Localization and uptake of fluorescently labelled gold nanoparticles by a T47D human breast cancer cell line

Finding new cancer treatments based on novel drug delivery approaches is critically important.Gold nanoparticles (AuNPs) for use in drug delivery and cellular imaging were functionalized using a two-step synthesis method using modified carboxylic terminated alkane-thiols to attach fluorescent dyes (DAPI or pyNH) to the carboxylic ends of the thiolated AuNPs.The cellular cytotoxicity showed that the fluorescently labelled AuNPs were non-toxic at low concentrations.Confocal laser scanning microscopy (CLSM) showed an efficient internalization and uptake of AuNPs by T47D breast cancer cells within 1 hour of incubation.The fluorescence intensity increases over time for both conjugates.When conjugating DAPI with gold nanoparticles, the behaviour is quite different from free DAPI.TEM results showed the localization of AuNPs in the cytoplasm, the cell periphery and near the perinuclear region.The surface chemistry of AuNPs plays an important role in facilitating their cellular uptake as TEM images for conjugates containing DAPI show more AuNPs were internalized by the cells.These various forms of imaging give a clear insight into how these potential drug carriers interact with cells and are subsequently adsorbed into the cells.These are the core processes that will determine if the drug delivery approaches will ultimately be successful