Magnetophoresis at the nanoscale: tracking the magnetic targeting efficiency of nanovectors.
OBJECTIVE
Most of the research efforts in magnetic targeting have been focused on the development of magnetic nanovectors, while the investigation of methods for tracking their magnetic targeting efficiency remains inappropriately addressed. We propose herein a miniaturized approach for appraising magnetophoretic mobility at the nanoscale.


METHODS
A simple and easy-to-use chamber including a microtip as a magnetic attractor was developed to perform magnetophoretic measurement at the size scale of nano-objects, and under bright field or fluorescence microscopy. Different sets of magnetic nanocontainers were produced and their magnetophoretic mobility was investigated. Real-time observations of the Brownian motion of the nanocontainers were also carried out for simultaneous size determination.


RESULTS
Attraction of the nanocontainers at the microtip is demonstrated as a qualitative method that immediately distinguishes magnetically responsive nano-objects. The combination of the analysis of Brownian motion, together with the magnetophoretic mobility, inferred both the size, the magnetophoretic velocity and the magnetic content of the nanocontainers. Additionally, nanomagnetophoresis experiments under fluorescence microscopy provided information on the constitutive core/shell integrity of the nanocontainers and the co-internalization of a fluorescent cargo.


CONCLUSIONS
This nanomagnetophoresis method represents a promising tool to estimate the feasibility of magnetic targeting in laboratory routine.
Laboratoire Matière & Systèmes Complexes, UMR 7057, CNRS & Université Paris Diderot, 10 rue Alice Domon & Léonie Duquet, 75205 Paris cedex 13, France.
Amanda K
AK
Andriola Silva
Riccardo
R
Di Corato
Florence
F
Gazeau
Teresa
T
Pellegrino
Claire
C
Wilhelm
D004337:Drug Carriers / Q000032:analysis*; D016503:Drug Delivery Systems; D004867:Equipment Design; D005456:Fluorescent Dyes / Q000008:administration & dosage; D008280:Magnetics / Q000295:instrumentation*; D059346:Magnets / Q000032:analysis*; D008856:Microscopy, Fluorescence; D009038:Motion; D049329:Nanostructures / Q000032:analysis* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D010316:Particle Size
D004337:Drug Carriers; D005456:Fluorescent Dyes