Self-Assembled Gold Nanoclusters for Bright Fluorescence Imaging and Enhanced Drug Delivery.

Nanoparticles combining enhanced cellular drug delivery with efficient fluorescence detection are important tools for the development of theranostic agents. Here, we demonstrate this concept by a simple, fast, and robust protocol of cationic polymer-mediated gold nanocluster (Au NCs) self-assembly into nanoparticles (NPs) of ca. 120 nm diameter.

Multivalent Glycosylation of Fluorescent Gold Nanoclusters Promotes Increased Human Dendritic Cell Targeting via Multiple Endocytic Pathways.

We report the synthesis and characterization of gold nanoclusters (Au NCs) stabilized by a mixture of zwitterionic and multivalent mannose ligands. Characterization of this carbohydrated nanosystem confirms its small size (∼2 nm), intense red-NIR fluorescence, relatively high affinity to lectin (ConA), and stability in physiological media. Cell studies performed using human-monocyte-derived dendritic cells (DCs) show that Au NC uptake efficiency is greatly enhanced by the presence of surface carbohydrate (>250% compared to noncarbohydrated Au NCs), allowing their detection in cells by fluorescence following incubation with concentrations as low as 1 μg mL(-1).

Light induced cytosolic drug delivery from liposomes with gold nanoparticles.

Externally triggered drug release at defined targets allows site- and time-controlled drug treatment regimens. We have developed liposomal drug carriers with encapsulated gold nanoparticles for triggered drug release. Light energy is converted to heat in the gold nanoparticles and released to the lipid bilayers.

Intracellular accumulation and immunological properties of fluorescent gold nanoclusters in human dendritic cells.

We have studied the effect of highly fluorescent gold nanoclusters (Au NCs) (∅ < 3 nm) stabilized by different ligands on the intracellular accumulation and immune response of human derived-monocyte dendritic cells (DCs). Results indicate that the high uptake efficiency of Au NCs is strongly related to their small size and to the nature of the ligand, with zwitterionic ligands being more effective than PEGylated ones. Evidence from flow cytometry and microscopy demonstrate time and concentration-dependent Au NCs internalization by endocytic pathway(s) involving amorphous and laminar organelles, while maintaining their discrete size and photoluminescence properties.

Surface chemistry dependent immunostimulative potential of porous silicon nanoplatforms.

Nanoparticles (NPs) have been suggested for immunotherapy applications in order to optimize the delivery of immuno-stimulative or -suppressive molecules. However, low attention towards the impact of the NPs' physicochemical properties has presented a major hurdle for developing efficient immunotherapeutic agents. Here, the effects of porous silicon (PSi) NPs with different surface chemistries were evaluated on human monocyte-derived dendritic cells (MDDCs) and lymphocytes in order to highlight the importance of the NPs selection in immuno-stimulative or -suppressive treatment.