Cytotoxicity of RGD Functionalized Silver Nanoparticles on Eoma Cells

Studies have shown that silver nanoparticles (AgNPs) elicit a cytotoxic effect. The degree of cytotoxicity is dependent on size, concentration, time of exposure and surface chemistry. AgNPs can also be engineered to selectively interact with specific cell types by surface functionalization with biomimetic targeting moieties. To this end, citrate stabilized AgNPs were functionalized with thiol-containing cyclic RGD peptides by ligand exchange to target αvβ3-integrin receptors on the cell membrane of hemangioendothelioma (EOMA) cells.   Cells were incubated with AgNPs of variable diameter (10-40nm) or RGD- AgNPs in serum-containing media. An MTS assay was used to quantify the number of surviving cells following exposure and cell uptake was measured via absorbance spectrophotometry.   Higher cell uptake and cytotoxic responses correlated with decreased particle size.  RGD-peptide functionalization to AgNP surfaces was demonstrated by a shift in peak absorbance; however, there was not significant enhancement in cell uptake or cytoxocity relative to non-binding RAD control peptides.  This could be due insufficient ligand density on the AgNP surfaces and future work will be aimed at optimizing peptide conjugation.