Nanoscience & Nanotechnology-Asia - Volume 9, Issue 1, 2019

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

Introduction: Nanotechnology, an advanced science discipline has proved to be vital in solving the major issues or problems, the present world is facing. Nanotechnology has already proved to be the science of revolutionizing agriculture, energy conversions, applied & medical science and other domains. Conclusion: In this paper, we present the recent developments taken place in bio-nanotechnology related to different forms of nanomaterial's developed along with their application; overcoming hazardous effects of chemical pesticides, fertilizers and herbicides by promoting green and sustainable agriculture through the use of nanofertilizers, nano pesticides and detection & control of plant diseases by using nanoparticles; development of diagnostic tools for detection and control of human diseases; targeted delivery of drugs by using nanomaterial's, protection of the environment through nanoparticles based pollution checking, bioremediation, renewable energy production and role of nanotechnology in applied sciences.

Introduction: Nanomaterials are emerging as a fascinating delivery systems being explored for the delivery of different bioactives including drug, diagnostic agents and genetic materials etc. Among these nanomaterials dendrimers and Carbon Nanotubes (CNTs) are being investigated for various biomedical applications. Although both of these nanomaterials have shown great potential in drug delivery yet their promising clinical applications are still suspected due to problems like toxicity, dispersibility etc. Scientists have been investigating the potential of nanohybrids comprising of dendrimers and nanotubes for biomedical applications. Few reports are also available on the toxicological profile of CNTs and dendrimers nanohybrids. Conclusion: The results of these investigations suggest two possibilities, first, hybrids of CNTs and dendrimers could suppress each other's demerits while synergizing the potentials; second, prospective toxicity of nanohybrids on which different reports have discrimination in results. Future biomedical applications of CNTs-dendrimers nanohybrids require a thorough investigation on their toxicity and biological interactions.

Introduction: Nanomaterials are attractive because of these exhibits catalytic activity, optical, magnetic, electrically conducting properties and biological activities. Besides the potential economic values, the benefits offered by nanomaterials are expected to have significant impacts on almost all sectors of our society. The industries are releasing the nanoparticles into nearby water bodies like ponds, rivers, which causes toxicity to aquatic flora as well as fauna. Nanoparticles, especially which are prepared using heavy metals being toxic to organisms, ranging from phytoplankton (at the bottom of the food chain) to marine invertebrates such as oysters, snails and different types of fish, especially in their immature stages. Many species of fish and shellfish disrupts the ecosystem health on exposure to metals nanoparticles. Albeit, the academicians and researchers are trying to understand the toxicity of metal nanoparticles, particularly with respect to cascade pathways that lead to inflammatory responses, there is need to prepare and urgent implement laws to manage potential risks of nanomaterials which might become a major catastrophe in coming future. Conclusion: In the present review, the emphasis has given on the synthesis, characterization and toxic effects of metal nanoparticles on aquatic fauna and also the future tremendous prospects of these toxicants.

Introduction: Nanotechnology is a science, engineering conducted at nanoscale level for the manipulation of matter to create materials with significantly unusual, varied and new properties. Attributes of these synthesized nanomaterials promise to provide a number of applications in health including nanomedicine, nanorobots/nanobots, nanostars, nanofibers, chemotherapy and many more. There has been a remarkable interest in identification of adverse health effects associated with the use of nanotechnology too. The focus of this review is to highlight the current techniques and development of new technologies advancing medical science and disease treatment in human healthcare. Firstly, several Nano-pharmaceuticals and Nano-diagnostic methods offer numerous potential ways for targeted drug delivery, gene therapy, cancer treatment and clinical diagnosis to provide best rational use of the medicine and minimize the toxic effects. These techniques can also help to design certain drugs in a controlled way to avoid their structural complexity by dealing at the atomic and molecular level. Secondly, along with the discussion of potential applications of nanotechnology, some of the examples will be given to elaborate the various scientific and technical aspects in the real life. Conclusion: Finally, conclusion with the future scope and challenges of nanotechnology in health will be described and discussed.

Introduction: Neurodegenerative disease is a collective term for a number of diseases that affect the neurons in the human brain. The location of the neuronal loss in the brain leads to the specified disease based on the progression of the clinical symptoms. No drugs are available for complete cure of these diseases. Most of the drugs only slow down the progression of neuronal damage. The combination of drugs with nanotechnology gave a new promising hope for the treatment of neurological disorders. Nanomedicines are extremely useful for safe, effective, target oriented and sustained delivery. Due to their size in nanometer, they possess distinct and improved properties in comparison to their bulk counterpart. The utility of nanomedicines in neurological disorders including neurodegenerative diseases constitutes nanoneuromedicines. Conclusion: In this article, a comprehensive overview of the application of nanoneuromedicines in neurodegenerative diseases such as Alzheimer's Disease (AD), Parkinson's Disease (PD) and Amyotrophic Lateral Sclerosis (ALS) is provided.

Introduction: This review gives an overview of interesting properties of nanoparticles finding potential applications in nanomedicines and their considerations that need to be made such as toxicity while developing a nanomedicine by providing an understanding of a relationship between nanocarrier, targeting moieties and drugs with optical and magnetic properties. Here, we correlate the interesting properties of nanomaterials to their applications in living cells/body simultaneously promises, prospects and toxicity challenges of nanomedicines have also been discussed in detail. Exemplifying the usage of gold nanoparticles and its derivatives such as hetero and homo hybrid nanostructures that allow their use as contrast agents, therapeutic entities and supports to attach functional molecules and targeting ligand along with molecular framework structures. Here, we present the future prospects for potential applications in nanomedicines. These nanomaterials have been used for varieties of biomedical applications such as targeted drug delivery, photothermal cancer therapies, MRI, optical imaging, etc. in vitro and in vivo. Conclusion: In summary, this review provides innumerable aspects in the emerging field of nanomedicine and possible nanotoxicity.

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.

Introduction: Here we propose an accurate drain current model for a Symmetric Dual Gate Tunnel FET (SDG-TFET) using effective tunneling length and generation rate of carrier over tunneling junction area. Analytical Modeling: The surface potential of the model is obtained by solving 2-dimensional Poisson's equation and further extends to determine the magnitude of initial tunneling length and final tunneling length. The different DC performance indicators like drain current (ID), threshold voltage (Vth), transconductance (gm) and Subthreshold Slope (SS) for the present model are extensively investigated and the results are compared with that of Single Gate Tunnel FET (SGTFET). Conclusion: The practical importance of this model relies on its accuracy and improved electrostatic performance over SG-TFET. The analytical model results are validated using TCAD Sentaurus (Synopsys) device simulator.

Introduction: In this study the synthesis and characterization of copper oxide nanoparticles via solid state thermal decomposition of a recently synthesized aqua nitrato copper(II) complex with a tridentate Schiff-base ligand (1) as a new precursor are reported. Materials & Methods: The copper complexes were obtained by sonochemical and solvothermal process and characterized by Scanning Electron Microscopy (SEM), X-ray powder Diffraction (XRD) and FT-IR spectroscopy. The thermal stability of compound (1) was studied by Thermogravimetric Analysis (TGA). The amount of initial reagents and the role of reaction time on size and morphology of nanostructure compound (1) were studied. CuO nanoparticles were simply synthesized at 500 oC under air atmosphere. Results & Conclusion: The diameter of CuO nanoparticles was estimated to be about 200 and 30 nm from copper complex precursor obtained by sonochemical and solvothermal methods respectively.

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion: The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

Background: Fogging is a common phenomenon and often causes trouble to people in daily life. Antifogging (AF) and Antireflective (AR) coatings can be effectively used to provide resistance to fogging and maintain the optical clarity in day-to-day life. For this reason, they are useful for maintaining optical clarity in optical instrument and display devices. Methods: Antifogging and antireflective coatings were fabricated using a Spin-LbL assembly process, and this process is driven by electrostatic interactions between the positively charged ZrO2 NPs and negatively charged SiO2 NPs. Results: The textured surfaces and void fraction can significantly enhance the wettability of surfaces with water. And this may result in enhanced AF properties. In the Water contact angles (WCA) test, the ZrO2/SiO2 and SiO2/ZrO2 coatings were all superhydrophilic (almost 0°, less than 0.04 s). In the boiling test and low temperature AF test, the ZrO2/SiO2 and SiO2/ZrO2 samples showed excellent AF properties. Conclusion: Antifogging and antireflective coatings were fabricated via Spin-LbL assembly of the positively charged ZrO2 NPs and negatively charged SiO2 NPs followed by calcination. The resultant coatings showed excellent AF properties due to the superhydrophilicity of the coating, exhibited excellent AR properties due to the low refractive index coating and an appropriate coating thickness, and showed excellent superhydrophilic properties due to a nano-roughness structure.

Background: New application can be obtained by the integration between carbon nanotube technology Nano-Electro-Mechanical system (NEMs) and Micro-Electro-Mechanical system (MEMs). The new application is a transistor, which uses carbon nanotube as the channel between the source and drain, while MEMs resonator bridges are used as suspending gates. Methods: preparation process of the electrodes (source/drain), carbon nanotube growth between electrodes and the characterization of carbon nanotube channel using Raman spectroscopy to study the time and temperature effect on the quality of Carbon Nanotube channel (CNT-channel), field emission scanning electron microscope/Energy Dispersive X-ray Analysis (FESEM) to study CNT structure. Results: The result shows the increasing of quality with the increase of both temperature and time. Carbon nanotubes exist between electrodes, and the growth direction follow ethanol direction from source to drain. However, the carbon nanotube growth randomly not aligned. The channel between electrodes were well etched, this has been approved by EDX result. Conclusion: The characterization confirmed the CNT presence between source and drain. Increasing the growth temperature from 700 to 725 °C enhanced the quality of growing CNTs, which is clearly shown from Raman information. While, increasing growth time decreased quality, but the effect not that significant. FESEM characterization shows that CNT growth follows the ethanol flow from source to drain randomly, while EDX result shows that the channel between the electrodes was well etched and clear.

Background: A nano-tubular structure of Titanium dioxide (TiO2) was obtained using an electrochemical process based on the anodization of titanium foil in an organic electrolyte prepared with ethylene glycol (HOCH2CH2OH) containing Ammonium fluorides (NH4F) and ultrapure water under different anodization voltage. The morphological characteristics showed the formation of TiO2 nanotubes with different geometrical parameters. The electronic properties of the TiO2 NTs films were measured by the Mott-Schottky (MS) plots, indicating a positive slope for all graphs implying the n-type semiconductor nature of the TiO2 nanotubes (TiO2 NTs). The donor density (Nd) and the flat band potential (Efb) increases slightly with increase the anodization voltage. Methods: Prior the anodization, the titanium (Ti) foils were cut into square shape (2.25 cm2) with a selected work area of 0.6 cm2. The samples were subjected to a final polishing using a rotating felt pad (01 μm) impregnated with alumina until a metallic mirror surface was obtained. The Ti foils were degreased by sonication in acetone, methanol and 2-Propanol for 10 minutes respectively, rinsed with ultrapure water and dried in a stream of compressed air. To form a TiO2 NTs, electrochemical anodization process was carried out at room temperature in Ethylene Glycol (EG) solution containing 0.3 wt% Ammonium fluorides (NH4F) and 2wt % ultrapure water for three (03) hours at different anodization voltage (20, 40 and 60V). A two-electrode cell was used for all the anodization measurements, with a platinum plate as the counter electrode, separated from the working electrode (titanium foil) by 1.5 cm. Immediately after anodization, the samples were soaked in ultrapure water to remove residual electrolyte for 10 minutes and then dried in an oven at 50 °C for 10 minutes. Results: TiO2 NTs grown from anodization of Ti foil in fluoride EG solution for 3h by varying the anodization voltage. The micrographic analysis shows a strong influence of the anodizing voltage on the morphology and geometrical parameters of the TiO2 NTs. Non homogenous NTs morphology was observed at 20 V with the presence of corrugations along the walls of the tubes. A perfect and regular nanotublar structure with smooth's walls tubes was obtained at an anodization voltage of 60V. Moreover, the increase of anodization voltage leads to an increase in both the diameter and the length of tubes. In fact, the inner diameter and the length of the tubes (Di and L) values increase with increasing potential, being around (39 nm and 2 μm) respectively at 20 V and (106 nm and 16,1 μm) at 60 V. The measured electronic properties of TiO2 NTs indicating the n type semiconducting nature. It is remarkable that the donor density Nd increases toward higher values by increasing the anodizing voltage until 40V. However, for an anodization at 60V, the Nd has a small decrease value (7, 03 * 1019 cm-3) indicating a diminution of defects present in the material. Also, by increasing the anodizing voltage, Efb takes increasingly more positive values. In fact, the Efb values are – 0.12, 0.05 and 0.15 V for films prepared at 20, 40 and 60 V respectively. Therefore, this behavior can be attributed to a displacement of the Fermi level toward the conduction band edge which leads to a larger band bending at the interface. Conclusion: By varying the anodization voltage, titanium dioxide nanotubes (TiO2 NTs) were grown using electrochemical anodization of titanium foil in fluoride ethylene glycol solution for 3 hours. The morphology of the TiO2 NTs obtained was considerably affected; the anodizing potential determines the migration of ions in electrolyte during anodization process and simultaneously the tube diameter. An average small a nanotube diameter around 39 nm was obtained for 20V corresponding to 106 nm average diameter for TiO2 NTs structure synthesized at 60V. Furthermore, the semiconductor properties of the TiO2 NTs films have also been modified with increased values while increasing the anodization voltage. This behavior was attributed that the TiO2 NTs structure is more disordered, having much more defects provide abundant local donor energy levels which increases conductivity and decrease the probability of recombination of electrons and holes in these films, that can be integrated as active layer in the solar cells, in particular the Gratzel cells.

Introduction: Comparative studies of phase transitions in nanocomposites on the base of KNO3 and Al2O3 films with pores of 240 and 45 nm were carried out. Experiment: The temperature dependences of the linear dielectric constant and the amplitude of the third harmonic were measured. The measurements were carried out in the heating and cooling regime in the range from room temperature to 463 K. Anomalies, corresponding to structural phase transitions, were observed. Results & Conclusion: A considerable expansion of the temperature range of the potassium nitrate ferroelectric phase III was observed upon cooling, which increased with decreasing pore size of the Al2O3 films. The structural transition upon heating from phase II to phase I for nanocomposites with a pore size of 45 nm shifted relative to the transition in bulk KNO3 by 2 K toward high temperatures, whereas the temperature change for the sample in the Al2O3 film with pores of 240 nm did not occur.

Introduction: The utilization of biodiesel as an alternative fuel is turning out to be progressively famous these days because of worldwide energy deficiency. The enthusiasm for utilizing Jatropha as a non-edible oil feedstock is quickly developing. The performance of the base catalyzed methanolysis reaction could be improved by a continuous process through a microreactor in view of the high mass transfer coefficient of this technique. Materials & Methods: Nanozirconium tungstovanadate, which was synthetized using sol-gel preparation method, was utilized in a complementary step for biodiesel production process. The prepared material has an average diameter of 0.066 μm. Results: First, the NaOH catalyzed methanolysis of Jatropha oil was investigated in a continuous microreactor, and the efficient mixing over different mixers and its impact on the biodiesel yield were studied under varied conditions. Second, the effect of adding the nanocatalyst as a second stage was investigated. Conclusion: The maximum percentage of produced methyl esters from Jatropha oil was 98.1% using a methanol/Jatropha oil molar ratio of 11 within 94 s using 1% NaOH at 60 °C. The same maximum conversion ratio was recorded with the nanocatalyst via only 0.3% NaOH.