Abstract: Objective To compare the viral inactivation effects of methylene blue(MB) plus light (MB/light) treatment using white light LEDs, red light LEDs, and fluorescent lamps on plasma. Methods Plasma samples were treated with methylene blue at a final concentration of 1 μM, followed by 30 minutes of irradiation using white light LEDs, red light LEDs, or fluorescent lamps. The study evaluated the impact of these treatments on coagulation factors (FIB, FⅡ, FⅤ, FⅦ, FⅧ、FⅨ, FⅩ, FⅪ, FⅫ, vWF:Ag, vWF:Ac), anticoagulant proteins (AT, PC), PT, and APTT. Additionally, the efficacy of SINDBIS virus inactivation in plasma was assessed. Results All three methylene blue photodynamic therapies significantly reduced the activity of coagulation factors and anticoagulant proteins, and prolonged coagulation times. No significant differences were found in the activity of FⅤ, FⅦ, FⅨ, FⅪ, vWF:Ac, and AT among the three light sources (P=0.115 8, 0.434 2, 0.610 8, 0.094 3, 0.137 7, 0.166 7). There were no significant differences in the changes of PT and APTT (P=0.652 6, 0.138 2). Red light LEDs treatment resulted in lower FIB, FⅧ, FⅫ, and PC levels compared to white light LED (P<0.000 1, P<0.000 1, P=0.023 2, P<0.000 1) and fluorescent lamps (P<0.000 1, P<0.000 1, P=0.003 4, P<0.000 1). Fluorescent lamps treatment resulted in higher FII levels than red light LED (P=0.012 2), and higher FX levels than both white light LEDs and red light LEDs (P=0.036 6, 0.006 8). White light LEDs treatment yielded higher vWF:Ag levels than red light LED and fluorescent lamps (P=0.014 3, 0.017 2). Following MB/light treatment with the three light sources, the Sindbis virus titer in plasma decreased by>4 LogTCID₅₀/0.1 mL. Conclusion All three MB/light treatments effectively inactivated Sindbis virus in plasma. Red light LED had the most significant effect on FIB and FⅧ activity. White light LED is the preferred light source for future plasma viral inactivation treatments.

Key words: Different light source LEDs, Methylene blue photochemical method, Coagulation factor, Plasma viral inactivation