Absorbing approach to patient treatment

Scientists, engineers and medics are busy developing a host of biotech innovations that could benefit health and help people overcome disease.

GlaxoSmithKline is offering a US$1 million prize to stimulate innovation in the field of electroceuticals, which employ electrical impulses to modulate the body's nervous system. GlaxoSmithKline via Bloomberg News
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Medical boffins are turning to laptop and mobile phone radio waves and battery power as they consider how such forces might assist the healing power of medicine.

Scientists are working on the latest innovations in the field of "electroceuticals", also known as bioelectronics and biotechnology, which are remote-controlled devices that perform therapeutic roles. What's more, they're designing these next-generation electronics to be wireless - and dissolvable.

It is a major breakthrough that could help stimulate nerve and bone growth, help heal wounds, deliver drugs and act as antibiotics.

Researchers at Carnegie Mellon University, in Pittsburgh, Pennsylvania, are developing electronics that can essentially be swallowed like a pill to improve patient care.

"The direct link between the stomach and organs in the gastrointestinal tract and the brain through the nervous system is our basic premise," says Dr Christopher Bettinger, an assistant professor in the departments of materials science and Engineering and biomedical engineering at Carnegie Mellon University.

"Your brain interacts with a lot of the vital organs in the body, with your gastrointestinal tract serving as a highway of signals for those organs and your brain," Dr Bettinger says. "We're just trying to use that pathway as a way to tickle the brain - through devices you can eat - that will potentially stimulate or shock nerves in the stomach and then induce therapeutic outcomes from that."

These bioelectronics may potentially be used to measure biomarkers or monitor gastric problems, stimulate damaged tissue recovery, assist in drug delivery for certain types of cancer, or treat inflammatory diseases such as arthritis.

A biomarker indicates a change a protein that correlates with the risk or progression of a disease, or with the susceptibility of the disease to a given treatment. The bioelectronic device is an estimated at five to 10 years away from being cleared by the US food and drug administration (FDA), with some obstacles to overcome that are well under way.

A major challenge in the development of these devices involves identifying materials in the daily diet that can function as "edible power sources" that are disposable and nontoxic. Dr Bettinger and his team have turned to flexible polymer electrodes and a sodium ion electrochemical cell, which lets them fold the device into an edible pill.

Dr Bettinger's work is a new development in the study of "nonconventional electronics", he says.

"We go beyond computers and servers and think about conveying new kinds of electronic functionalities in new spaces, with different constraints that require the use of different materials."

That means constructing a battery of the right size and voltage that is edible and will last for, say, an hour before running out and being absorbed. From a medical industry standpoint, this innovation could lower costs because it eliminates the need for sterilisation. While other devices that are implantable must be sterilised, those that are edible and dissolvable will not.

Over at the University of Illinois, Professor John Rogers, an expert in materials science and engineering, and his team are also looking at implantable devices that function for medically useful time frames and then completely disappear by being absorbed into the body.

"The development of wireless technologies is important, especially with implantable devices, because it affords us a way to communicate with them and deliver power to them," says Prof Rogers.

"We think radio waves are a good way to do that, similar to the kind that come from your cell phone, so we're working to build antennae and electronic circuits that operate in radio frequency range and can be implanted in the body."

Prof Rogers and his team are researching several classes of devices, including the development of a transient electronic one that will perform sterilisation and eliminate bacterial colonies that can cause infection at the site of a surgical procedure. "If you look at rates of incidence for patients needing to be readmitted back into the hospitals, infections that develop at the site of surgery are a major cause, and a lot of that is due to bacteria," Prof Rogers says.

"With the use of a transient electronic, the wound can be sewn up, the patient can be released from the hospital, and the device can be implanted and powered for a two to three-week period before dissolving. In this kind of scenario, you wouldn't necessarily like the device to hang around after the surgery's healing process has been completed," he adds.

Prof Rogers says the ideal construct would involve an electronic sensor, perhaps wireless communication capability and actuators, in a form can be put into the patient and provide a function for a prescribed amount of time, After that, it is completely absorbed into the body.

While the process of defining the set of materials and the building blocks for such transient electronics is well under way, Prof Rogers believes it will take about five to seven years for this technology to become FDA-approved.

Along with post-surgical healing, potential applications include nerve manipulation to eliminate pain, bone growth stimulation and treating burns.

In tests, Prof Rogers and his team have implanted electronics in mice, just beneath the skin, and are monitoring whether these transient electronics are problematic.

He says so far, the mice have shown no signs of inflammation or adverse reaction during the course of surgical implantation or absorption.

In a separate but related project, Prof Rogers is taking his consumer electronic-inspired research beyond the medical realm and contemplating how his findings can deliver advancements directly back to the consumer electronics market.

"If you look at smartphones, this class of technology has a useful lifetime of only two to three years, because people like to update their phones, for example," he says.

"It's a consequence of that rapid evolution in technology that modern societies are now becoming absolutely overwhelmed with waste streams associated with discarded electronics."

Prof Rogers emphasises the need for key components of a consumer electronic to be completely dissolvable after, say, a two to three year period - similar to the way his implantable medical devices would be dissolvable after a two or three-week period. In this case, the components would be reabsorbed into the environment aftertheir functional time has expired.

The materials Prof Rogers and his team are finding most useful for this concept include a purified form of silk derived from silkworm cocoons - with which they create a thin type of plastic material that is "a great platform for building electronics". Other substances include magnesium, very thin sheets of silicon and magnesium oxide or silicon dioxide.

"If you take those materials and put them together, you can manufacture with them and make very high-quality transistors, integrated circuits, sensors, photo detectors, solar cells, all of the key building blocks that we think form a foundation for a very diverse range of function in this kind of transient technology," Prof Rogers says.

He adds the niche sector is gaining in popularity.

"It's a growing area, with more people entering this space.

"There's a lot of room for new innovation and new ideas, and personally, we like the fact that there's a lot of momentum."