In vitro study of cytotoxicity of cadmium sulfide quantum dots in aqueous solutions

Abstract

Over the last decades, significant progress in the development of methods for obtaining and applying quantum dots (QDs) in various fields of biology, medicine and technology has been made. As a result, a detailed study of their toxic effect on living organisms and cells is becoming crucial. Physicochemical interaction takes place between the surface of biological component and surface of NPs. This “bio–nano” interaction depends on concentration, size, charge, shape of NPs and cells culture properties. In the present work, early cytopathic changes in fibroblast cells and HeLa cells were studied during conjugation with colloidal solutions of CdS QDs. To meet modern requirements of green chemistry, QDs were obtained by using a simple synthesis method, in an aqueous solution, without the use of high-temperature. To obtain trustworthy results, MTT test, NCR method and vital staining with trypan blue were used. The results of these methods were compared. All precursors of CdS QDs solutions affected the vital activity of cells, but the mechanisms of influence and early pathological changes in cells were different. It was shown that additional removing residues of unreacted precursors from solutions after synthesis reduce cytotoxicity index (IC) from moderate to low. Simultaneous use of several in vitro methods allows one to observe early pathological changes in cells before the onset of cytopathic effect (CPE) and to obtain the most complete information about possible CPE of new functional materials.