Determination and development of alternative mechanical methods for thrombocyte activation

Platelets are blood cells involved in clot formation, wound healing, and tissue regeneration. By enriching the blood plasma with various separation methods, platelet-rich plasma (PRP) is obtained. The effectiveness of PRP has been proven by various clinical studies on wound healing and tissue regeneration. In addition, it is known that this efficiency increases with the use of activated PRP. Studies with activated PRP have shown that the healing process accelerates. However, biochemical methods used in PRP activation can create an inflammatory effect. For this reason, it is aimed to develop alternative mechanical methods for platelet activation within the scope of the thesis. Activation by applying shear stress in microfluidic systems and excitation with ultrasonic sound waves are the methods investigated. Within the scope of the thesis, pillar-shaped and nodal designs with different widths were made in microfluidic systems. These designs were tested in the flow simulation and the applied shear stresses were determined. Subsequently, these chips were fabricated from PMMA (polymethyl methacrylate) sheets by processing with CO2 laser. Characterization of the fabricated chips was done with an optical profilometer and a USB mini microscope. On the other hand, a kit consisting oftwo piezoelectrode holder chambers and a plasma chamber is designed for excitation with ultrasonic waves. One of these two piezoelectrodes is used as a transmitter and the other as a receiver. The validation of the generated acoustic wave was done in this way. Between the two piezoelectrodes is the plasma chamber containing the platelets. This kit was prepared using PMMA and acetate sheets. Activated platelets were examined by flow cytometry for CD62P (P-Selectin) expression. In microfluidic chips, the 8node500 design with a shear stress of 97.5 dyne/cm2 gave the highest platelet activation rate of 83.0%, while sound waves with a frequency of 0.55 MHz gave the highest activation rate of 53.9% in ultrasonic methods. These prototypes will shed light on the kits to be fabricated for use in biomedical applications.