Title: Organic Polymers for Triggering Cell Death in Cancer Cells.

 Speaker: Fatma ÖZ

 Time: August,9,2022, 11:00

Thesis Committee Members:

Prof. Özlem Yalçın (Advisor, Koç University)

Prof. Sacit Karamürsel (Koç University)

Asst. Prof. Ahmet Erten (İstanbul Technical University)


Organic polymers are promising candidates for semiconductor-cell interfaces due to their advantages such as lightness, biocompatibility, and flexibility. Especially, hybrid interfaces bear a significant potential to regulate cell activities. Photoelectrical stimulation of cancer cells using organic polymers has shown a promising future in cell death. However, long treatment duration may be disadvantageous. In this respect, this thesis is focused on the effect of increasing photocurrent level using P3HT (poly(3-hexylthiophene2,5-diyl)): PC70BM ([6,6]-phenyl-C71-butyric acid methyl ester) to decrease treatment duration. Moreover, we are interested in the impact level of different parameters such as polymer concentration, frequency, and light intensity to induce cell death. This work examines for the first-time opportunity to use a hybrid biointerface for cell death in A375-P and MDA-MB-231 cell lines.

First, polymer concentration was optimized to increase photocurrent produced by photoelectrode. Subsequently, the proper extracellular matrix (ECM) was tested to provide the best cell dynamics. Trypan blue counting indicated that cell viability has decreased in the presence of photocurrent. Flow cytometry results proved the activation of Annexin-V and Propidium Iodide which demonstrates apoptosis/necrosis, has the highest percentage toward photocurrent. Further, Live Cell Imaging allowed us to analyze calcium signaling for understanding death pathways. We studied the reactive oxygen species (ROS) production of substrates to evaluate toxicity.

Altogether, the experimental results reported in this thesis may be useful for the in vivo experiments and future characterization of potential devices.