title: Functionalization and characterization of persistent luminescence nanoparticles by dynamic light scattering, laser Doppler and capillary electrophoresis.
abstract: Zinc gallate nanoparticles doped with chromium (III) (ZnGa1.995O4:Cr0.005) are innovative persistent luminescence materials with particular optical properties allowing their use for in vivo imaging. They can be excited in the tissue transparency window by visible photons and emit light for hours after the end of the excitation. This allows to observe the probe without any time constraints and without autofluorescence signals produced by biological tissues. Modification of the surface of these nanoparticles is essential to be colloidally stable not only for cell targeting applications but also for proper distribution in living organisms. The use of different methods for controlling and characterizing the functionalization process is imperative to better understand the subsequent interactions with biological elements. This work explores for the first time the characterization and optimization of a classic functionalization sequence, starting with hydroxyl groups (ZGO-OH) at the nanoparticle surface, followed by an aminosilane-functionalization intermediate stage (ZGO-NH2) before PEGylation (ZGO-PEG). Dynamic light scattering and laser doppler electrophoresis were used in combination with capillary electrophoresis to characterize the nanoparticle functionalization processes and control their colloidal and chemical stability. The hydrodynamic diameter, zeta potential, electrophoretic mobility, stability over time and aggregation state of persistent luminescence nanoparticles under physiological-based solution conditions have been studied for each functional state. Additionally, a new protocol to improve ZGO-NH2 stability based on a thermal treatment to complete covalent binding of (3-aminopropyl) triethoxysilane onto the particle surface has been optimized. This thorough control increases our knowledge on these nanoparticles for subsequent toxicological studies and ultimately medical application.
authors.affiliation: PSL Research University, Chimie ParisTech, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France; INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (U 1022), 75006 Paris, France; CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé UMR 8258, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75006 Paris, France; Departamento de Química, Universidad de Guanajuato, 36050 Guanajuato, Mexico; Departamento de Farmacia, Universidad de Guanajuato, 36050 Guanajuato, Mexico.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Ramírez-García
authors.affiliation: PSL Research University, Chimie ParisTech, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France; INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (U 1022), 75006 Paris, France; CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé UMR 8258, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75006 Paris, France.
authors.forename: Fanny
authors.initials: F
authors.lastname: d'Orlyé
authors.affiliation: Departamento de Química, Universidad de Guanajuato, 36050 Guanajuato, Mexico.
authors.forename: Silvia
authors.initials: S
authors.lastname: Gutiérrez-Granados
authors.affiliation: Departamento de Farmacia, Universidad de Guanajuato, 36050 Guanajuato, Mexico.
authors.forename: Minerva
authors.initials: M
authors.lastname: Martínez-Alfaro
authors.affiliation: PSL Research University, Chimie ParisTech, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France; INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (U 1022), 75006 Paris, France; CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé UMR 8258, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75006 Paris, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Mignet
authors.affiliation: PSL Research University, Chimie ParisTech, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France; INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (U 1022), 75006 Paris, France; CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé UMR 8258, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75006 Paris, France. Electronic address: cyrille.richard@parisdescartes.fr.
authors.forename: Cyrille
authors.initials: C
authors.lastname: Richard
authors.affiliation: PSL Research University, Chimie ParisTech, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France; INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (U 1022), 75006 Paris, France; CNRS, Unité de Technologies Chimiques et Biologiques pour la Santé UMR 8258, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75006 Paris, France. Electronic address: anne.varenne@chimie-paristech.fr.
authors.forename: Anne
authors.initials: A
authors.lastname: Varenne
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008027:Light; D049449:Luminescence; D053758:Nanoparticles; D012542:Scattering, Radiation
keywords: Colloidal stability; Dynamic light scattering; Electrophoretic mobility; Persistent luminescence; Polydispersity; Surface modification; Zeta potential