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Preparation of Microstructured Surface of Pyrolytic Carbon by Laser and Its Blood Compatibility Application

After implanting pyrocarbon into human body, patients will have symptoms such as inflammation and thromboembolism, so they must take anticoagulant drugs for life. To improve the blood compatibility of the pyrolytic carbon, a nanosecond laser was used to prepare microstructures on the surface of the pyrolytic carbon. The effects of laser power, scanning times and scanning spacing on the wettability of pyrolytic carbon are discussed. At the same time, dynamic coagulation, hemolysis rate and platelet adhesion test were performed on smooth samples and samples prepared at different scanning spacing. The results show that the contact angle of the modified parallel grating pyrocarbon surface is larger than that of the smooth sample. As the scanning spacing increases, the contact angle increases and then decreases, and the higher the contact angle, the better the blood compatibility of the sample. When the laser power is 27.5 W, the scanning times is 6, and the scanning distance is 90 μm, the contact angle of the sample reaches the best, which is 153.21°; the number of platelets adhering to the surface was the least, about 2, and mostly in an unactivated state; the anticoagulant effect is also the best, and the surface hemolysis is the lowest, which is only 0.88%.