Synthesis, characterization and application of plasmonic hollow gold nanoshells in a photothermal therapy-New particles for theranostics.

This article describes the work on synthesis, surface functionalization and characterization of hollow gold nanoshells (HGNs), and their application in a photothermal tumor therapy. The studied gold nanoshells were synthesized using a method based on a reduction of HAuCl4 onto silver nanoparticle templates. A selected aptamer - AS1411 - selective towards nucleolin, with a terminal thiol group was conjugated to HGNs. Surface functionalization of synthesized nanoparticles was necessary to gain the affinity to tumor cells, thus allowing the selective delivery of the modified nanoparticles to target cells. As expected, an increased selectivity of nanoconjugates towards tumor cells (A375) in a comparison to normal ones (HaCaT) was observed (2.67 times). In the framework of our studies the biological activity of the obtained nanoconjugates was evaluated using MTT assay. For this aim, both normal and tumor cell cultures respresenting skin tissue were exposed to gold nanoparticles solutions. It was found, that HGN-AS1411 conjugates cause less than 10% loss in a cell viability in the case of both cell lines at the highest tested concentration. The potential of the developed nanoconjugates as agents in PTT of skin cancer was investigated in a subsequent stage of our research. It was found, that A375 cell viability amounted to less than 40% for 75μM of nanoconjugates (expressed as a concentration of Au atoms) as a result of the laser irradiation of this cell culture after desired accumulation of the tested nanoconjugates inside A375 cells.