title: Protection of mammalian cell used in biosensors by coating with a polyelectrolyte shell.
abstract: In order to detect xenoestrogens which induce perturbations of mammalian cells, design of biosensor using a mammalian cell line enable to detect these compounds is necessary. MELN cell line is suitable to detect estrogen activity, since they are stably transfect with an estrogen regulated luciferase gene. To realize this biosensor, it appeared necessary to add a protection to the mamalian cell, which is devoided, of the wall protecting yeasts or plant cells. With this aim in view, MELN cells have been isolated with a polyelectrolyte shell using the layer-by-layer technique. Among several polyelectrolyte-couples, the best cell survival (>80%) was obtained by alternating the polycation poly-diallyldimethyl ammonium chloride layer and the negatively charged poly-styrene sulfonate. We observed that the composition of the buffer used for layer-deposition was crucial to preserving cell viability, e.g. potassium ions were preferred to sodium ions during the coating. Furthermore, viability was increased when cells were allowed to recover for 2 h between each bilayer deposition. The use of engineered mammalian cells that synthesize luciferase as a response to exposure to estradiol, demonstrated that coating not only permits cell survival, but also allows essential metabolic functions, such as RNA and protein synthesis to take place. Capsule formation allows free diffusion of small molecules, while it prevents internalization in the cells of proteins larger than 60 kDa.
authors.affiliation: IPBS-CNRS UMR5089, Toulouse, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Germain
authors.forename: Patrick
authors.initials: P
authors.lastname: Balaguer
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Nicolas
authors.forename: Frederic
authors.initials: F
authors.lastname: Lopez
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Esteve
authors.forename: Gleb B
authors.initials: GB
authors.lastname: Sukhorukov
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
authors.forename: Hélène
authors.initials: H
authors.lastname: Richard-Foy
authors.forename: Didier
authors.initials: D
authors.lastname: Fournier
mesh_terms: D000643:Ammonium Chloride / Q000737:chemistry*; D001681:Biological Assay / Q000295:instrumentation / Q000379:methods*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004967:Estrogens / Q000008:administration & dosage* / Q000032:analysis; D006801:Humans; D011137:Polystyrenes / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D004967:Estrogens; D011137:Polystyrenes; D000643:Ammonium Chloride; C003321:polystyrene sulfonic acid