title: Engineering erythrocytes to be erythrosensors: first steps.
abstract: Molecules can be loaded into mammalian erythrocytes through a reversible lysis pore that forms in the membrane when placed in hypotonic media, the result being resealed red cell ghosts. Many studies on the sidedness of transport processes have utilized this approach. In addition, red cell ghosts encapsulated with enzymes have been used in patients to treat specific enzyme deficiencies, particularly when the substrate can cross the red cell membrane. Our long-term goal is to put fluorescent sensors inside erythrocytes, return the loaded red cell ghosts to the animal or patient, and then monitor the fluorescence non-invasively to follow changes in plasma analyte concentration. In this paper, we present a novel dialysis method for making the red cell ghosts. In addition, we present a theoretical analysis showing that it is not necessary that every loaded red cell ghost has the same dye concentration. Finally we discuss the constraints on the optimal affinity for the sensor/analyte interaction.
authors.affiliation: Dalton Cardiovascular Research Center, Department of Medical Pharmacology and Physiology, University of Missouri, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Milanick
authors.forename: Sarah
authors.initials: S
authors.lastname: Ritter
authors.forename: Kenith
authors.initials: K
authors.lastname: Meissner
mesh_terms: D000818:Animals; D001692:Biological Transport; D015374:Biosensing Techniques / Q000379:methods*; D060846:Cell Engineering / Q000379:methods*; D015314:Dialysis Solutions; D004337:Drug Carriers / Q000737:chemistry / Q000378:metabolism*; D004906:Erythrocyte Count; D004910:Erythrocyte Membrane / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate / Q000032:analysis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry; D006033:Glycylglycine / Q000737:chemistry; D006461:Hemolysis; D007700:Kinetics; D008567:Membranes, Artificial; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000032:analysis / Q000737:chemistry; D012756:Sheep
chemical_list: D015314:Dialysis Solutions; D004337:Drug Carriers; D005456:Fluorescent Dyes; D008567:Membranes, Artificial; D015335:Molecular Probes; D006033:Glycylglycine; D016650:Fluorescein-5-isothiocyanate