A Multiparametric Evaluation of Quantum Dot Size and Surface-Grafted Peptide Density on Cellular Uptake and Cytotoxicity

Abstract

Despite the progress in nanotechnology for biomedical applications, great efforts are still employed in optimizing nanoparticle (NP) design parameters to improve functionality and minimize bio-nanotoxicity. In this study, we developed CdSe/CdS/ZnS core/shell/shell quantum dots (QDs) that are compact ligandcoated and surface-functionalized with an HIV-1-derived TAT cell-penetrating peptide (CPP) analog to improve both biocompatibility and cellular uptake. Multiparametric studies were performed in different mammalian and murine cell lines to compare the effects of varying QD size and number of surface CPPs on cellular uptake, viability, generation of reactive oxygen species, mitochondrial health, cell area, and autophagy. Our results showed that the number of cell-associated NPs and their respective toxicity is higher for the larger QDs. Meanwhile, increasing the number of surface CPPs also enhanced cellular uptake and induced cytotoxicity through the generation of mitoROS and autophagy. Thus, here we report the optimal size and surface CPP combinations for improved QD cellular uptake.

Quantum Dot-Conjugated SARS-CoV-2 Spike Pseudo-Virions Enable Tracking of Angiotensin Converting Enzyme 2 Binding and Endocytosis

“…The negative control cells treated with QD 608 -RBD alone and the positive control cells treated with Optimem I alone both had equal levels of ATP as reported by the ATPlite luminescence-based reading. These data support the idea that QDs used in this study were not cytotoxic, as previously reported, 33 nor was the RBD domain from SARS-CoV-2 itself.…”

The Use of Alternative Strategies for Enhanced Nanoparticle Delivery to Solid Tumors

“…As a result, in addition to the fact that even the smallest differences in NM physicochemical properties such as size, coatings, synthesis methods, structural defects, concentrations, exposure times, etc . may significantly affect the degree of cell–nano interactions and associated NM toxicity, research groups are employing different methodologies in attempt to evaluate NM toxicity in vitro , leading to discrepancies in published data and irreproducible results . NMs have also been shown to induce toxicity to different cell lines by a variety of mechanisms, either by ROS-mediated apoptosis ( via mitochondrial membrane potential disruption, DNA damage, or activation of MAPK and p53 signaling pathways), endoplasmic reticulum-mediated apoptosis, autophagy, or necrosis, rendering it even more difficult to understand the critical factors involved in their toxicity and to standardize assays, and calling for innovative solutions in the field of nanotoxicology …”

“…The HTS approach developed by Nel and colleagues is a powerful tool for the rapid kinetic analysis of cell–nano interactions, although it requires limited numbers of cells and parameters per analysis to sustain fast data acquisition . HCI, on the other hand, is able to conduct rapid multiparametric acquisitions and automated analyses of images consisting of thousands of cells per condition, generating large data sets that allow the quantitative comparison of the effects of even the smallest differences between NMs on their behavior in various cellular environments. ,, Cellular parameters evaluated using such techniques include viability, proliferation, oxidative stress, damage to cell membrane, mitochondria, lysosomes and DNA, autophagy, cell morphology and cytoskeletal rearrangements, endosomal network changes, among others. These large generated data sets can then be extensively analyzed using statistical tools such as in silico hazard ranking to understand their QSARs, based on which computational paradigms can be developed to predict the toxicological outcome of other NMs both in vitro and in vivo.…”

Bioluminescence-Based Energy Transfer Using Semiconductor Quantum Dots as Acceptors

“…However, this has to be tempered with first building a full understanding of QD toxicity in vivo. Although much work has been done to date on cellular toxicity of QDs [22,[64][65][66], it certainly does not provide the necessary detail needed for in vivo use nor a full appreciation of the cost-benefit analysis that will form the basis for approved use as determined by regulatory agencies.…”