Laser Induced Heating of Polymer Nanocomposites for Hyperthermia in the Treatment of Triple Negative Breast Cancer

Onyekanne, Maria Chinyerem Euphemia (2022-07-02)

Main Thesis


The work presents the results of an experimental and computational study of the effects of laser-induced heating provided by magnetite polymer-based nanocomposite structures that are being developed for the localized laser-induced hyperthermic treatment of triple-negative breast cancer. Magnetite nanoparticle-reinforced polydimethylsiloxane (PDMS) nanocomposites were fabricated with weight percentages of (1 %, 5 %, and 10 %) magnetite nanoparticles. The fabricated nanocomposites were exposed to incident Near Infrared (NIR) laser beams with well-controlled powers to generate specific elevated temperatures at different times. The mechanical and thermal properties of the different PDMS-based nanocomposites were critically studied. This was because the unique characteristics during the laser-nanocomposite interactions were driven by the both thermal, microstructural, and physicochemical properties (mechanical properties) of the PDMS-based nanocomposites. Under in vitro conditions, our results from the laser-nanocomposites interactions show a decrease in the cell viability of triple-negative breast cancer cells (MDA-MB-231). Using an ex vivo chicken tissue, laser-nanocomposites interactions resulted in well-controlled temperatures in the hyperthermia domain (41 °C and 44°C) in a submillimeter range using a chicken tissue model. Interestingly, laser irradiation and interaction with the nanocomposites did not cause any observed physical damage to the chicken tissue but resulted in significant breast cancer cell dead. The potential in vivo performance of the PDMS nanocomposites was also investigated using computational finite element models of the effects of laser-magnetite nanocomposites interactions on the temperatures and thermal doses experienced by tissues that surround the nanocomposites devices. The outcomes of the experimental studies were validated using the results from the computational analyses. The implications of the results are discussed for the potential design of plasmonic/magnetic-based nanocomposites devices with attractive combinations of mechanical, structural, and thermal properties that are relevant to laser hyperthermia and photo-thermal-ablation for the localized treatment of triple-negative breast cancer tissue.