Radiopharmaceuticals and nanoparticles used to kill cancer cells

Researchers have successfully developed a novel cancer treatment approach that utilises Cerenkov radiation energy to target and destroy cancer cells more effectively. The approach, created at the University of Wisconsin-Madison, US, uses light from decaying radiopharmaceuticals, known as Cerenkov luminescence, as an energy source to activate semiconducting polymer nanoparticles that kill cancer cells.

According to the researchers, many studies have been conducted on photodynamic therapy, which uses an external light source to activate nanomaterials for cancer therapy. This therapy, however, is limited by the ability of external light to penetrate tissues. As Cerenkov luminescence is spontaneously produced from certain radiopharmaceuticals as they decay in the body, it has recently been proposed as an internal energy source for cancer therapy.

While Cerenkov luminescence is advantageous because it is a light source produced inside of the body, the light source is generally very weak.

“The good news is that the light source can be amplified with semiconducting polymers, which greatly increases its potential to target and destroy cancer cells,” said Zachary Rosenkrans, graduate research assistant. “In our study we aimed to determine how to best utilise radiopharmaceuticals and nanoparticles to create the ideal cancer theranostics nanosystem.”

Researchers found that semiconducting polymer nanoparticles optimised with photosensitisers dramatically intensified Cerenkov luminescence to kill cancer cells. Positron emission tomography and optical imaging studies also clearly visualised tumour uptake of these optimised semiconducting polymer nanoparticles. This approach was found to have excellent potential as a cancer theranostics nanosystem without any tissue penetration limits in pre-clinical models.

“This work is an important step toward translating nanomaterials that are activated by light, using radiopharmaceuticals as an activation source. The basic concept, using semiconducting polymers to harness and amplify light produced from radiopharmaceuticals, is also very exciting and could have many interesting applications in the future,” Rosenkrans noted.

The research was presented at the Society of Nuclear Medicine and Molecular Imaging’s 2021 Virtual Annual Meeting.