ONLINE ChemE FacultyColloquium by Huanhuan Liu

26 April 2021 12:30 till 13:30 - Location: Online - By: Communication ChemE

Polymeric micelles in the fight against cancer

Polymeric micelles composed of block copolymers have been extensively studied as carriers for various anticancer substances in chemotherapy. Most of these micelles are composed of amphiphilic block copolymers forming a hydrophobic core in which water-insoluble drugs can be encapsulated and a hydrophilic shell which reduces interaction with the mononuclear phagocyte system and improves tumour uptake. These micelles accumulate at the tumour due to the so-called Enhanced Permeability and Retention (EPR) effect. The reason to use such nano-carriers in chemotherapy is to reduce side-effects to healthy tissue. However, there are two challenges still need to be overcome: side effects are still not significantly reduced and the EPR effect differs tremendously between patients making treatment efficacy extremely variable. In this presentation, we will show approaches to help to solve both challenges.

In the first part of the presentation, we will show how ionizing radiation can help to induce drug release and thus diminish side effects. Ionizing radiation is often used alongside chemotherapy to treat tumours, and therefore was considered to be a suitable trigger. Our results show that when combining photosensitizers and chemotherapeutic drugs such release can be achieved although the mechanism behind the observed effect remains unsolved.

In the second part of the presentation, we will show a new, very easy radiolabeling method to incorporate radionuclides into the core of polymeric micelles and therefore to follow their fate in vivo using nuclear imaging techniques such as SPECT (Single Photon Emission Computed Tomography).  This radiolabeling method allows selecting patients that would benefit from chemotherapy using nano-carriers. Moreover, chemotherapeutic drugs can be incorporated together with radionuclides, making combination of radionuclide therapy and chemotherapy possible. The radiolabeling mechanism is also explored and can be applied to develop general methods for the radiolabeling of polymeric micelles.