Researchers Develop New Tracking Method for Chemotherapy Drugs

Researchers at the Cancer Center at Illinois (CCIL) have introduced a revolutionary technique to track chemotherapy drugs inside cancer cells. This advancement addresses a significant challenge in oncology: understanding how effectively drugs, particularly doxorubicin, can penetrate and distribute within tumors. The study focuses on a modified version of this widely used chemotherapy drug, known as DOX-IR, which enables real-time observation of drug behavior within cells.

Innovative Drug Tracking Technique

The research team, led by Craig Richard, a postdoctoral research fellow at CCIL, and Pei-Hsuan Hsieh, a principal scientist at Eli Lilly and Company, employed a novel approach by chemically modifying doxorubicin. By attaching a metal carbonyl compound to the drug, they created a label that absorbs infrared light, allowing for precise tracking through an infrared microscope.

“Infrared spectroscopy can see doxorubicin’s chemical signature, but since it’s an organic molecule, its signal overlaps with that of cells,” Richard explained. “When it’s labeled, though, it stands out very clearly because of that metal carbonyl group.” This breakthrough provides researchers with the ability to visualize drug uptake at a cellular level, facilitating a better understanding of treatment effectiveness and resistance.

Results and Future Implications

The team’s findings revealed that cancer cells absorbed DOX-IR over time, with increasing signal intensity correlating to drug concentration within the cells. This capability also allows for measurement of drug levels on a single-cell basis, a significant advancement that could lead to personalized cancer therapies.

“This could have both therapeutic and diagnostic potential,” Richard stated. “You can take these metal carbonyls, and you can also give them signals to release the carbon monoxide that’s on them, which can be used as a treatment for other diseases including cancer.”

Despite the promising results, the researchers acknowledged limitations in the current methodology. “Adding the infrared label changes how the drug behaves inside the cell,” Richard noted. The modified drug may not target the same cellular sites as unmodified doxorubicin. Nevertheless, they suggest that engineering a linkage that breaks under specific conditions could restore doxorubicin’s original efficacy while retaining the infrared label.

The implications of their research extend beyond doxorubicin. Richard emphasized that using infrared spectroscopy can provide insights into the behavior of various cancer drugs, potentially leading to improved treatment strategies. “This gives researchers the template for how to do this with other drugs,” he said.

Richard holds a PhD in Bioengineering from the University of Illinois Urbana-Champaign, where his research has focused on developing infrared-active nanoparticle probes to study tumor microenvironments. His expertise includes effectively communicating complex scientific concepts to a broader audience, further bridging the gap between research and application.

This study, titled “Monitoring Molecular Uptake and Cancer Cells’ Response by Development of Quantitative Drug Derivative Probes for Chemical Imaging,” has been published in Analytical Chemistry and is accessible through the National Institutes of Health’s support.

For further inquiries, Richard can be reached at [email protected].