glucose and nitrites.
Many clinical laboratory professionals are aware of the significant amount of waste going into landfills from spent COVID-19 rapid PCR tests that use biosensors to produce results. These biosensor systems “use printed circuit boards, or PCBs, the same materials used in computers. PCBs are difficult to recycle and slow to biodegrade, using large amounts of metal, plastic, and non-eco-friendly materials,” according to a Penn Engineering Today blog post.
UPenn’s new test does not use PCBs. Instead, its biosensor uses “bacterial cellulose (BC), an organic compound synthesized from several strains of bacteria,” the blog post noted.
“This new BC test is non-toxic, naturally biodegradable and both inexpensive and scalable to mass production, currently costing less than $4.00 per test to produce. Its cellulose fibers do not require the chemicals used to manufacture paper, and the test is almost entirely biodegradable,” the blog post continued.
“There is a need for biodegradable diagnostic testing,” said Cesar de la Fuente, PhD (above), Presidential Assistant Professor in the Psychiatry Department at the University of Pennsylvania’s Perelman School of Medicine. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.” Clinical laboratories engaged in SARS-CoV-2 testing during the COVID-19 pandemic can attest to the massive amounts of waste generated by traditional PCR testing. (Photo copyright: University of Pennsylvania.)
Evolution of Improvement for SARS-CoV-2 Diagnostic Assays
Cesar de la Fuente, PhD, is Presidential Assistant Professor in the Psychiatry Department at the Perelman School of Medicine. His lab has been hard at work since the start of the pandemic to improve COVID-19 testing. The recent study was a collaboration between University of Pennsylvania’s de la Fuente Lab and William Reis de Araujo, Professor in Analytical Chemistry at the State University of Campinas (UNICAMP) in São Paulo, Brazil.
De Araujo leads the Portable Chemical Sensors Lab and has been pairing his electrochemistry expertise with de la Fuente’s lab for years, Penn Engineering Today noted.
The team wanted to combine the speed and cost-effectiveness of previous rapid tests with an eco-friendly biodegradable substrate material.
Bacterial cellulose (BC) was a great choice because it “naturally serves as a factory for the production of cellulose, a paper-like substance which can be used as the basis for biosensors,” Penn Engineering Today reported.
Additionally, BC has an excellent track record for a variety of uses, such as regenerative medicine, wound care, and point-of-care (POC) diagnostics, the blog post noted. UPenn’s test offers speed and accuracy without needing costly equipment making it desirable for clinical laboratories preparing to fight the next pandemic.
The test has shown to be capable of “correctly identifying multiple variants in under 10 minutes. This means that the tests won’t require ‘recalibration’ to accurately test for new variants,” Penn Engineering Today added.
Innovation Born from Inspiration
Though rapid tests are essential to help curb the spread of COVID-19, the negatives that come with these tests didn’t sit well with the UPenn team. This spurred them to strive for improvements.
PCR tests “are hampered by waste [metal, plastic, and the aforementioned PCBs]. They require significant time [results can take up to a day or more] as well as specialized equipment and labor, all of which increase costs,” Penn Engineering Today noted.
Additionally, “Sophistication of PCR tests makes them harder to tweak and therefore slower to respond to new variants,” the blog post concluded.
“There’s a tension between these two worlds of innovation and conservation,” de la Fuente told Penn Engineering Today. “When we create new technology, we have a responsibility to think through the consequences for the planet and to find ways to mitigate the environmental impact.”
Need for Biodegradable Diagnostic Tests
“COVID-19 has led to over 6.8 million deaths worldwide and continues to affect millions of people, primarily in low-income countries and communities with low vaccination coverage,” the Cell Reports Physical Science paper noted.
“There is a need for biodegradable diagnostic testing,” de la Fuentes told Penn Engineering Today. “We will be continuing to perfect this technology, which could hopefully help many people in the future, while also looking to expand it to other emerging pathogens in anticipation of future pandemics.”
While UPenn’s test will require clinical trials and FDA approval before it can become available to clinical laboratories and for point-of-care testing, it promises a bright, eco-friendly future for rapid viral testing.
Precision medicine programs can benefit from wearable usage data; however, little information has been collected on personalities and behaviors of the device users
Wearables medical devices have the potential to monitor some of the same biomarkers used in medical laboratory tests today. In addition, these mobile technologies can make it possible for clinical laboratories to monitor patients in real time, as well as allow labs to incorporate such into a patient’s historical record of lab test results.
The trend toward personalized medicine (aka, Precision Medicine) is increasing, with many payment programs based on it. Thus, monitoring and correcting activities that cause chronic disease, or work against treatments, is becoming standard procedure for forward-thinking, technically proficient doctors and hospitals. But are patients onboard with all of it?
Activity Trackers for Monitoring Patient Behavior
With the popularity of activity trackers on the rise, researchers are examining their usage patterns to determine how the devices are being utilized, their target market, and ways to encourage sustained use of the gadgets.
A recent article published in Annals of Internal Medicine provided insight regarding who is using this type of wearable device, how activity trackers are being employed, and the length of time consumers will maintain their usage.
“Many people are excited by the potential of using activity trackers to monitor healthy behaviors, but there is very little evidence on who is using them and whether or not use is sustained over time,” Patel stated in a Penn Medicine news release. “We found that, though use grew over time, it really varied depending on individual characteristics like age and income. We also found that once someone started using an activity tracker, sustained use at six months was high at 80%.”
Patel is also Director of the Penn Medicine Nudge Unit, a behavioral design team that is studying the impact that nudges or small interventions may have on healthcare. The team is examining ways in which nudges can influence choices, and also direct medical professionals and patients toward optimal decisions to improve healthcare delivery and results. (Photo copyright: University of Pennsylvania.)
Gaming the Study Improves Usage of Test Devices
To perform the study, 4.4 million members of a national wellness program were invited to take part in data collection. Approximately 55,000 of those individuals actually participated in the study, which involved downloading an app to record pertinent information. Researchers tracked and interpreted the data during a two-year period in 2014 and 2015.
The information analyzed included:
When participants initially activated their tracker;
How often the device was utilized;
The average number of steps taken per day; and,
Sociodemographic characteristics.
The results of the study were not entirely unexpected, but there were surprises:
80% of the people who initially activated the devices were still using them after six months;
Only 0.2% of the invited individuals used the devices in the first year;
However, that number increased to 1.2% during the second year.
The usage of wearable activity trackers was nearly double among younger people than it was for older individuals. In addition, people from households with an annual income of less than $50,000 used the gadgets at lower rates than those at higher income levels.
A mere 0.1% of the potential participants were over 65-years old. However, 90% of individuals in this age group were still using the devices six months after initial activation.
The authors of the study stated that adding game elements, such as points, levels, badges and financial incentives may have played a role in the sustained use of the activity trackers.
“Gamification and financial incentives are commonly used within wellness programs, but their impact has not been well studied,” Patel stated in the news release. “Our findings provide initial evidence suggesting that these types of engagement strategies may show promise for keeping sustained use high. However, more studies are needed to determine the best way to combine these types of engagement strategies with activity trackers to improve health outcomes.”
Most Commonly Used Mobile Activity Tracking Devices
There were 60 different types of wearable activity trackers that could be used by participants for the study. Seventy-six percent of those participants elected to use the FitBit activity tracker. This mobile healthcare device is worn on the wrist like a watch. It monitors activity, exercise, food, weight, and sleep to provide consumers with real-time data about their activities.
The data collected by the device is sent automatically and wirelessly to the user’s phone or computer. Individuals then can use the FitBit dashboard to view their progress through online charts and graphs. The dashboard also offers progress notifications to the consumer and gives achievement badges when established goals have been reached.
The second most common activity trackers used were Apple devices, such as Apple Watches, which were chosen by 9% of the participants.
Biometric data on patients’ behavior and activities that is collected and transmitted from mobile devices has swiftly become critical data doctors use in precision medicine diagnoses and treatments. Clinical laboratories will likely be including biomarker data taken by these devices in their testing and procedures in the future. The only question is how quickly the data generated by such devices becomes acceptable to add to a patient’s permanent health record.
Clinical laboratories must stay informed about the success of bundled-payment initiatives because they will need to negotiate a share of these payments where medical laboratory testing is involved
Research published this year concluded that bundled payments for joint replacement services performed on Medicare patients reduce Medicare’s costs without negatively affecting patient outcomes. Because these types of surgeries do not generally utilize many lab tests, the question is still out as to whether bundled payments allow clinical laboratories to be adequately reimbursed for their services.
The study of the bundled payment program was published in the Journal of the American Medical Association (JAMA). The researchers sought to determine the cause of the reduction in Medicare payments and hospital savings when bundled payment models for joint replacement surgeries were used.
The research was performed by staff at the Perelman School of Medicine at the University of Pennsylvania (UPenn). They examined hospital costs and Medicare claims for patients requiring hip and knee replacements at the 5-hospital Baptist Health System (BHS) in San Antonio. (more…)
