ETH Zurich Develops Implantable Molecular Device Capable of Monitoring Blood pH and Regulating Insulin Production in Mice; May One Day Allow Pathologists to Remotely Monitor Patients
Prototype could provide glimpse of radically different future for patient monitoring and present new opportunities for pathologists and medical laboratory scientists
Are pathologists and medical laboratory scientists ready for a new diagnostic paradigm? Instead of specimens transported into a central medical laboratory, how about in vivo real-time monitoring of patients with chronic diseases, where pathologists are able to remotely spot changes in a patient’s condition as they happen and alert physicians to take timely action?
Researchers are combining several technologies to create sensor-based systems for in vivo real-time monitoring of body processes. In Basel, Switzerland, a team at ETH Zurich’s Department of Biosystems Science and Engineering created an implantable sensor for continuous monitoring of blood pH that is paired up with a gene feedback mechanism to produce the necessary amount of insulin. The dual function device has been described as a “molecular prosthesis.” The purpose of this device is to monitor patients with diabetes.
While ETH Zurich’s prototype needs more development before it will be ready for clinical uses, the university’s research shows pathologists and medical laboratory scientists how fast new capabilities are being developed that can eventually support a radically different approach to patient diagnosis and patient monitoring. Use of such real-time in vivo diagnostic devices could allow laboratory professionals to remotely monitor patients and trigger clinical interventions when the biomarkers being tracked indicate such a need.
Device Monitors Blood Acidity: Responds to Diabetic Acidosis by Producing Insulin
What is particularly intriguing about the device created by the Swiss university’s bioengineers is that it is capable of both diagnostic and therapeutic actions. Both modules of the device—the blood pH sensor and insulin production mechanism—are constructed from biological components, such as various genes and proteins. These are incorporated into cultivated renal cells. The researchers then embedded millions of these customized cells in capsules that can be used as implants in the body.
According to an ETH news release, the pH sensor transmits a signal to trigger the production of insulin if pH values fall below 7.35, a low pH value specific for type 1 diabetes. Once blood pH returns to the ideal range, the sensor turns itself off and the reprogrammed cells stop producing insulin.
In tests using mice with type 1 diabetes, the ETH device was able to successfully monitor the blood’s acidity and respond to diabetic acidosis by producing insulin. Mice with capsules implanted produced the amount of insulin appropriate to their individual acid measurements, enabling them to have hormone levels comparable to that of healthy mice. The implant also compensated for larger deviations in blood sugar. The system design and test results were published in an August 7, 2014, Molecular Cell article.
ETH Prototype Shows the Possibility of Creating Applications for Humans
Despite the promising results, Martin Fussenegger, Ph.D., Professor in ETH Zurich’s Department of Biosystems Science and Engineering, says the university will need an industrial partner in order to consider commercial development of the molecular device.
“Applications for humans are conceivable based on this prototype, but they are yet to be developed,” stated Fussenegger in the news release. “We wanted to create a prototype first to see whether molecular prostheses could even be used for such fine adjustments to metabolic processes.”
Until recently, most progress in diabetes care focused on improvements to continuous glucose monitors and insulin delivery systems, with implantable, long-lasting sensors for continuous monitoring on the horizon. ETH Zurich’s implantable molecular device would represent a major leap forward.
Diabetes in U.S. Continues to Increase
A 2014 report from the U.S. Centers for Disease Control and Prevention (CDC) shows that diabetes is on the rise, with 29.1 million people (9.3% of the U.S. population) living with diabetes. By comparison, in 2010 there were an estimated 26 million people in the U.S. with diabetes.
The CDC says that nearly 28% of people with diabetes are undiagnosed, which increases risk for heart disease, stroke, blindness, kidney failure, amputation of toes, feet or legs, and early death.
The report also estimates that the total cost in medical bills and lost work and wages due to diabetes and related complications adds up to $245 billion, up from $174 billion in 2010.
“These new numbers are alarming and underscore the need for an increased focus on reducing the burden of diabetes in our country,” said Ann Albright, Ph.D., R.D., Director of the CDC’s Division of Diabetes Translation, in a CDC news release. “Diabetes is costly in both human and economic terms. It’s urgent that we take swift action to effectively treat and prevent this serious disease.”
The need for new methods to control diabetes was underscored in a 2010 study published at PubMed Central (PMC) on the U.S. National Institutes of Health’s National Library of Medicine (NIH/NLM) website. It painted a “sobering picture of the future growth of diabetes.”
“Under an assumption of low incidence and relatively high diabetes mortality, total prevalence is projected to increase to 21% of the U.S. adult population by 2050,” the authors wrote. “On the other hand, if recent increases in diabetes incidence continue (middle incidence projections) and diabetes mortality ratios are relatively low, diabetes prevalence will increase to 33% by 2050.”
The study blames the rise in diabetes in the U.S. in part on demographic changes brought about by an aging population—older adults are more likely to develop diabetes—an increase in minority populations that report higher diabetes rates, and reduced mortality rates for those living with the disease.
In Vivo and In Vitro Diagnostics Continue to Merge
Dark Daily has reported on the evolution of implantable diagnostic tests for some time. As we noted in “In Vivo Pathology Testing Might Use Injectable Microbeads to Detect Excessive Glucose Levels” (Dark Daily, January 1, 2011), pathology researchers continue to find novel ways to integrate in vivo and in vitro diagnostic tests. This trend does not appear to be slowing.
Implantable diagnostic technology continues to develop, which should indicate to clinical laboratories the possibility that disease diagnosis and monitoring is shifting away from centralized laboratories and towards medical communities and patients’ homes. The added twist in the new in vivo device created by researchers at ETH Zurich is that, after the diagnostic component of the device has tracked a change in the biomarker, the device can then automatically produce the appropriate therapy, also in real time and in vivo.
—Andrea Downing Peck