New Method Enables Tracking of Chemotherapy Drugs in Cells

Researchers have developed a new technique that allows for the tracking of chemotherapy drugs within cancer cells, potentially transforming cancer treatment strategies. This innovation focuses on a modified version of the widely used chemotherapy drug doxorubicin, enabling scientists to monitor its distribution and effectiveness in real-time.

The team leading this groundbreaking research includes Craig Richard, a postdoctoral research fellow at the Cancer Center at Illinois, and Pei-Hsuan Hsieh, a Principal Scientist at Eli Lilly and Company. They have created a derivative called DOX-IR, which incorporates a metal carbonyl compound. This modification allows the drug to absorb infrared light, making it detectable through infrared microscopy as it moves through cancer cells.

Richard explained the challenge of tracking doxorubicin, stating, “Infrared spectroscopy can see doxorubicin’s chemical signature, but since it’s an organic molecule, its signal overlaps with that of cells. It’s very hard to distinguish those signals inside a cellular context.” With the addition of the metal carbonyl group, DOX-IR produces a clearer signal, helping researchers monitor the drug’s absorption over time.

The research findings indicate that cancer cells progressively absorb DOX-IR, with the signal intensifying as drug concentration increases within individual cells. This capability not only facilitates the assessment of drug efficacy but also opens avenues for personalized cancer therapies. Richard noted, “This could have both therapeutic and diagnostic potential.”

The implications of this research extend beyond tracking drugs. The metal carbonyls can be engineered to release carbon monoxide, which may serve as a treatment for various diseases, including cancer. While the results are promising, Richard cautioned about the limitations of using DOX-IR as a chemotherapy agent. He remarked, “Adding the infrared label changes how the drug behaves inside the cell. The modified drug doesn’t go to the same places as unmodified doxorubicin.”

Looking ahead, researchers aim to develop linkages that could restore doxorubicin’s normal activity while retaining the infrared label within the cell. This innovative approach demonstrates how infrared spectroscopy can enhance understanding of drug behavior, helping to identify treatment-resistant cells and improve therapeutic strategies.

Richard emphasized that this research provides a template for applying similar techniques to other drugs, potentially advancing cancer treatment methodologies. The 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 supported by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health.

For inquiries, Craig Richard can be contacted at [email protected].