The interaction between human blood neutrophil granulocytes and quantum dots

Low-dose cadmium telluride quantum dots trigger M1 polarization in macrophages through mTOR-mediated transcription factor EB activation

The increasing application of quantum dots (QDs) increases interactions with organisms. The inflammatory imbalance is a significant manifestation of immunotoxicity. Macrophages maintain inflammatory homeostasis. Using macrophages differentiated by phorbol 12-myristate 13-acetate-induced THP-1 cells as models, the study found that low-dose (5 μM) cadmium telluride QDs (CdTe-QDs) hindered monocyte-macrophage differentiation. CD11b is a surface marker of macrophage, and the addition of CdTe-QDs during induction resulted in a decrease in CD11b expression. Moreover, exposure of differentiated THP-1 macrophage (dTHP-1) to 5 μM CdTe-QDs led to the initiation of M1 polarization. This was indicated by the increased surface marker CD86 expression, along with elevated level of NF-κB and IL-1β proteins. The potential mechanisms are being explored. The transcription factor EB (TFEB) plays a significant role in immune regulation and serves as a crucial regulator of the autophagic lysosomal pathway. After exposed to CdTe-QDs, TFEB activation-mediated autophagy and M1 polarization were observed to occur simultaneously in dTHP-1. The mTOR signaling pathway contributed to TFEB activation induced by CdTe-QDs. However, mTOR-independent activation of TFEB failed to promote M1 polarization. These results suggest that mTOR-TFEB is an advantageous target to enhance the biocompatibility of CdTe-QDs.

Quantum Dot Imaging Agents: Haematopoietic Cell Interactions and Biocompatibility

Quantum dots (QDs) are semi-conducting nanoparticles that have been developed for a range of biological and non-biological functions. They can be tuned to multiple different emission wavelengths and can have significant benefits over other fluorescent systems. Many studies have utilised QDs with a cadmium-based core; however, these QDs have since been shown to have poor biological compatibility. Therefore, other QDs, such as indium phosphide QDs, have been developed. These QDs retain excellent fluorescent intensity and tunability but are thought to have elevated biological compatibility. Herein we discuss the applicability of a range of QDs to the cardiovascular system. Key disease states such as myocardial infarction and stroke are associated with cardiovascular disease (CVD), and there is an opportunity to improve clinical imaging to aide clinical outcomes for these disease states. QDs offer potential clinical benefits given their ability to perform multiple functions, such as carry an imaging agent, a therapy, and a targeting motif. Two key cell types associated with CVD are platelets and immune cells. Both cell types play key roles in establishing an inflammatory environment within CVD, and as such aid the formation of pathological thrombi. However, it is unclear at present how and with which cell types QDs interact, and if they potentially drive unwanted changes or activation of these cell types. Therefore, although QDs show great promise for boosting imaging capability, further work needs to be completed to fully understand their biological compatibility.

Impact of gold nanoparticles (AuNPs) in human neutrophils in vitro and in leukocytes attraction in vivo: A sex-based analysis

Some differences exist between the male and female immune systems. Despite this, a sex-based analysis is not frequently performed in most studies. Knowing that inflammation is a common undesired effect observed resulting from nanoparticle (NP) exposure, we investigate here how gold NPs with a primary size of 20 (AuNP20) and 70 nm (AuNP70) will alter the biology of polymorphonuclear neutrophil cells (PMNs) isolated from men and women as well as their potential pro-inflammatory effect in vivo in male and female mice. We found that AuNP20 significantly delay apoptosis only in PMN isolated from men. The production of interleukin (IL)- 8 by PMNs was increased by both AuNPs regardless of sex although significance was only observed in AuNP20-induced PMNs. Using the murine air pouch model of inflammation, AuNPs did not induce a neutrophilic infiltration regardless of sex. In conclusion, AuNPs could differently alter the biology of PMNs according to sex.

An update on the biological effects of quantum dots: From environmental fate to risk assessment based on multiple biological models

Quantum dots (QDs) are zero-dimension nanomaterials with excellent physical and chemical properties, which have been widely used in environmental science and biomedicine. Therefore, QDs are potential to cause toxicity to the environment and enter organisms through migration and bioenrichment effects. This review aims to provide a comprehensive and systematic analysis on the adverse effects of QDs in different organisms based on recently available data. Following PRISMA guidelines, this study searched PubMed database according to the pre-set keywords, and included 206 studies according to the inclusion and elimination criteria. CiteSpace software was firstly used to analyze the keywords of included literatures, search for breaking points of former studies, and summarize the classification, characterization and dosage of QDs. The environment fate of QDs in the ecosystems were then analyzed, followed with comprehensively summarized toxicity outcomes at individual, system, cell, subcellular and molecular levels. After migration and degradation in the environment, aquatic plants, bacteria, fungi as well as invertebrates and vertebrates have been found to be suffered from toxic effects caused by QDs. Aside from systemic effects, toxicity of intrinsic QDs targeting to specific organs, including respiratory system, cardiovascular system, hepatorenal system, nervous system and immune system were confirmed in multiple animal models. Moreover, QDs could be taken up by cells and disturb the organelles, which resulted in cellular inflammation and cell death, including autophagy, apoptosis, necrosis, pyroptosis and ferroptosis. Recently, several innovative technologies, like organoids have been applied in the risk assessment of QDs to promote the surgical interventions of preventing QDs' toxicity. This review not only aimed at updating the research progress on the biological effects of QDs from environmental fate to risk assessment, but also overcame the limitations of available reviews on basic toxicity of nanomaterials by interdisciplinarity and provided new insights for better applications of QDs.

Differences in bacteria nanomotion profiles and neutrophil nanomotion during phagocytosis

The main goal of this work is to highlight the connection between nanomotion and the metabolic activity of living cells. We therefore monitored the nanomotion of four different clinical strains of bacteria (prokaryotes) and the bacterial phagocytosis by neutrophil granulocytes (eukaryotes). All clinical strains of bacteria, regardless of their biochemical profile, showed pronounced fluctuations. Importantly, the nature of their nanomotions was different for the different strains. Flagellated bacteria (Escherichia coli, Proteus mirabilis) showed more pronounced movements than the non-flagellated forms (Staphylococcus aureus, Klebsiella pneumoniae). The unprimed neutrophil did not cause any difference in cantilever oscillations with control. However, in the process of phagocytosis of S. aureus (metabolically active state), a significant activation of neutrophil granulocytes was observed and cell nanomotions were maintained at a high level for up to 30 min of observation. These preliminary results indicate that nanomotion seems to be specific to different bacterial species and could be used to monitor, in a label free manner, basic cellular processes.

An overview of quantum dots-induced immunotoxicity and the underlying mechanisms

Quantum dots (QDs) have bright luminescence and excellent photostability. New synthesis techniques and strategies also enhance QDs properties for specific applications. With the continuous expansion of the applications, QDs-mediated immunotoxicity has become a major concern. The immune system has been confirmed to be an important target organ of QDs and is sensitive to QDs. Herein, review immunotoxic effects caused by QDs and the underlying mechanisms. Firstly, QDs exposure-induced modulation in immune cell maturation and differentiation is summarized, especially pre-exposed dendritic cells (DCs) and their regulatory roles in adaptive immunity. Cytokines are usually recognized as biomarkers of immunotoxicity, therefore, variation of cytokines mediated by QDs is also highlighted. Moreover, the activation of the complement system induced by QDs is discussed. Accumulated results have suggested that QDs disrupt the immune response by regulating intracellular oxidative stress (reactive oxygen species) levels, autophagy formation, and expressions of pro-inflammatory mediators. Furthermore, several signalling pathways play a key role in the disruption. Finally, some difficulties worthy of further consideration are proposed. Because there are still challenges in biomedical and clinical applications, this review hopes to provide information that could be useful in exploring the mechanisms associated with QD-induced immunotoxicity.

Effect of lentivirus-mediated CFTR overexpression on oxidative stress injury and inflammatory response in the lung tissue of COPD mouse model

We aimed to investigate the regulatory mechanism of lentivirus-mediated overexpression of cystic fibrosis transmembrane conductance regulator (CFTR) in oxidative stress injury and inflammatory response in the lung tissue of mouse model of chronic obstructive pulmonary disease (COPD). COPD mouse model induced by cigarette smoke was established and normal mice were used as control. The mice were assigned into a normal group (control), a model group (untreated), an oe-CFTR group (injection of lentivirus overexpressing CFTR), and an oe-NC group (negative control, injection of lentivirus expressing irrelevant sequences). Compared with the oe-NC group, the oe-CFTR group had higher CFTR expression and a better recovery of pulmonary function. CFTR overexpression could inhibit the pulmonary endothelial cell apoptosis, reduce the levels of glutathione (GSH), reactive oxygen species (ROS), and malondialdehyde (MDA) and increase the values of superoxide dismutase (SOD), GSH peroxidase (GSH-Px), and total antioxidant capacity (T-AOC). The overexpression also led to reductions in the white blood cell (WBC) count in alveolus pulmonis, the concentrations of C-reactive protein (CRP), interleukin (IL)-6, and tumor necrosis factor-α, and the protein expressions of NF-κB p65, ERK, JNK, p-EPK, and p-JNK related to MAPK/NF-κB p65 signaling pathway. In conclusion, CFTR overexpression can protect lung tissues from injuries caused by oxidative stress and inflammatory response in COPD mouse model. The mechanism behind this may be related to the suppression of MAPK/NF-κB p65 signaling pathway.

Serum Protein Corona Abolishes Changes in the Expression of Proinflammatory Genes Induced by Quantum Dots in Human Blood Mononuclear Cell

We studied changes in the transcription of genes encoding cytokines (TNF, IL-6, IL-10, and IL-32), cell activation markers (ICAM1, CD38, Fas, and FCGRIII), ROS production catalyst (NOX2), autophagy (Beclin 1, LC3B, and p62) and apoptosis (BAX, BCL2) regulators in peripheral blood mononuclear cells upon contact with quantum dots CdSe/ZnS-MPA and CdSe/CdSeZnS/ZnS-PTVP. Up-regulation of TNF, ICAM1, Fas, p62 mRNA and down-regulation of the FCGRIII and NOX2 mRNA in response to the presence of quantum dots were revealed. The formation of serum protein corona on the surface of quantum dots abolished this effect.

Conditioning adhesive contacts between the neutrophils and the endotheliocytes by Staphylococcus aureus

We have developed a model for evaluating the integral intercellular interactions in the "endotheliocyte-neutrophil" system and have shown the high variability of adhesion contacts in different donors associated with different expression profiles of neutrophils. Two methods (forсe spectroscopy-spectroscopy and scanning ion-conductance microscopy) showed a decrease in the rigidity of the membrane-cytoskeletal complex of neutrophils under the influence of Staphylococcus aureus 2879 M. Adding this strain to the "endotheliocyte-neutrophil" system caused a statistically significant decrease in the adhesion force and adhesion work, which indicates a change in the expression profile and physicochemical properties of membranes of both types of interacting cells (neutrophils and endotheliocytes).

Methods of Granulocyte Isolation from Human Blood and Labeling with Multimodal Superparamagnetic Iron Oxide Nanoparticles

This in vitro study aimed to find the best method of granulocyte isolation for subsequent labeling with multimodal nanoparticles (magnetic and fluorescent properties) to enable detection by optical and magnetic resonance imaging (MRI) techniques. The granulocytes were obtained from venous blood samples from 12 healthy volunteers. To achieve high purity and yield, four different methods of granulocyte isolation were evaluated. The isolated granulocytes were labeled with multimodal superparamagnetic iron oxide nanoparticles (M-SPIONs) coated with dextran, and the iron load was evaluated qualitatively and quantitatively by MRI, near-infrared fluorescence (NIRF) and inductively coupled plasma mass spectrometry (ICP-MS). The best method of granulocyte isolation was Percoll with Ficoll, which showed 95.92% purity and 94% viability. After labeling with M-SPIONs, the granulocytes showed 98.0% purity with a yield of 3.5 × 10⁶ cells/mL and more than 98.6% viability. The iron-loading value in the labeled granulocytes, as obtained by MRI, was 6.40 ± 0.18 pg/cell. Similar values were found with the ICP-MS and NIRF imaging techniques. Therefore, our study shows that it is possible to isolate granulocytes with high purity and yield and labeling with M-SPIONs provides a high internalized iron load and low toxicity to cells. Therefore, these M-SPION-labeled granulocytes could be a promising candidate for future use in inflammation/infection detection by optical and MRI techniques.

Differences between Neutrophilic Granulocytes and Lymphocytes in Fixation of Quantum Dots of Different Composition

Studies by flow cytometry, scanning electron microscopy, and X-ray microanalysis have shown that fixation/internalization of quantum dots differ in lymphocytes and neutrophilic granulocytes. Punctate fixation of quantum dots to cell surface is characteristic of lymphocytes, while phagocytosis with perinuclear location of quantum dot aggregations is characteristic of neutrophils. The presence of complex functional groups on the surface of quantum dots can inhibit significantly the fixation/internalization of quantum dots by blood cells.

Characteristics of quantum dots phagocytosis by neutrophil granulocytes

This article describes the main morphological and biochemical features of neutrophil granulocytes in the process of phagocytosis of two types of quantum dots (CdSe/ZnS-MPA and CdSe/CdSeZnS/ZnS-PTVP). This study is the first to observe the transfer of large aggregates of quantum dots through neutrophils. During this process the cells demonstrate high chemotactic activity. Furthermore, neutrophil pseudopodia underwent alterations during the early stages of phagocytosis. The findings demonstrated that the biochemical profile of neutrophils is practically identical after phagocytosis of both types of quantum dots, but differs significantly from neutrophil metabolism after bacterial phagocytosis.