Preparation of Platelet Membrane Microparticles with High Pressure Homogenization Method.

Objective To investigate the preparation technique of infusible platelet membrane microparticles (IPMs), and evaluate hemostatic function and effect of IPMs on pathological thrombogenicity after transfused into model of rabbit thrombocytopenia.

Methods Whole bloods collected in the street were used to prepare platelet concentrates(PCs),white cells were removed by white cell filter, and red cells by centrifugation at 1000rpm in for 10min. After that, platelets were washed twice with 0.9% NaCl solution by repeated resuspension and centrifugation, and adjusted concentration to 2×109/ml with 0.9% NaCl. The washed platelets were disrupted by repeated freezing (at −80°) and thawing (at 25°) three times, and were heated at 60° for twenty hours to inactivate any viral contaminants. Finally, the heat 2 treated platelets were crushed by high pressure homogenizer to form IPMs. In this study, particle analyser was applied to mean diameter and the particle size distribution of IPMs, APCT to test the procoagulation activity of IPMs in vitro. Hemostatic function and effect of IPMs onpathological thrombogenicity were observed after IPMs were transfused into thrombocytopenia rabbitmodels.

Results mean diameter of IPMs was from 200 to 300 nm. The procoagulation activity of 50Lg/ml of IPMs was equal to 250×10⁹/L of fresh platelets. Rabbit ear bleeding time and APCT significantly shortened from two hours to twelve hours after transfusion of 2mg IPMs per Kg into thrombocytopenia rabbit models, but other indexes such as PT, APTT, Fg, and TT changed less.

Conclusions IPMs possess good hemostatic function and less effect on pathological thrombogenicity. It is a kind of promising biologic hemostatic reagent.