title: Freeze-drying of human platelets: influence of saccharide, freezing rate and cell concentration.
abstract: Freeze-drying of human platelets is one potentially ideal approach for long-term preservation of platelets. In this study, effects of concentration and type of saccharides, freezing rate and initial cell concentration on the recovery of freeze-dried platelets were investigated. Annexin V binding platelet activation assays, scanning electron microscopy and platelet aggregation upon thrombin (1 U/ml) addition were used to evaluate the effectiveness of platelet freeze-drying. The numerical recovery of freeze-dried platelets was reached as high as 93.0+/-5.2 percent and the recovery of nonactive platelets was reached up to 85.7 +/- 3.4 percent in the presence of 1% BSA and 20% trehalose. Frozen by shelf pre-cooling was the best way to freeze the sample in this study and the numerical recovery of freeze-dried platelets was reached 93.0 +/- 5.2 percent at about 10 degree C/min. When the platelet concentration was increased from 0.2 to 4x10(9) platelets/ml, recovery remained higher than 81.4 percent. The morphology of freeze-dried and rehydrated platelets was intact but a little rounder compared with fresh platelets. The maximum aggregation rate to thrombin (1 U/ml) of freeze-dried platelets was 83.9 percent of the fresh ones, but aggregation speed was 43.0 percent of the fresh ones. Further research on rehydration process and scale up are required.
authors: Institute of Biothermal Sciences, University of Shanghai for Science and Technology, Shanghai 200093, China.
authors: Xin-Li
authors: XL
authors: Zhou
authors: Hong
authors: H
authors: Zhu
authors: Shao-Zhi
authors: SZ
authors: Zhang
authors: Fa-Ming
authors: FM
authors: Zhu
authors: Guang-Ming
authors: GM
authors: Chen
authors: Li-Xing
authors: LX
authors: Yan
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D005612:Freeze Drying; D005615:Freezing; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009005:Monosaccharides / Q000008:administration & dosage / Q000494:pharmacology*; D009994:Osmolar Concentration; D015539:Platelet Activation; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D011134:Polysaccharides / Q000008:administration & dosage / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology; D013997:Time Factors; D014199:Trehalose / Q000494:pharmacology
chemical_list: D017304:Annexin A5; D004338:Drug Combinations; D009005:Monosaccharides; D011134:Polysaccharides; D012710:Serum Albumin, Bovine; D014199:Trehalose; D013917:Thrombin