Surface functionalization of gold nanoparticles using hetero-bifunctional poly(ethylene glycol) spacer for intracellular tracking and delivery.
For the development of surface-functionalized gold nanoparticles as cellular probes and delivery agents, we have synthesized hetero-bifunctional poly(ethylene glycol) (PEG, MW 1500) having a thiol group on one terminus and a reactive functional group on the other for use as a flexible spacer. Coumarin, a model fluorescent dye, was conjugated to one end of the PEG spacer and gold nanoparticles were modified with coumarin-PEG-thiol. Surface attachment of coumarin through the PEG spacer decreased the fluorescence quenching effect of gold nanoparticles. The results of cellular cytotoxicity and fluorescence confocal analyses showed that the PEG spacer-modified nanoparticles were essentially non-toxic and could be efficiently internalized in the cells within 1 hour of incubation. Intracellular particle tracking using a Keck 3-D Fusion Microscope System showed that the functionalized gold nanoparticles were rapidly internalized in the cells and localized in the peri-nuclear region. Using the PEG spacer, the gold nano-platform can be conjugated with a variety of biologically relevant ligands such as fluorescent dyes, antibodies, etc in order to target, probe, and induce a stimulus at the target site.
Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
Dinesh
D
Shenoy
Wei
W
Fu
Jane
J
Li
Curtis
C
Crasto
Graham
G
Jones
Charles
C
DiMarzio
Srinivas
S
Sridhar
Mansoor
M
Amiji
D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D016503:Drug Delivery Systems / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods*; D015336:Molecular Probe Techniques; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000494:pharmacology; D013499:Surface Properties
D011092:Polyethylene Glycols; D006046:Gold