Dark-Field Microscopic Study of Cellular Uptake of Carbon Nanodots: Nuclear Penetrability

Abstract

Carbon nanodots are fascinating candidates for the field of biomedicine, in applications such as bioimaging and drug delivery. However, the nuclear penetrability and process are rarely studied and lack understanding, which limits their applications for drug carriers, single-molecule detection and live cell imaging. In this study, we attempt to examine the uptake of CNDs in cells with a focus on the potential nuclear penetrability using enhanced dark-field microscopy (EDFM) associated with hyperspectral imaging (HSI) to quantitatively determine the light scattering signals of CNDs in the cells. The effects of both CND incubation time and concentration are investigated, and plausible nuclear penetration involving the nuclear pore complex (NPC) is discussed. The experimental results and an analytical model demonstrate that the CNDs’ uptake proceeds by a concentration-dependent three-stage behavior and saturates at a CND incubation concentration larger than 750 µg/mL, with a half-saturated concentration of 479 μg/mL. These findings would potentially help the development of CNDs’ utilization in drug carriers, live cell imaging and other biomedical applications.

Label-Free Light Scattering Imaging with Purified Brownian Motion Differentiates Small Extracellular Vesicles in Cell Microenvironments

“…Dark-field imaging reveals the positions of NPs and sEVs as bright spots within the cell microenvironment. In our results, the NPs are in the cell microenvironment, which agrees with those reported that the NPs appear as brighter spots in the cell microenvironment than the particles inside the cell Figure c,e shows the image processing results of the 120 nm NPs-cell dark-field light scattering image.…”

“…In our results, the NPs are in the cell microenvironment, which agrees with those reported that the NPs appear as brighter spots in the cell microenvironment than the particles inside the cell. 39 Figure 4h,i shows the cancerous liver cells with normal and cancerous (after 2 days of cell injection) plasma-derived sEVs using dark-field light scattering imaging, respectively. Label-Free Light Scattering Imaging Differentiates Normal and Cancerous Plasma-Derived sEVs in the Microenvironment of Cancerous Cells.…”

CARBON DOTS: Bioimaging and Anticancer Drug Delivery

“…M. Leblanc et al reported the penetration of the BBB and delivery of cargo to the central nervous system in animal models by CDs derived from glucose (GluCDs) without conjugation of the targeting ligand. [238][239][240] Efficacy Enhancement and Toxicity Reduction…”

Multifunctional Carbon Nanodot‐Based Advanced Diagnostics and Therapeutics

“…CNDs have demonstrated the ability to penetrate the cell nucleus. [58] Jung et al developed zwitterionic CNDs that could cross the negative plasma membrane by interacting with its positive charge, enter the cytosol, and diffuse into the cell nucleus by interacting with the nuclear membrane via a negative charge on CNDs. [96] Functionalizing the CND surface with folic acid or nuclear localization signal peptides facilitated localization in HeLa or SKOV3 cells overexpressing folate receptors [97] and accumulation in the nucleus, respectively.…”

“…CNDs have demonstrated the ability to penetrate the cell nucleus. [ 58 ] Jung et al. developed zwitterionic CNDs that could cross the negative plasma membrane by interacting with its positive charge, enter the cytosol, and diffuse into the cell nucleus by interacting with the nuclear membrane via a negative charge on CNDs.…”