Functionalized gold nanoparticles manifested as potent carriers for nucleolar targeting

Area of Science:

• Nanomedicine
• Cell Biology
• Neuroscience

Background:

• Gold nanoparticles typically localize in the cytoplasm.
• Small gold nanoparticles or those functionalized with specific proteins can enter the cell nucleus.
• The role of surface functionalization in nucleolar accumulation of gold nanoparticles is not well-established.

Purpose of the Study:

• To investigate the effect of surface functionalization on gold nanoparticle localization within dorsal root ganglion neurons.
• To explore the potential of polyethyleneimine (PEI) functionalization for directing gold nanoparticles to the nucleolus.
• To assess the utility of PEI-functionalized gold nanoparticles for theranostic applications.

Main Methods:

• Functionalization of gold nanoparticles with a thin layer of polyethyleneimine (PEI).
• Introduction of functionalized nanoparticles into hard-to-transfect post-mitotic dorsal root ganglion neurons.
• Microscopic analysis (confocal and two-photon) to visualize nanoparticle biodistribution.
• Evaluation of nanoparticle size-independent accumulation.

Main Results:

• Polyethyleneimine (PEI) functionalization directs gold nanoparticles to the nucleolus in a size-independent manner.
• PEI coating enhances the emission signal intensity of gold nanoparticles.
• Clear visualization of cellular biodistribution of nanoparticles was achieved using confocal and two-photon microscopy.
• Demonstrated potential for theranostic applications.

Conclusions:

• Surface functionalization with polyethyleneimine (PEI) is crucial for targeting gold nanoparticles to the nucleolus in neurons.
• PEI-functionalized gold nanoparticles offer improved cellular visualization for theranostic purposes.
• This study provides a novel strategy for nucleolar targeting of nanoparticles in challenging cell types.