Upconversion nanoparticles for imaging cells

Abstract

Lanthanide doped upconversion nanoparticles (UCN's) were synthesized for imaging applications. The particles obtained are hydrophobic in nature. It is of great interest to make them hydrophilic for biological applications. Core/shell particles with UCN's as core and silica as shell were synthesized by Stober method in a basic medium. The silica shell was functionalized with amine group to enable antibody conjugation. TNBS(tri-nitrobenzene sulfonic acid) assay was performed to ensure amine functionalization. These particles were conjugated to an antibody targeted against Connexin 43, a well known gap junction protein. TEM was done on particles prior to conjugation of antibody. Characterization of the particles before and after conjugation was done by DLS, Zeta potential measurement. Confocal imaging experiment was done on the cardiomyocytes (H9c2 cells) with the UCN-silica- NH2 particles conjugated with anti-Cx43. Experiments show the feasibility of using UCN's for targeting and imaging gap junctions.