Effects of freeze-drying and dry heat virus inactivation processes on the biological activities of human plasma derived α2-macroglobulin

To assess the impact of freeze-drying and dry heat virus inactivation processes on the activity of α2-macroglobulin (A2M) derived from human plasma Cohn fraction Ⅳ.

A2M derived from human plasma Cohn fraction Ⅳ was prepared and subjected to programmed freeze-drying with dry heat virus inactivation. The lyophilized products were evaluated for their appearance, water content, and validation of the viral inactivation process. The bioactivity of the products before and after lyophilization as well as before and after dry heat inactivation was determined via trypsin inhibition, and the comparisons were studied.

The appearance of the lyophilized product was fluffy, and the water content was (5.83±0.45)%. The specific activities of the samples before and after lyophilization were (10.199±0.137) and (10.033±0.201) μg/mg, respectively, with no statistically significantdifference between the two groups (P> 0.05).The viral inactivation of the samples was carried out by using dry heat inactivation conditions at 100 ℃ for 30 min. After inactivation, the reduction was ≥5.125 LgTCID₅₀/0.1 mL in Pseudorabies virus (PRV) titers, ≥4.500 LgTCID₅₀/0.1 mL in Sindbis virus (SinV) titers ,≥6.375 LgTCID₅₀/0.1 mL in encephalomyocarditis virus (EMCV) titers , and ≥4.500 LgTCID₅₀/0.1 mL in porcine parvovirus (PPV) titers. The specific activities of the samples before and after dry heat were (9.921±0.292) and (10.091±0.278) μ g/mg, respectively, with no statistically significant difference between the two groups.

A2M derived from human plasma Cohn fraction Ⅳ, when subjected to freeze-drying followed by dry heat inactivation at 100 ℃ for 30 minutes, can effectively inactivate viruses without altering the biological activity of the product.