Synthesis, cellular delivery and in vivo application of dendrimer-based pH sensors.
The development of fluorescent indicators represented a revolution for life sciences. Genetically encoded and synthetic fluorophores with sensing abilities allowed the visualization of biologically relevant species with high spatial and temporal resolution. Synthetic dyes are of particular interest thanks to their high tunability and the wide range of measureable analytes. However, these molecules suffer several limitations related to small molecule behavior (poor solubility, difficulties in targeting, often no ratiometric imaging allowed). In this work we introduce the development of dendrimer-based sensors and present a procedure for pH measurement in vitro, in living cells and in vivo. We choose dendrimers as ideal platform for our sensors for their many desirable properties (monodispersity, tunable properties, multivalency) that made them a widely used scaffold for several biomedical devices. The conjugation of fluorescent pH indicators to the dendrimer scaffold led to an enhancement of their sensing performances. In particular dendrimers exhibit reduced cell leakage, improved intracellular targeting and allow ratiometric measurements. These novel sensors were successfully employed to measure pH in living HeLa cells and in vivo in mouse brain.
Institute for Complex Molecular Systems & Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology & NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR.
Lorenzo
L
Albertazzi
Barbara
B
Storti
Marco
M
Brondi
Sebastian
S
Sulis Sato
Gian Michele
GM
Ratto
Giovanni
G
Signore
Fabio
F
Beltram
D000818:Animals; D001923:Brain Chemistry; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry; D005260:Female; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
D050091:Dendrimers; D005456:Fluorescent Dyes; C104700:PAMAM Starburst