L to R: PhD candidate Matthew Nguyen, who was lead author on the study, and NMIN research leader Dr. Warren Chan
NMIN-supported research out of the University of Toronto lab of NMIN research leader Dr. Warren Chan sheds new light on the mechanisms by which nanoparticles enter and exit the tumours they are intended to treat.
This new research, published recently in Nature Materials, overturns the dominant understanding that has guided cancer nanomedicine since the mid-1980s.
Previously, based on the concept of the Enhanced Permeability and Retention (EPR) effect, it was believed that nanoparticles carrying cancer-fighting drugs became trapped in the tumours they entered because the lymphatic vessel cavities were thought to be too small for the nanoparticles to exit.
Dr. Chan and colleagues, however, found that some 45 percent of the nanoparticles that accumulate in tumours up exiting the tumours through their lymphatic vessels.
The findings help explain why treatments based on the EPR effect are failing in clinical trials, and build on earlier research from the Chan lab that showed less than one per cent of nanoparticles actually reach tumours in the first place.
“We are excited to have a better understanding of the nanoparticle tumour delivery process,” said Dr. Chan. “The results of these fundamental studies on nanoparticle entry and exit will be important for engineering nanoparticles to treat cancer.”
“Trying to translate cancer nanomedicine to the clinic is like a working with a black box — some drugs work, some don’t, and it’s difficult to know why,” said NMIN researcher Dr. Gang Zheng, who was not involved in the study.
“Dr. Chan’s dedication to better understanding the mechanisms of nanoparticle uptake and exit is shining light on these processes to help make our translation efforts more efficient and successful.”