Au-thymine, thymidine and thymidine 5’-monophosphate nanoparticles: chemical characterisation and cellular uptake studies into U87 cancer cells

Gold nanoparticles were obtained by reduction of a tetrachloroaurate aqueous solution in the presence of a RGD-(GC)2 peptide as stabiliser. As comparison, the behaviour of the (GC)2 peptide has been studied. The (GC)2 and RGD-(GC)2 peptides were prepared ad hoc by Fmoc syntheses. The colloidal systems have been characterised by UV-visible, ATR-FTIR, mono and bidimensional NMR techniques and Confocal and TEM microscopies. The efficient cellular uptake of Au-RGD-(GC)2 and Au-(GC)2 stabilised gold particles into U87 cells (human glioblastoma cell), were investigated by confocal microscopy and compared with the behaviour of the (GC)2 capped gold nanoparticles. A quantitative determination of the uptaken nanoparticles have been carried out by measuring the pixel brightness of the images that highlighted the importance of the RGD termination of the peptide. A deep insight of the cellular uptake mechanism was investigated by TEM microscopy. Various important evidences indicated the selective uptake of RGD-(GC)2 gold nanoparticles into the nucleus.