Immunostimulating Activity of Gold-modified Nanodiamond Particles

The fight against infectious diseases includes two main components – immediate direct anti-infective action and stimulation of one's own immunity. In this study, we investigated the properties of diamond nanoparticles modified with gold. The use of such gold nanoparticles as indirect anti-infectious agents and immunostimulators has certain prospects. Gold hydrosols were synthesized by the reduction in an aqueous solution of gold (III) with sodium citrate (Na3Cit) under heating. Modification procedure of nanodiamond by gold requires incubation, a small sample of nanodiamond in a defined volume of a gold sol for about 24 hours in a dark place. We use human blood cells as test objects. The reaction of blastic transformation of lymphocytes was applied here as a test of biological actions of modified nanodiamond. Modified nanodiamond do not have a toxic influence on blood cells. Modified nanodiamond possesses stimulation effects on spontaneous proliferation of lymphocytes and does not significantly affect phytohemagglutinin-induced proliferation. Nanodiamond slightly increases phagocytosis parameters of neutrophil leucocytes. Thus, results showed that the nanodiamond modified by gold possesses immunostimulating activity, increases the phagocytic activity of neutrophilic leukocytes and stimulates lymphocytes in the spontaneous proliferation test. Gold-modified nanodiamond could be considered as a non-direct anti-infective agent through immune stimulation.