Current Nanoscience - Volume 16, Issue 1, 2020

Following progress in modern medicine, advances have been made in diagnosis and treatment tools. Multifunctional nanomaterials that combine therapeutic and diagnostic functions in a single nanostructured complex are known as ‘theranostics’. To obtain a theranostic, a single particle, usually a nanoparticle, is manufactured to contain a therapeutic element (such as a drug) coupled with an imaging element. There are many kinds of nanoparticles available today that can be used to obtain theranostics, such as liposomes, cyclodextrin, conjugates and complexes, dendrimers, vesicles, micelles, core-shell particles, microbubbles, and carbon nanotubes. Because these materials interact with and should have effects on biological systems, their use may overcome health challenges. Considering the novelty and importance of this subject, this review aims to present general information about theranostics and discuss the safety and presumable toxicity of these constructs. In addition, we describe the methodologies that can be used to assess the safety of theranostics. This review is based on a literature search on theranostics, using the Web of Science, PubMed and Science Direct as the main sources of information. The period of publication was not delimited due to the scarcity of information and publications on this topic. Although many promising theranostic systems have been investigated and may revolutionise therapy, when designing new tools, researchers need to find alternatives to minimise their toxicity. The study of the toxicology and biocompatibility of theranostics needs to be continued, including clinical studies, with the aim of benefitting many patients in the future.

Exosomes are nanoscale extracellular vesicles that encapsulate a diverse range of biomolecules such as nucleic acids, proteins, and lipids. They are involved in several biological processes and mediate intracellular communication. Recent reports that they exhibit unique traits in pathological conditions have generated significant interest in employing them as diagnostic and therapeutic tools. Particularly, their potential to serve as drug delivery vehicles for the treatment of cancer and other diseases has been explored in numerous studies. This manuscript reviews recent developments in the field and discusses important considerations for further refinement of this approach and realization of more effective exosome-based drug delivery systems.

Emerging applications in the field of nanotechnology are able to solve a gamut of problems surrounding the applications of agroecosystems and food technology. Nano Engineered Material (NEM) based nanosensors are important tools for monitoring plant signaling pathways and metabolism that are nondestructive, minimally invasive, and can provide real-time analysis of biotic and abiotic threats for better plant health. These sensors can measure chemical flux even at the singlemolecule level. Therefore, plant health could be monitored through nutrient management, disease assessment, plant hormones level, environmental pollution, etc. This review provides a comprehensive account of the current trends and practices for the proposed NEM related research and its (i) structural aspect, (ii) experimental design and performance as well as (iii) mechanisms of field application in agriculture and food system. This review also discusses the possibility of integration of data from NEM based nanosensors in current and emerging trends of precision agriculture, urban farming, and plant nanobionics to adopt a sustainable approach in agriculture.

Cancer is the second leading cause of death worldwide. There are various classes of medications available for the management of cancer. Nanoparticles based drugs are the most preferred category among them due to their specificity towards target and reduction in the dose of drugs. Nanotechnology includes multiple subdisciplines like nanostructures, nanomaterials, and nanoparticles. These nanostructure-based drugs have gained extrusion in the medical field because of their small size, shape and high pharmacological efficacy. Nanomedicine is a booming field involving the use of different types of nanoparticles to kill tumor and tumorous cells. Biodegradable nanometersized particles have novel structural and physical properties that are attracting great interests from pharmaceuticals for the targeted delivery of anticancer drugs and imaging contrast agents. These nanoparticles are designed to increase more uptake of drugs or therapeutic genes into cancerous cells while noncancerous cells are intact. In this review, different nanomaterials-based strategies for a safe, fast, effective and targeted delivery system for drugs are discussed in relation to their anticancer activities.

Background: Biosynthetic nanomaterials have recently received increasing attention because they are non-toxic, clean, environmentally acceptable, safe, and biocompatible. Objective: In the present study, cell-free culture filtrate of Aspergillus sp. was used for extracellular synthesis of zinc oxide (ZnO) nanoparticles. MethodS: Plackett-Burman and Taguchi designs were implemented to optimize conditions for maximum ZnO nanoparticle production. In the Plackett-Burman design, 15 factors, representing different carbon and nitrogen sources, were studied. For the Taguchi design, an L-27 (313) standard orthogonal array was constructed to examine nine factors. Results: The maximum yield of ZnO nanoparticles of 21.73 g/L was achieved with 1.0 mM ZnSO4 under optimal conditions of peptone extract (20 g/L), yeast extract (10 g/L), meat extract (10 g/L), K2HPO4 (0.25 g/L), FeSO47H2O (0.002 g/L), NaCl (2.5 g/L), pH 6, 32°C, and a 200-mL volume. The ZnO nanoparticles’ production was confirmed by the formation of white aggregates. The UV absorption spectrum showed one peak at 376 nm, which also confirmed the formation of nanoparticles. Transmission electron microscopy revealed that the nanoparticles were large rods of 11.6-43.97 nm diameter, and 355.91 nm length. Importantly, the ZnO nanoparticles exhibited broad antimicrobial activity against gram-positive and gram-negative bacteria and a unicellular fungus. Conclusion: The concentrations of ZnSO4 ions, ferrous ions, and peptone and meat extracts, and the interactions between them, were observed to be the main parameters influencing ZnO nanoparticles’ yield.

Background: Erosive wear causes increase in the bore diameter of firearms barrels and nozzles. Most responsible factors for this erosion are friction and heat generated during the shot. Protection from erosive wear is very important for gun tube life cycle, and various protection methods are used: adding phlegmatizers in gunpowder composition or applying protective layers on the gun bore inner surface. Objective: In this research, a possibility is examined to protect the surface of a nozzle exposed to gunpowder erosion applying a layer of tungsten disulfide fullerene-like nanoparticles, IF-WS2, known as outstanding solid lubricant of a great mechanical resistance. Methods: Nanoparticles on the nozzle surface before and after the gunfire tests were observed using scanning electron microscopy/energy dispersive X-ray spectroscopy. Gunfire tests were performed on designed erosion device. Temperatures in the defined position near the affected surface were measured with thermocouples and compared for the nozzles with and without nanoprotection, as well as the nozzle mass loss after each round. Results: For the sample with IF-WS2 lower temperatures after firing and lower mass losses were observed. Mass loss after first round was 25.6% lower for the sample with protective nanoparticles layer, and the total mass loss was about 5% lower after five rounds. After the first round the nozzle without IF-WS2 was heated up to a temperature which was for 150.8°C higher than the nozzle with IF-WS2. Conclusion: Protective function of IF-WS2 is the most pronounced for the first round. The observed results encourage its further application in firearms gun bores protection.

Background: Mn doped ZnS is selected as the right element which is prominent among quantum dot for its high luminescent and quantum yield property and also non toxicity while comparing with other organometallic quantum dot synthesized by using different capping agents. Methods: An interesting observation based on colorimetric sensing of dopamine using manganese doped zinc sulfide quantum dot is discussed in this study. Mn doped ZnS quantum dot surface passivated with capping agents such as L-histidine and also in polymers like chitosan, PVA and PVP were studied and compared. The tunable fluorescence effect was also observed in different polymers and amino acid as capping agents. Optical characterization studies like UV-Visible spectroscopy and PL spectroscopy have been carried out. The functional group modification of Quantum dot has been analyzed using FTIR and size and shape analysis was conducted by using HRTEM image. Results: The strong and broad peak of FTIR in the range of 3500-3300 cm-1 confirms the presence of O-H bond. It is also observed that quenching phenomena in the luminescent peak are due to weaker confinement effect. The average size of the particle is shown to be around 4-5 nm. Changes in color of the quantum dot solution from transparent to dark brown has been due to the interaction with dopamine. Conclusion: Finally, L-Histidine amino acid capped Mn:ZnS shows better results in luminescence and size confinement properties. Hence, it was chosen for dopamine sensing due to its colloidal nature and inborn affinity towards dopamine, a neurotransmitter which is essential for early diagnosis of neural diseases.

Background: Of late, supercapacitors have been drawing great attention over other rechargeable energy storage devices. More efforts are made on the electrode materials of the supercapacitors, in order to improve the specific capacitance and energy density. Based on the past literature, it was stated that pure TiO2 (as electrode material) could promote faradaic reaction to a limited extent due to its low electronic conductivity. Further, this low conductivity could hinder the ion transfer process between electrolyte and electrode during intercalation and de-intercalation, resulting in poor energy density. Hence, it is essential to incorporate high electronic conductivity material into TiO2, for improving the electrochemical performance. Objective: In the present study, the preparation and electrochemical performance of NiO/TiO2 nanocomposites as an electrode material for supercapacitor were extensively studied. Method: NiO/TiO2 nanocomposites were synthesized by sol-gel method. The as-prepared nanocomposites were characterized by high-resolution TEM, field emission SEM and XRD. The electrochemical behaviors of the electrode using nanocomposites were assessed by means of cyclic voltammetry (CV) and galvanostatic charge-discharge tests. Result: The maximum specific capacitance of the nanocomposites based electrode witnessed through CV test was 405 F g-1 at the scan rate of 5 mV s-1 in 1M Na2SO4 electrolyte. The capacitance retention after 5000 charge-discharge cycles was estimated as 92.32%. The energy and power densities at current density of 1 A g-1 were found to be 5.67 Wh kg-1 and 210.52 W kg-1, respectively. Conclusion: NiO/TiO2 nanocomposites synthesized via sol-gel technique appeared to be flake-like structure. NiO incorporated into TiO2 increased higher electronic conductivity while comparing to pure TiO2. Also, an introduction of NiO into TiO2 improved the specific capacitance, power density, energy density and cycle stability. Due to these facts, combining NiO with TiO2 could be considered to be an efficient way of enhancing the electrochemical performance of electrodes of the supercapacitor.

Background: Optical reflection loss can be reduced more than 30% when multilayers ARC are deposited on the optoelectronic devices surface. Besides that, sub-wavelength structures, which have a period sufficiently smaller than the wavelength of light, have been introduced as an antireflection layer to offer a new possibility to suppress the Fresnel reflection. Normally, e-bean and nano-imprint lithography techniques are used to create nano-scale etch mask patterns. Metallic nanoparticles, which can be formed by a thermal dewetting process of metal thin film without any nanolithography techniques, can be utilized as an etch mask for the nano structure fabrications. The nano-patterned structures were fabricated on a silicon nitride passivation layer of a GaInP/GaAs/Ge triple-junction solar cell and showed an enhancement of its performance due to improved optical transmission and current matching. Objective: Investigate the influences of InGaP nano-pattern structures on the optical characteristics and applied for compound solar cells. Methods: In this report, disordered InGaP nano-pattern structures were formed by thermally dewetted Au nanoparticles and anisotropic dry etching processes. The effects of the InGaP nano-patterned structure on the optical reflection characteristics were investigated. Results: The result indicated that the InGaP nano-patterned structure can reduce the optical reflection in a wide range of wavelengths and, thus, can work as an antireflection layer. The InGaP nanostructure can improve up to 14.8% in the short circuit current density compared to that of the planar cell. Conclusion: The InGaP nano structures have been successfully fabricated by thermal dewetted Au nanoparticles and anisotropic dry etching methods. The fabricated Au nanoparticles pattern was found to be the best when annealing temperature is 400°C for 30 minutes with the 5nm thick of Au film. By controlling dry etching time, the height of InGaP nanostructures can be varied from 95 nm to 150 nm. With the increasing of the height, the optical reflectance can be down to 22%. The InGaP nanostructure with the height of 150 nm was also introduced to the window layer of a single junction GaAs soar cell. The result indicated that the InGaP nanostructure only affects on the short circuit current density.

Background: Iron Oxide nanoparticles have enormous applications in environmental remediation and catalysis. The synthesis of such nanoparticles through a green approach provides a significant advantage due to the non-toxic nature of the ingredients involved. Methods: In the present work, Diospyros lotus fruit extract was used for the synthesis of iron oxide nanoparticles (NPs). The plant biomolecules were extracted employing two different solvents, i.e. water and methanol. The effect of both the extracts on the reduction of metal salt as well as on the shape and size of the produced NPs was investigated. Results: UV-Visible spectroscopy confirmed the synthesis of iron oxide NPs, Fourier Transform Infrared (FTIR) spectrum depicted the presence of biomolecules on the surface of NPs as capping agents, X-ray Diffraction (XRD) diffractogram confirmed the crystalline structure of mixed iron oxide NPs and Scanning Electron Microscopy (SEM) images showed the spherical shape of NPs. The synthesized NPs were exploited to catalyze the degradation of methylene blue dye in the Fenton type catalytic reaction. The degradation reaction was monitored using UV-Visible spectroscopy, which indicated that the percent degradation increased from 15% (without iron oxide NPs) to 91% in the presence of organic extract prepared iron oxide NPs and to 81% in the presence of aqueous extract prepared iron oxide NPs. The effect of the concentration of methylene blue and iron oxide NPs on the degradation process was also investigated. Conclusion: The results indicated the potential of synthesized nanoparticles to promote catalytic reactions involved in environmental remediation.

Background: The present study reveals the synthesis of copper oxide nanoparticles (CuO NPs) by probiotic bacteria (Lactobacillus casei subsp. casei) and demonstrates the cytotoxic effects of these nanoparticles against gram negative and positive bacteria and cancer cell lines. Methods: The CuO NPs are biosynthesized from Lactobacillus casei subsp. casei (L. casei) in an eco-friendly and cost-effective process. These nanoparticles are characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and transmittance electron microscope (TEM) analysis. The antibacterial activity is examined by Well-diffusion, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) assays using Broth microdilution. Anticancer effects of these nanoparticles are evaluated by methyl thiazolyl diphenyl-tetrazolium bromide (MTT) assay and Griess test. Results: Our results confirm the biosynthesis of CuO NPs from L. casei. Antibacterial assays demonstrate that treatment of gram-negative and gram-positive bacteria with CuO NPs inhibits the growth of these bacteria. Furthermore, the cell viability of human cancer cells decreases while treated by nanoparticles. These nanoparticles increase nitric oxide (NO) secretion determined by NO production measurement. Conclusion: These results suggest that CuO NPs may exert antibacterial effects as well as cytotoxic effects on cancer cells by suppressing their growth, increasing the oxidative stress and inducing apoptosis.

Background: Photodynamic therapy (PDT) has become a very promising and effective strategy for the treatment of cancers and other malignant diseases. In recent years, photosensitizers (PS) with aggregation-induced emission (AIE) property have attracted great attention. Objective: A high-performance AIE-active PS, E- 1-allyl-3-(2-(5-(4-(diphenylamino)phenyl) thiophene- 2-yl)vinyl)quinoxalin-2 (1H)-one (SJ-1), was synthesized and its PDT effect was preliminarily tested in vitro. Methods: SJ-1 was designed using a quinoxalinone scaffold as the core chromophore. It could selfassembled into AIE-active nanoparticles with a mean size of 155 nm in aqueous medium and show maximum emission at 633 nm. Results: SJ-1 nanoparticles at a concentration of 20 μM showed effective reactive oxygen species (ROS) production and could induce almost 90% decrease of cell viability under laser irradiation in Hela and HT-29 cells, with negligible dark toxicity. Conclusion: In vitro results indicated that SJ-1 may be a potential PS for PDT.

Background: Cancer is deadly to most of its patients. Consequently, researchers and modelers studies show that there are many ways to cure and destroy it. One of the effective ways is to inject the blood vessel close to the tumor with magnetic nanoparticles. Another way called the radiation therapy or radiotherapy, which eradicates cancer cells through high doses of radiation. Objective: This paper opts to investigate the influences of thermal radiation and variable electrical conductivity on peristaltic flow of Carreau Nanofluids. First order chemical reaction, Dufour and Soret effects are taken into consideration. Methods: The resulting system of partial differential equations is solved numerically with the aid of Parametric-NDSolve. Results for velocity, temperature and concentration distributions are obtained in the analytical two-dimensional and three-dimensional forms. The streamlines graphs are offered in the terminus, elucidating the trapping bolus phenomenon. Results: It has been found that thermal radiation is a decreasing function in the temperature of the fluid. As the temperature decreases, the diameter of the nanoparticles increases i.e., the volume of nanoparticle and its concentration increases and become more effective near tumor tissues. Conclusion: Radiotherapy and Thermotherapy are effective methods to cure and damage the tumor tissues.