Gang Zheng, Ph.D.

Effective internalization of lipid nanoparticles for photodynamic cancer therapy

In order to deliver cancer therapeutics to tumor cells, the cells’ membranes must be overcome. A team of researchers have discovered a simple way to achieve this using lipid nanoparticles containing the reagent EDTA (ethylenediaminetetraacetic acid). As the team report in the journal Angewandte Chemie, an unusual mechanism of action of EDTA is responsible for this useful effect.

One of the greatest challenges in cancer therapy is the targeted delivery of drugs, contained in nanoparticles, to tumor cells, where they can then kill the cells. Unfortunately, cell membranes are highly selective in terms of what they allow to pass… Continue reading.

TORONTO, Canada – July, 14, 2016 – Dr. Gang Zheng and a team of biomedical researchers have discovered a “smart” organic, biodegradable nanoparticle that uses heat and light in a controlled manner to potentially target and ablate tumours with greater precision.

The proof-of-concept findings, published online today and designated a “very important paper” in the leading chemistry journal Angewandte Chemie, provide a viable approach to boosting the clinical utility of photo-thermal therapy in treating cancer, says Dr. Zheng, Senior Scientist at the Princess Margaret and Professor of Medical Biophysics at the University of Toronto. Dr. Zheng also holds the Joey and Toby Tanenbaum/Brazilian Ball Chair in Prostate Cancer Research. He talks about and demonstrates the research at https://youtu.be/EEN6Mz5iWBI.

In the lab, using phantom models, the “smart” nanoparticle the team has dubbed  PEARLs – photo-thermal enhancing auto-regulating liposomes – showed how it can solve the two bottlenecks currently preventing more effective use of photo-thermal therapy with patients.  These are overheating of tissue that can cause collateral damage during treatment, and the inability to ablate larger tumour volumes because the light stops travelling when it is absorbed.

Dr. Zheng, a chemist, explains: “Our smart nanoparticle is super cool. It can absorb light, generate heat and ablate the tumour. It’s a thermal sensor and once it reaches the desired ablation temperature of 55C, it becomes invisible allowing the light to move deeper into more areas of tumour and repeat the treatment process.

Hi Reddit! I’m Gang Zheng, Senior Scientist at the Princess Margaret Cancer Center in Toronto, Canada. Our lab focused on creating clinically usable nanotechnology to combat cancer. Inspired by how plants use porphyrins to do photosynthesis, our colourful porphyrins self-assemble into biodegradable nanoparticles called “porphysomes”, which target cancer. Once they’re there, the now-coloured tumours can absorb laser light, heating and killing the tumour, and sparing healthy cells.

We’ve also shown that these nanoparticles can be designed to do all sorts of medical imaging and therapeutics. We’ve used porphysomes for MRI, PET, fluorescence, photoacoustic imaging, ultrasound, photodynamic therapy, and drug delivery, all with a nanoparticle that, unlike others, can be metabolized by the body. Some have called porphysomes the “One particle to rule them all”.

WASHINGTON, D.C.— The American Institute for Medical and Biological Engineering (AIMBE) has announced the pending induction of Gang Zheng, Ph.D., Professor Senior Scientist, Princess Margaret Cancer Centre, Medical Biophysics & IBBME, University of Toronto, to its College of Fellows. Dr. Zheng was nominated, reviewed, and elected by peers and members of the College of Fellows For outstanding contributions on activatable photosensitizers for photodynamic therapy and discovery of porphysome nanotechnology in cancer imaging and therapy.