In Vivo Assessment of Acute Toxicity and Immunotoxicity of Quantum Dots with Different Physicochemical Properties

Abstract

Fluorescent semiconductor nanocrystals called quantum dots (QDs) have gained attention in biomedical applications, including imaging, molecular tracking, and drug delivery, due to their unique optical properties. However, their use is limited because of safety issues. This study was aimed at assessment the acute toxicity of QDs with different core chemical compositions and surface charges in mice. In addition, the immunotoxicity of CdSe/ZnS QDs was estimated. CdSe/ZnS, PbS/CdS/ZnS, and CuInS2/ZnS QDs were synthesized and modified with PEG derivatives. The hydrodynamic diameters and surface charges of solubilized QDs were characterized. The QD acute toxicity has been shown to depend on both surface charge and core composition. The immunotoxicity of CdSe/ZnS-PEG-OH QDs in mice was assessed after a single intravenous administration of 0.2 LD100 of the QDs. The QDs have been found to increase the spleen weight and cause spleen, thymus, and bone marrow cell depletion. However, these changes are reversible. A transient increase in the levels of proinflammatory cytokines (MCP1 and IL-6) indicates an acute inflammatory response to a single low dose of QDs. Thus, systemic comparative analysis of QD toxicity has shown how the QD core composition and surface properties affect living organisms.

In Vivo Assessment of Hepatic and Kidney Toxicity Induced by Silicon Quantum Dots in Mice

“…The histopathological analysis indicated the most significant morphology changes in the kidney and liver tissues and immunopositivity for TNF-α 6 h after SiQDs administration, the degree of modification being dependent on the dose tested. Regarding the extent of inflammation over time, Gerasimovich et al [ 49 ] showed that the serum level of the majority of pro-inflammatory cytokines, including TNF, was similar to that of control 7 days after injection with CdSe/ZnS QDs, suggesting that the immune reaction to QDs is reversible. Hepatic impairments, such as disordered hepatic cords and enlarged central veins, were also detected after CdSe QDs administration [ 43 ], and apoptotic and necrotic cells with an increased level of TNF-α were previously shown after only 6 mg/kg of b.w.…”