title: Sodium sensing in neurons with a dendrimer-based nanoprobe.
abstract: Ion imaging is a powerful methodology to assess fundamental biological processes in live cells. The limited efficiency of some ion-sensing probes and their fast leakage from cells are important restrictions to this approach. In this study, we present a novel strategy based on the use of dendrimer nanoparticles to obtain better intracellular retention of fluorescent probes and perform prolonged fluorescence imaging of intracellular ion dynamics. A new sodium-sensitive nanoprobe was generated by encapsulating a sodium dye in a PAMAM dendrimer nanocontainer. This nanoprobe is very stable and has high sodium sensitivity and selectivity. When loaded in neurons in live brain tissue, it homogenously fills the entire cell volume, including small processes, and stays for long durations, with no detectable alterations of cell functional properties. We demonstrate the suitability of this new sodium nanosensor for monitoring physiological sodium responses such as those occurring during neuronal activity.
authors.affiliation: Department of Cell Biology and Morphology, University of Lausanne, Rue du Bugnon 9, CH-1005 Lausanne, Switzerland. christophe.lamy@unil.ch
authors.forename: Christophe M
authors.initials: CM
authors.lastname: Lamy
authors.forename: Olivier
authors.initials: O
authors.lastname: Sallin
authors.forename: Céline
authors.initials: C
authors.lastname: Loussert
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Chatton
mesh_terms: D050091:Dendrimers / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D057054:Molecular Imaging / Q000379:methods*; D009474:Neurons / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
chemical_list: D050091:Dendrimers; D005456:Fluorescent Dyes; D012964:Sodium