Structural and Optical Properties of Varies Thickness of Znte Nanoparticle

ZnTe thin films of different thicknesses were deposited onto glass substrates for optical devices applications. Xray diffractogram of different thicknesses for ZnTe films are measured and their patterns exhibits polycrystalline nature with a preferential orientation along the (111) plane. X-ray diffraction techniques have been employed to determine themicrostructure parameters, both crystallite size and microstrain. Film thickness and the optical constants of ZnTe films were calculated based on the measured transmittance spectral data using Swanepole’s method in the wavelength range 400–2500 nm. The refractive index n and absorption index k were calculated and the refractive index exhibits a normal dispersion. The refractive index could be extrapolated by Cauchy dispersion relationship over the whole spectra range, which extended from 400 to 2500 nm. The optical band gap can be calculated in strong absorption region and displays an allowed direct transition. Both the refractive index and the band gap increase with the increase film thickness, thus ZnTe/glass substrates are good candidates in optoelectronic devices.Keywords: ZnTe, thin film, cry crystallitze size; microstrain; optical constants

Structural and Optical Properties of Varies Thickness of Znte Nanoparticle

ZnTe thin films of different thicknesses were deposited onto glass substrates for optical devices applications. Xray diffractogram of different thicknesses for ZnTe films are measured and their patterns exhibits polycrystalline nature with a preferential orientation along the (111) plane. X-ray diffraction techniques have been employed to determine the microstructure parameters, both crystallite size and microstrain. Film thickness and the optical constants of ZnTe films were calculated based on the measured transmittance spectral data using Swanepole’s method in the wavelength range 400–2500 nm. The refractive index n and absorption index k were calculated, and the refractive index exhibits a normal dispersion. The refractive index could be extrapolated by Cauchy dispersion relationship over the whole spectra range, which extended from 400 to 2500 nm. The optical band gap can be calculated in strong absorption region and displays an allowed direct transition. Both the refractive index and the band gap increase with the increase film thickness, thus ZnTe/glass substrates are good candidates in optoelectronic devices

Poly-lactic acid nanoparticles (PLA-NP) promote physiological modifications in lung epithelial cells and are internalized by clathrin-coated pits and lipid rafts

BackgroundPoly-lactic acid nanoparticles (PLA-NP) are a type of polymeric NP, frequently used as nanomedicines, which have advantages over metallic NP such as the ability to maintain therapeutic drug levels for sustained periods of time. Despite PLA-NP being considered biocompatible, data concerning alterations in cellular physiology are scarce.MethodsWe conducted an extensive evaluation of PLA-NP biocompatibility in human lung epithelial A549 cells using high throughput screening and more complex methodologies. These included measurements of cytotoxicity, cell viability, immunomodulatory potential, and effects upon the cells’ proteome. We used non- and green-fluorescent PLA-NP with 63 and 66 nm diameters, respectively. Cells were exposed with concentrations of 2, 20, 100 and 200 µg/mL, for 24, 48 and 72 h, in most experiments. Moreover, possible endocytic mechanisms of internalization of PLA-NP were investigated, such as those involving caveolae, lipid rafts, macropinocytosis and clathrin-coated pits.ResultsCell viability and proliferation were not altered in response to PLA-NP. Multiplex analysis of secreted mediators revealed a low-level reduction of IL-12p70 and vascular epidermal growth factor (VEGF) in response to PLA-NP, while all other mediators assessed were unaffected. However, changes to the cells’ proteome were observed in response to PLA-NP, and, additionally, the cellular stress marker miR155 was found to reduce. In dual exposures of staurosporine (STS) with PLA-NP, PLA-NP enhanced susceptibility to STS-induced cell death. Finally, PLA-NP were rapidly internalized in association with clathrin-coated pits, and, to a lesser extent, with lipid rafts.ConclusionsThese data demonstrate that PLA-NP are internalized and, in general, tolerated by A549 cells, with no cytotoxicity and no secretion of pro-inflammatory mediators. However, PLA-NP exposure may induce modification of biological functions of A549 cells, which should be considered when designing drug delivery systems. Moreover, the pathways of PLA-NP internalization we detected could contribute to the improvement of selective uptake strategies

Tailored Approaches in Drug Development and Diagnostics: From Molecular Design to Biological Model Systems

Approaches to increase the efficiency in developing drugs and diagnostics tools, including new drug delivery and diagnostic technologies, are needed for improved diagnosis and treatment of major diseases and health problems such as cancer, inflammatory diseases, chronic wounds, and antibiotic resistance. Development within several areas of research ranging from computational sciences, material sciences, bioengineering to biomedical sciences and bioimaging is needed to realize innovative drug development and diagnostic (DDD) approaches. Here, an overview of recent progresses within key areas that can provide customizable solutions to improve processes and the approaches taken within DDD is provided. Due to the broadness of the area, unfortunately all relevant aspects such as pharmacokinetics of bioactive molecules and delivery systems cannot be covered. Tailored approaches within (i) bioinformatics and computer-aided drug design, (ii) nanotechnology, (iii) novel materials and technologies for drug delivery and diagnostic systems, and (iv) disease models to predict safety and efficacy of medicines under development are focused on. Current developments and challenges ahead are discussed. The broad scope reflects the multidisciplinary nature of the field of DDD and aims to highlight the convergence of biological, pharmaceutical, and medical disciplines needed to meet the societal challenges of the 21st century

Phytoestrogen <i>β</i>-Sitosterol Exhibits Potent In Vitro Antiviral Activity against Influenza A Viruses

Influenza is a contagious infection in humans that is caused frequently by low pathogenic seasonal influenza viruses and occasionally by pathogenic avian influenza viruses (AIV) of H5, H7, and H9 subtypes. Recently, the clinical sector in poultry and humans has been confronted with many challenges, including the limited number of antiviral drugs and the rapid evolution of drug-resistant variants. Herein, the anti-influenza activities of various plant-derived phytochemicals were investigated against highly pathogenic avian influenza A/H5N1 virus (HPAIV H5N1) and seasonal low pathogenic human influenza A/H1N1 virus (LPHIV H1N1). Out of the 22 tested phytochemicals, the steroid compounds β-sitosterol and β-sitosterol-O-glucoside have very potent activity against the predefined influenza A viruses (IAV). Both steroids could induce such activity by affecting multiple stages during IAV replication cycles, including viral adsorption and replication with a major and significant impact on the virus directly in a cell-free status “viricidal effect”. On a molecular level, several molecular docking studies suggested that β-sitosterol and β-sitosterol-O-glucoside exhibited viricidal effects through blocking active binding sites of the hemagglutinin surface protein, as well as showing inhibitory effects against replication through the binding with influenza neuraminidase activity and blocking the active sites of the M2 proton channel activity. The phytoestrogen β-sitosterol has structural similarity with the active form of the female sex hormone estradiol, and this similarity is likely one of the molecular determinants that enables the phytoestrogen β-sitosterol and its derivative to control IAV infection in vitro. This promising anti-influenza activity of β-sitosterol and its O-glycoside derivative, according to both in vitro and cheminformatics studies, recommend both phytochemicals for further studies going through preclinical and clinical phases as efficient anti-influenza drug candidates

Comparative study of acid functionization of carbon nanotube via ultrasonic and reflux mechanism

© 2018 Elsevier Ltd. Multi-walled carbon nanotubes (MWCNTs) have a great potential in wide applications due to their extraordinary physical, thermal and mechanical properties. However, the known shortcomings, such as hydrophobic nature, poor solubility and dispersibility in most solvents have impeded the technology to further develop. In the present study, various types of acid functionalized MWNCTs (f-MWCNTs) samples were prepared. The investigated process parameters include type of acids, acid concentrations, treatment methods, operating temperature and treatment duration. The f-MWCNTs were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Energy dispersive X-ray (EDX), Field Emission Scanning Electron Microscopy (FESEM) and Zetasizer. The optimum conditions for acid functionalization of MWCNTs were achieved by dispersing MWCNTs in concentrated nitric and sulfuric acid mixture (1:3 v/v ratio), via ultrasonication treatment method at 40 °C for 2.5 h. EDX analysis also revealed that, 21.36 wt% of oxygenated functional groups, with no strong detection of inorganic and metal impurities. In addition, FESEM results also revealed that there is no any severe structural damage on the surface. Acid functionalization of MWCNTs via ultrasonic bath methods is more desirable than reflux method as it can result in high yields of MWCNTs with high density of oxygenated functional groups and minimum structural destruction on the surface of MWCNTs