Agradecimentos: The authors are grateful to Coordenação de Aperfeiçoamento de Pessoal de Nível Supeior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE), Fundação de Hematologia e Hemoterapia de Pernambuco (HEMOPE), L’óreal, Academia Brasileira de Ciências, Organização das Nações Unidas para a Educação, a Ciência e a Cultura (UNESCO) and Aggeu Magalhães Institute (FIOCRUZ - Fundação Oswaldo Cruz). This work is also linked to Optics and Photonics Research Center (CEPOF) from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), National Institute of Photonics Applied to Cell Biology, National Institute of Photonics and National Institute of Science and Blood Technology Ver menos

Abstract: During storage, red blood cells (RBCs) for transfusion purposes suffer progressive deterioration. Sialylated glycoproteins of the RBC membrane are responsible for a negatively charged surface which creates a repulsive electrical zeta potential. These charges help prevent the interaction between RBCs and other cells, and especially among each RBCs. Reports in the literature have stated that RBCs sialylated glycoproteins can be sensitive to enzymes released by leukocyte degranulation. Thus, the aim of this study was, by using an optical tweezers as a biomedical tool, to measure the zeta potential in standard RBCs units and in leukocyte reduced RBC units (collected in CPD-SAGM) during storage. Optical tweezers is a sensitive tool that uses light for measuring cell biophysical properties which are important for clinical and research purposes. This is the first study to analyze RBCs membrane charges during storage. In addition, we herein also measured the elasticity of RBCs also collected in CPD-SAGM. In conclusion, the zeta potential decreased 42% and cells were 134% less deformable at the end of storage. The zeta potential from leukodepleted units had a similar profile when compared to units stored without leukoreduction, indicating that leukocyte lyses were not responsible for the zeta potential decay. Flow cytometry measurements of reactive oxygen species suggested that this decay is due to membrane oxidative damages. These results show that measurements of zeta potentials provide new insights about RBCs storage lesion for transfusion purposes Ver menos