Zn(II) released from zinc oxide nano/micro particles suppresses vasculogenesis in human endothelial colony-forming cells

Cutting-edge nanotechnology: unveiling the role of zinc oxide nanoparticles in combating deadly gastrointestinal tumors

Zinc oxide nanoparticles (ZnO-NPs) have gained significant attention in cancer therapy due to their unique physical and chemical properties, particularly in treating gastrointestinal (GI) cancers such as gastric, colorectal, and hepatocellular carcinoma. These nanoparticles generate reactive oxygen species (ROS) upon entering cancer cells, causing oxidative stress that leads to cellular damage, DNA fragmentation, and apoptosis. ZnO-NPs affect the expression of key proteins involved in apoptosis, including p53, Bax, and Bcl-2, which regulate cell cycle arrest and programmed cell death. Additionally, ZnO-NPs can reduce mitochondrial membrane potential, further enhancing apoptosis in cancer cells. Furthermore, ZnO-NPs inhibit cancer cell proliferation by interfering with cell cycle progression. They reduce levels of cyclins and cyclin-dependent kinases (CDKs), leading to cell cycle arrest. ZnO-NPs also exhibit anti-metastatic properties by inhibiting the migration and invasion of cancer cells through modulation of signaling pathways that affect cell adhesion and cytoskeletal dynamics. The efficacy of ZnO-NPs in overcoming chemotherapy resistance has been demonstrated by their ability to reduce the IC50 values of chemotherapeutic agents, making cancer cells more susceptible to drug-induced cell death. In this review, we summarize the mechanisms by which ZnO-NPs exert anticancer effects in GI cancers, focusing on apoptosis, cell cycle regulation, and metastasis inhibition, while also highlighting the current limitations in translating these findings into effective clinical treatments.

Effects of engineered nanomaterials on the cardiovascular system

With the explosive development of nanotechnology, engineered nanomaterials are currently being used in various industries, including food and medicine. Concern about the health effects of nanomaterials has been raised, and available research indicates that the relative surface area of nanomaterials seems to correlate with the severity of their toxicity. With regard to engineered nanomaterials, the scope of their acute and chronic toxicities and their mechanisms are not fully understood. Studies suggest that exposure to certain nanomaterials can generate reactive oxidant species and enhance permeability of the phagolysosomal membrane, which leads to inflammasome activation, causing oxidative stress and inflammation. Since the latter 2 are implicated in the development of cardiovascular diseases, such as hypertension and atherosclerosis, it can be presumed that exposure to engineered nanomaterials could significantly impact cardiovascular function. In this review, I raise issues that should be considered in the assessment of the effects of engineered nanomaterials on cardiovascular function, and evaluate their cardiovascular toxicity as described in various in vitro and/or in vivo toxicological studies and industrial investigations.

Ultrasonic Coating of Poly(D,L-lactic acid)/Poly(lactic-co-glycolic acid) Electrospun Fibers with ZnO Nanoparticles to Increase Angiogenesis in the CAM Assay

Critical-size bone defects necessitate bone void fillers that should be integrated well and be easily vascularized. One viable option is to use a biocompatible synthetic polymer and sonocoat it with zinc oxide (ZnO) nanoparticles (NPs). However, the ideal NP concentration and size must be assessed because a high dose of ZnO NPs may be toxic. Electrospun PDLLA/PLGA scaffolds were produced with different concentrations (0.5 or 1.0 s of sonocoating) and sizes of ZnO NPs (25 nm and 70 nm). They were characterized by SEM, EDX, ICP-OES, and the water contact angle. Vascularization and integration into the surrounding tissue were assessed with the CAM assay in the living chicken embryo. SEM, EDX, and ICP-OES confirmed the presence of ZnO NPs on polymer fibers. Sonocoated ZnO NPs lowered the WCA compared with the control. Smaller NPs were more pro-angiogenic exhibiting a higher vessel density than the larger NPs. At a lower concentration, less but larger vessels were visible in an environment with a lower cell density. Hence, the favored combination of smaller ZnO NPs at a lower concentration sonocoated on PDLLA/PLGA electrospun meshes leads to an advanced state of tissue integration and vascularization, providing a valuable synthetic bone graft to be used in clinics in the future.

Antihelminthic and antiangiogenic effects of zinc oxide nanoparticles on intestinal and muscular phases of trichinellosis

Trichinellosis is a worldwide zoonotic disease affecting a wide range of mammals, including humans. It has intestinal and muscular phases. The current work was done to experimentally evaluate the efficacy of zinc oxide nanoparticles (ZnO NPs) and their combination with albendazole on intestinal and muscular stages of Trichinella spiralis (T. spiralis) infection. We had five main groups of mice: Group 1, non-infected control; Group 2, infected control; Group 3, infected and treated with albendazole; Group 4, infected and treated with ZnO NPs; and Group 5, infected and treated with albendazole and ZnO NPs. Each group was divided into two subgroups (A for the intestinal phase and B for the muscular phase). Drug effects were evaluated by parasitological, histopathological, and biochemical studies, including oxidant/antioxidant analysis and vascular endothelial growth factor (VEGF) gene expression in muscle tissue by quantitative real-time PCR. ZnO NPs resulted in a significant reduction of both intestinal and muscular phases of T. spiralis. Their combination with albendazole resulted in the complete eradication of adult worms and the maximum reduction of larval deposition in muscle tissue. Additionally, the treatment showed improvement in T. spiralis-induced pathological changes and oxidative stress status. Moreover, a significant decrease in VEGF gene expression was detected in the treated groups when compared with the infected control. In conclusion, ZnO NPs presented an antihelminthic effect against both adult and larval stages of T. spiralis. In addition, it enhanced antioxidant status and suppressed angiogenesis in muscle.

Copper and Zinc Particles as Regulators of Cardiovascular System Function-A Review

Copper and zinc are micronutrients that play a crucial role in many cellular pathways, act as cofactors in enzymatic systems, and hence, modulate enzyme activity. The regulation of these elements in homeostasis is precisely controlled by various mechanisms. Superoxide dismutase (SOD) is an enzyme requiring both copper and zinc for proper functioning. Additionally, there is an interaction between the concentrations of copper and zinc. Dietary ingestion of large amounts of zinc augments intestinal absorption of this trace element, resulting in copper deficiency secondary to zinc excess. The presence of an overabundance of copper and zinc has a detrimental impact on the cardiovascular system; however, the impact on vascular contractility varies. Copper plays a role in the modulation of vascular remodeling in the cardiac tissue, and the phenomenon of cuproptosis has been linked to the pathogenesis of coronary artery disease. The presence of copper has an observable effect on the vasorelaxation mediated by nitric oxide. The maintenance of proper levels of zinc within an organism influences SOD and is essential in the pathogenesis of myocardial ischemia/reperfusion injury. Recently, the effects of metal nanoparticles have been investigated due to their unique characteristics. On the other hand, dietary introduction of metal nanoparticles may result in vascular dysfunction, oxidative stress, and cellular DNA damage. Copper and zinc intake affect cardiovascular function, but more research is needed.

Revealing the Role of Zinc Ions in Atherosclerosis Therapy via an Engineered Three-Dimensional Pathological Model

An incomplete understanding of the cellular functions and underlying mechanisms of zinc ions released from zinc-based stents in atherosclerosis (AS) therapy is one of the major obstacles to their clinical translation. The existing evaluation methodology using cell monolayers has limitations on accurate results due to the lack of vascular architectures and pathological features. Herein, the authors propose a 3D biomimetic AS model based on a multi-layer vascular structure comprising endothelial cells and smooth muscle cells with hyperlipidemic surroundings and inflammatory stimulations as AS-prone biochemical conditions to explore the biological functions of zinc ions in AS therapy. Concentration-dependent biphasic effects of zinc ions on cell growth are observed both in cell monolayers and 3D AS models. Nevertheless, the cells within 3D AS model exhibit more accurate biological assessments of the zinc ions, as evidenced by augmented pathological features and significantly higher half-maximal inhibitory concentration values against zinc ions. Based on such a developed 3D biomimetic AS model, the inhibitory effects on the deoxyribonucleic acid (DNA) synthesis, significantly influenced biological processes like cell motility, proliferation, and adhesion, and several potential bio-targets of zinc ions of cells are revealed.

Albalawi H, Darwish DBE, Sharaf EM. Inhibition Mechanism of Methicillin-Resistant Staphylococcus aureus by Zinc Oxide Nanorods via Suppresses Penicillin-Binding Protein 2a

Methicillin-resistant Staphylococcus aureus (MRSA) causes life-threatening infections. Zinc oxide is well known as an effective antibacterial drug against many bacterial strains. We investigated the performance of zinc oxide nanorods synthesized by Albmiun as a biotemplate as an antibacterial drug in this study; the fabrication of zinc oxide nanorods was synthesized by sol-gel methods. We performed physicochemical characterization of zinc oxide nanorods by physiochemical techniques such as FTIR spectroscopy, X-ray diffraction, and TEM and investigation of their antimicrobial toxicity efficiency by MIC, ATPase activity assay, anti-biofilm activity, and kill time assays, as well as the mecA, mecR1, blaR1, blaZ, and biofilm genes (ica A, ica D, and fnb A) by using a quantitative RT-PCR assay and the penicillin-binding protein 2a (PBP2a) level of MRSA by using a Western blot. The data confirmed the fabrication of rod-shaped zinc oxide nanorods with a diameter in the range of 50 nm, which emphasized the formation of zinc oxide nanoparticles with regular shapes. The results show that zinc oxide nanorods inhibited methicillin-resistant S. aureus effectively. The MIC value was 23 μg/mL. The time kill of ZnO-NRs against MRSA was achieved after 2 h of incubation at 4MIC (92 μg/mL) and after 3 h of incubation at 2MIC (46 μg/mL), respectively. The lowest concentration of zinc oxide nanorods with over 75% biofilm killing in all strains tested was 32 μg/mL. Also, we examined the influence of the zinc oxide nanorods on MRSA by analyzing mecA, mecR1, blaR1, and blaZ by using a quantitative RT-PCR assay. The data obtained revealed that the presence of 2× MIC (46 μg/mL) of ZnO-NRs reduced the transcriptional levels of blaZ, blaR1, mecA, and mecR1 by 3.4-fold, 3.6-fold, 4-fold, and 3.8-fold, respectively. Furthermore, the gene expression of biofilm encoding genes (ica A, ica B, ica D, and fnb A) was tested using quantitative real-time reverse transcriptase-polymerase chain reaction (rt-PCR). The results showed that the presence of 2× MIC (46 μg/mL) of ZnO-NRs reduced the transcriptional levels of ica A, ica B, ica D, and fnb A. Also, the PBP2a level was markedly reduced after treatment with ZnO-NRs.

Ultrastructural analysis of zinc oxide nanospheres enhances anti-tumor efficacy against Hepatoma

Zinc oxide nanomaterial is a potential material in the field of cancer therapy. In this study, zinc oxide nanospheres (ZnO-NS) were synthesized by Sol-gel method using yeast extract as a non-toxic bio-template and investigated their physicochemical properties through various techniques such as FTIR, XR, DLS, and TEM. Furthermore, free zinc ions released from the zinc oxide nanosphere suspended medium were evaluated by using the ICP-AS technique. Therefore, the cytotoxicity of ZnO nanospheres and released Zn ions on both HuH7 and Vero cells was studied using the MTT assay. The data demonstrated that the effectiveness of ZnO nanospheres on HuH7 was better than free Zn ions. Similarly, ZnO-Ns were significantly more toxic to HuH7 cell lines than Vero cells in a concentration-dependent manner. The cell cycle of ZnO-Ns against Huh7 and Vero cell lines was arrested at G2/M. Also, the apoptosis assay using Annexin-V/PI showed that apoptosis of HuH7 and Vero cell lines by ZnO nanospheres was concentration and time-dependent. Caspase 3 assay results showed that the apoptosis mechanism may be intrinsic and extrinsic pathways. The mechanism of apoptosis was determined by applying the RT-PCR technique. The results revealed significantly up-regulated Bax, P53, and Cytochrome C, while the Bcl2 results displayed significant down-regulation and the western blot data confirmed the RT-PCR data. There is oxidative stress of the ZnO nanospheres and free Zn+2 ions. Results indicated that the ZnO nanospheres and free Zn+2 ions induced oxidative stress through increasing reactive oxygen species (ROS) and lipid peroxidation. The morphology of the HuH7 cell line after exposure to ZnO nanospheres at different time intervals revealed the presence of the chromatin condensation of the nuclear periphery fragmentation. Interestingly, the appearance of canonical ultrastructure features of apoptotic morphology of Huh7, Furthermore, many vacuoles existed in the cytoplasm, the majority of which were lipid droplets, which were like foamy cells. Also, there are vesicles intact with membranes that are recognized as swollen mitochondria.

Zinc-doped calcium silicate additive accelerates early angiogenesis and bone regeneration of calcium phosphate cement by double bioactive ions stimulation and immunoregulation

Calcium phosphate cement (CPC), a popular injectable bone defect repairing material, has deficiencies in stimulating osteogenesis and angiogenesis. To overcome the weaknesses of CPC, zinc-doped calcium silicate (Zn-CS) which can release bioactive silicon (Si) and zinc (Zn) ions was introduced to CPC. The physicochemical and biological properties of CPC and its composites were evaluated. Firstly, the most effective addition content of calcium silicate (CaSiO₃, CS) in promoting the in vitro osteogenesis was first sorted out. On this basis, the most effective Zn doping content in CS for improving osteogenic differentiation of CPC-based composites was screened out. Finally, the immunoregulation of CS/CPC and Zn-CS/CPC in promoting angiogenesis and osteogenesis was studied. The results showed that the most effective incorporation content of CS was 10 wt%. Zn at a doping content of 30 mol% in CS (30Zn-CS) further enhanced the osteogenic capacity of CS/CPC and simultaneously maintained excellent proangiogenic activity. CS/CPC and 30Zn-CS/CPC promoted the recruitment of macrophages and enhanced M2 polarization while inhibiting M1 polarization, which was beneficial to the early vascularization as well as subsequent new bone formation. When implanted into the femoral condylar defects of rabbits, 30Zn-CS/CPC showed high in vivo materials degradation rate, angiogenesis and osteogenesis, due to the synergistic effects of Si and Zn on bio-stimulation and immunoregulation. This study shed light on the synergistic effects of Si and Zn on regulating the angiogenic, osteogenic, and immunoregulatory activity, and 30Zn-CS/CPC is expected to repair the lacunar bone defects effectively.

Food Additive Zinc Oxide Nanoparticles: Dissolution, Interaction, Fate, Cytotoxicity, and Oral Toxicity

Food additive zinc oxide (ZnO) nanoparticles (NPs) are widely used as a Zn supplement in the food and agriculture industries. However, ZnO NPs are directly added to complex food-matrices and orally taken through the gastrointestinal (GI) tract where diverse matrices are present. Hence, the dissolution properties, interactions with bio- or food-matrices, and the ionic/particle fates of ZnO NPs in foods and under physiological conditions can be critical factors to understand and predict the biological responses and oral toxicity of ZnO NPs. In this review, the solubility of ZnO NPs associated with their fate in foods and the GI fluids, the qualitative and quantitative determination on the interactions between ZnO NPs and bio- or food-matrices, the approaches for the fate determination of ZnO NPs, and the interaction effects on the cytotoxicity and oral toxicity of ZnO NPs are discussed. This information will be useful for a wide range of ZnO applications in the food industry at safe levels.

The High-Throughput In Vitro CometChip Assay for the Analysis of Metal Oxide Nanomaterial Induced DNA Damage

Metal oxide nanomaterials (MONMs) are among the most highly utilized classes of nanomaterials worldwide, though their potential to induce DNA damage in living organisms is known. High-throughput in vitro assays have the potential to greatly expedite analysis and understanding of MONM induced toxicity while minimizing the overall use of animals. In this study, the high-throughput CometChip assay was used to assess the in vitro genotoxic potential of pristine copper oxide (CuO), zinc oxide (ZnO), and titanium dioxide (TiO2) MONMs and microparticles (MPs), as well as five coated/surface-modified TiO2 NPs and zinc (II) chloride (ZnCl2) and copper (II) chloride (CuCl2) after 2–4 h of exposure. The CuO NPs, ZnO NPs and MPs, and ZnCl2 exposures induced dose- and time-dependent increases in DNA damage at both timepoints. TiO2 NPs surface coated with silica or silica–alumina and one pristine TiO2 NP of rutile crystal structure also induced subtle dose-dependent DNA damage. Concentration modelling at both post-exposure timepoints highlighted the contribution of the dissolved species to the response of ZnO, and the role of the nanoparticle fraction for CuO mediated genotoxicity, showing the differential impact that particle and dissolved fractions can have on genotoxicity induced by MONMs. The results imply that solubility alone may be insufficient to explain the biological behaviour of MONMs.

Functionalized zinc oxide microparticles for improving the antimicrobial effects of skin-care products and wound-care medicines

ZnO is an important component in skin-protection products and wound-care medicines. However, ZnO's antibacterial activity is moderate. We developed two types of ZnO microparticles loading with phthalocyanine-type photosensitizers (ZnO/PSs) introducing the photodynamic effects. These photosensitive ZnO microparticles exhibited long-term while moderate antimicrobial effects by continuously releasing Zn²⁺ ions. The antimicrobial efficacies were remarkably enhanced by triggering the photodynamic antimicrobial effects. Compared to the sole ZnO which showed non-measurable antimicrobial activity at a concentration of 10 mg/L, both ZnO/PSs demonstrated antimicrobial rates ranged 99%-99.99% against Escherichia coli, normal and drug-resistant Staphylococcus aureus. In a dorsal wound infection mouse model, treatment with ZnO/PSs significantly accelerated the wound recovery rates. ZnO/PSs promoted wound healing by a dual effect: 1) the release of Zn²⁺ ions from ZnO facilitating tissue remodeling; 2) the photodynamic effect efficiently eliminates pathogens avoiding infection. Notably, ZnO/PSs inherited the high biosafety of ZnO without causing noticeable toxicity against erythrocyte and endothelial cells. This study not only provides a highly safe and efficient antimicrobial ZnO material for skin cares and wound modulations, but also proposes a strategy to functionalize ZnO materials.

Investigation of Angiogenesis and Wound Healing Potential Mechanisms of Zinc Oxide Nanorods

The angiogenesis process is an essential issue in tissue engineering. Zinc oxide nanorods are biocompatible metals capable of generating reactive oxygen species (ROS) that respond to induced angiogenesis through various mechanisms; however, released Zn (II) ions suppress the angiogenesis process. In this study, we fabricated green ZnO nanorods using albumin eggshell as a bio-template and investigate its angiogenic potential through chorioallantoic membrane assay and excision wound healing assay. This study demonstrated that angiogenesis and wound healing processes depend on pro-angiogenic factors as VEGF expression due to ZnO nanorods' exiting. Angiogenesis induced via zinc oxide nanorods may develop sophisticated materials to apply in the wound healing field.

Zinc Oxide Nanoparticles Exhibit Favorable Properties to Promote Tissue Integration of Biomaterials

Due to the demographic change, medicine faces a growing demand for tissue engineering solutions and implants. Often, satisfying tissue regeneration is difficult to achieve especially when co-morbidities hamper the healing process. As a novel strategy, we propose the incorporation of zinc oxide nanoparticles (ZnO NPs) into biomaterials to improve tissue regeneration. Due to their wide range of biocompatibility and their antibacterial properties, ZnO NPs are already discussed for different medical applications. As there are versatile possibilities of modifying their form, size, and function, they are becoming increasingly attractive for tissue engineering. In our study, in addition to antibacterial effects of ZnO NPs, we show for the first time that ZnO NPs can foster the metabolic activity of fibroblasts as well as endothelial cells, both cell types being crucial for successful implant integration. With the gelatin sponge method performed on the chicken embryo’s chorioallantoic membrane (CAM), we furthermore confirmed the high biocompatibility of ZnO NPs. In summary, we found ZnO NPs to have very favorable properties for the modification of biomaterials. Here, incorporation of ZnO NPs could help to guide the tissue reaction and promote complication-free healing.

Investigating the Internalization and COVID-19 Antiviral Computational Analysis of Optimized Nanoscale Zinc Oxide

Global trials are grappling toward identifying prosperous remediation against the ever-emerging and re-emerging pathogenic respiratory viruses. Battling coronavirus, as a model respiratory virus, via repurposing existing therapeutic agents could be a welcome move. Motivated by its well-demonstrated curative use in herpes simplex and influenza viruses, utilization of the nanoscale zinc oxide (ZnO) would be an auspicious approach. In this direction, ZnO nanoparticles (NPs) were fabricated herein and relevant aspects related to the formulation such as optimization, structure, purity, and morphology were elucidated. In silico molecular docking was conducted to speculate the possible interaction between ZnO NPs and COVID-19 targets including the ACE2 receptor, COVID-19 RNA-dependent RNA polymerase, and main protease. The cellular internalization of ZnO NPs using human lung fibroblast cells was also assessed. Optimized hexagonal and spherical ZnO nanostructures of a crystallite size of 11.50 ± 0.71 nm and positive charge were attained. The pure and characteristic hexagonal wurtzite P63mc crystal structure was also observed. Interestingly, felicitous binding of ZnO NPs with the three tested COVID-19 targets, via hydrogen bond formation, was detected. Furthermore, an enhanced dose-dependent cellular uptake was demonstrated. The obtained results infer a rationale, awaiting validation from further biological and therapeutic studies.

The Anti-Breast Cancer Effects of Green-Synthesized Zinc Oxide Nanoparticles Using Carob Extracts

BACKGROUND

The use of nanoparticles synthesized by the green method to treat cancer is fairly recent. The aim of this study was to evaluate cytotoxicity, apoptotic and anti-angiogenic effects and the expression of involved genes, of Zinc Oxide Nanoparticles (ZnO-NPs) synthesized with Carob extracts on different human breast cancer cell lines.

METHODS

ZnO-NPs were synthesized using the extracts of Carob and characterized with various analytical techniques. The MCF-7 and MDA-MB231 cells were treated at different times and concentrations of ZnO-NPs. The cytotoxicity, apoptosis, and anti-angiogenic effects were examined using a series of cellular assays. Expression of apoptotic genes (Bax and Bcl2) and anti-angiogenic genes, Vascular Endothelial Growth Factor (VEGF) and its Receptor (VEGF-R) in cancer cells treated with ZnO-NPs were examined with Reverse Transcriptionquantitative Polymerase Chain Reaction (RT-qPCR). The anti-oxidant activities of ZnO-NPs were evaluated by ABTS and DPPH assay.

RESULTS

Exposure of cells to ZnO-NPs resulted in a dose-dependent loss of cell viability. The IC50 values at 24, 48, and 72 hours were 125, 62.5, and 31.2μg/ml, respectively (p<0.001). ZnO-NPs treated cells showed, in fluorescent microscopy, that ZnO-NPs are able to upregulate apoptosis and RT-qPCR revealed the upregulation of Bax (p<0.001) and downregulation of Bcl-2 (p<0.05). ZnO-NPs increased VEGF gene expression while decreasing VEGF-R (p<0.001). The anti-oxidant effects of ZnO-NPs were higher than the control group and were dose-dependent (p<0.001).

CONCLUSION

ZnO-NPs synthetized using Carob extract have the ability to eliminate breast cancer cells and inhibit angiogenesis, therefore, they could be used as an anticancer agent.

Functionalized Surface-Charged SiO2 Nanoparticles Induce Pro-Inflammatory Responses, but Are Not Lethal to Caco-2 Cells

Nanoparticles (NPs) are widely used in food, and analysis of their potential gastrointestinal toxicity is necessary. The present study was designed to determine the effects of silica dioxide (SiO₂), titanium dioxide (TiO₂), and zinc oxide (ZnO) NPs on cultured THP-1 monocyte-derived macrophages and human epithelial colorectal adenocarcinoma (Caco-2) cells. Exposure to ZnO NPs for 24 h increased the production of redox response species (ROS) and reduced cell viability in a dose-dependent manner in THP-1 macrophages and Caco-2 cells. Although TiO₂ and SiO₂ NPs induced oxidative stress, they showed no apparent cytotoxicity against both cell types. The effects of functionalized SiO₂ NPs on undifferentiated and differentiated Caco-2 cells were investigated using fluorescently labeled SiO₂ NPs with neutral, positive, or negative surface charge. Exposure of both types of cells to the three kinds of SiO₂ NPs significantly increased their interaction in a dose-dependent manner. The largest interaction with both types of cells was noted with exposure to more negatively surface-charged SiO₂ NPs. Exposure to either positively or negatively, but not neutrally, surface-charged SiO₂ NPs increased NO levels in differentiated Caco-2 cells. Exposure of differentiated Caco-2 cells to positively or negatively surface-charged SiO₂ NPs also upregulated interleukin-8 expression. We conclude that functionalized surface-charged SiO₂ NPs can induce pro-inflammatory responses but are noncytotoxic.

Alterations in ZnT1 expression and function lead to impaired intracellular zinc homeostasis in cancer

Zinc is vital for the structure and function of ~3000 human proteins and hence plays key physiological roles. Consequently, impaired zinc homeostasis is associated with various human diseases including cancer. Intracellular zinc levels are tightly regulated by two families of zinc transporters: ZIPs and ZnTs; ZIPs import zinc into the cytosol from the extracellular milieu, or from the lumen of organelles into the cytoplasm. In contrast, the vast majority of ZnTs compartmentalize zinc within organelles, whereas the ubiquitously expressed ZnT1 is the sole zinc exporter. Herein, we explored the hypothesis that qualitative and quantitative alterations in ZnT1 activity impair cellular zinc homeostasis in cancer. Towards this end, we first used bioinformatics to analyze inactivating mutations in ZIPs and ZNTs, catalogued in the COSMIC and gnomAD databases, representing tumor specimens and healthy population controls, respectively. ZnT1, ZnT10, ZIP8, and ZIP10 showed extremely high rates of loss of function mutations in cancer as compared to healthy controls. Analysis of the putative functional impact of missense mutations in ZnT1-ZnT10 and ZIP1-ZIP14, using homologous protein alignment and structural predictions, revealed that ZnT1 displays a markedly increased frequency of predicted functionally deleterious mutations in malignant tumors, as compared to a healthy population. Furthermore, examination of ZnT1 expression in 30 cancer types in the TCGA database revealed five tumor types with significant ZnT1 overexpression, which predicted dismal prognosis for cancer patient survival. Novel functional zinc transport assays, which allowed for the indirect measurement of cytosolic zinc levels, established that wild type ZnT1 overexpression results in low intracellular zinc levels. In contrast, overexpression of predicted deleterious ZnT1 missense mutations did not reduce intracellular zinc levels, validating eight missense mutations as loss of function (LoF) mutations. Thus, alterations in ZnT1 expression and LoF mutations in ZnT1 provide a molecular mechanism for impaired zinc homeostasis in cancer formation and/or progression.

Protein and lipid homeostasis altered in rat macrophages after exposure to metallic oxide nanoparticles

Metal oxide nanoparticles (NPs), such as ZnO, ZnFe₂O₄, and Fe₂O₃, are widely used in industry. However, little is known about the cellular pathways involved in their potential toxicity. Here, we particularly investigated the key molecular pathways that are switched on after exposure to sub-toxic doses of ZnO, ZnFe₂O₄, and Fe₂O₃ in the in vitro rat alveolar macrophages (NR8383). As in our model, the calculated IC₅₀ were respectively 16, 68, and more than 200 μg/mL for ZnO, ZnFe₂O₄, and Fe₂O₃; global gene and protein expression profiles were only analyzed after exposure to ZnO and ZnFe₂O₄ NPs. Using a rat genome microarray technology, we found that 985 and 1209 genes were significantly differentially expressed in NR8383 upon 4 h exposure to ¼ IC₅₀ of ZnO and ZnFe₂O₄ NPs, respectively. It is noteworthy that metallothioneins were overexpressed genes following exposure to both NPs. Moreover, Ingenuity Pathway Analysis revealed that the top canonical pathway disturbed in NR8383 exposed to ZnO and ZnFe₂O₄ NPs was eIF2 signaling involved in protein homeostasis. Quantitative mass spectrometry approach performed from both NR8383 cell extracts and culture supernatant indicated that 348 and 795 proteins were differentially expressed upon 24 h exposure to ¼ IC₅₀ of ZnO and ZnFe₂O₄ NPs, respectively. Bioinformatics analysis revealed that the top canonical pathways disturbed in NR8383 were involved in protein homeostasis and cholesterol biosynthesis for both exposure conditions. While VEGF signaling was specific to ZnO exposure, iron homeostasis signaling pathway was specific to ZnFe₂O₄ NPs. Overall, the study provides resource of transcriptional and proteomic markers of response to ZnO and ZnFe₂O₄ NP-induced toxicity through combined transcriptomics, proteomics, and bioinformatics approaches.

Green synthesis of zinc oxide nanoparticles and evaluation of anti-angiogenesis, anti-inflammatory and cytotoxicity properties

In this study, zinc oxide nanoparticles (ZnO-NPs) were synthesized using the extract of Hyssops officinalis L. via green method and confirmed by transmission electron microscopy, field emission scanning electron microscopy, X-ray powder diffraction and Fourier transforms infrared spectroscopy techniques. In the in vivo section, the anti-angiogenesis and antiinflammatory properties of the NPs were evaluated by the chorioallantoic membrane (CAM) assay and mouse paw edema test (induced by carrageenan), respectively. In the in vitro section, changes in the expression of angiogenesis genes (VEGF and VEGFR) and inflammatory genes (IL-1B and IL-10) were investigated by real-time quantitative polymerase chain reaction technique. In order to evaluate the cytotoxicity of ZnO-NPs, 3-5, 4-dimethylthiazol-2-yl) -5, 2-tetrazolium bromide (MTT) test was used on MDA-MB231 breast adenocarcinoma cell line. The results of the CAM assay showed that the ZnO-NPs significantly reduced the number and length of blood vessels, as well as the size and weight of the embryos. Evaluation of mouse paw edema showed that the NPs are able to decrease inflammation. Changes in the expression pattern of VEGF and VEGFR genes in MCF7 cells showed that the NPs have inhibitory effect on the expression of both genes. Expression levels of IL-10 and IL-1B genes also increased and decreased, respectively. The MTT test showed that the NP have the ability to decrease breast cancer cells. In conclusion, our results confirm that the ZnO-NPs synthesized by green method have promising anti-cancer properties.

Common Injuries and Repair Mechanisms in the Endothelial Lining

Objective:

Endothelial cells (ECs) are important metabolic and endocrinal organs which play a significant role in regulating vascular function. Vascular ECs, located between the blood and vascular tissues, can not only complete the metabolism of blood and interstitial fluid but also synthesize and secrete a variety of biologically active substances to maintain vascular tension and keep a normal flow of blood and long-term patency. Therefore, this article presents a systematic review of common injuries and healing mechanisms for the vascular endothelium.

Data Sources:

An extensive search in the PubMed database was undertaken, focusing on research published after 2003 with keywords including endothelium, vascular, wounds and injuries, and wound healing.

Study Selection:

Several types of articles, including original studies and literature reviews, were identified and reviewed to summarize common injury and repair processes of the endothelial lining.

Results:

Endothelial injury is closely related to the development of multiple cardiovascular and cerebrovascular diseases. However, the mechanism of vascular endothelial injury is not fully understood. Numerous studies have shown that the mechanisms of EC injury mainly involve inflammatory reactions, physical stimulation, chemical poisons, concurrency of related diseases, and molecular changes. Endothelial progenitor cells play an important role during the process of endothelial repair after such injuries. What's more, a variety of restorative cells, changes in cytokines and molecules, chemical drugs, certain RNAs, regulation of blood pressure, and physical fitness training protect the endothelial lining by reducing the inducing factors, inhibiting inflammation and oxidative stress reactions, and delaying endothelial caducity.

Conclusions:

ECs are always in the process of being damaged. Several therapeutic targets and drugs were seeked to protect the endothelium and promote repair.

Exposure to ZnO nanoparticles alters neuronal and vascular development in zebrafish: Acute and transgenerational effects mitigated with dissolved organic matter

Exposure to ZnO-nanoparticles (NPs) in embryonic zebrafish reduces hatching rates which can be mitigated with dissolved organic material (DOM). Although hatching rate can be a reliable indicator of toxicity and DOM mitigation potential, a fish that has been exposed to ZnO-NPs or any other toxicant may also exhibit other abnormal phenotypes not readily detected by the unaided eye. In this study, we moved beyond hatching rate analysis to investigate the consequences of ZnO-NPs exposure on the nervous and vascular systems in developing zebrafish. Zebrafish exposed to ZnO-NPs (1-100 ppm) exhibited an array of cellular phenotypes including: abnormal secondary motoneuron (SMN) axonal projections, abnormal dorsal root ganglion development and abnormal blood vessel development. Dissolved Zn (<10 kDa) exposure also caused abnormal SMN axonal projections, but to a lesser extent than ZnO-NPs. The ZnO-NPs-induced abnormal phenotypes were reversed in embryos concurrently exposed with various types of DOM. In these acute mitigation exposure experiments, humic acid and carbohydrate, along with natural organic matter obtained from the Suwannee River in Georgia and Milwaukee River in Wisconsin, were the best mitigators of ZnO-NPs-induced motoneuron toxicity at 96 h post fertilization. Further experiments were performed to determine if the ZnO-NPs-induced, abnormal axonal phenotypes and the DOM mitigated axonal phenotypes could persist across generations. Abnormal SMN axon phenotypes caused by ZnO-NPs-exposure were detected in F1 and F2 generations. These are fish that have not been directly exposed to ZnO-NPs. Fish mitigated with DOM during the acute exposure (F0 generation) had a reduction in abnormal motoneuron axon errors in larvae of subsequent generations. Therefore, ZnO-NPs exposure results in neurotoxicity in developing zebrafish which can persist from one generation to the next. Mitigation with DOM can reverse the abnormal phenotypes in an acute embryonic exposure context, as well as across generations, resulting in healthy fish.

Synthesis, characterization, and pharmacological evaluation of zinc oxide nanoparticles formulation

Zinc oxide nanoparticles (ZnONPs) are being used extensively in manufacturing skin lotions and food products and in various biological and pharmaceutical industries because of their immunomodulatory and antimicrobial properties. In this study, ZnONPs were synthesized by a precipitation method and characterized by X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy to investigate their structural, morphological, and optical properties. For in vivo evaluation, 40 healthy albino mice were randomly allocated to four equal groups among which the first one was the control group, while the second, third, and fourth were treated with carbon tetrachloride (CCl₄), a blend of CCl₄ and ZnONPs, and ZnONPs alone, respectively, for 21 days. The XRD analysis confirmed hexagonal wurtzite type structures having an average crystallite size of 41.54 nm. The morphology of ZnONPs analyzed through SEM showed uniform distribution of the grains and shape of the synthesized oxide. The energy band gap of the ZnONPs was found to be 3.498 eV. Hepatic and renal damage following CCl₄ administration was apparent after 14 days and was increased at the 21st day, showing nodular fibrotic masses in the liver and bumpy surfaces in the kidney as observed by gross and histological examination. Coadministration of ZnONPs (15 mg/kg b.w. intragastrically 5 days a week) significantly prevented the CCl₄-dependent increases in alanine transaminase, aspartate transaminase, creatinine, and urea levels, suggesting a protective potential of ZnONPs.

The most important inferences from the Ekaterinburg nanotoxicology team's animal experiments assessing adverse health effects of metallic and metal oxide nanoparticles

During 2009-2017 we have studied nanoparticles of elemental silver or gold and of iron, copper, nickel, manganese, lead, zinc, aluminium and titanium oxides (Me-NPs) using, in most cases, a single low-dose intratracheal instillation 24 h before the bronchoalveolar lavage to obtain a fluid for cytological and biochemical assessment and, in all cases, repeated intraperitoneal injections in non-lethal doses to induce subchronic intoxications assessed by a lot of toxicodynamic and toxicokinetic features. We have also studied the same effects for a number of relevant combinations of these Me-NPs and have revealed some important patterns of their combined toxicity. Besides, we have carried out long-term inhalation experiments with Fe2O3, NiO and amorphous SiO2 nano-aerosols. We have demonstrated that Me-NPs are much more noxious as compared with their fine micrometric counterparts although the physiological mechanisms of their elimination from the lungs proved to be highly active. Even if water-insoluble, Me-NPs are significantly solubilized in some biological milieus in vitro and in vivo, which may explain some important peculiarities of their toxicity. At the same time, the in situ cytotoxicity, organ-systemic toxicity and in vivo genotoxicity of Me-NPs strongly depends on specific mechanisms characteristic of a particular metal. For some of the Me-NPs studied, we have proposed standards of presumably safe concentrations in workplace air. Along with this, we have proved that the adverse effects of Me-NPs could be significantly alleviated by background or preliminary administration of adequately composed combinations of some bioprotectors.

Zinc and Skin Disorders

The skin is the third most zinc (Zn)-abundant tissue in the body. The skin consists of the epidermis, dermis, and subcutaneous tissue, and each fraction is composed of various types of cells. Firstly, we review the physiological functions of Zn and Zn transporters in these cells. Several human disorders accompanied with skin manifestations are caused by mutations or dysregulation in Zn transporters; acrodermatitis enteropathica (Zrt-, Irt-like protein (ZIP)4 in the intestinal epithelium and possibly epidermal basal keratinocytes), the spondylocheiro dysplastic form of Ehlers-Danlos syndrome (ZIP13 in the dermal fibroblasts), transient neonatal Zn deficiency (Zn transporter (ZnT)2 in the secretory vesicles of mammary glands), and epidermodysplasia verruciformis (ZnT1 in the epidermal keratinocytes). Additionally, acquired Zn deficiency is deeply involved in the development of some diseases related to nutritional deficiencies (acquired acrodermatitis enteropathica, necrolytic migratory erythema, pellagra, and biotin deficiency), alopecia, and delayed wound healing. Therefore, it is important to associate the existence of mutations or dysregulation in Zn transporters and Zn deficiency with skin manifestations.

Comparative Numerical Study of Titanium and Silver Nano-particles Migration from Nano-composite of Polystyrene into Simulants on Experimental Data Basis

Nano-titanium dioxide and nano-silver combined with polystyrene granules to form a nano-composite film. Migration assess were performed by using food simulants 3% acetic acid (indicative acidic food) and 95% ethanol (indicative fatty food) at 40°C on different times of  2, 4, 6, 8 and 10 days. It was found that nanoparticle migration rate in acidic food was higher than fatty food. Diffusion coefficients of nanoparticles into simulants were estimated by inverse simulation of the migration process using finite-element method and experimental data of varied concentration. Simulation revealed an acceptable consistency between experimental data and predicted values. The numerical results indicated that the greatest diffusion coefficient was obtained by nano-titanium (2.8E-10 to 4.1E-9 m2s−1) in the 3% acetic acid. Results of concentration distribution confirmed a higher release rate and more uniformed distribution of nanoparticles for nano-titanium in the 3% acetic acid. It also found that in the migration process the diffusion coefficient is more important than the amount of nanoparticles concentration.

Single- and double-walled carbon nanotubes enhance atherosclerogenesis by promoting monocyte adhesion to endothelial cells and endothelial progenitor cell dysfunction

BACKGROUND

The use of carbon nanotubes has increased lately. However, the cardiovascular effect of exposure to carbon nanotubes remains elusive. The present study investigated the effects of pulmonary exposure to single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) on atherosclerogenesis using normal human aortic endothelial cells (HAECs) and apolipoprotein E-deficient (ApoE^-/-) mice, a model of human atherosclerosis.

METHODS

HAECs were cultured and exposed to SWCNTs or DWCNTs for 16 h. ApoE^-/- mice were exposed to SWCNTs or DWCNTs (10 or 40 μg/mouse) once every other week for 10 weeks by pharyngeal aspiration.

RESULTS

Exposure to CNTs increased the expression level of adhesion molecule (ICAM-1) and enhanced THP-1 monocyte adhesion to HAECs. ApoE^-/- mice exposed to CNTs showed increased plaque area in the aorta by oil red O staining and up-regulation of ICAM-1 expression in the aorta, compared with vehicle-treated ApoE^-/- mice. Endothelial progenitor cells (EPCs) are mobilized from the bone marrow into the circulation and subsequently migrate to the site of endothelial damage and repair. Exposure of ApoE^-/- mice to high-dose SWCNTs or DWCNTs reduced the colony-forming units of EPCs in the bone marrow and diminished their migration function.

CONCLUSION

The results suggested that SWCNTs and DWCNTs enhanced atherosclerogenesis by promoting monocyte adhesion to endothelial cells and inducing EPC dysfunction.

Titanium Dioxide Particle Type and Concentration Influence the Inflammatory Response in Caco-2 Cells

Titanium dioxide (TiO₂) nanoparticles are widely used in cosmetics, sunscreens, biomedicine, and food products. When used as a food additive, TiO₂ nanoparticles are used in significant amounts as white food-coloring agents. However, the effects of TiO₂ nanoparticles on the gastrointestinal tract remain unclear. The present study was designed to determine the effects of five TiO₂ particles of different crystal structures and sizes in human epithelial colorectal adenocarcinoma (Caco-2) cells and THP-1 monocyte-derived macrophages. Twenty-four-hour exposure to anatase (primary particle size: 50 and 100 nm) and rutile (50 nm) TiO₂ particles reduced cellular viability in a dose-dependent manner in THP-1 macrophages, but in not Caco-2 cells. However, 72-h exposure of Caco-2 cells to anatase (50 nm) TiO₂ particles reduced cellular viability in a dose-dependent manner. The highest dose (50 µg/mL) of anatase (100 nm), rutile (50 nm), and P25 TiO₂ particles also reduced cellular viability in Caco-2 cells. The production of reactive oxygen species tended to increase in both types of cells, irrespective of the type of TiO₂ particle. Exposure of THP-1 macrophages to 50 µg/mL of anatase (50 nm) TiO₂ particles increased interleukin (IL)-1β expression level, and exposure of Caco-2 cells to 50 µg/mL of anatase (50 nm) TiO₂ particles also increased IL-8 expression. The results indicated that anatase TiO₂ nanoparticles induced inflammatory responses compared with other TiO₂ particles. Further studies are required to determine the in vivo relevance of these findings to avoid the hazards of ingested particles.