Recent Patents on Nanotechnology - Volume 13, Issue 1, 2019

Background: High concentration of phosphate has been threatening human health and the ecosystem. Adsorption is one of high-efficiency and low-cost techniques to reduce the concentration of phosphate. This mini review aims to summarize the recent development of adsorption materials for phosphate removal. Method: We conducted a detailed search of “adsorption of phosphate” in the published papers and the public patents on the adsorbents for phosphate based on Web of Science database in the period from January 1 2012 to December 31 2017. The corresponding literature was carefully evaluated and analyzed. Results: One hundred and forty one papers and twenty two recent patents were included in this review. An increased trend in scientific contributions was observed in the development of adsorption materials for phosphate removal. Three kinds of promising adsorbents: layered double hydroxides, natural materials, and metal oxides were paid special attention including removal mechanism, performance as well as the relationship between adsorption performance and structure. Both the chemical composition and the morphology play a key role in the removal capacity and rate. Conclusion: The findings of this review confirm the importance of phosphate removal, show the development trend of high-performance and low-cost adsorption materials for phosphate removal, and provide a helpful guide to design and fabricate high-efficiency adsorbents.

Background: During past decades, liposomes have emerged as efficient carriers for drugs, diagnostics, vaccines, nutrients and other bioactive agents. Liposomes, the spherical vesicles consisting of phospholipids bilayer have the ability to encapsulate both lipophilic and hydrophilic drugs. Extensive studies have been done in the past for investigating a number of drugs and genes for controlled release with liposomal formulation. Liposomes have also been investigated for their use in cancer treatment. Liposomes offer various advantages because of their biocompatible, biodegradable, nontoxic and non-immunogenic nature. Methods: Liposomes have cell-specific targeting with important applications in the fields of nanotechnology like cancer therapy, diagnosis, gene delivery, cosmetics, agriculture and in food technology. They are prepared by various methods like sonication method, ethanol injection method, lipid film hydration method, micro-emulsion method. Conclusion: This review will provide an overview of classification, the various formulation methods, characterization, patented formulations and applications of liposomes with future prospects.

Background: Diabetes Mellitus (DM) has emerged as an epidemic that has affected millions of people worldwide in the last few decades. Nanotechnology is a discipline that is concerned with material characteristics at nanoscale and offers novel techniques for disease detection, management and prevention. Objective: Diabetes mellitus is an epidemic disease that has affected millions of people globally. Nanotechnology has greatly enhanced the health status by providing non-obtrusive techniques for the management and treatment of diabetic patients. Method: In diabetes research, the nanotechnology has encouraged the advancement of novel glucose monitoring and several modalities for insulin delivery holding possibilities to enhance the personal satisfaction and life quality for diabetic patients. Result: Nanoparticles hold a great potential in the areas of drug delivery and are explored as vehicles for orally administered insulin formulations. Glucose biosensors equipped with nanoscale materials such as Quantum Dots (QDs), Carbon Nanotubes (CNTs), Magnetic Nanoparticles (MNPs) etc. have shown greater sensitivity. Nanotechnology in diabetic research is heading towards the novel techniques which can provide continuous glucose monitoring offering accurate information and improving patient’s compliance. Conclusion: The present review addresses the different aspects of nanoparticles and recent patents related to diabetic management based on nanotechnology.

Background: Most of the currently available Mg-based biomaterials corrode too fast in the physiological environment, causing many problems including hydrogen bubble release and premature mechanical failure. It is commonly recognized that high biodegradation rate is the major factor limiting their clinical applications. Objective: The present research aims to develop a new magnesium (Mg)-based biomaterial with a controlled biodegradation rate. Methods: A magnesium-hydroxyapatite (Mg-1.61Zn-0.18Mn-0.5Ca/1HA) nanocomposite was developed by a novel technique which combines high shear solidification and hot extrusion, followed by heat treatment. The microstructure and biodegradation rate of the nanocomposite in HBSS Hanks’ Balanced Salt Solution were assessed. Biodegradation behaviour was studied using electrochemical corrosion and immersion test. Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to characterize the surface microstructure, biodegradation morphology and to analyse the biodegradation products. Few patents were also cited in the article. Results: Under the optimized procedure of high shear solidification, extrusion and heat treatment at 400°C, the Mg-1.61Zn-0.18Mn-0.5Ca/1HA exhibited a satisfactory biodegradation rate of 0.12±0.04 mm/year. Conclusion: This technology shows a potential of breakthrough innovation in the manufacturing of Mg-based biomaterials with a decreased biodegradation rate.

Background: Docetaxel is a notably efficient anticancer drug administered for several types of malignancies including ovarian cancer. However, various side effects caused either by the nonspecific distribution of the active ingredient or by high contents of Tween 80 and ethanol in the currently marketed formulations, could even deprive the patients of the treatment. Objectives: In the current study, a novel targeted delivery system composed of Ecoflex® polymeric nanoparticles loaded with docetaxel and equipped with HER-2 specific aptamer molecules was evaluated regarding blood and tissue toxicity, and biodistribution. Method: The tumor-bearing nude mice, achieved by subcutaneous injection of SKOV-3 cells, were divided into four groups treated with normal saline, Taxotere®, targeted docetaxel nanoparticles, and non-targeted docetaxel nanoparticles. Few patents were alos cied in the article. Results: According to the results of hematologic evaluations, almost all hematologic parameters were in normal range with no significant difference among the four groups. Histopathological studies revealed that treatment with targeted nanoparticles caused a remarkable reduction in mitosis in tumor sections and overall reduced organ toxicity compared with Taxotere®. The only exception was spleen in which more damage was caused by the nanoparticles. The results of the biodistribution study were also in accordance with pathological assessments, with significantly lower drug concentration in non-tumor tissues, except for spleen, when targeted nanoparticles were used compared with Taxotere®. Conclusion: These results could evidence the efficiency of the targeted delivery system in concentrating the drug cargo mostly in its site of action leading to the elimination of its adverse effects caused by exposure of other tissues to the cytotoxic agent.

Background: Synthesis and applications of Ag-coated carbon nanotubes are currently under intensive research, resulting in a series of recent patents. Silver nanoparticles are normally obtained from silver nitrate. However, there are also other silver-containing compounds that can facilitate the production of silver nanoparticles, such as silver(I) acetate and silver(II) oxide. Being combined with carbon nanotubes, silver nanoparticles can transfer to them some of their useful properties, such as conductivity and antibacterial properties, and contribute to improving their dispersion in solvents. Objective: To apply three different silver-containing precursors of Ag nanoparticles for the decoration of carbon nanotubes and study the morphology of formed composites by several methods. Method: Three different silver compounds were used as Ag source to carry out the functionalization and decoration of carbon nanotubes under ultrasonic treatment of the reaction system, containing, commercial carbon nanotubes, organic peroxides as oxidants or hydrazine as a reductant, and a surfactant. Resulting samples were analyzed by XRD and XPS spectroscopy, as well as TEM and SEM microscopy to study the morphology of formed nanocomposites. Results: Silver nanoparticles can be produced without the presence of a reducing agent. Applying hydrazine, as a reducing agent, it is possible to obtain functionalized carbon nanotubes doped with silver nanoparticles, in which their sizes are smaller (1-5 nm) compared to those obtained without using hydrazine. Conclusion: Silver nanoparticles having a size range between 2-60 nm can be produced without the presence of a reducing agent. The use of a reducing agent, such as hydrazine, affects the size of silver nanoparticles.

Background: Nanofiber membrane/non-woven composite material is composed of electrospinning nanofiber membrane and non-woven fabric, which combines the supporting role of nonwoven material and the special nano-size effect of nanomaterials. Objective: These composite material can be widely used in biomedical, filtration and other related fields. In the actual use process, nanofiber membrane/non-woven composite material is often subjected to external forces such as puncture or bursting. As a result, the mechanical study of nanofiber membrane/ non-woven composite materials has a high value and practical significance. Methods: The nanofiber membrane/non-woven composite material was obtained by spraying solution (different concentrations of titanium dioxide-loaded Poly (vinyl alcohol) (PVA)) on meltblown polyester non-woven fabric. The surface morphology and fiber diameter of different concentrations nanotitanium dioxide-loaded Poly (vinyl alcohol) fiber were investigated by Field Emission Scanning Electron Microscopy (FESEM). The surface distribution of TiO2 on the electrospun fibrous membranes was characterized by Energy Disperse Spectroscopy (EDS). The semi-blunt puncture behavior of different concentrations of nano-titanium dioxide-loaded nanofiber membrane/non-woven composite material was conducted by universal material machine. Results: With the increase of concentrations of nano-titanium dioxide particles, the surface smoothness of nanofibers diminishes, the unevenness of the diameter distribution of the fiber increased and the maximum semi-blunt puncture strength increased. Conclusion: The addition of hard particles does contribute to improving the puncture properties of the composite materials. Several patents, related to electrospinning and bubble electrospinning equipment for nanofiber fabrication, have been reported.