Researchers Unveil Light-Sensitive Nanoparticles for Medical Imaging

A team of researchers at Martin Luther University Halle-Wittenberg (MLU) has developed a novel class of light-sensitive nanoparticles that could revolutionize medical imaging techniques. These particles, known as single-chain nanoparticles (SCNPs), absorb laser light and convert it into heat, altering their internal structure in a manner reminiscent of folded proteins. The findings were published in the journal Communications Chemistry in March 2025.

The SCNPs are composed of individually folded polymer chains that incorporate polypyrrole molecules. These molecules are adept at absorbing light in the near-infrared spectrum and converting it to heat. As the nanoparticles are irradiated with laser light, they undergo a significant transformation, clumping together to form spherical structures that measure just a few nanometers in diameter. Professor Wolfgang Binder, who led the study, explained, “This opens up the possibility of concentrating them in specific areas of the body – precisely where there is light.”

Innovative Applications in Medical Imaging

One of the standout features of these nanoparticles is their remarkable thermoresponsivity. Their structure reacts dynamically to changes in temperature, a property derived from their unique molecular design. Laboratory experiments demonstrated that even a weak laser beam, combined with a small number of nanoparticles, could generate extremely high local temperatures, reaching up to 85 degrees Celsius. This rapid heating is crucial for advanced imaging techniques in medical diagnostics.

When tissues are heated quickly, they emit sound waves that can be captured using photoacoustic imaging methods. These techniques enable the creation of detailed 3D models of the human body, enhancing the accuracy of medical assessments. The research team anticipates that these nanoparticles could significantly improve the study of cancer progression by making tumors and their responses to treatments more visible and easier to monitor.

Future Potential and Therapeutic Applications

The implications of this research extend beyond imaging. Professor Binder envisions a future where these nanoparticles could facilitate targeted drug delivery. By using light and heat to activate specific active ingredients within the body, it may be possible to treat conditions more effectively. Notably, the nanoparticles could also be employed in hyperthermia therapy, a technique that uses heat to destroy cancer cells.

While the initial findings are promising, further research is essential to fully explore the therapeutic potential of SCNPs. The project received funding from the German Research Foundation (DFG), under project number BI-1337/17-1. The collaborative effort included contributions from Dr. Justus Friedrich Thümmler, Professor Karsten Mäder from the Institute of Pharmacy, and Professor Jan Laufer from the Institute of Physics.

As research in this field progresses, these light-sensitive nanoparticles hold the potential to transform both diagnostic and therapeutic approaches in modern medicine.