And because the particles can be seen in MRI images, they are traceable.
Both therapeutic and diagnostic in function, the so-called “theranostic” particles were developed by a team including KTH Professor Eva Malmström-Jonsson, from the School of Chemical Science, as well as researchers at Sweden’s Chalmer’s University and the Karolinska Institute in Stockholm.
Malmström-Jonsson says that the particles, which the team developed for breast cancer treatment, are biodegradable and non-toxic. Their research was published in the science journal Particle & Particle Systems Characterization.
The study resulted in a method to make nanoparticles spontaneously build themselves up with tailored macromolecules. The formation requires a balance between the particle’s hydrophilic (capable of dissolving in water) and hydrophobic (not dissolvable in water) parts. The hydrophobic portion makes it possible to fill the particle with the drug.
A relatively high concentration of the natural isotope 19F (fluorine) makes the particles clearly visible on high-resolution images taken by MRI (magnetic resonance imaging). By following the path of theranostic nanoparticles in the body, it is possible to obtain information about how the drug is taken up by the tumor and whether the treatment is working.
Scientists filled nanoparticles with the chemotherapy drug doxorubicin (known as chemo), which is used to treat bladder, lung, ovarian and breast cancer, In experiments on cultured cells, they showed that the particles themselves are not harmful but can effectively kill cancer cells after being loaded with the drug.
The next step is to develop the system to target tumors that are difficult to treat with chemotherapy, such as brain tumors, pancreatic cancer, and drug-resistant breast cancer tumors.
“By targeting groups on the surface, or by changing the size or introducing ionic groups on our nanoparticles, one can increase the selective uptake in these tumors,” says Andreas Nystrom, an associate professor of nanomedicine at the Swedish Medical Nanoscience Center and Department of Neuroscience, Karolinska Institute.
In the long term, the research can result in tailored chemotherapy treatments that seek out tumor cells. This would enable the toxic drug to be delivered more specifically to the tumor, making the treatment more effective while reducing side effects.
“What we want to do is try to give nanoparticles a homing function on the surface so that the drug is as effective as possible and can be transported to the right place,” Malmström-Jonsson says.
The study is funded in part by two grants from the Swedish Research Council to Andreas Nystrom and Eva Malmström-Jonsson. Malmström-Jonsson and Nystrom are also active in the company Polymer Factory Sweden AB.
For more information, contact Eva Malmström-Jonsson at +46 (0) 8 7907225, mavem @ kth.se; or Andreas Nystrom +46 (0) 8 52486942, andreas.nystrom @ ki.se.
By Karin Söderlund Leifler and Peter Larsson