Experimental Investigation of Microfluidic Device for Platelet Activation

Objective: Wound healing is accelerated when Platelet Rich Plasma is activated and growth factors are released. In this study, it was aimed to stimulate platelets without using chemical stimulants. Method: Two types of mechanical platelet activation methods have been proposed in this study. The first one is a microfluidic chip developed with the shear-induced platelet activation approach. The second one is a piezo-based ultrasound-assisted device which provides platelet activation by stimulating with an ultrasonic wave (0.55 and 1.1 MHz). Three different microfluidic chip designs were worked out to determine the optimal shear stress characteristics; 8-nodes (2789 mu s, 288 shear pulses, and 98.3 dyne/cm(2)), 40-nodes (2765 mu s, 1440 shear pulses, and 95.5 dyne/cm(2)) and pillar-shaped (1030 mu s, 1656 shear pulses, and 48.1 dyne/cm(2)). Results: The highest platelet activation rate (72.7%) was obtained from the chips with 8-nodes. In the ultrasound-assisted device, 32.4% activation rate was obtained from ultrasound waves with 0.55 MHz frequency and 10 Vp-p amplitude. These activation rates, determined by CD62P (P-Selectin) expression, are significantly higher than spontaneous activation of intact platelets (8.5%). In addition, the gradual increase in activation of stimulated platelets with incubation at room temperature showed that activation continued after stimulation. Conclusion: The results showed that these microfluidic devices can be used for platelet activation to enhance the effect of PRP treatment and might reduce adverse immune reactions that may happened due to the use of exogenous activator substances. Significance: Fast-response, low-cost, easy-to-use and controllable biomedical device have been developed for PRP applications.