title: Microconfined flow behavior of red blood cells.
abstract: Red blood cells (RBCs) perform essential functions in human body, such as gas exchange between blood and tissues, thanks to their ability to deform and flow in the microvascular network. The high RBC deformability is mainly due to the viscoelastic properties of the cell membrane. Since an impaired RBC deformability could be found in some diseases, such as malaria, sickle cell anemia, diabetes and hereditary disorders, there is the need to provide further insight into measurement of RBC deformability in a physiologically relevant flow field. Here, RBCs deformability has been studied in terms of the minimum apparent plasma-layer thickness by using high-speed video microscopy of RBCs flowing in cylindrical glass capillaries. An in vitro systematic microfluidic investigation of RBCs in micro-confined conditions has been performed, resulting in the determination of the RBCs time recovery constant, RBC volume and surface area and RBC membrane shear elastic modulus and surface viscosity. It has been noticed that the deformability of RBCs induces cells aggregation during flow in microcapillaries, allowing the formation of clusters of cells. Overall, our results provide a novel technique to estimate RBC deformability and also RBCs collective behavior, which can be used for the analysis of pathological RBCs, for which reliable quantitative methods are still lacking.
authors.affiliation: Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy. Electronic address: g.tomaiuolo@unina.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tomaiuolo
authors.affiliation: Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Lanotte
authors.affiliation: Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: D'Apolito
authors.affiliation: CNR-SPIN and Dipartimento di Scienza Fisiche, Università di Napoli Federico II, Napoli, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Cassinese
authors.affiliation: Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Guido
mesh_terms: D048430:Cell Shape; D004907:Erythrocyte Deformability; D004911:Erythrocyte Volume; D004912:Erythrocytes / Q000166:cytology*; D006801:Humans; D044085:Microfluidics / Q000379:methods*; D010949:Plasma / Q000166:cytology
keywords: Clustering; Deformability; Microcirculation; Red blood cells