When Dr. Gang Zheng and his colleagues at the University Health Network in Toronto first introduced porphysomes to the scientific community back in 2011, they outlined how they believed these tiny, light-capturing organic structures could transform cancer care.
Their theory was the following: having observed how similar light-absorbing nanoparticles operated in nature, they would try to recreate them in the lab, modifying them so that they could be given to cancer patients. Once inside a patient’s body, the porphysomes would accumulate in tumours, and, when activated by light, they would not only help surgeons locate the tumors more accurately using fluorescence and photoacoustic imaging technologies (which the team is also developing) but would also release heat or highly reactive short-lived compounds that could kill the tumor cells while sparing surrounding tissue.
Their vision may have seemed far-fetched eight years ago, but today it is close to becoming a reality.
“It is a truly exciting time for us,” says Dr. Zheng who, together with biophysicist Dr. Brian Wilson and cancer surgeon Dr. Jonathan Irish, leads a Terry Fox New Frontiers Program looking at the use of porphysomes for cancer diagnosis and treatment. “Most of our pre-human trials are completed, and now we are transitioning these technologies from bench-side to bedside so we can start changing the lives of cancer patients.”
Throughout their research Dr. Zheng and his team have been able to further enhance the nanoparticle structure and performance and to investigate several new potential clinical applications. Several key papers in top scientific journals have been published in recent months showing how porphysomes may improve diagnosis and treatment of peripheral lung cancers in high-risk patients and men with intermediate-risk prostate, as well as thyroid, endometrial and ovarian cancers.
According to Dr. Zheng, who is now the associate research director at the Princess Margaret Cancer Centre in Toronto, funding from the Terry Fox Research Institute has been a catalyst to advance this budding technology into a new era, serving as an anchor that has attracted new talent and more funding. The multidisciplinary team now includes physicists, chemists, engineers and biologists as well as different clinical researchers, all of whom are excited about the real-world applications of these fascinating nanoparticles.
“Ever since our PPG was renewed two years ago, Terry Fox funding has truly moved our porphysomes closer to the clinic and we are very excited for what we will be able to do in the next few years,” says Dr. Zheng.
Dr. Zheng’s research is funded through the Terry Fox New Frontiers Program Project Grant in Porphysome nanoparticle-enabled image-guided cancer interventions.
Cited papers from Dr. Zheng’s team
- Rational design of photosynthesis-inspired nanomedicines. Kara M. Harmatys, Marta Overchuk, and Gang Zheng. Accounts of Chemical Research 2019 52 (5), 1265-1274. DOI: 10.1021/acs.accounts.9b00104
- Tailoring Porphyrin Conjugation for Nanoassembly-Driven Phototheranostic Properties. Marta Overchuk, Mark Zheng, Maneesha A. Rajora, Danielle M. Charron, Juan Chen, and Gang Zheng. ACS Nano 2019 13 (4), 4560-4571. DOI:10.1021/acsnano.9b00494
- Research tools for extrapolating the disposition and pharmacokinetifcs of nanomaterials from preclinical animals to humans. Valic MS, and Gang Zheng. Theranostics. 2019 May 18;9(11):3365-3387. doi: 10.7150/thno.34509.
- Use of Porphysomes to detect primary tumour, lymph node metastases, intra-abdominal metastases and as a tool for image-guided lymphadenectomy: proof of concept in endometrial cancer. Philp L, Chan H, Rouzbahman M, Overchuk M, Chen J, Zheng G, Bernardini MQ. Theranostics 2019; 9(9):2727-2738. doi:10.7150/thno.31225.
- An Orthotopic Endometrial Cancer Model with Retroperitoneal Lymphadenopathy Made From In Vivo Propagated and Cultured VX2 Cells. Philp, L, Chan H, Rouzbahman M, Rostami A, Bratman SV, Akens MK, Irish JC, Bernardini MQ, Zheng G*,J. Vis. Exp. 2019, 151, e59340, doi:10.3791/59340, Epub 2019, Sep 13.
- Evaluation of Novel Imaging Devices for Nanoparticle-Mediated Fluorescence-Guided Lung Tumor Therapy. Kinoshita T, Ujiie H, Chen J, Ding L, Chan H, Gregor A, Bernards N, McVeigh PZ, Fujino K, Lee CY, Motooka Y, Inage T, Valic MS, Effat A, Weersink R, Wilson BC, Zheng G, Asamura H, Yasufuku K. Ann Thorac Surg. 2019 Jun;107(6):1613-1620. doi: 10.1016/j.athoracsur.2019.01.008. Epub 2019 Feb 8.
- A Novel Laser Fiberscope for Simultaneous Imaging and Phototherapy of Peripheral Lung Cancer. Kinoshita T, Effat A, Gregor A, Inage T, Ishiwata T, Motooka Y, Ujiie H, Wilson BC, Zheng G, Weersink R, Asamura H, Yasufuku K. Chest. 2019, 156, 571–578, Epub 2019, April 26.