Home page Description:
Researchers develop a ‘smart’ technology that uses light and heat to destroy tumours.
Posted On: September 16, 2016
Image Caption:
PEARL nanoparticles function similarly to solar panels: they convert light into usable energy—in this case heat to destroy cancer cells.
Photothermal therapy uses light and heat to treat cancer. The approach involves injecting small substances called nanoparticles into the body, where they accumulate in tumours. Light is then targeted to the tumour area; the nanoparticles absorb this light and convert it into heat—destroying the tumour cells.
Although the therapy is promising, its widespread use is limited for two reasons: too much heat can be generated, damaging the surrounding normal tissue; and light stops travelling after it is absorbed, making the therapy ineffective for treating the inside of large tumours. Dr. Gang Zheng (Techna Core Lead and PM Senior Scientist) has now developed nanoparticles to address these issues.
Dr. Zheng’s nanoparticles are formulated with two main components: J-aggregates, which absorb light and convert it to heat; and lipid membrane sensors, which respond to the heat generated by the J-aggregates. When light is absorbed by J-aggregates at the surface of a tumour, the heat that is generated destroys cancer cells. This also activates the lipid membrane sensors, which cause the J-aggregates to dissolve and become non-functional—stopping excessive heat production. Because the J-aggregates are dissolved, light is no longer absorbed and is allowed to travel into a deeper part of the tissue. This process is repeated with the next layer of nanoparticles until the tumour is destroyed from the outside in.
“Our nanoparticles, which we’ve called photothermal enhancing auto-regulated liposomes (PEARLs), are a new form of ‘smart’ technology that—after being targeted to tumours—provide the right amount of heat required to kill cancer cells,” explains Dr. Zheng. “Our next step is to test this concept further in preclinical models.”
This work was supported by the Terry Fox Research Institute, Prostate Cancer Canada, the Canadian Institutes of Health Research, the Ontario Institute for Cancer Research, the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, the Tanenbaum Chair in Prostate Cancer Research and The Princess Margaret Cancer Foundation.
Controlling spatial heat and light distribution by using photothermal enhancing auto-regulated liposomes (PEARLs). Ng KK, Weersink RA, Lim L, Wilson BC, Zheng G. Angewandte Chemie (International Edition in English). 10.1002/anie.201605241. 2016 Jul 14. [Pubmed abstract]
Although the therapy is promising, its widespread use is limited for two reasons: too much heat can be generated, damaging the surrounding normal tissue; and light stops travelling after it is absorbed, making the therapy ineffective for treating the inside of large tumours. Dr. Gang Zheng (Techna Core Lead and PM Senior Scientist) has now developed nanoparticles to address these issues.
Dr. Zheng’s nanoparticles are formulated with two main components: J-aggregates, which absorb light and convert it to heat; and lipid membrane sensors, which respond to the heat generated by the J-aggregates. When light is absorbed by J-aggregates at the surface of a tumour, the heat that is generated destroys cancer cells. This also activates the lipid membrane sensors, which cause the J-aggregates to dissolve and become non-functional—stopping excessive heat production. Because the J-aggregates are dissolved, light is no longer absorbed and is allowed to travel into a deeper part of the tissue. This process is repeated with the next layer of nanoparticles until the tumour is destroyed from the outside in.
“Our nanoparticles, which we’ve called photothermal enhancing auto-regulated liposomes (PEARLs), are a new form of ‘smart’ technology that—after being targeted to tumours—provide the right amount of heat required to kill cancer cells,” explains Dr. Zheng. “Our next step is to test this concept further in preclinical models.”
This work was supported by the Terry Fox Research Institute, Prostate Cancer Canada, the Canadian Institutes of Health Research, the Ontario Institute for Cancer Research, the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, the Tanenbaum Chair in Prostate Cancer Research and The Princess Margaret Cancer Foundation.
Controlling spatial heat and light distribution by using photothermal enhancing auto-regulated liposomes (PEARLs). Ng KK, Weersink RA, Lim L, Wilson BC, Zheng G. Angewandte Chemie (International Edition in English). 10.1002/anie.201605241. 2016 Jul 14. [Pubmed abstract]