CdS Quantum Dots Obtained by “Green” Synthesis: Comparative Analysis of Toxicity and Effects on the Proliferative and Adhesive Activity of Human Cells

A novel alternative approach for extracellular synthesis of CdS quantum dots using Escherichia coli bacteria, the fungus Pleurotus ostreatus, and the plant Linaria maroccana as biological matrices was previously developed. The nanoparticles obtained had stable luminescent properties and diameters of 2–10 nm. This paper presents the results of MTT assay- and flow cytometry-based analysis of cytotoxic/cytostatic effects, proliferative activity, and the ability of the CdS quantum dots synthesized to adhere to HeLa cells (human cervical cancer), malignized human T- and B-lymphocytes, and tumor cells of the AGS line (stomach cancer). The toxicity of the CdS quantum dots obtained by the “green” synthesis method was lower than that of inorganic cadmium sulfide, and this makes the quantum dots attractive candidates for a new type of nontoxic luminescent probes for bioimaging in cytological studies.