2025 AIChE Annual Meeting

(619c) Influence of Ratiometric Dosing on Intracellular Fluorescence of DNA-Swcnts

Authors

Daniel Roxbury, University of Rhode Island
It has been demonstrated that DNA-functionalized single-walled carbon nanotubes (DNA-SWCNTs) bind to cell surface receptors and are trafficked via the endosomal pathway into live cells. The time duration of this process varies depending on cell type and state. Preliminary findings suggest that dosing DNA-SWCNTs in vitro (i.e. into plated and cultured live cells) at a concentration of 1mg/L and incubated for 30 minutes has been shown to have minimal toxicity and adverse effects on cell viability and health. Here, we introduce a nanoparticle dosing parameter (NDP) in terms of concentration x time and propose to vary both concentration and time while maintaining a constant NDP (30 mg-minutes/L). By varying the concentration versus time ratio (i.e. NDP ratio) while keeping NDP constant, we investigate apparent brightness in terms of NIR fluorescence intensity per cell as well as absolute uptake, confirmed via hyperspectral NIR fluorescence and confocal Raman microscopies, respectively. We uncovered cell type-dependent NDP ratios for optimized cell internalization and bright NIR fluorescence while minimizing cytotoxicity from the exogenous nanomaterials. We envisioned that the results of this study can be extended to other types of nanoparticles as well as cell types. The inspiration behind ratiometric dosing lies in the well performing 1mg/L for 30 minutes standard. If the concentration and incubation times are scaled while maintaining the ratio, what impacts are had on fluorescence intensity, retention, and cell health and viability. We anticipated that stronger concentrations with short incubation times will have a rapid uptake of SWCNTs but low retention over time while lower concentrations with longer incubation times will have a greater long-term retention with a more heterogeneous distribution of internalized SWCNTs. Additionally, how do those changes hold true across cell types. We also expect to see the intrinsic traits of cells, such as phagocytic vs non phagocytic or cancerous vs noncancerous, will assist in highlighting considerations when determining a dosing strategy. Investigating this experimental setup can potentially describe themes of endosomal recycling, decreased cellular uptake specificity, and chirality dependent biosignaling.