A new biosensor technology by Stanford engineers helps monitor and maintain drug levels in the bloodstream of animals. If this experiment is successful and works on people, the device can be used as life-saving drugs and prevents harmful dosing usage.
The medication for each individual is different as with coffee or alcohol. The dosage for one individual may be perfect but for other, it may be a deadly overdose. So, it is very difficult to prescribe the right amount of critical drugs for chemotherapy or diabetes.
A researcher from Stanford has developed a prototype of biosensor design which is used to detect the active levels of medicine in the bloodstream. This helps in personalizing the drug dosage.
“This is the first time someone is able to continuously monitor and control the drug levels in the body in real time,” Soh said. “This is a novel concept with big implications because we believe our technology can be adapted to control the levels of a wide range of drugs.”
The device has three basic components: a real-time biosensor to continuously monitor drug levels in the bloodstream, a control system to calculate the right dose, and a programmable pump to maintain the desired dose which delivers enough medicine.
The sensor contains molecules called aptamers which have been designed to bind a drug. These aptamers are a focus of the lab. If the drug is present in the bloodstream, an electric sensor detects and the aptamers change shape. The more drugs in the bloodstream, the drastic change in aptamers shape.
Every second, the information is captured and routed through the software which now allows the pump to deliver additional drugs as required. Researchers call this as a closed-loop system, one that monitors and adjusts continuously.
The researchers are now administering and testing the technology for the chemotherapy drug doxorubicin in animals. Despite physiological and metabolic differences among animals, the device was able to keep a constant dosage, something which is not possible with current drug delivery methods. The researchers have also tested for acute drug interactions, by introducing a second drug which causes wide swings in chemotherapy drug levels. And they found that their system stabilizes the drug levels to moderate which is a dangerous spike or dip.
If the technology works in people as studied in animals, it could have big implications, Soh said. “For example, what if we could detect and control not only glucose level but also of insulin and glucagon that regulates glucose levels?” he said. This allows researchers to create an electronic system to replicate the function of the dysfunctional pancreas for patients with type 1 diabetes. “Now this is an exciting future,” Soh said.
After so many years of tests, the researchers are ensuring the technology as safe and effective for people. The researchers also believe this might be a big step towards personalized medicine. Doctors know that the same drug can have different effects on people with different genetic makeups. Doctors also know that patients who take more than one medication can experience unwanted drug interactions. But they lack tools to deal with this.
“Monitoring and controlling the actual dosage of a patient is receiving a practical way to take individual factors into account,” said Soh. He said the technology is especially helpful for pediatric cancer patients, who are difficult to dose because children’s metabolism is usually different from adults.
The team has plans to miniaturize the model so that the device can be implanted or worn by the patient. As of now, the technology is an external apparatus, like a smart IV drip, is as a size of the microscope slide. The current setup might be suitable for a chemotherapy drug, but not for continuous use. The group is also adapting this system with different aptamers so that it can sense and regulate the levels of other biomolecules in the body.
More information can be found at: Stanford University.