Validation of a Novel Vacuum Freeze-Drying Method (µPD) for Red Blood Cells : A Preliminary Study on Comparison with Conventional Methods and Potential for Long-Term Storage

Freeze-drying is essential for the preservation of biopharmaceuticals and transfusion-ready blood products. However, conventional methods can cause significant cellular damage, leading to hemolysis in red blood cells (RBCs). This study compares the micro powder dry (µPD) method to the slow freeze-drying method to evaluate their effects on RBCs stability. RBCs were freeze-dried using both techniques, and their moisture content and hemolysis rates were measured immediately after drying and again after one month of storage at both refrigerated (2℃) and room temperatures (28℃). The µPD method resulted in lower hemolysis rates immediately after drying compared to the slow method. Furthermore, both moisture content and hemolysis rates showed minimal changes after one month of storage, demonstrating potential for long-term stability. These findings indicate that the µPD method is superior for preserving RBCs, as it effectively minimizes cellular damage during the freeze-drying process.