Abstract:
This thesis aims to microfluidic systems have been developed to determine the
mechanical properties of cancer cells and healthy cells as a single cell with a holographic
imaging technique. The most important innovations brought by microfluidic chips are
that they can perform many operations at the same time, cell separation processes, and
the microchannels can be continuously identified and followed. They also provide a
suitable environment for processing and analyzing cells in a narrow and restricted area.
Therefore, the use of microfluidic chip applications in processes such as analysis,
evaluation, replication on cells has become widespread. In the microfluidic systems
developed within the scope of the thesis PDMS based microchips are produced and
designed as a platform in which microchannels are contained, the cells can be
immobilized individually and exposed to acoustic effects. HCT-116 (Colon Cancer),
ONCO-DG-1 (Ovarian Cancer), MDA-MB-1 (Mammary Cancer) were chosen as the
appropriate cancer cell line and HUVECs (Human Umbilical Vein Endothelial Cells)
selected as a healthy cell line for the experiments. First of all, a microfluidic system has
been developed in which cells can be controlled. In order to control microfluidic
systems, the flow must also be controlled. For this reason, a flow rate in the microfluidic
system was measured by developing a micro-flow sensor based on diamagnetic
levitation. Thanks to this developed sensor, optimum values were determined in the
micro-flow system for cell culture studies. Afterward, ultrasonic transducers were
integrated into the microfluidic system. Acoustic surface waves were created on cell
surfaces using acoustic transducers. These transducers have been used to create
discernible waves on the cell surface due to their high-frequency modes. As a result, the
acoustic mechanical effect on cancer cells was obtained by the holographic imaging
technique.
In experiments, acoustic waves were sent in the frequency range between 1 Hz and
2kHz and amplitude range between 3Vpp and 5Vpp applied to determine the
mechanical stiffness of cancer cells. Optimum frequency ranges are determined, and
results are compared. With these studies conducted in the thesis, a microfluidic system
that can reveal the morphological structures of cancer cells based on acoustoholographic has been developed.
