Toxicity evaluation of gold-dendrimer composite nanodevices in vitro - Difference found between tumour and proliferating endothelial cells

Composite nanodevices (CNDs) are a well-studied class of multifunctional nanomaterials with several potential medical uses, including cancer imaging and therapy. Gold/ dendrimer CNDs are organic/inorganic hybrid materials consisting of physical networks of dendrimer(s) and inorganic materials. This design permits properties of dendrimers and inorganic materials to be individually modified and optimized. A detailed understanding of factors regulating toxicity is lacking. We develop and test toxicity assays for CNDs in vitro both for cancer cells and for normal endothelial cells. We show how CND surface charge (positive, negative or neutral) and exposure time affects biosafety for d = 5 nm nanodevices. We also show that formation of the CND (incorporation of gold into a dendrimer template) can lower toxicity of a dendrimer. Interestingly, we also show that tumour cells and proliferating endothelial cells have different toxicity profiles.