Silicon Quantum Dots and Their Impact on Different Human Cells

Silicon quantum dots (SiQDs) are interesting low-dimensional nanostructures whose unique optical and electronic properties can be exploited for imaging, biosensing, or drug delivery. SiQDs with a diameter of around 4nm co-doped with boron and phosphorus and evincing fluorescence and dispersibility in aqueous solutions were studied with respect to their impact on different human cells. The level of SiQD cytotoxicity in different types of human cells - osteoblasts, monocytes, macrophages, and mesenchymal stromal cells - was determined. Exposing the cells to increasing concentrations of quantum dots under different conditions and the subsequent evaluation of their cytotoxicity provided an overview of cell-specific reactions to identical doses. The results revealed the importance of cultivation conditions (e.g., the formation of a protein corona on nanoparticles originating from the media supplement) as well as the significant impact of cell type (the increased sensitivity of monocytes to quantum dots in comparison to other cell types).