Investigating the Stability of Polymer Coating of Methoxy Polyethylene Glycol Activated by Succinimidyl Valerate on the Surface of Red Blood Cells under In Vitro and In Vivo Conditions
M odares Journal of M edical Sciences: Pathobiology
Objective: The host immune response against minor donor blood groups may be considered a significant problem in certain groups of patients that undergo transfusions such as those who require repeat transfusions (thalassemia). A proposed solution is to coat the surface antigens on red blood cells (RBCs) by covalent binding of methoxy polyethylene glycol (mPEG). This study aims to determine the storage time of PEGylated cells before injection and its effective time during in vivo conditions.
... vo conditions. Methods: We used mPEG activated by succinimidyl valerate (SVA) to PEGlayte the cells. The stability of the created coating during in vitro conditions was investigated by three methods: counting the numbers of free cells, flow cytometry and qualitative investigation. The appropriate concentration of mPEG for rabbit RBC PEGylation was determined by electron microscopy. The effective time of PEGylated rabbit RBCs was determined with flow cytometric analysis after the injection. In addition, we investigated the serum biochemical properties at 24 hours after the injection. Results: The appropriate concentration of 15 mg/mL for rabbit RBC PEGyla tion was determined. At 48 hours after injection, 83% of the cells that were alive in the host circulatory system kept their polymeric coating. Conclusion: We determined that 18 days was an appropriate storage time for PEGylated RBCs under in vitro conditions. The effective time of 14 days was determined for PEGylated RBCs by tracking the cells in vivo. An investigation of the serum biochemical properties of rabbits at 24 hours after the injection showed that the RBC coating significantly inhibited stimulation of the host immune system and cell destruction.