Dye Acridine Orange Research Articles

Entrapment of Acridine Orange in Metakaolin-Based Geopolymer: A Feasibility Study.

Few studies have explored the immobilization of organic macromolecules within the geopolymer matrix, and some have found their chemical instability in the highly alkaline geopolymerization media. The present work reports on the feasibility of encapsulating the potentially toxic acridine orange (AO) dye in a metakaolin based geopolymer while maintaining its structural integrity. The proper structural, chemical, and mechanical stabilities of the final products were ascertained using Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric (TGA/DTG), and mechanical analyses, whereas the dye integrity and its stability inside the geopolymer were investigated by the UV-Vis analysis. In addition, the antimicrobial activity was investigated. The FT-IR and XRD analyses confirmed the geopolymerization occurrence, whereas the TGA/DTG and mechanical (compressive and flexural) strength revealed that the addition of 0.31% (AO mg/ sodium silicate L) of AO to the fresh paste did not affect the thermal stability and the mechanical properties (above 6 MPa in flexural strength and above 20 MPa for compressive strength) of the hardened product. UV-Vis spectroscopy revealed that the dye did not undergo chemical degradation nor was it released from the geopolymer matrix. The results reported herein provide a useful approach for the safe removal of toxic macromolecules by means of encapsulation within the geopolymer matrix.

Plasmon-Exciton Coupling Effect in Nanostructured Arrays for Optical Signal Amplification and SARS-CoV-2 DNA Sensing.

A surface plasmon resonance (SPR)-enhanced optical signal using a nanoslit array and acridine orange (AO) dye system at a flexible poly(dimethylsiloxane) (PDMS) substrate was achieved in this work and demonstrated a simple sensing scheme to directly detect SARS-CoV-2 nucleic acid via DNA hybridization. A simple nanoimprinting pattern transfer technique was introduced to form uniform reproducible nanoslit arrays where the dimensions of the slit array were controlled by the thickness of the gold film. The plasmon-exciton coupling effect on the optical enhancement of different dye molecules, i.e., AO, propidium iodide (PI), or dihydroethidium (DHE) attached to the nanoslit surfaces, was examined thoroughly by measuring the surface reflection and fluorescence imaging. The results indicate that the best overlap of the plasmon resonance wavelength to the excitation spectrum of AO presented the largest optical enhancement (∼57×) compared to the signal at flat gold surfaces. Based on this finding, a sensitive assay for detecting DNA hybridization was generated using the interaction of the selected SARS-CoV-2 ssDNA and dsDNA with AO to trigger the metachromatic behavior of the dye at the nanoarray surfaces. We found strong optical signal amplification on the formation of acridine-ssDNA complexes and a quenched signal upon hybridization to the complementary target DNA (ct-DNA) along with a blue shift in the fluorescence of AO-dsDNAs. A quantitative evaluation of the ct-DNA concentration in a range of 100-0.08 nM using both the reflection and emission imaging signals demonstrated two linear regimes with a lowest detection limit of 0.21 nM. The sensing method showed high sensitivity and distinguished signals from 1-, 2-, and 3-base mismatched DNA targets, as well as high stability and reusability. This approach toward enhancing optical signal for DNA sensing offers promise in a general, rapid, and direct vision detection method for nucleic acid analytes.

Comparative evaluation of diagnostic methods for detection of Theileria spp. in cows

Theileriosis is a hemoprotozoan illness of cattle in tropical regions that poses a severe economic loss to dairy farmers in the form of production loss and mortality. We designed and optimized a multiplex real-time PCR by using Taq-Man® probe for detection and quantification of Theileria orientalis and Theileria annulata simultaneously by targeting 18 s rRna and MPSP (surface merozoite protein) genes, respectively. Fifty-five EDTA blood samples from clinically Theileria–suspected cows of three Theileria–endemic districts of Odisha were processed using acridine dye based fluorescent microscopy, Giemsa staining, and PCR. PCR revealed T. annulata and T. orientalis in 11/42 (26.11%) and 24/42 (57.14%) cases, respectively. Mixed infection due to both the Theileria spp. was recorded in 7/42 (16.66%). On comparison with gold standard test (PCR), the accuracy, sensitivity, and specificity were 92.72, 95.12, and 85.71% for Giemsa staining and 96.36, 97.56, and 92.85% for acridine orange dye. Multiplex real time PCR using Taq-Man probe detected two species of T. annulata and T. orientalis simultaneously. Acridine dye based fluorescent microscopy is comparatively easy and rapid method in detection of Thelieria spp.

Progressive Motility, DNA Fragmentation, Intact Plasma Membrane, and Acrosome Status of Frozen Semen Bali and Simmental Bulls

In increasing the population of bulls in Indonesia, it is necessary to utilize Artificial Insemination (AI) technology. AI reproductive technology aims to increase reproductive efficiency and use superior semen in livestock and can prevent the spread of reproductive diseases. Frozen semen is one of the factors that influence the success of AI. Thus, the quality of frozen semen must be maintained so fertility remains good. This study aimed to determine the quality of frozen semen of Bali and Simmental bulls at the Artificial Insemination Center, South Sulawesi. This study used frozen semen from two Bali and Simmental bulls. Parameters observed were progressive motility, deoxyribonucleic acid fragmentation (DNA), acrosome status, and intact plasma membrane. The progressive motility was tested using Computer-assisted sperm analysis (CASA Sperm Vision Minitube), the DNA fragmentation using acridine orange dye, the acrosome status using peanut agglutinin, and the intact plasma membrane staining using HOS solution. This study gives a result that the progressive motility, DNA fragmentation, and acrosome status of spermatozoa in frozen semen of Bali and Simmental bulls were not significantly different (P>0.05). In contrast, the whole plasma membrane of spermatozoa in Bali bulls' frozen semen was significantly higher (P<0.05) than in Simmental bulls. The results indicate that based on the parameters of progressive motility, DNA fragmentation, and acrosome status of spermatozoa, both bull breeds had the same quality of frozen semen. Meanwhile, according to the spermatozoa intact plasma membrane, the frozen semen of Bali bulls had better quality than that of Simmental bulls. Keywords: Artificial Insemination, frozen semen quality, Bali and Simmental bulls

Efficient photodegradation of Victoria Blue B and Acridine Orange dyes by nickel oxide nanoparticles

Nickel oxide (NiO) nanoparticle has been conveniently prepared by solution combustion method using urea as a fuel. Characterization of NiO nanoparticles has been performed by XRD, SEM with EDX, TEM, BET surface area determination, and UV-absorption spectroscopy. The band gap of the nanoparticle is 3.08 eV and average size of the nanoparticle is 26 nm, and the nanoparticles exhibited a cubic structure. Further, TEM confirms the average size is<35 nm. The synthesized nanoparticle has been successfully used against Victoria Blue B (VBB) and Acridine Orange (AO) dye degradation under natural solar irradiation by varying catalyst concentration, pH, and initial dye concentration. The prepared NiO nanoparticles showed excellent photocatalytic degradation of VBB and AO. The degradation efficiency was assessed by varying catalyst concentration, solution pH, and dye concentration. We obtained a high percentage of photodegradation at 1 × 10-4 mol/dm3 dye concentration and pH 4 for both dyes.

Single-cell microglial transcriptomics during demyelination defines a microglial state required for lytic carcass clearance

BackgroundMicroglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia respond and regulate demyelination is not fully understood.MethodsTo understand how microglia respond during demyelination, we fed mice cuprizone—a potent demyelinating agent—and assessed the dynamics of genetically fate-mapped microglia. We then used single-cell RNA sequencing to identify and track the microglial subpopulations that arise during demyelination. To understand how microglia contribute to the clearance of dead oligodendrocytes, we ablated microglia starting at the peak of cuprizone-induced cell death and used the viability dye acridine orange to monitor apoptotic and lytic cell morphologies after microglial ablation. Lastly, we treated serum-free primary microglial cultures to model distinct aspects of cuprizone-induced demyelination and assessed the response.ResultsThe cuprizone diet generated a robust microglial response by week 4 of the diet. Single-cell RNA sequencing at this time point revealed the presence of several cuprizone-associated microglia (CAM) clusters. These clusters expressed a transcriptomic signature indicative of cytokine regulation and reactive oxygen species production with altered lysosomal and metabolic changes consistent with ongoing phagocytosis. Using acridine orange to monitor apoptotic and lytic cell death after microglial ablation, we found that microglia preferentially phagocytose lytic carcasses. In culture, microglia exposed to lytic carcasses partially recapitulated the CAM state, suggesting that phagocytosis contributes to this distinct microglial state during cuprizone demyelination.ConclusionsMicroglia serve multiple roles during demyelination, yet their transcriptomic state resembles other neurodegenerative conditions. The phagocytosis of cellular debris is likely a universal cause for a common neurodegenerative microglial state.

Soil Actinomycetes of Vietnam Tropical Forests

Actinomycetes are an important group of bioactive hydrolytic bacteria in any ecosystem. However, the actinomycete biodiversity in tropical ecosystems, particularly in Vietnam, is still underexplored. The aim of this article is to analyze the abundance, taxonomic structure and ecophysiological features of actinomycete complexes of soils and litter in Vietnam’s protected areas. A total of 41 samples of soils, plant litter and suspended soils were collected from six of Vietnam’s national parks and nature reserves. The direct inoculation technique showed that the total abundance of actinomycetes varied from 2.0 × 104 to 1.0 × 108 CFU/g. According to the luminescent microscopy with acridine orange dye, the length of the actinomycete mycelium was as long as 1000 m/g in the litter of Xuan Son National Park. A total of 80 strains were isolated and tested for antagonistic activity against Bacillus subtilis, Aspergillus niger and Candida albicans. Inoculation on Getchinson’s medium showed high cellulolytic activity. The most active strains were isolated from alluvial brown soil, plant litter and suspended soil of the Pu Hoat Nature Reserve. In these samples, actinomycetes adapted to high temperatures and low pH were found to be predominant. High-throughput sequencing of the V3–V4 region of the 16S rRNA gene and bioinformatic analysis confirmed the high taxonomic diversity and high hydrolytic activity of actinomycete complexes of the Pu Hoat Nature Reserve samples.

Biointerfacial Analysis of HEK293 Cells in Contact with Hydrogels based on Poly‐N‐Isopropylacrylamide and Copolymers

AbstractSeveral researches have demonstrated that synthetic hydrogels can mimic the mechanical and physicochemical properties of native extracellular matrices and act as cell‐scaffold. The biointerface can influence over tissue activities such as adhesion, signaling, cell–cell communications, and proliferation. In this work, the behavior of human embryonic kidney cells (HEK293) in contact with hydrogel surfaces based on poly‐N‐isopropylacrylamide (PNIPAM) and copolymers is studied. Ionic and neutral hydrogel surfaces are synthesized by free radical polymerization and characterized by Fourier‐transform infrared spectroscopy, swelling capacity, and wettability at culture conditions. Viability, proliferation, and bioadhesive capacity are analyzed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide and Neutral Red assays, [3H]‐thymidine technique, Acridine Orange and Hoechst dye. Noncytotoxic and proliferative effects are observed in all cases. HEK293 cells are mainly adapted and adhered on neutral and low ionic charge surfaces showing typical cell morphology, and normal mitotic rates. While, lower adhesion, abnormal nuclear and cytoplasmic morphologies with mitotic/fragmentation processes are observed after contact with high ionic surfaces. The cellular cycle after cultive on PNIPAM, assessed by flow cytometry, is not affected regarding control surfaces (polystyrene). Therefore, hydrogel surfaces with neutral and low ionic charges can be apt to in vitro tissue development and possible applications of biomedical treatments.

New insights into the antiviral activity of nordihydroguaiaretic acid: Inhibition of dengue virus serotype 1 replication

BackgroundDengue virus (DENV) is considered one of the most important pathogens in the world causing 390 million infections each year. Currently, the development of vaccines against DENV presents some shortcomings and there is no antiviral therapy available for its infection. An important challenge is that both treatments and vaccines must be effective against all four DENV serotypes. Nordihydroguaiaretic acid (NDGA), isolated from Larrea divaricata Cav. (Zygophyllaceae) has shown a significant inhibitory effect on a broad spectrum of viruses, including DENV serotypes 2 and 4. PurposeWe evaluated the in vitro virucidal and antiviral activity of NDGA on DENV serotype 1 (DENV1), including the study of its mechanism of action, to provide more evidence on its antiviral activity. MethodsThe viability of viral particles was quantified by the plaque-forming unit reduction method. NDGA effects on DENV1 genome and viral proteins were evaluated by qPCR and immunofluorescence, respectively. Lysosomotropic activity was assayed using acridine orange and neutral red dyes. ResultsNDGA showed in vitro virucidal and antiviral activity against DENV1. The antiviral effect would be effective within the first 2 h after viral internalization, when the uncoating process takes place. In addition, we determined by qPCR that NDGA decreases the amount of intracellular RNA of DENV1 and, by immunofluorescence, the number of cells infected. These results indicate that the antiviral effect of NDGA would have an intracellular mechanism of action, which is consistent with its ability to be incorporated into host cells. Considering the inhibitory activity of NDGA on the cellular lipid metabolism, we compared the antiviral effect of two inhibitors acting on two different pathways of this type of metabolism: 1) resveratrol that inhibits the sterol regulatory element of binding proteins, and 2) caffeic acid that inhibits the 5-lipoxygenase (5-LOX) enzyme. Only caffeic acid produced an inhibitory effect on DENV1 infection. We studied the lysosomotropic activity of NDGA on host cells and found, for the first time, that this compound inhibited the acidification of cell vesicles which would prevent DENV1 uncoating process. ConclusionThe present work contributes to the knowledge of NDGA activity on DENV. We describe its activity on DENV1, a serotype different to those that have been already reported. Moreover, we provide evidence on which stage/s of the viral replication cycle NDGA exerts its effects. We suggest that the mechanism of action of NDGA on DENV1 is related to its lysosomotropic effect, which inhibits the viral uncoating process.

Multi dye degradation, antibacterial, antidiabetic and antioxidant assessment of silver nanoparticles (Ag-NPs) derived via leaves of Smilax aspera

Biosynthesized nanomaterials are in high demand due to their potential in medical applications and the search for efficient biosynthesized nanomaterials continues. The endeavor of this research work is to synthesize silver nanoparticles (Ag-NPs) utilizing an aqueous extract of Smilax aspera (S. aspera) leaves. Several analytical techniques were used to investigate the shape, morphology and size of NPs. UV–visible spectroscopy exhibited a band at 472 nm indicating the formation of Ag-NPs, phytoconstituents functioning as capping or reducing agent are revealed by FT-IR, XRD (X-Ray diffraction) verified cubic crystalline structure having (h,k,l) values at (1 1 1), (2 0 0), (2 2 0), (3 1 1) and (2 2 2). Energy dispersive X-rays spectroscopy confirmed the purity of elemental silver, Scanning electron microscopy as well as Transmission electron microscopy (TEM) reported that particles are in a spherical shape with a normal particle size of 34 nm. Furthermore, in DLS data two peaks at 5.89 nm (5%) and 39.99 nm (95%) were observed, which supports the TEM finding. The Synthesized Ag-NPs have shown significant antibacterial activity against pathogens due to the capping of the bioactive components of Smilax aspera leaves. Furthermore, The antioxidant potential of synthesized Ag-NPs was calculated performing 2,2 diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging assay. Moreover, Methylene blue, Rose bengal, and Acridine orange dyes have also been degraded employing Ag-NPs as a catalyst. Inhibition of carbohydrate hydrolyzing enzymes, in addition to the previously mentioned actions, emphasized the antidiabetic efficacy of these produced Ag-NPs. Overall, Ag-NP’s efficient bioactivities indicate their promising future in biomedical and environmental remediation applications.

Visible light assisted heterojunction composite of AgI and CDs doped ZIF-8 metal-organic framework for photocatalytic degradation of organic dye

• CDs@ZIF-8@AgI was prepared by a solvent-free way coupled to ion deposition strategy. • Acridine Orange can be effectively degraded by CDs@ZIF-8@AgI under visible light. Water pollution induced by the productive process of organic dyes would lead to various diseases, and so treatment of the wastewater is an urgent task for protecting human health and ecological environment. In this work, visible light responsive heterojunction material based on silver iodide and carbon dots (CDs) doped ZIF-8 metal organic frameworks (CDs@ZIF-8@AgI) has been prepared by a green solvent-free strategy and in-situ ion deposition method. The CDs@ZIF-8@AgI composites have high photocatalytic performance for degradation of acridine orange (AO) dye under visible light, and the maximum degradation percentage can reach to 96.0%, which was estimated by the UV-visible spectroscopy. The porous structure and large surface area of the photocatalyst were favorable to absorption of the target dye on the catalyst, which can promote the kinetic degradation rate for low level concentration of the dye. The introduction of CDs into the AgI heterojunction can improve the electron transport efficiency and visible light absorption capacity, and thus significantly enhancing the photocatalytic activity of the catalyst. The photocatalytic mechanism was proposed as indirect Z-scheme heterojunction type based on the energy band structure of the catalyst. This work provides a visible light photocatalyst for removal of the AO dye in wastewater and offers a promising strategy for developing photocatalyst for treatment of organic pollutants in the environment using solar energy.

Hydrothermally controllable fabrication of Bi2WO6 nanocapsules decorated by CuO nanorods with enhanced visible photocatalytic performance

A Bi2WO6 nanocapsules-like structure decorated by CuO nanorods for the construction of n–p heterojunction CuO/Bi2WO6 nanocomposites was developed through a facile two-step process, which utilized a hydrothermal approach. The optical properties and structural morphology of CuO/Bi2WO6 nanocomposite photocatalysts were demonstrated. The synthesized photocatalysts were assessed via the degradation of acridine orange (AO) dye as the target pollutant under visible illumination. The 15% CuO/Bi2WO6 nanocomposite showed the highest photocatalytic ability, which oxidized 100% of the AO dye within 40 min. The 15% CuO/Bi2WO6 nanocomposite showed the highest rate constant of 0.0484 min−1 for AO dye, which was approximately 4.75- and 4.28-fold larger than those of Bi2WO6 (0.0102 min−1) and CuO (0.0113 min−1), respectively. The enhanced photocatalytic abilities of the CuO/Bi2WO6 nanocomposites were attributed to the strengthening absorption of visible light, the construction of the n–p heterojunction, the effective charge separation according to the S-scheme mechanism and the extended carrier lifetime, which efficiently suppressed photoinduced electron/hole recombination. The obtained CuO/Bi2WO6 nanocomposites were stable over five consecutive cycles with almost constant degradation ability. Therefore, due to their promising photocatalytic abilities, the CuO/Bi2WO6 nanocomposites are suitable photocatalysts for environmental treatment applications.

PH responsive biohybrid BSA-poly(DPA) nanoparticles for interlysosomal drug delivery

pH-responsive nanocarrier systems exhibit diverse applications due to their relevance to biological systems where, discrete pH differences are displayed between tissues and cellular compartments. Changes in the physicochemical properties of responsive nanocarriers due to variations in pH, can cause release of their cargos in a targeted and controllable manner offering spatiotemporal control. In this study, bovine serum albumin-poly(2-(diisopropylamino)ethyl methacrylate) (BSA-poly(DPA)) biohybrid nanoparticles were synthesized via controlled radical polymerization and found to be stable in neutral pH (7.4) while, at lower pHs (4–5.5) they were shown to disassemble and release their payload. In vitro tests demonstrated low cytotoxicity and energy-, dose- and time-depended internalization. BSA-poly(DPA) nanocarriers loaded with the metachromatic dye acridine orange, were successfully delivered in HeLa cells where, a pH-triggered release of their cargo into lysosomes was evidenced paving the way for applications related with the treatment of lysosomal diseases.

Absorption Properties of Polyvinyl Alcohol Films Filled with Nanoparticles Doped with Acridine Orange Dye

Polyvinyl Alcohol (PVA) polymer/ Acridine Orange (AO) dye films prepared via casting technique at room temperature. The effect of adding (Acridine Orange (AO) dye solution, Magnesium Oxide (MgO), and Aluminum Oxide (Al2O3) NPs) to the PVA polymer matrix were studied on the absorption spectra. The effect of AO addition on the absorption spectrum of PVA film is occurrence blue shift (5nm) from 280nm to 275 nm in the PVA and red shift (10nm) from 490nm to be 500 nm for AO maximum absorbance wavelength. The absorbance of AO dye decreases when adding PVA, but increases When the volume ratio of AO dye solution is increased to 0.49 for 18ml, the volume ratio of AO dye solution decreases for 24- and 30-ml volume ratios. Adding NPs led to enhancing the photophysical properties of polymer composite, noted that absorbance of adding alumina nanoparticles more than it is in the case of adding magnesia nanoparticles. Also, there is a 10 nm red shift in AO and a 5 nm blue shift in AO when they are added to the polymer matrix filled with MgO and Al2O3 NPs.

Fabrication of highly sensitive 4-Nitrophenol sensor and photocatalytic performance of multifunctional Ba0.5Sr0.5CoxHfxFe12-2xO19 Ferrite

In this approach, Ba0.5Sr0.5Fe12-2x(CoHf)xO19 ferrite samples have been successfully prepared using the conventional solid-state method, and single hexagonal crystal structure of the M-type hexaferrite phase have been formed according to the space group No. 194 (P63/mmc). The cation distribution in Ba0.5Sr0.5Fe12-2x(CoHf)xO19 has been defined. The bandgap energies of ferrite compositions are found to be 2.86, 2.83, 2.85, 2.89, 2.89, and 2.89 eV for different concentrations x = 0, 0.2, 0.4, 0.6, 0.8 and 1, respectively. The photocatalytic efficiencies were evaluated by degradation of an aqueous solution of Acridine Orange (AO) dye [0.03 mM] under visible light. Interestingly, the Ba0.5Sr0.5CoxHfxFe12-2xO19 at x = 0.4 exhibited the highest degradation rate of AO which was about 3.6 times larger than Ba0.5Sr0.5CoxHfxFe12-2xO19 at x = 0. The findings showed a slight decrease in the photocatalytic performance of compositions x = 0.0 after five cycles, indicating a stable photo-catalyst behavior. Additionally, a highly sensitive and selective electrochemical sensor on a glassy carbon electrode (GCE) for the detection of 4-nitrophenol (4-NP) has been fabricated with the similar Ba0.5Sr0.5CoxHfxFe12-2xO19 (x = 0.4) composition. The electrochemical linear responses of the 4-NP chemical sensor were studied over the concentration range (0.1 nM–0.01 mM), known as a linear dynamic range (LDR). The obtained slope from the calibration curve was applied in the calculation of the sensitivity (16.9114 μAμM−1cm−2), and detection limit (96.11 ± 4.81 pM) of the proposed 4-NP electrochemical sensor with Ba0.5Sr0.5CoxHfxFe12-2xO19 (x = 0.4) fabricated Nafion coated GCE. The Ba0.5Sr0.5CoxHfxFe12-2xO19 (x = 0.4)/Nafion/GCE sensor parameters were found to be reliable in performance of response time and repeatability in comparison to previous reports. Finally, the prepared Ba0.5Sr0.5CoxHfxFe12-2xO19 (x = 0.4) material is introduced in a new route by the photocatalytic and electrochemical approaches to remove colored and carcinogenic chemicals from the environmental and healthcare fields in a broad scale.

Unraveling pH-responsive contrasting supramolecular interaction of acridine orange with γ-Cyclodextrin

• Protonated (AOH + ) and neutral (AO) forms of the acridine orange dye showed contrasting changes in their photophysical properties on complexation with γCD. • In the AOH + - γCD system, both dimeric AOH + -γCD and monomeric AOH + -γCD complexes are formed. • In the AO-γCD system, mainly the dimeric AO-γCD complexes are formed. • Nature of the protonation state of the dye and involvement of mainly hydrophobic interactions play a governing role in the present systems. Current study explores the contrasting supramolecular recognition behavior of protonated (AOH + , pH ∼ 7) and neutral (AO, pH ∼ 12) forms of the acridine orange dye with γ-cyclodextrin (γCD) host, investigated using various photophysical and NMR measurements. Intriguingly, AOH + undergoes sequential multi-mode binding interactions with the γCD host showing the predominant formation of dimeric AOH + -γCD inclusion complexes at lower γCD concentration region, and subsequently, these initially formed γCD bound AOH + dimers undergo disintegration to form a monomeric AOH + -γCD inclusion complexes at higher γCD concentration region. On the contrary, surprisingly, upon interaction with γCD, the neutral AO dye preferentially undergoes only dimeric AO-γCD complex formation throughout the entire host concentration used. The distinctly different supramolecular recognition of the AOH + and AO with γCD suggests that the difference in the protonation state of the dye and involvement of mainly hydrophobic driving forces in the complexation process plays the directing role in determining the overall distinctly different complexation behavior of the present AOH + -γCD and AO-γCD systems. Notably, the present study is the first report to reveal the pH dependent contrasting interaction mechanism of the different protonation states of the dye with the γCD host. The observed results may provide a suitable approach to design pH-controlled supramolecular assemblies, potentially applying to drug delivery, molecular sensor, molecular devices, logic gates, and stimuli-responsive functional material. Present study demonstrates the remarkable pH-dependent contrasting interaction mechanism of the protonated (AOH + ) and neutral (AO) forms of the acridine orange dye upon complexation with γ-cyclodextrin (γCD) host.

Validation of automated fluorescent-based technology for measuring total nucleated cell viability of hematopoietic progenitor cell products.

A reliable rapid method for measuring total nucleated cell (TNC) viability is essential for cell-based products manufacturing. The trypan blue (TB) exclusion method, commonly used to measure TNC viability of hematopoietic progenitor cell (HPC) products, is a subjective assay, typically uses a microscope, and includes a limited number of cells. The NucleoCounter NC-200 is an automated fluorescent-based cell counter that uses pre-calibrated cartridges with acridine orange and DAPI dyes to measure cell count and viability. This study describes the validation of the NC-200 for testing HPC's viability. Samples from 189 fresh and 60 cryopreserved HPC products were included. Fresh products were tested for viability after collection by both TB and NC-200. 7-aminoactinomycin D (7AAD) CD45+ cell viability results were obtained from a flow cytometry test. Cryopreserved products thawed specimens were tested for viability by both TB and NC-200. The NC-200 viability results were compared with the other methods. Acceptability criteria were defined as ≤10% difference between the NC-200 method and the other methods for at least 95% of the samples. Fresh products' mean viability difference between NC-200 and TB or 7AAD CD45+ method was 4.9% (95%CI 4.6-5.4) and 2.8% (95%CI 2.2-3.4), respectively. Thawed products' mean viability difference between NC-200 and TB was 3.0% (95%CI 0.4-5.6). The NC-200 automated fluorescent-based method can be used effectively to determine HPC's viability for both fresh and cryopreserved products. It can help eliminate human bias and provide consistent data and operational ease.

Sunlight assisted photocatalytic dye degradation using zinc and iron based mixed metal-oxides nanopowders

For the photocatalytic degradation of the organic dyes present in wastewater, the ternary composites of metal-oxides nanopowders of zinc-iron-calcium (Zn-Fe-Ca), zinc-iron-antimony (Zn-Fe-Sb), zinc-iron-titanium (Zn-Fe-Ti) and zinc-iron-cobalt (Zn-Fe-Co) were synthesized and characterized by different instruments. The average particle size of the Zn-Fe-Ca and Zn-Fe-Ti mixed-oxides nanopowders was 10 ± 5 nm and that of Zn-Fe-Sb nanopowder was 20 ± 10 nm. The flakes of Zn-Fe-Co nanopowder were 10 ± 5 nm thick and 100 nm to 300 nm long. All the mixed-oxides were utilized for photocatalytic degradation of acridine orange (AO) where Zn-Fe-Sb degraded the 98 % of acridine orange (AO), within 20 min, while the same level of degradation was attained by Zn-Fe-Ti and Zn-Fe-Ca mixed-oxides in 80 min and 90 min, respectively. The more efficient Zn-Fe-Sb photocatalyst was further utilized for the degradation of malachite green (MG), brilliant green (BG), methyl orange (MO) and congo red (CR). Zn-Fe-Sb was found to be fast and efficient photocatalyst for the degradation of AO and therefore, the effect of various parameters was studied in detail to optimize the reaction conditions. Moreover, the Zn-Fe-Sb mixed-oxides were used to photodegrade the AO dye in four different environmental water samples (sea, tap and sewage). Keeping in view the practical conditions, a tube-type and funnel-type filters were designed for dynamic purification process using Zn-Fe-Sb mixed-oxides as catalyst under sunlight. The synthesized nanomaterials have great potential to contribute in the wastewater treatment technologies.

Efficiency and mechanism of acridine orange removal by citric-acid-crosslinked β-cyclodextrin

Herein, three types of citric-acid-crosslinked β-cyclodextrin (CA/β-CD) adsorbents with different mass ratios were synthesized, which application in remove of cationic dye Acridine Orange (AO) from water was investigated. The CA/β-CD materials were characterized and analysised by scanning electron microscopy (SEM), X-ray diffraction (XRD), Infrared spectrometer (IR), and thermogravimetry (TG). Effects of adsorbent dosage, adsorption time, solution initial pH and initial concentration on adsorption performance were researched. The aggregate analysis of molecular docking and experimental results inferred that high theoretical adsorption capacity (666.67 mg/g) was attributed to the abundance of adsorption sites, the reactivity of the carboxyl groups on CA, and the cavities in β-CD. Furthermore, the “adsorption-desorption” cycle analysis proved that the CA/β-CD adsorbent exhibited excellent recyclability. Consequently, the conversion of CA/β-CD material into advanced cationic dye sorbent is a promising production for environmentally friendly and industrial development.

Comparing the Efficiency of Nanostructured Pure and Modified ZnO in the Photocatalytic Degradation of Acridine Orange Dye from Wastewater

Comparing the Efficiency of Nanostructured Pure and Modified ZnO in the Photocatalytic Degradation of Acridine Orange Dye from Wastewater