Nanoparticles labeled with antibodies hit their target
Nanoparticles labeled with antibodies hit their target lead image
Nanoparticles have the potential to efficiently deliver cancer fighting drugs to select cells. But before they are used in treatment, researchers must show nanoparticles can accurately target cells and then exit the body.
Kogos et al. demonstrated spot-on targeting of gold-coated nanoparticles containing lutetium-177 and labelled with mAB-201b antibodies, which are attracted to thrombomodulin, an antigen in lungs.
Single photon emission computed tomography showed 85% of the nanoparticles injected into mice 24 hours earlier were in lung cells, indicating successful targeting of thrombomodulin. Electron microscopy confirmed the ultrastructural location of the nanoparticles in the cells. None of the examined tissues displayed apoptosis or necrosis, suggesting the radioactive nanoparticles are safe.
“The successful targeting of the nanoparticles and the demonstration of no tissue toxicity makes them ideal theranostic agents for human pulmonary and other metastatic diseases,” said author Benjamin Kogos.
The authors determined after the nanoparticles reached thrombomodulin in the lungs, they were removed from blood circulation by cells in the liver and spleen before being eliminated through the biliary tract and bowel.
Injecting clodronate liposomes into the mice beforehand allowed the authors to prolong circulation of the nanoparticles. The liposomes reduced the number of circulating macrophages that eat nanoparticles.
These results suggest nanoparticles labelled with antibodies should be able to target and destroy a variety of cancers without harming surrounding healthy cells, making them a potential theranostic agent for pulmonary and other cancers.
Before nanoparticles are used to treat cancer, researchers will need to identify antibodies and antigens for different cancer cells in human tissue, as well as study the safety and efficiency of antibody-labelled nanoparticles in clinical trials.
Source: “Electron microscopy of antibody-conjugated, Lutetium-177 lanthanide gold-coated nanoparticles proof of concept of targeted loci - A potential theranostic agent,” by Benjamin Kogos, Leona Cohen-Gould, Cristina Rodriguez-Rodriguez, Vesna Sossi, Nicholas Sobol, Richard Johnson, Douglas C. Miller, J. David Robertson, and Paul H Pevsner, AIP Advances (2021). The article can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0044515 .
