Nanoscience & Nanotechnology-Asia - Volume 11, Issue 2, 2021

Aim: The manuscript aims to discuss the advanced biomedical applications and patents on metallic nanoparticles. Discussion: The preparation of metallic nanoparticles and their application are an influential area for research. There are various physical and chemical methods (viz. chemical reduction, thermal decomposition, etc.) for synthesizing silver nanoparticles; biological methods have been suggested as possible eco-friendly alternatives. The synthesis of metallic nanoparticles encounters many problems including solvent toxicity, the formation of hazardous by-products and consumption of energy. So it is important to design eco-friendly benign procedures for the synthesis of metallic nanoparticles. It is investigated from the study that metallic nanoparticles are used in the treatment of different diseases. Metallic nanoparticles are also used in the detection and therapy of cancer. These also have antifungal, antibacterial, anti-inflammatory, antiviral and anti-angiogenic properties. Conclusion: It is concluded from the manuscript that the synthesis of metallic nanoparticles is easy, eco-friendly, less time consuming and affordable. The metallic nanoparticles used in the biomedical field have an emerging future in nanoscience and nanotechnology.

Background: In this paper, we have discussed the rheological analysis of the twodimensional stagnation-point flow of carbon nanotubes towards a stretching sheet with water as a base nanofluid with convective boundary conditions based on the advantages of nanofluid flows in CNT. Methods: Our main focus is to study on the rheological analysis of CNT suspended nanofluid with convective boundary condition using spectral method. Here, similarity transformations are used to transform the governing boundary layer equations. Results: The resulting nonlinear coupled equations with the relevant boundary conditions are solved numerically using recently developed Spectral Quasilinearization Method (SQLM). Conclusion: The influence of the flow parameters on the dimensionless velocity, temperature and concentration profiles along with skin friction, Nusselt number and Sherwood number are depicted and described in forms of graphs and tables.

Background: In computational and theoretical chemistry, real numbers programming certain structural skin appearance of natural molecules and derivative from parallel molecular graphs are called the graph invariants or more frequently structural descriptors (topological indices). Methods: Structural descriptors are numeric quantities, which are resulting from a molecular structure by mathematical calculations. Results: In Quantitative Structure-Activity Relation (QSAR) and Quantitative Structure-Property Relation (QSPR) study, these parameters are utilized to compute the biological properties of chemical composites. Conclusion: In this computational research paper, we find a degree based on the edge version of topological indices of Titanium dioxide nanotube and nanosheet.

Background: Nowadays, the era is of saving energy by working efficiently and effectively. As the temperature of the atmosphere increases globally, there is a keen demand for a vapor compression refrigeration system among people, especially in a region which has fervent climatic conditions. The technology is advancing day by day, thus using the vapor compression refrigeration system efficiently is a way to contribute to saving energy. Objective: Previously, a lot of work is carried out to boost the performance by changing the design of the evaporator, using different refrigerants, and by adopting different methods. We are now being equipped with nanotechnology in the field of refrigeration in a better way as it was earlier, nanofluids have far better heat transfer properties as compared to the vintage fluid. Methods: In this paper, the performance improvement of a vapor compression refrigeration system has been accomplished by using Al2O3, TiO2, and CuO nanoparticles in the deionised water (DIW) as a base fluid. Three different concentrations 0.01%, 0.005% and 0.001% by wt. of oxide nanoparticles have been used at three different operating temperatures i.e. 29°C, 33°C and 37°C. Results: The results showed that CuO nanofluids show better performance as compared to Al2O3, TiO2 nanofluids, and normal water. Conclusion: CuO nanofluids show better results as compared to Al2O3, TiO2 nanofluid, and normal water. Therefore, we should prefer CuO nanofluid to save power consumption.

Background: Neurodegeneration shows the distressing effects of miscommunications between brain cells. Insulin signaling dysregulation and small vessel disease in the base of diabetes may be important contributing factors in Alzheimer’s disease and vascular dementia. Gliptins play a role in neurodegeneration due to its neuroprotective effects. Eye is an extension of the brain. Ocular route reduces drug’s adverse effects offering an advantage in minimizing risk by targeted delivery to the brain. Conventional ophthalmic formulations exhibit poor bioavailability. Liposomes serve as promising active carriers of drugs to posterior segment eye disorders due to improvement in intravitreal half-life and targeted sustained drug delivery to the retina. Liposomes act as drug carriers for entrapment of hydrophilic and hydrophobic drugs. Objective: The study aimed to formulate and evaluate sitagliptin liposomal formulation for sustained effect in individuals suffering from neurodegeneration owing to high patient compliance, especially in geriatric patients. Methods: Sitagliptin liposomes were prepared by the ethanol injection method and were evaluated for various physicochemical properties such as visual appearance, particle size distribution, zeta potential, % drug entrapment efficiency, % drug loading capacity and in vitro drug release studies. Results: The optimized formulation (L-3) showed round-shaped distinct particles with good stability. The L-3 shows average diameter (281.9 nm); zeta potential (-11.9 mV); % entrapment efficiency (82.7 ± 0.89%); % drug loading (33.11 ± 0.67%). L-3 followed Korsmeyer- Peppas model with fickian diffusion transport of drug release giving n’ (0.3094), r2 (0.9753), with 83.78 ± 0.97% of sustained drug release. The L-3 passes the sterility test indicating its safe use in ophthalmic purposes. Conclusion: Thus, liposomal drug delivery is a highly effective approach for sustained drug delivery and minimizing the side effects of gliptins for effective therapy in neurodegeneration.

Objective: Herein, we report zinc oxide (ZnO) nanoparticles (NPs) synthesized by a simple precipitation method using zinc acetate dihydrate (Zn(CH3CO2)2. 2H2O) and sodium hydroxide (NaOH) precursors in aqueous media. Methods: Synthesized material was annealed at different temperatures to check phase formation and its purity. Results: At room temperature, the sample shows the formation of zinc hydroxide and at high temperature (100, 200, and 300°C) shows the formation of ZnO. Synthesized materials were analyzed by different techniques. X-ray diffraction analysis shows the formation of a hexagonal crystal structure. Morphological features were analyzed by the SEM technique which shows agglomerated nanoparticles. Conclusion: The optical properties of ZnO were studied by using UV analysis and showed intrinsic excitonic transition property of the ZnO semiconductor. Further, with an increase in annealing temperature crystalline size, agglomeration of nanoparticles found to be increased whereas the bandgap decreased.

Background: Present malignant cancer medicines have the advantage of magnetic nanoparticles as delivery carriers to magnetically accumulate anticancer medication in malignant growth tissue. Aim: In the present investigation, silica nanoparticles (MSNs) stacked with hydroxyurea were combined and optimized for dependent and independent variables. Methods: In this study, microporous silica nanoparticles stacked with neoplastic medication were prepared through emulsification followed by the solvent evaporation method. Prepared MSNs were optimized for dependent and independent variables. Different formulations were prepared with varying ratios of polymer, lipid and surfactant which affect drug release and kinetics of drug release pattern. The obtained MSNs were identified by FTIR, SEM, drug entrapment, in-vitro drug release, drug release kinetics study, and stability testing in order to investigate the nanoparticle characteristics. Results: The percentage drug entrapment of the drug for the formulations F1, F2, F3 was found to be 27.78%, 65.52% and 48.26%. The average particle size for F2 formulation was found to be 520 nm through SEM. The cumulative drug release for the formulations F1, F2, F3 was found to be 64.17%, 71.82% and 32.68%. The formulations were found to be stable which gives controlled drug delivery for 6 hours. Conclusion: From the stability studies data, it can be concluded that formulations are most stable when stored at a lower temperature or in a refrigerator, i.e. 5°C ± 3°C. It can be concluded that MSNs loaded with hydroxyurea is a promising approach towards the management of cancer due to sustained release and few side effects.

Background: Moisture damage and aging take place together in asphalt binder as it is on road-pavement in service life and, therefore, quite challenging to overcome. Various techniques, such as crumb rubber, fibers, etc. have been applied to improve the behaviour of asphalt materials. The use of nanomaterials was found as one of the effective techniques to develop temperature performances of asphalt binder. Methods: This study investigated moisture damage and aging of asphalt binder mixing with the carbon nanotubes (CNTs) using Atomic Force Microscopy (AFM). The base binder was primarily modified with 4% SBS polymer. Later on, CNTs were mixed in different percentages (i.e. 0.5%, 1%, and 1.5%) by weight with the 4% styrene–butadiene–styrene (SBS) modified binders. A special functionalized (-NH3) AFM probe with spring constant 3.44 N/m was utilized to complete the study. Results: The results were compared with 4% SBS modified asphalt with and without CNT addition. The adhesion forces of dry samples were found smaller as compared to wet and aged asphalt samples of with and without CNT. However, the adhesion forces of wet and aged samples with the investigated percentage of CNT performed considerably better than those without CNT. Conclusion: This result indicated significant improvement of asphalt to overcome moisture damage and aging owing to exposure in the outdoor environment as a paving material. This study recommends any dosage (i.e. 0.5 to 1.5% by weight) of CNT with 4% SBS modified asphalt to resist moisture damage and aging in the field.

Background: In this work, CdS thin films were synthesized by the sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, and 5 wt.%) were investigated. The optical properties of thin films, such as the refraction index, extinction coefficient, dielectric constant, and optical bandgap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration have an influence on the optical properties of thin films by decreasing the rotation speed of the substrate, which results in films with more thicknesses, and more optical interferences were observed in the results. Conclusion: The samples doped with Ni, when compared to pure ones, were found to have more optical bandgap energy.

Background: Evaluation of the toxic effects of nanoparticle-drug in vitro is an important step in the design of new pharmaceutical formulations. Rapid results, reduced cost and easy handling make cell culture models first line in initial toxicological assessment of nano-drug preparations. Objective: To evaluate the in vitro cytotoxicity of oxytetracycline loaded calcium carbonate aragonite nanoparticle in normal mouse fibroblast (NIH3T3) cell line. Methods: NIH3T3 cells were exposed to varying concentrations (6.25-100 μg/mL) of calcium carbonate aragonite nanoparticle (CS-CaCO3NP), oxytetracycline loaded calcium carbonate aragonite nanoparticle (OTC-CS-CaCO3NP) and oxytetracycline (OTC) in 96 well plates for 24, 48 and 72 hours. Cell viability was determined by MTT and trypan blue assays. Results: Both assays showed that CS-CaCO3NP and OTC-CS-CaCO3NP had higher cell viability values compared to OTC. Conclusion: Encapsulating OTC into CS-CaCO3NP reduced its cytotoxicity to NIH3T3 cells using both MTT and trypan blue assay.

Background: Terminalia arjuna has many biological applications including synthesis of metal nanoparticles, which have no hazardous effect on the environment. We have demonstrated that metal nanoparticles synthesized using Terminalia arjuna bark can be used to enhance the germination of seeds. Methods: To evaluate the effect on germination, we treated Vigna unguiculata (black-eyed peas) seeds with copper, silver and gold nanoparticles synthesized by Terminalia arjuna bark. The synthesized metal nanoparticles were characterized by UV-spectroscopy and their size was confirmed by diffraction light scattering technique. Results: After incubation of 48 hours, the effects were observed. It was observed that Vigna unguiculata (black-eyed peas) seed showed 30% germination in silver nanoparticles solution and 70% in copper nanoparticles, whereas 0% germination was observed in gold nanoparticles. Conclusion: The results obtained in the study show that nanobiotechnology can be applied in agriculture to boost the production of crops.