Plenary Event
Nano/Biophotonics Plenary
31 January 2023 • 10:30 AM - 11:30 AM PST | Moscone Center, Room 207 (Level 2 South) 
10:30 AM
Welcome and Opening Remarks

Paras Prasad, Univ. at Buffalo (USA)

10:40 AM
Porphysome nanotechnology: from discovery toward first-in-patients

Gang Zheng, Univ. of Toronto (Canada) and Princess Margaret Cancer Ctr. (Canada)

Porphysomes are intrinsically multifunctional liposome-like nanoparticles self-assembled from a single porphyrin-lipid building block. High-density porphyrin packing in the nanoparticle bilayer enables light absorption and conversion to heat with extremely high efficiency, making porphysomes ideal candidates for photothermal therapy and photoacoustic imaging. Upon nanostructure dissociation during cell uptake, the fluorescence and photodynamic activity of the porphyrin monomers is restored. In addition, metal ions can be directly incorporated into the porphyrin building blocks, thus unlocking porphysome’s potential for PET and MRI. Beyond porphysomes, we developed HDL-mimicking porphyrin nanoparticles, CT-capable porphyrin nanoemulsions, ultrasound-activated porphyrin microbubbles and nanodroplets, protocell-like giant porphyrin vesicles, and metal-chelating nanotexaphyrins, thus greatly broadened the purview of porphyrin nanophotonics. By mimicking light harvesting complexes in nature, a family of high-ordered porphyrin supramolecular assemblies were developed, resulting unprecedented nanophotonic properties (e.g., self-regulating photothermal effect). Such optical properties are also responsible for our discovery of the ultrasound-induced microbubbles-to-nanobubbles conversion phenomenon, offering exciting new opportunities for ultrasound theranostics and drug delivery. The porphysome nanotechnology has trod a path towards the clinic for the past ten years, using only academic resources to complete regulatory requirements and pre-clinical validation. The first veterinary trials (canines and cats) are underway with the first-in-human study to be launched shortly. The simple, intrinsically theranostic nature of the porphysome epitomizes a “one-for-all” nanomedicine design paradigm and confers exciting clinical promise.

Gang Zheng is a Professor and Canada Research Chair at the University of Toronto and Associate Research Director of the Princess Margaret Cancer Center. He obtained his BSc in 1988 from Hangzhou University and PhD in 1999 from SUNY Buffalo. Following a postdoctoral training in photodynamic therapy at the Roswell Park Cancer Institute, he joined the University of Pennsylvania in 2001 as an Assistant Professor of Radiology and moved to Canada in 2006. His lab is best known for introducing activatable photosensitizers and porphysome nanotechnology. Dr. Zheng is a Fellow of AIMBE and an Associate Editor for Bioconjugate Chemistry.