Freeze-drying of red blood cells using ultrafast cooling by spraying into a vacuum

Ultrafast cooling inhibits the growth of ice crystals and prevents red blood cells from being damaged by ice crystals. Micro-Powder-Dry(μPD), a novel freeze-drying technique, was applied in this work. Using the µPD approach, we looked at the hemolysis and morphology of frozen/freeze-dried red blood cells. After freezing, the µPD method had a higher recovery rate than the slow freezing method. The recovery of the red blood cells was maintained after freeze-drying. This study aims to develop freeze-dried red blood cells using a novel spray freeze-drying mathod called µPD(micro-powder-dry). In the µPD process, the solution is injected into a vacuum. Then the droplets self-freeze due to the decrease in temperature, forming ice particles. Lastly, they are heated and dried under a vacuum. The µPD powder is porous and exhibits excellent solubility.