Nanomaterials have gained a rapid increase in use in a variety of applications that pertain to many aspects of human life. The majority of these innovations are centered on medical applications and a range of industrial and environmental uses ranging from electronics to environmental remediation. Despite the advantages of NPs, the knowledge of their toxicological behavior and their interactions with the cellular machinery that determines cell fate is extremely limited. This review is an attempt to summarize and increase our understanding of the mechanistic basis of nanomaterial interactions with the cellular machinery that governs cell fate and activity. We review the mechanisms of NP-induced necrosis, apoptosis and autophagy and potential implications of these pathways in nanomaterial-induced outcomes. Abbreviations: Ag, silver; CdTe, cadmium telluride; CNTs, carbon nanotubes; EC, endothelial cell; GFP, green fluorescent protein; GO, graphene oxide; GSH, glutathione; HUVECs, human umbilical vein endothelial cells; NP, nanoparticle; PEI, polyethylenimine; PVP, polyvinylpyrrolidone; QD, quantum dot; ROS, reactive oxygen species; SiO2, silicon dioxide; SPIONs, superparamagnetic iron oxide nanoparticles; SWCNT, single-walled carbon nanotubes; TiO2, titanium dioxide; USPION, ultra-small super paramagnetic iron oxide; ZnO, zinc oxide.

https://www.tandfonline.com/doi/pdf/10.1080/15548627.2018.1509171

Necrotic, apoptotic and autophagic cell fates triggered by nanoparticles

Graphene, a two-dimensional carbon sheet with single-atom thickness, shows immense promise in several nanoscientific and nanotechnological applications, including in sensors, catalysis, and biomedicine. Although several studies have shown the cytotoxicity of graphene oxide in different cell types, there are no comprehensive studies on human embryonic kidney (HEK293) cells that include transcriptomic analysis and an in vitro investigation into the mechanisms of cytotoxicity following exposure to graphene oxide. Therefore, we exposed HEK293 cells to different concentrations of graphene oxide for 24 h and performed several cellular assays. Cell viability and proliferation assays revealed a significant dose-dependent cytotoxic effect on HEK293 cells. Cytotoxicity assays showed increased lactate dehydrogenase (LDH) leakage and reactive oxygen species (ROS) generation, and decreased levels of reduced glutathione (GSH) and increased level of oxidized glutathione indicative of oxidative stress. This detailed mechanistic approach showed that graphene oxide exposure elicits significant decreases in mitochondrial membrane potential and ATP synthesis, as well as in DNA damage and caspase 3 activity. Furthermore, our RNA-Seq analysis revealed that HEK293 cells exposed to graphene oxide significantly altered the expression of genes involved in multiple apoptosis-related biological pathways. Moreover, graphene oxide exposure perturbed the expression of key transcription factors, promoting these apoptosis-related pathways by regulating their downstream genes. Our analysis provides mechanistic insights into how exposure to graphene oxide induces changes in cellular responses and massive cell death in HEK293 cells. To our knowledge, this is the first study describing a combination of cellular responses and transcriptome in HEK293 cells exposed to graphene oxide nanoparticles, providing a foundation for understanding the molecular mechanisms of graphene oxide-induced cytotoxicity and for the development of new therapeutic strategies.

https://www.mdpi.com/2079-4991/9/7/969/pdf

Evaluation of Graphene Oxide Induced Cellular Toxicity and Transcriptome Analysis in Human Embryonic Kidney Cells.

An overview on nanoparticles used in biomedicine and their cytotoxicity

Quantum dots (QDs), as one of the emerging nanomaterials, have been widely studied by scientists due to their advantages and potential in bioimaging, especially cell imaging. Cadmium (Cd)-based QDs, which have the best photoluminescence property, have received widespread attention. However, due to the obvious toxicity problem of these QDs, their cell imaging application is hindered. Recently, the emergence of Cd-free-metal and metal-free QDs with lower toxicity makes people consider that Cd-based QDs may be substituted by these QDs. However, problems of these QDs in cytotoxicity also cannot be ignored. Some reports claimed that their prepared emerging QDs for cell imaging were low toxicity, but there still exist up-regulation of oxidative stress, inflammation, and apoptosis from other reports. And, up to now, few reports have separately summarized and discussed the issues of cell imaging and cytotoxicity of different types of QDs. Therefore, in this review, we classify QDs as following three types, Cd-based, Cd-free-metal and metal-free QDs, focus on the cell, the essential unit of life, discuss cell imaging application and cytotoxicity of QDs, and finally elucidate main mechanisms of cytotoxicity respectively. This review provides reference for the toxicity evaluation of QDs and highlights the potential cytotoxicity of Cd-free QDs.

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

PANI/PbS QD nanocomposite structure for visible light driven photocatalytic degradation of rhodamine 6G.

Colloidal quantum dots (CQD) have attracted considerable attention for biomedical diagnosis and imaging as well as biochemical analysis and stem cell tracking. In this study, quasi core/shell lead sulfide/reduced graphene oxide CQD with near infrared emission (1100 nm) were prepared for potential bioimaging applications. The nanocrystals had an average diameter of ~4 nm, a hydrodynamic size of ~8 nm, and a high quantum efficiency of 28%. Toxicity assay of the hybrid CQD in the cultured human mononuclear blood cells does not show cytotoxicity up to 200 µg/ml. At high concentrations, damage to mitochondrial activity and mitochondrial membrane potential (MMP) due to the formation of uncontrollable amounts of intracellular oxygen radicals (ROS) was observed. Cell membrane and Lysosome damage or a transition in mitochondrial permeability were also noticed. Understanding of cell-nanoparticle interaction at the molecular level is useful for the development of new fluorophores for biomedical imaging.

/pdf/biochemical-mechanisms-of-dose-dependent-cytotoxicity-and-3kubtwj4ud.pdf

Biochemical mechanisms of dose-dependent cytotoxicity and ROS-mediated apoptosis induced by lead sulfide/graphene oxide quantum dots for potential bioimaging applications.

Mohammad Taghi Hashemi

Papers

Biochemical mechanisms of dose-dependent cytotoxicity and ROS-mediated apoptosis induced by lead sulfide/graphene oxide quantum dots for potential bioimaging applications.

Influence of stoichiometry on the corrosion response of titanium oxide coatings produced by plasma electrolytic oxidation

Electron ptychography dose reduction using Moiré sampling on periodic structures.