Nanoparticles for Bioapplications: Study of the Cytotoxicity of Water Dispersible CdSe(S) and CdSe(S)/ZnO Quantum Dots

Abstract

Semiconductor nanocrystals or quantum dots (QDs) have unique optical and physical properties that make them potential imaging tools in biological and medical applications. However, concerns over the aqueous dispersivity, toxicity to cells, and stability in biological environments may limit the use of QDs in such applications. Here, we report an investigation into the cytotoxicity of aqueously dispersed CdSe(S) and CdSe(S)/ZnO core/shell QDs in the presence of human colorectal carcinoma cells (HCT-116) and a human skin fibroblast cell line (WS1). The cytotoxicity of the precursor solutions used in the synthesis of the CdSe(S) QDs was also determined in the presence of HCT-116 cells. CdSe(S) QDs were found to have a low toxicity at concentrations up to 100 µg/mL, with a decreased cell viability at higher concentrations, indicating a highly dose-dependent response. Meanwhile, CdSe(S)/ZnO core/shell QDs exhibited lower toxicity than uncoated QDs at higher concentrations. Confocal microscopy images of HCT-116 cells after incubation with CdSe(S) and CdSe(S)/ZnO QDs showed that the cells were stable in aqueous concentrations of 100 µg of QDs per mL, with no sign of cell necrosis, confirming the cytotoxicity data.

Research advance on cell imaging and cytotoxicity of different types of quantum Dots

“…Although shell greatly reduces ion release, QDs can continue to release ions in the acidic environment of lysosomes, leading to severe oxidative stress and increased apoptosis rate (Brunetti et al, 2013). Moreover, as a recent report by Mirnajafizadeh et al, the preparation of ZnS shell will introduce a new toxic ion of acetate contributing to other portions of cytotoxicity (Mirnajafizadeh, Ramsey, McAlpine, Wang, & Stride, 2019). Therefore, preparation conditions greatly affect the release of ions and subsequently affect toxicity (Murase, Horie, Sawai, & Kawasaki, 2019).…”

<p>A Lysosome-Targetable Fluorescence Probe Based on L-Cysteine-Polyamine-Morpholine-Modified Quantum Dots for Imaging in Living Cells</p>

“…[14][15][16][17][18] In addition, the cytotoxicity of QDs can be reduced and targeting of tumor cells can be enhanced through modification of QD surfaces using biomolecules. [19][20][21][22][23] Therefore, when interfaced with biological molecules including proteins, peptides, carbohydrates or DNA, the resulting QD-biocomposites have widespread applicability in areas ranging from cellular fluorescence imaging to in vivo fluorescence imaging. [24][25][26][27][28][29][30] However, following surface modification of QDs, it is important to retain its fundamental properties, such as uniform dispersion and to ensure that functional groups remain available for biological applications.…”

MOF-Derived Porous Fe2O3 Nanoparticles Coupled with CdS Quantum Dots for Degradation of Bisphenol A under Visible Light Irradiation

“…Semiconductor quantum dots (QDs)—including CdS [ 7 , 8 ], CdSe [ 9 , 10 ], CdTe [ 11 , 12 ], C 3 N 4 [ 13 ], ZnO [ 14 ] and ZnSe [ 15 ]—have been coupled with photocatalysts to form heterostructures with improved photoactivity. For instance, Sun et al reported a CdS QDs-sensitized TiO 2 photocatalyst with outstanding NO photo-oxidation performance [ 16 ].…”