The U.S. Food and Drug Administration (FDA) defines personalized medicine as “the tailoring of medical treatment to the individual characteristics, needs, and preferences of each patient.” It also describes this approach as one that uses “genetic or other biomarker information to make treatment decisions about patients.”
According to Professor Heather Clark at Northeastern University in Boston, personalized medicine might one day include using fluorescent nanosensors for the monitoring of therapeutic drugs, dosing information, or pharmacokinetic data. The researchers in Clark’s laboratory at the school’s Department of Pharmaceutical Sciences develop nanosensors that are composed of a variety of chemistries contained in a plasticized, fluorescent polymer bead.
The goal of this research is that one day these nanosensors would be used in vitro and in vivo for analyte detection and the measurement of ion and small molecule concentrations in intracellular and extracellular environments. “We do physiological monitoring,” said Clark. “We don’t detect a disease, but our goal is to monitor the overall health and wellness of an individual through a set of small molecules that look for changes in a big background of an analyte.”
While this is early stage academic research, Clark hopes that she, along with her students and postdoctoral researchers, will change medicine and make an impact one day. “We would like to measure anything that was relevant to disease in the body. We are working on nanoscale tools that can potentially measure different processes in the body, such as both the treatment and the effect of therapeutic drugs,” Clark added.
“Imagine if we could provide people with an individual readout of how their body was processing a therapeutic they’re taking for an illness,” Clark shared. “We could potentially pair the ability to measure a drug with the ability to measure its downstream effect.” This would help evaluate whether or not an antibiotic, for instance, is working and if a person’s immune system is functioning correctly. “If we could effectively monitor this,” Clark said, “then it could make personalized medicine a reality.”
The nanosensors in Clark’s lab are about 100 nanometers in diameter and made out of a bio-friendly polymer. “In plasticized, fluorescent polymer beads, we put sensing elements that are in continuous equilibrium with the environment,” Clark explained. “Essentially, these sensors are always reporting about the environment that they are in. We use our sensors to detect the environment of a cell, and they are continuously reporting of the efflorescence what they’re sensing.”
Clark and her fellow researchers are always exploring different applications for these nanosensors. “We are making sensors for a variety of different biological molecules and items, such as sodium, which might be important for electrolyte balance, or glucose, which might be important for diabetes,” she said.
“We go through a really vigorous process of analytical development to assess the dynamic range of things like glucose,” Clark explained. “Our sensors must detect in the correct range with an appropriate sensitivity to make these small measurements, accurately. The sensors also have to be reversible because they’re measuring both the increase and decrease in levels.” Clark added that they have to last a long time, for up to weeks or months without breaking down or drifting in the signal.
Because of the early stage of this research, it may be years before these kinds of nanosensors can be tested on humans. “From my point of view, I am interested in the science behind these nanosensors and their applications,” Clark said. According to Clark, there still needs to be a certain amount of maturity in the lab and proof of concept development before it would transition to a commercial process. At that point, there would need to be a fairly vigorous set of testing for accuracy and biocompatibility before it could go through FDA approval.