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The growing resistance of bacteria to antibiotics has posed challenges in treating associated bacterial infections, while the development of multi-model antibacterial strategies could efficient sterilization to prevent drug resistance. High-entropy MXene has emerged as a promising candidate for antibacterial synergy with inherent photothermal and photodynamic properties. Herein, a high-entropy nanomaterial of MXene/CDs was synthesized to amplify oxidative stress under near-infrared laser irradiation. Well-exfoliated MXene nanosheets have proven to show an excellent photothermal effect for sterilization. The incorporation of CDs could provide photo-generated electrons for MXene nanosheets to generate ROS, meanwhile reducing the recombination of electron-hole pairs to further accelerate the generation of photo-generated electrons. The MXene/CDs material demonstrates outstanding synergistic photothermal and photodynamic effects, possesses excellent biocompatibility and successfully eliminates drug-resistant bacteria as well as inhibits biofilm formation. While attaining a remarkable killing efficiency of up to 99.99% against drug-resistant Escherichia coli and Staphylococcus aureus, it also demonstrates outstanding antibacterial effects against four additional bacterial strains. This work not only establishes a synthesis precedent for preparing high-entropy MXene materials with CDs but also provides a potential approach for addressing the issue of drug-resistant bacterial infections., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

β-Lactum antibiotics are broad class of antibiotics which kills bacteria by inhibiting the formation of peptidoglycan that constitutes the bacterial cell wall. The resistance that develops in bacteria for antibiotics led the scientific world to think about the future aspects for modifying the way through which antibiotics are acted on the bacteria and become lethal for them. In this consequence, the potential of latest marketed antibiotics e.g. Amoxiciline (I), ceftazidim (II) have been evaluated after being conjugated with quantum dots. The surface of quantum dots has been conjugated with antibiotics by carbodiimide coupling with the help of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as conjugating agent between antibiotic and functionalized quantum dots. The antibacterial properties of QD-conjugated antibiotics have been determined by disc diffusion assay. The potency of QD-conjugated antibiotics has been estimated by determining their MIC 50 for the selected strain of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Minimum inhibitory concentration study, minimum bactericidal concentration and growth pattern analysis revealed that QD-antibiotic conjugates showed slightly more prospective than pure native antibiotics against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Semiconductor nanoparticles generate photoelectrons and photo-induced holes under light excitation, and thus may influence the growth of microbial cells. The highly oxidative holes may severely damage the cells, while the photoelectrons may promote microbial metabolism. In this study, we evaluated the effect of exogenous cadmium sulfide (CdS) nanoparticles on bacterial growth using OD 600 and colony forming unit (CFU) as indicators. The oxidase activities, the concentration of pyruvate and malondialdehyde, and the expression of relevant genes assessed by real-time fluorescent quantitative PCR were analyzed to investigate the effect of excited CdS on cellular metabolism. The results showed that the OD 600 and pyruvate accumulation of E . coli increased by 32.4% and 34.6%, respectively, under light conditions. Moreover, the relative expression level of the division protein gene ftsZ was increased more than 50%, and the tricarboxylic acid cycle pathway gene icdA and gltA increased by 86% and 103%, respectively. The results indicated that photoelectrons could be used by microorganisms, resulting in promoted growth and metabolism. This study gives a deep insight into the interaction between nanoparticles and bacteria.

In the present work, CdTe/ZnS high luminescence quantum dots (QDs) were synthesized by a facile, fast, one-pot, and room temperature photochemical method. Synthesized QDs were characterized by different structural and optical analyses such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR), Raman, photoluminescence (PL) and UV-visible (UV-vis) spectroscopies. The results confirmed the successful growth of the ZnS shell and formation of CdTe/ZnS core/shell structure. CdTe/ZnS prepared QDs indicated a PL quantum yield of about 51%. These high luminescence QDs were used for detection of Hg 2+ ions in aqueous media, as catalyst for photodegradation of different organic dyes, and as antibacterial material for the inhibition of bacterial growth. PL intensity of the CdTe/ZnS QDs was completely quenched after addition of 1 m molar Hg 2+ in to the media. Photocatalyst activity of CdTe/ZnS QDs was studied by rhodamine b, methylene blue, and methylene orange as organic dyes under both the sun and UV illuminations, and results showed that CdTe/ZnS QDs had the best photocatalyst activity for methylene blue degradation under UV irradiation and radical scavenger results indicated that electrons have a main role in photodegradation of methylene blue dye by CdTe/ZnS QDs under UV illumination. Antibacterial effects of CdTe/ZnS QDs evaluated by Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) methods against two strains of bacteria. The results of the antibacterial test showed that CdTe/ZnS could inhibit bacterial growth in Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative G) bacteria., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The biological applicability of nanomaterials has been limited due to cytotoxicity. Studies have described the effects of nanomaterials on different tissues and cell types, but their actions on immune cells are less elucidated. This study describes unprecedented in vitro and in vivo antioxidant activities of cadmium selenide magic-sized quantum dots (CdSe MSQDs) with implications on rheumatoid arthritis. While the generation of ROS induced by nanomaterials is linked to cytotoxicity, we found that CdSe MSQDs reduced ROS production by neutrophils and macrophages following opsonized-zymosan stimuli, and we did not find cytotoxic effects. Interestingly, inherent antioxidant properties of CdSe MSQDs were confirmed through DPPH, FRAP, and ORAC assays. Furthermore, CdSe MSQDs reduced ROS levels generated by infiltrating leukocytes into joints in experimental model of rheumatoid arthritis. Briefly, we describe a novel application of CdSe MSQDs in modulating the inflammatory response in experimental rheumatoid arthritis through an unexpected antioxidant activity., (Copyright © 2022 Elsevier Inc. All rights reserved.)

CdSe magic-sized quantum dots (MSQDs) have been widely used as fluorescent probes in biological systems due to their excellent optical properties with a broader fluorescence spectrum and stable luminescence in biological media. However, they can be cytotoxic and alter the redox balance depending on the amounts of Cd 2+ adsorbed on their surface. Thus, the present study aimed to evaluate whether increases in selenium concentration in the synthesis of CdSe-MSQDs decrease the oxidative stress caused by Cd 2+ -based quantum dots. CdSe-MSQDs synthesized with different concentrations of selenium were investigated against oxidative stress in the brain of chicken embryos by examining total antioxidant capacity, lipid peroxidation, thiol, and glutathione contents, as well as the activities of glutathione peroxidase, superoxide dismutase (SOD), catalase (CAT), and glutathione reductase. In addition, the vascularization of the chorioallantoic membrane (CAM) analysis was performed. Higher selenium concentrations alter the surface defect levels (decrease free Cd 2+ ) and controlled the oxidative effects of CdSe-MSQDs by reducing the lipid peroxidation, restoring the glutathione defense system and the antioxidant enzymes SOD and CAT, and maintaining the vascular density of the CAM. The current findings reinforce the study of the effects of the presence of Cd 2+ ions on the surface of quantum dots, changing toxicity, and aiming interesting strategies of nanomaterials in biological systems., (© 2021 Wiley Periodicals LLC.)

Ternary nanocomposites, including graphene oxide (GO), hydroxyapatite (HAP), and cadmium selenite (CdSe) have been encapsulated into nanofibrous scaffolds of polylactic acid. These compositions were indexed as HAP@PLA (C1), CdSe@PLA (C2), HAP/CdSe@PLA (C3), HAP/GO@PLA (C4), and HAP/CdSe/GO@PLA (C5). Structural confirmation is executed by XRD and XPS techniques, while FESEM performs morphological characteristics. CdSe and GO dopants cause a significant increase in nanofiber diameter, HAP/GO@PLA (C4), showing thin surface fibers with fiber diameter up to 3.1 μm, followed by HAP/CdSe/GO@PLA (C4) composite that belongs to filament size up to 2.1 μm. On the other hand, the mechanical properties reveal that the dual dopant composites HAP/CdSe@PLA (C3) and HAP/GO@PLA (C4) hit the maximum tensile fracture values with 1.49 ± 0.3 and 0.99 ± 0.2 MPa. Further, the ternary C5 composite represents the lowest contact angle of 86.1 ± 3.7°. The antibacterial activity increased from 32.4 ± 9.7 and 28.4 ± 6.5% to be 85.3 ± 4.6 and 88.1 ± 5.6% for C1 and C5, respectively, against both E. coli and S. aureus in dark conditions. Moreover, the antibacterial potency enhanced from 75.4 ± 7.6 to be 83.5 ± 6.5 from dark to light conditions against E. coli for the composition of PLA containing the binary composition of HAP/CdSe., (Copyright © 2021 Elsevier B.V. All rights reserved.)

To explore in vivo application of quantum dots (QDs), it is essential to understand the dynamics and energetics of interactions between QDs and proteins. Here, surface plasmon resonance (SPR) and molecular docking were employed to investigate the kinetics and thermodynamics of interactions between human serum albumin (HSA) and CdTe QDs (~3 nm) functionalized with mercaptopropionic acid (MPA) or thioglycolic acid (TGA). Kinetic analysis showed that HSA-QD interactions involved transition-complex formation. Despite the structural similarities between MPA and TGA, the [HSA-CdTe@TGA] ‡ formation by association of free HSA and QDs demanded 70% more energy and higher entropic gain (E a-TGA ‡ = 65.10 and T∆S a-TGA ‡ = 28.62 kJ mol -1 ) than the formation of [HSA-CdTe@MPA] ‡ (E a-MPA ‡  = 38.13 and T∆S a-MPA ‡  = 0.53kJ mol -1 ). While the [HSA-CdTe@MPA] ° dissociation required higher energy and lower entropy loss (E d-MPA ‡  = 49.96 and T∆S d-MPA ‡  = - 32.18kJ mol -1 ) than the [HSA-CdTe@TGA] ° dissociation (E d-TGA ‡ = 30.78 and T∆S d-TGA ‡ = - 51.12 kJ mol -1 ). The stability of [HSA-QDs] ° was independent of the temperature and functionalizing group. However, the enthalpic and entropic components were highly affected by the substitution of MPA (ΔH° = - 11.83 and TΔS° = 32.72 kJ mol -1 ) with TGA (ΔH° = 34.31 and TΔS° = 79.73 kJ mol -1 ). Furthermore, molecular docking results indicated that the metal site on the QDs contributes to the stabilization of [HSA-QDs] ° . Therefore, differences in QD functionalization and surface coverage densities can alter the HSA-QD interaction, thus their application., (Copyright © 2021. Published by Elsevier B.V.)

Aim: Fluorescent semiconductor nanoparticles or quantum dots (QDs) have excellent properties as photosensitizers in photodynamic therapy. This is mainly a consequence of their nanometric size and the generation of light-activated redox species. In previous works, we have reported the low-cost biomimetic synthesis of glutathione (GSH) capped QDs (CdTe-GSH QDs) with high biocompatibility. However, no studies have been performed to determine their phototoxic effect. The aim of this work was to characterize the light-induced toxicity of green (QDs 500 ) and red (QDs 600 ) QDs in Escherichia coli, and to study the molecular mechanism involved., Methods and Results: Photodegradation and reduction power of biomimetic QDs was determined to analyse their potential for radical generation. Escherichia coli cells were exposed to photoactivated QDs and viability was evaluated at different times. High toxicity was determined in E. coli cells exposed to photoactivated QDs, particularly QDs 500 . The molecular mechanism involved in QDs phototoxicity was studied by determining Cd 2+ -release and intracellular reactive oxygen species (ROS). Cells exposed to photoactivated QDs 500 presented high levels of ROS. Cells exposed to photoactivated QDs 500 presented high levels of ROS. Finally, to understand this phenomenon and the importance of oxidative and cadmium-stress in QDs-mediated phototoxicity, experiments were performed in E. coli mutants in ROS and Cd 2+ response genes. As expected, E. coli mutants in ROS response genes were more sensitive than the wt strain to photoactivated QDs, with a higher effect in green-QDs 500 . No increase in phototoxicity was observed in cadmium-related mutants., Conclusion: Obtained results indicate that light exposure increases the toxicity of biomimetic QDs on E. coli cells. The mechanism of bacterial phototoxicity of biomimetic CdTe-GSH QDs is mostly associated with ROS generation., Significance and Impact of the Study: The results presented establish biomimetic CdTe-GSH QDs as a promising cost-effective alternative against microbial infections, particularly QDs 500 ., (© 2020 The Society for Applied Microbiology.)

Incorporating artificial photosensitizers with microorganisms has recently been recognized as an effective way to convert light energy into chemical energy. However, the incorporated biosystem is usually constructed in an extracellular manner and is vulnerable to the external environment. Here, we develop an intracellular hybrid biosystem in a higher organism protozoa Tetrahymena pyriformis , in which the in vivo synthesized CdS nanoparticles trigger photoreduction of nitrobenzene into aniline under visible-light irradiation. Integrating a photosensitizer CdS into T. pyriformis enables the photosensitizer CdS, inherent nitroreductase, and the cytoplasmic reductive substance in T. pyriformis to synergistically engage in the photocatalysis process, generating a greatly enhanced aniline yield with a 40-fold increment. Moreover, building an intracellular hybrid biosystem in mutant T. pyriformis could even grant it new capability of reducing nitrobenzene into aniline under visible-light irradiation. Such an intracellular hybrid biosystem paves a new way to functionalize higher organisms and diversify light energy conversion.

Feeding cadmium (II) and selenium (IV) simultaneously to anaerobic granular sludge with the aim of synthesizing cadmium selenide (CdSe) nanoparticles induces compositional changes in the extracellular polymeric substances (EPS) matrix of this sludge. A methanogenic anaerobic granular sludge was repeatedly exposed to Cd(II) (10-50 mg L -1 ) and selenite (79 mg L -1 ) for 300 days at pH 7.3 and 30 °C in a fed-batch feeding regime for enrichment of Se-reducing bacteria and synthesis of CdSe nanoparticles. EPS fingerprints of the granular sludge, obtained by size exclusion chromatography coupled to a fluorescence detector, showed a significant increase in the intensity of protein-like substances with > 100 kDa apparent molecular weight (aMW) upon repeated exposure to Cd(II) and Se(VI). This was accompanied by a prominent decrease in protein-like substances of aMW < 10 kDa. The fingerprint of the humic-like substances showed emergence of a new peak with aMW of 13 to 300 kDa in the EPS extracted from the Cd/Se fed granular sludge. Experiments on metal(loid)-EPS interactions showed that the CdSe nanoparticles interact mainly with loosely bound EPS (LB-EPS). This study showed that the formation of Se(0) and CdSe nanoparticles occurs in the LB-EPS fraction of the granular sludge and repeated exposure to Cd and Se induces compositional changes in the EPS matrix.

N -Hydroxy- p -(4-arylbutanamido)benzamides (HABAB) belong to one class of histone deacetylase inhibitors (HDACi), which regulate deacetylation of lysine residue's amino group in histone, which results in chromatin constriction. In addition, transcriptional knockdown of the genetic loci possessing the suppressor genes of tumor occurs. A tripodal, HABAB-capped gallamide dendron possessing thiol anchoring unit was prepared by the click method. The resultant hydrophilic dendritic unit was easily attached on the outer layer of CdSe/ZnS (i.e., core/shell type) quantum dots by thiolate-Zn interaction, as supported via 1 H NMR spectroscopic analysis of the conjugate with its original property of fluorescence. The resulting, water-miscible nanohybrid (nano-HTPB) which bore trivalent, peripheral HABABs as the HDACi was efficiently taken up by cells of lung cancer and transported into the nuclei of cells in 3 h, as confirmed by confocal microscopy analysis. The concentration levels of 50% inhibition (IC 50 ) after 48 h incubation of the nano-HTPB for A549 and H1299 lung cancer cell lines were 14 and 18 nM, respectively, which were about 150-fold lower than those of the parent HTPB analogues. Nano-HTPB at 20 nM induced the knockdown of cell cycle at second growth/mitosis (i.e., G2/M) transition, which eventually led to apoptosis of lung cancer cells, demonstrating that the nano-HTPB was much more potent in inhibiting lung cancer cell growth in a synergistic manner than the parent HTPB analogues. In addition, the dendritic HABAB-capped nanohybrid, nano-HTPB, is more effective than the parent HTPB analogues both in vitro and in vivo. Furthermore, the nano-HTPB is more effective than the parent HTPB to increase the acetylation level of proteins related to histone and nonhistone like p53 and tubulin. Our results confirmed that covalent encapsulation of quantum dots with peripheral, triantennary HDACis represented a feasible strategy for synergistic drug delivery with enhanced biological effects.

Translational control is essential in response to stress. We investigated the translational programmes launched by the fission yeast Schizosaccharomyces pombe upon five environmental stresses. We also explored the contribution of defence pathways to these programmes: The Integrated Stress Response (ISR), which regulates translation initiation, and the stress-response MAPK pathway. We performed ribosome profiling of cells subjected to each stress, in wild type cells and in cells with the defence pathways inactivated. The transcription factor Fil1, a functional homologue of the yeast Gcn4 and the mammalian Atf4 proteins, was translationally upregulated and required for the response to most stresses. Moreover, many mRNAs encoding proteins required for ribosome biogenesis were translationally downregulated. Thus, several stresses trigger a universal translational response, including reduced ribosome production and a Fil1-mediated transcriptional programme. Surprisingly, ribosomes stalled on tryptophan codons upon oxidative stress, likely due to a decrease in charged tRNA-Tryptophan. Stalling caused ribosome accumulation upstream of tryptophan codons (ribosome queuing/collisions), demonstrating that stalled ribosomes affect translation elongation by other ribosomes. Consistently, tryptophan codon stalling led to reduced translation elongation and contributed to the ISR-mediated inhibition of initiation. We show that different stresses elicit common and specific translational responses, revealing a novel role in Tryptophan-tRNA availability., (© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research.)

A simple ultrasonic assisted chemical technique was used to synthesise cadmium oxide (CdO) nanoparticles (NPs) and CdO NPs/c-Multiwalled carbon nanotube (c-MWCNT) nanocomposite fibres.To confirm the physio-chemico properties and to analyse surface morphology of the obtained nanomaterials X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were performed. To evaluate the anti-cancer property of CdO NPs, c-MWCNT NPs and CdO NPs/c-MWCNT nanocomposite fibres, an anti-proliferative assay test (Methylthiazolyl diphenyl- tetrazolium bromide - MTT assay) were performed on HeLa cells which further estimated IC50 value (Least concentration of sample in which nearly 50% of cells remain alive) under in-vitro conditions. On comparison, CdONPs/c-MWCNT based system was found to be superior by achieving 52.3% cell viability with its minimal IC50 value of 31.2 μg/ml. Lastly, the CdO NPs based system was taken up for an apoptotic study using DNA fragmentation assay for estimating its ability to cleave the DNA of the HeLa cells into internucleosomal fragments using the agarose gel electrophoresis method. In conclusion, based on our observations, CdO NPs/c-MWCNT hybrid based system can be further used for the development of efficient drug delivery and therapeutic systems.

Quantum dots (QDs), such as cadmium selenide (CdSe) and lead selenide (PbSe) exhibit excellent optical, magnetic and chemical properties due to their extremely size (ca. 1-10 nm) and are attractive semiconductor nanomaterials for optical studies and energy storage. In this study, aqueous synthesis of CdSe and PbSe QDs in a size range of 2-10 nm was described. Synthesized QDs were characterized using SEM and TEM, DLS, zeta potential, FTIR, EDX and XRD. Highest accumulation (72.5 ± 5.8 mg L -1 ) of PbSe QDs occurred at 10 ppm suspensions. In general accumulation increased up to 48 h exposure then fluctuate tended to decline. For CdSe QDs, accumulation tended to decrease for 72 h exposure except that for 5 ppm groups. For the elimination period, in general, the elimination levels of PbSe and CdSe QDs from exposed individuals decreased (p < 0.05) even it has some fluctuate.

This paper deals with the effect of photobiomodulation (PBM) on Daphnia magna S. and their sensitivity to cadmium sulfate, a known high toxic pollutant. In a first series of experiments, the effect of different He-Ne laser fluences irradiation (range 0.9-4300 mJ cm -2 ) on the fertility of both parent and filial generations (F1-F3) of the crustacean was studied. It was found that PBM in some cases significantly influenced the fertility of both irradiated crustaceans and their nonirradiated offspring. By selecting two fluences (9 ± 2 mJ cm -2 reducing fertility and 4.3 ± 0.9 J cm -2 increasing it), the effect of these on toxicity of cadmium sulfate was evaluated. These experiments have shown that prior irradiation with low-intensity light of a helium-neon laser with 632.8 nm wavelength can change the sensitivity of aquatic organisms to toxin cadmium sulfate. The degree and direction of changes depend on the toxicant concentration and the irradiation dose., (© 2020 American Society for Photobiology.)

The present research describes the synthesis of cadmium sulfide (CdS) nanoparticles from Escherichia coli under the influence of bacterial enzyme sulphate reductase and study on their cytotoxicity for applications in cancer therapy. Escherichia coli cells were used to synthesize CdS nanoparticles under different concentrations of cadmium chloride and sodium sulfide. The morphology of the nanoparticles was analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) was used for elemental analysis of nanoparticles. Fourier-transform infrared spectroscopy analysis (FTIR) was performed to assess the functional groups of the nanoparticles. Crystalline nature of nanoparticles was assessed using powder X-ray diffraction (XRD). Antibacterial studies of CdS nanoparticles were carried out on foodborne pathogens and cytotoxicity studies were carried out on Mus musculus skin melanoma (B16F10) and human epidermoid carcinoma (A431) cell lines. CdS nanoparticle showed more cytotoxic effect on cancer cells compared with standard 5-aminolevulinic acid (5-ALA). The Escherichia coli-synthesized CdS nanoparticles showed highest zone of inhibition in the ratio 4:1 of cadmium chloride and sodium sulfide on all tested bacterial strains. The nanoparticles were also tested for haemolytic activity on RBC cells, which exhibited lower cytotoxicity than sodium dodecyl sulphate which was used as positive control. The cytotoxicity of CdS nanoparticles assessed on A431 cells showed an inhibition of 81.53% at 100 μM concentration while the cytotoxicity assessed on B16F10 cells showed an inhibition of 75.71% at 200 μM concentration which was much efficient than 5-ALA which showed an inhibition of 31.95% at a concentration against B16F10 cells and 33.45% against A431 cells at a concentration of 1 mM. Cadmium sulfide nanoparticles were thus found to be highly toxic on cancer cells compare with standard anticancerous drug 5-ALA.

The bactericidal activity of metal oxide nanoparticles (NPs) offers extensive opportunities in bioengineering and biomedicines. Bioengineered transition metals used in various forms against lethal microbes. In this study, Cadmium Oxide nanoparticles (CdO-NPs) were prepared through the co-precipitation method using fungal strain Penicillium oxalicum and cadmium acetate solution. The structure and elemental composition of the prepared NPs were determined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Antibacterial activity was assessed through well diffusion method against Staphylococcus aureus (S. aureus), Shigella dysenteriae (S. dysenteriae), and Pseudomonas aeruginosa (P. aeruginosa). In addition, reactive oxygen species (ROS), reducing sugars and protein leakage contribution was examined against selected strains. The XRD analysis proved that the synthesized CdO-NPs possess a crystalline structure with an average crystalline size of 40-80 nm. FTIR confirmed the presence of organic compounds on the particle surface, while UV showed stability of the particles. SEM and EDS confirmed that CdO-NPs were successfully prepared and spherical. The maximum zone of inhibition against S. dysenteriae and P. aeruginosa was found and showed a less optical density of 0.086 after 18 h. ROS, reducing sugar, and protein leakage assay showed a significant difference as compared to control. Based on the present study, it is recommended that microbial mediated synthesized nanoparticles can be used as biomedicines for the treatment of different types of bacterial infections., Competing Interests: Declaration of competing interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Polyvinyl-pyrrolidone capped spherical cadmium sulphide quantum dots (CdS-PVP QDs), 2-6 nm in size, were developed as a selective turn-on fluorescence nanosensor for monohydrogen phosphate ion (HPO 4 2- ) in aqueous medium. Fluorescence intensity of CdS-PVP QDs significantly increased with addition of HPO 4 2- ions, whereas the other common inorganic ions had very little effect on the fluorescence intensity. The proposed sensor may be efficiently used for the detection of HPO 4 2- ions at a low level of concentration up to 213 nM in real urine sample. Cell imaging study indicates that the CdS-PVP QDs are cell permeable and can detect the intracellular distribution of HPO 4 2- ions under fluorescence microscope. The CdS-PVP QDs showed considerable activity against Staphylococcus aureus also., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Quantum dots (QDs) are semiconducting materials which have a wide array of applications starting from semiconducting devices, in humidity and pressure sensors and in medical imaging including cancer therapy. In the present study, cadmium telluride (CdTe) QDs were synthesized by a biological method using yeast cells, Saccharomyces cerevisiae in modified Czapek's medium. QDs were characterized by transmission electron microscopy and X-ray diffraction. Cancer cells were treated with 2, 4, 8 and 16 μ M concentrations of CdTe QDs for 24 h. The anti-proliferative activity was determined by using MTT assay, by evaluating the production of reactive oxygen species (ROS), and also by nuclear apoptosis and cell cycle analysis using a flow cytometer against human prostate carcinoma cell line PC-3. The size of the CdTe QDs was approximately 2 nm. In vitro anti-proliferative study showed that CdTe QDs induced cell death and nuclear apoptosis in a dosedependent manner. CdTe QDs induced significant increase in ROS level in PC-3 cells which was dose-dependent. Moreover, CdTe also arrested growth of PC-3 cells in the G2/M phase of the cell cycle. This study elucidates the apoptotic activity of CdTe QDs on prostate carcinoma which could provide useful insights to researchers for its clinical application.

Introduction: Since CdTe quantum dots (QDs) are still widely considered as advanced fluorescent probes because of their far superior optical performance and fluorescence efficiency over non-cadmium QDs, it is important to find ways to control their toxicity., Methods: In this study, the adverse effects of two cadmium-containing QDs, ie, CdTe QDs and CdTe@ZnS QDs, on the nervous system of nematode C. elegans , the hippocampus of mice, and cultured microglia were measured in order to evaluate the neuroinflammation caused by cadmium-containing QDs and the potential mechanisms., Results: Firstly, we observed that cadmium-containing QD exposure-induced immune responses and neurobehavioral deficit in nematode C. elegans . In the mice treated with QDs, neuroinflammatory responses to QDs in the hippocampus, including microglial activation and IL-1ß release, occurred as well. When investigating the mechanisms of cadmium-containing QDs causing IL-1ß-mediated inflammation, the findings suggested that cadmium-containing QDs activated the NLRP3 inflammasome by causing excessive ROS generation, and resulted in IL-1ß release., Discussion: Even though the milder immune responses and neurotoxicity of CdTe@ZnS QDs compared with CdTe QDs indicated the protective role of ZnS coating, the inhibitions of NLRP3 expression and ROS production completely reduced the IL-1ß-mediated inflammation. This provided valuable information that inhibiting target molecules is an effective and efficient way to alleviate  the toxicity of cadmium-containing QDs, so it is important to evaluate QDs through a mechanism-based risk assessment., Competing Interests: The authors report no conflicts of interest in this work., (© 2020 Wu et al.)

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.

ZnS quantum dots (QDs) and their core/shell (CdSe/ZnS) structures were studied for Zn based precursor reactivities. ZnS and CdSe/ZnS QDs were prepared selecting aqueous route and then characterized via XRD, TEM, EDX, PL, RAMAN and FTIR practices. Core/shell nanostructures were synthesized by taking dissimilar precursors for the shell formation. Photoluminescence spectra of prepared QDs corroborate the effectual luminescence. Prepared QDs have large surface area that make them useful alternative as organic antimicrobial agent which are highly irritant and unstable. Study of antimicrobial behavior of QD structures was carried out by disk diffusion method. Antimicrobial study of QDs and their core/shell structures was performed against gram negative and gram positive bacteria, E. coli, A. baumanni and Bacillus subtilis respectively. It is found that elemental composition and size of QDs plays important role in antimicrobial behavior. Prepared QDs are fluorescent and have a key role in complex microbial population studies and identification of bacteria., (Copyright © 2018. Published by Elsevier B.V.)

Cadmium oxide nanoparticles (CdO NPs) are among some of the most studied and industrially used metal oxide NPs. They have been widely used for industrial application, such as paint pigments and electronic devices, and medical therapeutics. With increasing use of CdO NPs and concerns for their potential adverse effects on the environment and public health, evaluation of the cytotoxicity and genotoxicity of CdO NPs becomes very important. To date, there is a limited understanding of the potential hazard brought by CdO NPs and a lack of information and research, particularly on the genotoxicity assessment of these NPs. In this study, 10 nm CdO core-PEG stabilized NPs were synthesized, characterized and used for evaluation of CdO NPs' cytotoxicity and genotoxicity. Release of cadmium ions (Cd +2 ) from the CdO NPs in cell culture medium, cellular uptake of the NPs, and the endotoxin content of the particles were measured prior to the toxicity assays. Cytotoxicity was evaluated using the MTS assay, ATP content detection assay, and LDH assay. Genotoxicity was assessed using the Ames test, Comet assay, micronucleus assay, and mouse lymphoma assay. The cytotoxicity of cadmium chloride (CdCl 2 ) was also evaluated along with that of the CdO NPs. The results showed that endotoxin levels within the CdO NPs were below the limit of detection. CdO NPs induced concentration-dependent cytotoxicity in TK6 and HepG2 cells with the MTS, ATP and LDH assays. Although the genotoxicity of CdO NPs was negative in the Ames test, positive results were obtained with the micronucleus, Comet, and mouse lymphoma assays. The negative response of CdO NPs with the Ames test may be the result of unsuitability of the assay for measuring NPs, while the positive responses from other genotoxicity assays suggest that CdO NPs can induce chromosomal damage, single or double strand breaks in DNA, and mutations. The toxicity of the CdO NPs results from the NPs themselves and not from the released Cd +2 , because the ions released from the NPs were minimal. These results demonstrate that CdO NPs are cytotoxic and genotoxic and provide new insights into risk assessment of CdO NPs for human exposure and environmental protection., Competing Interests: Declaration of Competing Interest The authors declare that there are no conflicts of interest., (Published by Elsevier B.V.)

Aims: E. coli is a widely known model organism for life science research, especially in modern bio-engineering and industrial microbiology. The goal of our current study is to understand the growth inhibitory mechanism of biosynthesized CdS nanoparticles on E. coli bacteria., Main Methods: Characterization of Aspergillus foetidus mediated CdS nanoparticles has been confirmed by Zeta potential, AFM and HRTEM analyses. Furthermore, we investigated the contribution of reactive oxygen species (ROS) and subsequently lipid peroxidation on the growth of E. coli. FACS and fluorometric studies were used to know the ROS production upon CdS nanoparticle treatment. Lipid peroxidation measurement was studied by thiobarbituric acid (TBA) assay., Key Findings: The synthesized CdS nanoparticles are roughly spherical, poly-dispersed in nature and are in ~15 nm of size. Furthermore, our investigation confirmed that the cells treated with 200 μl of CdS nanoparticles produce about 50 % more ROS and about 5 times of lipid peroxidation over control cells. In addition, the number of E. coli colony survival and cell filamentation strongly depend on such lipid peroxidation caused by ROS, which actually produced due to the interaction with biosynthesized CdS nanoparticles in growth media., Significance: The current research would be helpful for the mechanistic understanding of growth inhibition of E. coli by CdS nanoparticle. This may be useful for industrial applications of E. coli like bacteria., (Copyright © 2019. Published by Elsevier Ltd.)

A green, efficient synthesis of cadmium oxide decorated reduced graphene oxide nanocomposites (RGO/CdO) was prepared by one-step co-precipitation and hydrothermal method. Crystalline nature of the nanocomposites was characterized by X-ray diffraction analysis. To evaluate the structural morphology and particle size, high resolution transmission electron microscopy were used. X-ray photoelectron spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy techniques were employed to establish chemical structure of the nanocomposites and Atomic Force Microscopy was done to measure the thickness. The optical properties were evaluated by UV-visible absorption spectroscopy. Thermo-gravimetric analysis, BET surface area and zeta potential measurements were carried out to study the thermal and surface characteristics. The CdO nano-particles (NPs) decorated on RGO sheets exhibit better electrical conductivity compared to RGO. The antibacterial activity of the nanocomposites has also been monitored in different culture media imparting good potentiality than RGO., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Nanoparticles of cadmium selenide (CdSe) doped with europium, were synthesized as stabilizing agents using thioglycolic acid ligand. This method is based on the enhancing effect of CdSe quantum dots (QDs) doped with europium on chemiluminescence (CL) emission. This emission was generated by mixing CdSe QDs with manganese (II), iron (II) and chrome (II) sulfates as catalysts in the presence of hydrogen peroxide (H 2 O 2 ). The structural characteristics and morphology of these nanoparticles were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, X-ray pattern and dynamic light scattering methods. The CdSe QDs doped with europium were used as the sensitizer in a luminol-hydrogen peroxide CL system. The sensitized CdSe QDs were analyzed for antibacterial activity against Gram-positive or Gram-negative bacteria. The results showed that the CdSe QDs are effective against all the studied bacteria, effectiveness was especially higher for Bacillus subtilis., (© 2019 John Wiley & Sons, Ltd.)

This study investigated the abilities of a purple non-sulfur bacterium, Rhodopseudomonas palustris TN110 to bioremediate cadmium through the biosynthesis of CdS nanoparticles and to fix nitrogen simultaneously. Under microaerobic-light conditions, R. palustris TN110 synthesized CdS nanoparticles. The produced CdS nanoparticles had a spherical shape and an average size of 4.85 nm. The Fourier transform infrared spectrum of the nanoparticles reveals the carbonyl groups, bending vibrations of the amide I and II bands of proteins, and CN stretching vibrations of aromatic and aliphatic amines. These bands and groups suggest protein capping/binding on the surface of the nanoparticles. R. palustris TN110 converted 25.61% of 0.2 mM CdCl 2 to CdS nanoparticles under optimal conditions (pH 7.5, 30 °C and 3000 lux). The half maximal inhibitory concentration (IC 50 ) value of the produced CdS nanoparticles was 1.76 mM. The produced CdS nanoparticles at IC 50 up-regulated two genes associated with nitrogen fixation: Mo-Fe nitrogenase gene (nifH) and V-Fe nitrogenase gene (vnfG) at 2.83 and 2.27 fold changes, respectively. On the contrary, the produced CdS nanoparticles slightly down-regulated Fe-Fe nitrogenase gene (anfG). The amounts of ammonia released by the strain support the gene expression results. R. palustris TN110 has great potential to serve concurrently as a cadmium bioremediation agent and a nitrogen fixer. The strain could be beneficial to paddy fields that are contaminated with Cd through run off from mining and chemical fertilizer applications., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Recyclable magnetic photocatalysts of iron oxide (IO)/CdS core/shell nanocrystals (CSNCs) were prepared by a facile sequential one-pot method using 3, 3'-thiobispropanoic acid (TDP) as a bridge. The CSNCs showed redshift in absorption edge, decrease in the optical band gap, reduced exciton decay rates and increment in particle size. Quenching studies have been employed to understand the position of the electron/hole wave-functions at the IO/CdS interface. Antimicrobial tests have also been performed using broth tube dilution and disc diffusion methods against S. aureus. Additionally, photocatalytic properties of IO/CdS CSNCs have been evaluated for the decomposition of xylenol blue. In comparison with CdS quantum dots (QDs) and iron oxide nanoparticles (IONPs), the IO/CdS CSNCs showed improved photocatalytic and bactericidal activities. Finally, levels of oxidative damage to proteins and lipids were evaluated., (Copyright © 2018. Published by Elsevier B.V.)

Cadmium selenide nanoparticles (CdSe NPs) were synthesized by an easy and simple method and their properties were assessed by XRD, TEM and SEM techniques. The effects of CdSe NPs as well as Cd 2+ ions on Lemna minor plants were investigated. The absorption of CdSe NPs by the plants had some adverse consequences that were assessed by a range of biological analyses. The results revealed that both CdSe NPs and the ionic form of cadmium noticeably caused toxicity in L. minor. Morphological parameters as well as peroxidase (POD) activity were deteriorated. In contrast, the activities of some other antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) as well as the contents of total phenol and flavonoids went up. Taken all together, it could be implied that CdSe NPs as well as Cd 2+ were highly toxic to plants and stimulated the plant defense system in order to scavenge produced reactive oxygen species (ROS)., Competing Interests: The authors declare no conflict of interest.

Fluorescent inorganic quantum dots are highly promising for biomedical applications as sensing and imaging agents. However, the low internalization of the quantum dots, as well as for most of the nanoparticles, by living cells is a critical issue which should be solved for success in translational research. In order to increase the internalization rate of inorganic CdSe/ZnS quantum dots, they were functionalized with a fluorinated organic ligand. The fluorinated quantum dots displayed an enhanced surface activity, leading to a significant cell uptake as demonstrated by in vitro experiments with HeLa cells. We combined the experimental and computational results of Langmuir monolayers of the DPPC phospholipid as a model cell membrane with in vitro experiments for analyzing the mechanism of internalization of the fluorinated CdSe/ZnS quantum dots. Surface pressure-molecular area isotherms suggested that the physical state of the DPPC molecules was greatly affected by the quantum dots. UV-vis reflection spectroscopy and Brewster Angle Microscopy as in situ experimental techniques further confirmed the significant surface concentration of quantum dots. The disruption of the ordering of the DPPC molecules was assessed. Computer simulations offered detailed insights in the interaction between the quantum dots and the phospholipid, pointing to a significant modification of the physical state of the hydrophobic region of the phospholipid molecules. This phenomenon appeared as the most relevant step in the internalization mechanism of the fluorinated quantum dots by cells. Thus, this work sheds light on the role of fluorine on the surface of inorganic nanoparticles for enhancing their cellular uptake., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Signaling by glutamatergic synapses plays an important role in visual processing in the retina. In this study, we used an enzyme-linked fluorescence assay system to monitor the dynamics of extracellular glutamate in a slice preparation from the mouse retina. High K stimulation induced an elevation of fluorescence in the inner plexiform layer (IPL) of the retina when glutamate transporters were inhibited by dl-threo-β-benzyloxyaspartic acid (TBOA). The high K-induced fluorescence signals in the IPL were inhibited by the calcium channel blocker Cd 2+ . Blockade of GABAergic and glycinergic circuits by picrotoxin and strychnine also elevated the fluorescence signals in the IPL. Thus, the enzyme-linked fluorescence assay system might be useful for monitoring the bulk concentration of extracellular glutamate released by synapses in the inner retina., (Copyright © 2018 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.)

We studied the influence of magnetite nanoparticles (FeO•Fe 2 O 3 ) and quantum dots (CdSe/ZnS coated with mercaptopropionic acid) on the expression of 5 common reference genes (BA, B2M, PPIA, UBC, and YWHAZ) in peripheral blood cells from 20 volunteers by reverse transcription PCR method. The stability of the expression of reference genes varied depending of the cells type and chemical structure of nanoparticles. The level of YWHAZ mRNA after exposure by nanoparticles demonstrated highest stability in lymphocytes, neutrophils, and monocytes. Stability of YWHAZ expression was confirmed by Western blotting. Our findings suggest that YWHAZ is the most suitable as the reference gene.

Cigarette smoking is a well-established risk factor for various diseases, such as cardiovascular diseases, neurodegeneration, and cancer. Cadmium nitrate (Cd(NO 3 ) 2 ) is one of the major products from the cigarette smoke. Up to now, no supporting evidence on Cd(NO 3 ) 2 -induced apoptosis and its related working mechanism in neurons has been found. In present study, the mode of cell death, caspase activities, reactive oxygen species (ROS) generation, and mitochondrial dysfunction in N2a cells, which are neuron-like cells, were assessed by Annexin V-FITC and PI assays, caspase fluorometric assay, DCFH-DA fluorescence assay, and JC-1 fluorescence assay respectively. The results showed that not only Cd(NO 3 ) 2 induced apoptosis and necrosis but also the activities of caspase-3 and -9 expressed in a concentration-dependent manner. In addition, Cd(NO 3 ) 2 also induced both mitochondrial dysfunction and ROS generation in a concentration-dependent manner. All these indicated that in N2a cells parallel trends could be observed in apoptosis, caspase-3 and -9 activities, mitochondrial dysfunction, and ROS generation when induced by Cd(NO 3 ) 2 . Furthermore, Cd(NO 3 ) 2 -induced apoptosis, caspases activities, mitochondrial dysfunction, and ROS generation were reduced by N-acetyl-l-cysteine (NAC). These results indicated that Cd(NO 3 ) 2 -induced neuronal apoptosis was reduced by NAC via intrinsic apoptotic caspase cascade activities and their up-stream factors, including mitochondrial dysfunction and ROS generation., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Cadmium compounds are highly toxic substances characterized by mutagenic, genotoxic and carcinogenic effects, and having high cumulative properties. Application of cadmium nanoparticles (NPs) in medicine stimulates the study of their mechanism of action at the cellular level and at the level of organs and systems, determination of biomarkers of their action, particularly in comparison with the ionic form. The aim of the study was to compare the features of cytotoxic and genotoxic effects of cadmium sulfide (CdS) NPs of different sizes on cell cultures of different histogenesis with those of cadmium chloride (CdCl2)., Materials and Methods: In this work, we used cadmium compounds in the nanoform: NPs CdS of 4-6 nm and of 9-11 nm in size; and in the ionic form: CdCl2. The studies were conducted in vitro in cell lines - IMR-32, НEК-293 and MАEC. To count viable cells we compared the results of three basic tests: MTT (methyl tetrasolium test), SRB (sulforhodamine B test) and NRU (neutral red uptake test). We evaluated the genotoxic effect of the substances studied in vitro using DNA comet assay in alkaline conditions., Results: CdS NPs and CdCl2 demonstrated pronounced dose-dependent cytotoxic effect in MАEC, НEК-293 and IMR-32 cell lines, by impairing membrane permeability, functioning of mitochondria and lysosomes, and inhibiting the function of protein synthesis. Cytotoxic effect of CdCl2 was the most pronounced, this effect of CdS NPs of 9-11 nm in size being the least pronounced. The comet DNA assay in alkaline conditions revealed a statistically significant increase in DNA comet index when exposed to CdCl2 and CdS NPs in comparison with the negative control, which indicates their genotoxic effect. CdS NPs of 4-6 nm in size showed a more pronounced effect in comparison with those of 9-11 nm in size., Conclusion: Elucidation of mechanisms underlying the implementation of toxic effects of cadmium NPs will help in assessing the potential risks associated with their use in industry and developing effective preventive measures. For instance, when planning in vivo studies for toxicological evaluation of nanomaterials and nano-substances containing NPs of cadmium, it is necessary to investigate the mutagenic and carcinogenic risks and to take into account the high likelihood of neurotoxic and cardiovasotoxic effects, along with nephrotoxic effects, since high cytotoxic activity of the investigated compounds of cadmium was detected on the cells of the MАEC line (endothelial origin) and IMR-32 (neuronal origin).

Bacillus subtilis 1JN2 can serve as an effective biocontrol agent against Ralstonia wilt on tomato, but the efficiency of control depends on the levels of heavy metals in the rhizosphere soil. Here, we investigated how the heavy metal Cd 2+ affects the biocontrol efficacy of B.subtilis 1JN2 on Ralstonia wilt. We found that low Cd 2+ content of 2 mM or lower had no effects on the biofilm formation of 1JN2, while media containing 3 mM or higher Cd 2+ levels inhibited biofilm formation. Interestingly, high concentration of Cd 2+ (5 mM) showed inhibition of B.subtilis 1JN2 cell growth. We next tested the effects of Cd 2+ on the colonization of 1JN2 by supplementing artificial Cd 2+ in the tomato rhizosphere in a greenhouse setting. We found that 3 mM Cd 2+ in the tomato rhizosphere inhibited the colonization of B.subtilis 1JN2, Only 10 3  CFU/mL 1JN2 was detected one week post treated with 10 7  CFU/mL but 10 5  CFU/mL could be detected without Cd 2+ in the soil. The presence of Cd 2+ had no effect on the colonization of Ralstonia solanacearum on tomato, but the biocontrol efficacy against Ralstonia wilt by 1JN2 decreased 54.2% when the soil contained 3 mM Cd 2+ compared to the control without Cd 2+ . Taken together, we found that the failure of biofilm formation of Bacillus subtilis 1JN2 that affected by Cd 2+ lead to the decrease of its biocontrol efficacy against Ralstonia wilt on tomato., (Copyright © 2018. Published by Elsevier GmbH.)

Nanoparticles (NPs) are inevitably released into the aquatic environment for being widely used and may affect the toxicity of other contaminants already present in the environment, such as trace metals. However, the effects of NPs on the ecotoxicity of cadmium (Cd), a common environmental trace metal pollutant, are not well explored. In this study, effects of four widely used NPs TiO 2 (n-TiO 2 ), SiO 2 (n-SiO 2 ), Ag (n-Ag) and CdTe/CdS core/shell quantum dots (QD) on the toxicity of Cd to the freshwater algae Chlamydomonas reinhardtii were assessed respectively. Cd reduced the algae biomass, impaired the photosynthetic activities, and led to intracellular oxidative stress of algae. At non-toxic concentrations, both n-TiO 2 (100 mg L -1 ) and n-SiO 2 (400 mg L -1 ) attenuated the toxicity of Cd towards the algae for reducing the intracellular Cd contents, and the former was more pronounced. QD (0.5 mg L -1 ) increased the toxicity of Cd to algae, but n-Ag (0.2 mg L -1 ) had no significant influence on the Cd toxicity to algae. The microscopic observations on the ultrastructure of algae cells presented the same phenomena and n-TiO 2 , n-SiO 2 aggregations were clearly observed outside the cell wall. Furthermore, the regulation of NPs to the Cd toxicity towards algae was related to the intracellular nitric oxide (NO), an important signaling molecule, rather than the phototaxis of algae. Above all, this study provided a basic understanding about the difference in joint toxicity of different kinds of NPs and Cd to aquatic organisms., (Copyright © 2018 Elsevier Inc. All rights reserved.)

In this study, monodispersed, highly biocompatible and substantially stable glucose encapsulated CdO nanoparticles (G-CdO NPs) of uniform sizes were synthesized using a sol-gel route. In addition, naked CdO (n-CdO) NPs without any capping or surface functionalization were synthesized using the same method. These NPs were uniformly dispersed in an aqueous solution. The synthesis of G-CdO and n-CdO NP was confirmed by UV-Vis spectroscopy, transmission electron microscopy (TEM), zeta potential, and dynamic light scattering analyses. The average size of G-CdO and n-CdO NP was found to be 17±1and 27 ± 1 nm, under TEM, respectively. X-ray diffraction analysis of G-CdO and n-CdO NPs confirmed their sizes to be 18.83 and 28.41 nm, respectively, and revealed their cubic crystal structures with no impurity. The surface functionalization of G-CdO NPs with glucose was confirmed by Nuclear Magnetic Resonance and Fourier-transform infrared spectroscopy analyses. As per our knowledge, this is the first report to investigate the potencies of G-CdO and n-CdO NPs against gram-negative and gram-positive multi-drug resistant (MDR) bacteria. The minimum inhibitory concentrations of G-CdO and n-CdO NPs were6.42 and 16.29 μg/ml, respectively, against Escherichia coli (NCIM 2571-MDR), whereas 7.5 μg/ml & 11.6 μg/ml, respectively against S. aureus (NCIM- 2079) as determined by the double dilution method. The minimum bactericidal concentration was determined at the concentration for which no growth was observed. TEM analysis of E. coli cells treated with G-CdO NPs revealed cell shrinkage and degraded cell membranes, while the cell surfaces of untreated viable cells were smooth., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The currently utilized ligand fishing for bioactive molecular screening from complex matrixes cannot perform imaging screening. Here, we developed a new solid-phase ligand fishing coupled with an in situ imaging protocol for the specific enrichment and identification of heat shock protein 90 (Hsp 90) inhibitors from Tripterygium wilfordii, utilizing a multiple-layer and microkernel-based mesoporous nanostructure composed of a protective silica coating CdTe quantum dot (QD) core and a mesoporous silica shell, i.e., microkernel-based mesoporous (SiO 2 -CdTe-SiO 2 )@SiO 2 fluorescent nanoparticles (MMFNPs) as extracting carries and fluorescent probes. The prepared MMFNPs showed a highly uniform spherical morphology, retention of fluorescence emission, and great chemical stability. The fished ligands by Hsp 90α-MMFNPs were evaluated via the preliminary bioactivity based on real-time cellular morphology imaging by confocal laser scanning microscopy (CLSM) and then identified by mass spectrometry (MS). Celastrol was successfully isolated as an Hsp 90 inhibitor, and two other specific components screened by Hsp 90α-MMFNPs, i.e., demecolcine and wilforine, were preliminarily identified as potential Hsp 90 inhibitors through the verification of strong affinity to Hsp 90 and antitumor bioactivity. The approach based on the MMFNPs provides a strong platform for imaging screening and discovery of plant-derived biologically active molecules with high efficiency and selectivity.

Exploring morphology and surface structure of semiconductor photocatalyst is crucial for researching their photocatalytic performance. In this paper, hollow CdS nanospheres (CdS-HSs) were successfully fabricated via simple template self-removal strategy. The prepared CdS-HSs were characterized by XRD, SEM, HR-TEM, UV-vis diffuse reflectance spectra (DRS), XPS, photocurrent response (I-T), photoluminescence (PL) and electrochemistry impedance spectroscopy (EIS). It was found that the prepared CdS-HSs have nanoparticles-textured surface composed of ultra-small CdS nanoparticles (∼20 nm) and large surface areas. DRS result demonstrated that the CdS-HSs exhibit strong visible light absorption capacity. The results of photocurrent response, photoluminescence and EIS revealed that hollow structure and nanoparticles-textured surface can effectively increase light reflection effect and decrease recombination rate of electrons and holes. Compared to the traditional CdS, the hollow CdS nanospheres exhibit higher photocatalytic activity on Cr(VI) reduction under visible light irradiation, which are primarily attributed to its rapid separation of electron-hole pairs and improved visible light absorption. Moreover, CdS-HSs was also demonstrated as an effective and potential material on photocatalytic disinfection. The result of mechanism experiments proved that h + , e - and O 2 - play important roles on the bacteria inactivation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The present study reports the biogenic synthesis of Cadmium Oxide Nanoparticles (CdO NPs) using plant pathogenic fungus Nigrospora oryzae culture filtrate. Further, the effect of the NPs on the cancer cell line (HeLa) is explored. The sample was characterized using Thermogravimetric/Differential Thermal (TG/DTA), Powder X-ray Diffraction (XRD), X-ray Photoelectron spectroscopy (XPS), UV-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Field Emission Transmission Electron Microscopy (FE-SEM) with Energy Dispersive X-ray Spectroscopy (EDX), High Resolution Transmission Electron Microscopy (HR-TEM) and Selected Area Electron Diffraction (SAED) analysis. Antibacterial activity was evaluated against both Gram positive and Gram negative bacterial strains and it showed maximum activity against Proteus vulgaris. The larvicidal activity was performed to evaluate the maximum ability of synthesized CdO NPs against Anopheles stephensi. Subsequently, MTT assay also depicted the dose-dependent anticancer activity of CdO NPs against cancer cell line (HeLa). Additionally, the inhibitory effect of CdO NPs was analyzed through extensive docking with cancerous protein agent. Results enlighten that Transketolase protein exhibited high docking score of -4.8 k/mol with H-bond interactions found with Lys75 and Asn185 amino acid residues. DFT study was performed on CdO to understand the charge transfer reaction for the inhibitory mechanism. Convincingly, this study explores the understanding of CdO NPs against HeLa cells., (Copyright © 2018. Published by Elsevier B.V.)

Hypoxia, an outstanding characteristic of various solid tumors, has been considered a critical factor of aggressive tumor phenotypes, poor clinical prognosis, and increased expression of the multidrug-resistant gene. Therefore, it is critical to develop a drug delivery system to enhance the delivery effect of the antitumor drug in the hypoxic tumor. We constructed two types of tumor targeting micelles based on chitosan and evaluated their properties in targeting hypoxic tumors. Chitosan-based micelles consisted of a hydrophobic group octyl group, a hydrophilic polyethylene glycol, tumor targeting ligands glucosamine or folic acid, and a transmembrane peptide 9-d-arginine. The molecular structure, morphology, size distribution, zeta potential, and biosafety of two micelles were characterized. Oil-soluble CdSe quantum dots were used as a fluorescent probe to evaluate the hypoxic tumor cell targeting properties of the micelles. Moreover, HepG2 human hepatocellular carcinoma cells and HeLa human cervical carcinoma cells were used as in vitro models. We demonstrated that, under hypoxic conditions, two chitosan micelles showed better targeting ability to HepG2 and HeLa cells, which enhanced the effect of antitumor drugs by specifically targeting transport in hypoxic tumors. Therefore, chitosan micelles may be a potential drug delivery system that can be used to deliver antitumor drugs to hypoxic tumors.

Cadmium sulfide nanoparticles (CdS NPs) are one of important nanoparticle materials which are widely used in photoelectric production, but their potential health hazard to the liver is not clear. This study is aimed at exploring the possible mechanisms of liver injury induced by CdS NPs. Male mice were treated with nanoparticles of 110-130 nm and 80-100 nm cadmium sulfide. The main methods were based on detecting the vigor of superoxide dismutase (SOD) and glutathione (GSH), and content of malondialdehyde (MDA) in both blood and liver tissues as well as on observing the pathological changes in liver tissue. CdS NPs suppressed the activity of SOD and GSH, and increased the serum MDA content (p < 0.05); both effects were observed together in liver tissues of 80-100 nm group (p < 0.05) and were accompanied by an obviously inflammatory response. CdS NPs induced oxidative damage and inflammatory response in liver tissue, which may be an underlying mechanism for its pulmonary toxicity. Additionally, the toxicity of CdS NPs was closely related to the size of nanoparticles. Pathological results showed that the hepatotoxicity of shorter CdS NPs is greater than that of longer CdS NPs (Tab. 6, Fig. 3, Ref. 20).

Histone deacetylases (HDACs) play an important role in the epigenetic regulation of gene expression through their effects on the compact chromatin structure. In clinical studies, several classes of histone deacetylase inhibitors (HDACi) have demonstrated potent anticancer activities with metal complexes. Hence, we synthesized cadmium-proline complexes using both the D- and L-isomers of proline and evaluated their biological activities by observing the efficiency of their inhibition of HDAC activity, ability to reduce the expression of HDAC isoforms in A549 cells and effect on apoptosis. The synthesized compounds were characterized by UV, IR, NMR spectroscopy and elemental analysis. In-vitro cell toxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and the 50% inhibitory concentration (IC 50 ; 2 μM) was obtained at 12 h. The morphological study at nuclear levels was performed by acridine orange/ethidium bromide (AO/EB) and Hoechst staining, and the results showed an association with cell cycle arrest at the G2/M phase. Both cadmium-proline complexes intensely inhibited HDAC activity at 2 μM concentration. Interestingly, Cd[L-proline] 2 was found to be a potent inhibitor for all HDAC isoforms, whereas Cd[D-proline] 2 inhibited only HDAC1 and 2. HDACi are novel chemotherapeutic drugs that induce hyperacetylation of histones H3 and H4, counteracting the aberrant repression of genes, such as insulin-like growth factor-binding protein 3 (IGFBP-3), p53, and p21. ERK/MAPK signaling pathway resulted in the downregulation of the expression of matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), contributing to the inhibition of metastasis in A549 cells. Apoptosis induction was accompanied by the activation of death receptors and their ligands which recruit initiator caspase 8, decrease in mitochondrial membrane potential (ΔΨm), as well as increased Bax/Bcl 2 ratio, followed by activation of caspases 9 and 3. Our finding suggests that Cd[L-proline] 2 complex accelerates epigenetic rearrangement by HDAC inhibition, which may be the key mechanism for its anticancer activity.

In the present study, binary oxide (cadmium oxide [CdO]) x (zinc oxide [ZnO]) 1-x nanoparticles (NPs) at different concentrations of precursor in calcination temperature were prepared using thermal treatment technique. Cadmium and zinc nitrates (source of cadmium and zinc) with polyvinylpyrrolidone (capping agent) have been used to prepare (CdO) x (ZnO) 1-x NPs samples. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray (EDX), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. XRD patterns analysis revealed that NPs were formed after calcination, which showed a cubic and hexagonal crystalline structure of (CdO) x (ZnO) 1-x NPs. The phase analysis using EDX spectroscopy and FTIR spectroscopy confirmed the presence of Cd and Zn as the original compounds of prepared (CdO) x (ZnO) 1-x NP samples. The average particle size of the samples increased from 14 to 33 nm as the concentration of precursor increased from x=0.20 to x=0.80, as observed by TEM results. The surface composition and valance state of the prepared product NPs were determined by X-ray photoelectron spectroscopy (XPS) analyses. Diffuse UV-visible reflectance spectra were used to determine the optical band gap through the Kubelka-Munk equation; the energy band gap was found to decrease for CdO from 2.92 to 2.82 eV and for ZnO from 3.22 to 3.11 eV with increasing x value. Additionally, photoluminescence (PL) spectra revealed that the intensity in PL increased with an increase in particle size. In addition, the antibacterial activity of binary oxide NP was carried out in vitro against Escherichia coli ATCC 25922 Gram (-ve), Salmonella choleraesuis ATCC 10708, and Bacillus subtilis UPMC 1175 Gram (+ve). This study indicated that the zone of inhibition of 21 mm has good antibacterial activity toward the Gram-positive B. subtilis UPMC 1175., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Pure and zinc-doped CdO NPs (Zn-CdO NPs) were synthesized through a facile co-precipitation method. The structural, morphology, chemical composition, optical and antibacterial activity of the NPs were studied with respect to pure and Zn-doped CdO concentration (0-7.5mol.%). Scanning electron microscope (SEM) images reveal that pure and Zn-doped CdO NPs were in the nano-scale regime with different crystalline morphology. The energy dispersive X-ray spectroscopy (EDS) spectrum predicts the presence of Cadmium (Cd), Zinc (Zn) and Oxygen (O) in the prepared samples. Optical studies divulge that Zn 2+ doping CdO decreases the band gap energy (Eg) (3.36-3.02eV) with an increase in Zn 2+ doping concentration. Optical absorption spectrum of CdO red-shifted as the Zn concentration varied from 2.5mol.% to 7.5mol.%. PL spectra displayed a strong UV emission peak at 380nm. Enhanced Visible emission at 430 and 522nm with Zn 2+ doping interprets the defect density in CdO by occupying Cd 2+ vacancies with Zn 2+ ions. Photocatalytic studies revealed that 7.5% Zn-doped CdO NPs show maximum degradation for atrazine (ATZ) as herbicide pollution under UV irradiation. Antibacterial studies against (Gram positive) and (Gram negative) bacteria's authenticate that Zn 2+ doped CdO nanostructures exhibit excellent antibacterial activity against all bacteria's with an increase in doping concentration., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Although quantum dot (QD)-induced toxicity occurs due to free radicals, generation of oxidative stress mediated by reactive oxygen species (ROS) formation is considered an important mechanism. However, free radical mechanisms are essentially difficult to elucidate at the molecular level because most biologically relevant free radicals are highly reactive and short-lived, making them difficult to directly detect, especially in vivo. Antioxidants play an important role in preventing or, in most cases, limiting the damage caused by ROS. Healthy people and animals possess many endogenous antioxidative substances that scavenge free radicals in vivo to maintain the redox balance and genome integrity. The antioxidant capacity of an organism is highly important but seldom studied. In this study, the dose and time effects of CdTe QDs on the antioxidant capacities of the liver and kidneys were investigated in mice using the electron paramagnetic resonance (EPR) spin-trapping technique. We found that the liver and kidneys of healthy mice contain specific antioxidant capacities that scavenge ·OH and ·O 2 - . Furthermore, oxidative stress markers (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], glutathione [GSH] and malondialdehyde [MDA]) were examined. In dose course studies, the free radical scavenging efficiencies of the liver and kidneys were found to gradually decrease with increasing concentration of CdTe QD exposure. The activities and levels of SOD, CAT, GPx and MDA were observed to increase in treated groups, whereas those of GSH were reduced. The time course studies revealed that the QD-induced antioxidant efficiency reduction was time dependent with GSH decrease and could recover after a period of time. These experimental results offer new information on QD toxicity in vivo. Specifically, CdTe QDs can deplete GSH to reduce the elimination ability of the liver and kidneys for ·OH and ·O 2 - , thus inducing oxidative damage to tissues., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Silver is known to possess anti-microbial properties that are of chemical origin. It is believed that either Ag atoms bind to thiol groups in bacterial enzymes or Ag + ions enter bacterial cells and denature the DNA molecule to kill bacteria. Silver nanorods , however, may kill bacteria by another mechanism: it is possible that the sharp tips of the nanorods puncture bacterial cells and kill bacteria via impalement-a physical mechanism. To test if this can indeed happen, we have compared the anti-microbial properties of silver and CdS nanorods. No significant difference is found between the two even though CdS does not possess the chemical properties of silver. This indicates that the physical kill mechanism is indeed likely and therefore nanorods of any material may possess anti-microbial properties. In that case, it is possible to overcome serious short- and long-term health hazard issues which have been posed by silver nanoparticles by replacing them with nanorods of innocuous elements or compounds. A surface containing nanorods of varying heights presents an undulating bed of spikes to microbes and is most inhospitable to bacteria.

Cadmium selenide (CdSe) based quantum dots modified with polyethylene glycol and chemically linked to interleukin-13 (IL13) were prepared with the aim of identifying the high affinity receptor (IL13Rα2) which is expressed in glioma stem cells and exosomes secreted by these cancer stem cells. IL13 conjugated quantum dots (IL13QD) were thoroughly characterized for their physicochemical properties including particle size and surface morphology. Furthermore, the specific binding of the IL13QD to glioma cells and to glioma stem cells (GSC) was verified using a competitive binding study. The exosomes were isolated from the GSC conditioned medium and the expression of IL13Rα2 in the GSC and exosomes was verified. The binding property of IL13QD to the tumor associated exosomes was initially confirmed by transmission electron microscopy. The force of attraction between the quantum dots and U251 glioma cells and the exosomes was investigated by atomic force microscopy, which indicated a higher force of binding interaction between the IL13QD and IL13Rα2 expressing glioma cells and exosomes secreted by glioma stem cells. Flow cytometry of the IL13QD and exosomes from the culture media and cerebrospinal fluid (CSF) of patients with glioma tumors indicated a distinctly populated complex pattern different from that of non-targeted quantum dots and bovine serum albumin (BSA) conjugated quantum dots confirming specific binding potential of the IL13QD to the tumor associated exosomes. The results of this study demonstrate that IL13QD can serve as an ex vivo marker for glioma stem cells and exosomes that can inform diagnosis and prognosis of patients harboring malignant disease., Statement of Significance: Functionalized quantum dots are flexible semiconductor nanomaterials which have an immense application in biomedical research. In particular, when they are functionalized with biomolecules like proteins or antibodies, they have the specialized ability to detect the expression of receptors and antigens in cells and tissues. In this study we designed a cytokine (interleukin-13) functionalized quantum dot to detect a cancer associated receptor expressed in cancer stem cells and the extracellular vesicles (exosomes) secreted by the cancer cells themselves. The binding pattern of these cytokine modified quantum dots to the cancer stem cells and exosomes alters the physical properties of the complex in the fixed and suspended form. This altered binding pattern can be monitored by a variety of techniques, including transmission electron microscopy, atomic force microscopy and flow cytometry, and subsequent characterization of this quantum dot binding profile provides useful data that can be utilized as a fingerprint to detect cancer disease progression. This type of functionalized quantum dot fingerprint is especially useful for invasive cancers including brain and other metastatic cancers and may allow for earlier detection of disease progression or recurrence, thus saving the lives of patients suffering from this devastating disease., (Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)