BIOE Seminar: Optically Activated Nanoplatform Creates Responsive Tumor Microenvironment
Friday, November 19, 2021
9:00 a.m.-10:00 a.m.
A. James Clark Hall, Room 2121
Huang Chiao (Joe) Huang
Photodynamic Therapy Team
Wellman Center for Photomedicine
Massachusetts General Hospital
Harvard Medical School, Boston
This seminar will be held in a hybrid format. Those interested in participating virtually should contact Alyssa Tomlinson (firstname.lastname@example.org) if they do not receive BIOE's weekly seminars emails.
Optically Activated Nanoplatform Creates an Immune-rich and Responsive Tumor Microenvironment?
Optical activation of materials leads to thermal, photochemical and radiative processes which can be captured for response-based therapeutic design, diagnostics and therapy monitoring. The ability to use light as a reagent to control drug release further allows for the fabrication of light controllable intelligent multiagent constructs that attack multiple pathways making the nanomedicines more effective against cancer and allows for combination treatments in a variety of disease. Typically, combinatorial agents are administered separately with their own pharmacokinetics, reaching targets at different times which reduces the synergism potential. Nanomedicines, to some extent can overcome this limitation by delivering the multiple agents to the target site at the same time and same place provided there is synergism in mechanistic aspects of the agents. Light-triggered release provides an increased level of of spatiotemporal control. Photodynamic therapy (PDT) is a photochemistry-based process that is approved for several clinical applications world-wide. It involves the exposure of light activatable molecules to appropriate wavelengths that leads to the generation of active molecular species that is responsible for targeted death. There are many unique attributes to this process. Because of the requirement of light and the photosensitizer being present at the same place at the same time there is an additional level of selectivity. Neither light alone nor the photosensitizer influence target cells by themselves. In addition to the direct cytotoxic effect, the photodynamic activation primes the microenvironment in a process call PhotoDynamic Priming (PDP) to enable a more potent response to adjuvant treatments, so the PDP becomes an enabler of treatments, particularly when administered in a Nanoplatform. Finally, the molecules used for therapeutic purposes also have fluorescence, so the same entity provides an imaging handle, thus making photodynamic activation a natural Theranostic process. This talk will provide an overview of the PDT/PDP with a focus on how this process impacts on the immunology of tumors making them more responsive to immune agents such as immune checkpoint inhibitors.
About the Speaker
Tayyaba Hasan is a Professor of Dermatology at the Wellman Center for Photomedicine, Harvard Medical School (HMS) and a Professor of Health Sciences and Technology (Harvard-MIT). She was the founding Director of the Office for Research Career Development at Massachusetts General Hospital until 2011. Dr. Hasan’s scientific efforts are focused on photochemistry-based approaches (photodynamic therapy, or PDT) for treatment and diagnosis of disease. PDT is a photochemistry-based approach that is increasingly used to treat a wide number of diseases and requires: (i) light of appropriate wavelength, (ii) a light activatable chemical compound (photosensitizer or PS), and (iii) molecular oxygen. PDT achieves its cytotoxic effect by producing active molecular species including oxygen radicals and singlet oxygen.