Researchers Develop New Method to Track Chemotherapy Drug in Cells

Scientists have made significant strides in cancer treatment by developing a new technique to track chemotherapy drugs within cells. This advancement addresses challenges in assessing drug effectiveness and ensuring uniform distribution among cancer cells, which often exist in dense tumor environments. The research focuses on a modified version of the widely used chemotherapy drug doxorubicin, known as DOX-IR, which incorporates a chemical signal that allows for precise tracking inside cells.

The research is led by Craig Richard, a postdoctoral research fellow at the Cancer Center at Illinois (CCIL), alongside Pei-Hsuan Hsieh, a principal scientist at Eli Lilly and Company. The modified DOX-IR includes a metal carbonyl compound that absorbs infrared light, enabling researchers to visualize the drug’s movement within cancer cells using infrared microscopy.

Richard explains, “Infrared spectroscopy can see doxorubicin’s chemical signature, but since it’s an organic molecule, its signal overlaps with that of cells. When it’s labeled, though, it stands out very clearly because of that metal carbonyl group.” This enhanced visibility allows for a more accurate understanding of how the drug interacts with cancer cells.

Through comparative studies, researchers observed that cancer cells gradually absorbed DOX-IR over time. The infrared signal increased in intensity as the concentration of the drug within the cells rose. This capability to measure drug concentration at the single-cell level holds promise for personalizing cancer therapies.

Richard emphasizes the dual potential of this approach, stating, “This could have both therapeutic and diagnostic potential. You can take these metal carbonyls and 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 promise of DOX-IR, Richard acknowledges limitations in its current application. He notes that the modification affects the drug’s behavior within cells, stating, “The modified drug doesn’t go to the same places as unmodified doxorubicin.” However, he suggests that engineering a linkage that breaks under specific conditions could restore doxorubicin’s normal functionality while retaining the infrared label within the cell.

The use of infrared spectroscopy in this study not only illustrates the behavior of the cancer drug inside cells but also aids in determining treatment effectiveness and identifying treatment-resistant cells. Richard notes, “This gives researchers the template for how to do this with other drugs potentially.”

Craig Richard, who recently obtained a PhD in Bioengineering from the University of Illinois Urbana-Champaign, is dedicated to bridging the gap between scientific research and public understanding. His work focuses on developing infrared-active nanoparticle probes to study tumor microenvironments. He is available for further inquiries at [email protected].

The findings of this research are documented in the paper titled “Monitoring Molecular Uptake and Cancer Cells’ Response by Development of Quantitative Drug Derivative Probes for Chemical Imaging,” published in Analytical Chemistry. The research received support from the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health.

This innovative technique opens new avenues for cancer treatment, potentially leading to more effective therapies tailored to individual patient needs.