Please login first

List of accepted submissions

 
 
Show results per page
Find papers
 
  • Open access
  • 50 Reads
Metal-Catechol Network (MCN) Based Bioactive Surface Engineering of Iron Reinforced Hydroxyapatite Nanorods for Bone Tissue Engineering
, , ,

Hydroxyapatite is a calcium phosphate-based mineral constitute found in bone and teeth. The production of nanostructured rods that mimics the mineralogical chemistry and structure of natural bone apatite has attracted considerable attention. Unfortunately, pure HAp is not suitable for direct clinical translation because of its brittleness, limited mechanical strength, aggregation, leaching, and poor surface properties. These limitations necessitate size reduction, surface modification, ion incorporation, to expand their scope in bone reconstruction. Herein. iron-reinforced nanohydroxyapatite nanorods were used as an inorganic com­ponent and catechol-modified gelatin methacryloyl was used as a surface modifier and functional agent. Our study concluded that Fe-doped nanorods are an intriguing choice for building bioactive interfaces to increase interaction between inorganic/organic matrix than other ion-doped nanorods due to the simplicity of metal-catechol network (MCN) surface engineering. Nanostructural, surface chemistries, thermal, physicochemical, cytocompatibility, and antioxidant potential of unmodified and tannin-modified nanorods has been detailed studies. The results support that metal-catechol networks on nanorods surfaces regulate interfacial interactions, nanorods cytocompatibility, antioxidant potential, and phase compatibility between organic and inorganic materials which is crucial for bone reconstruction.

  • Open access
  • 45 Reads
Chitosan-Based Hydrogels: Patent Analysis

Research on hydrogels, as a remarkable class of soft nanomaterials, is developing rapidly through the innovation and improvement of polymers, chemical synthesis, methods of preparation, formulations, and fabrication processes. This trend is justified by the several advantages that chitosan-based hydrogels offer for biofabrication and biomedical applications.

Hydrogels are synthetic matrices made up of a network of hydrophilic polymers that absorb water and/or biofluids. The current strategy to design and produce hydrogels involves a range of various polymers, among them chitosan. The non-toxic, biocompatible, and biodegradable characteristics of chitosan allow its use as a hydrogel in many successful applications. The design and fabrication of chitosan-based hydrogels is based on the association with glycerophosphate salt. The mixture remains liquid at room temperature, and it gels quickly when heated to body temperature. Chitosan solutions heated in the presence of glycerophosphate salt will become partly neutralized by transferring protons to glycerol phosphate and thereby reduce the repulsive forces among positively charged ammonium groups, allowing attractive interchain forces to form a physically crosslinked gel under the appropriate conditions.

This study, presents the patent analysis regarding chitosan-based hydrogels by introducing what has been innovated and patented in relation to chitosan-based hydrogels. Furthermore, a detailed analysis of the patentability of hydrogel applications is provided by determining publication year, jurisdictions, patent families, inventors, applicants, owners, and patent classifications.

  • Open access
  • 37 Reads
Toxic Effects of Nickel Nanoparticles at a Subacute Oral Administration to Rats
, , , , , ,
Published: 22 April 2022 by MDPI in 3rd International Online-Conference on Nanomaterials session Poster

Nickel nanoparticles (NiNPs) are used in catalysts for hydrogenation of dietary fats, in cosmetics, insecticides, preparations for theranostics in medicine, and can also expose people occupationally in the metallurgy and mining industry. Adverse effects of the long-term oral exposition to low doses of NiNPs are not well understood. The study aimed to evaluate the toxic effects of NiNPs at their 92-day administration to male Wistar rats as part of their diet at doses of 0.1; 1 and 10 mg/kg body weight. Two preparations of NiNPs were used, which contained spherical metal Ni particles with average diameters of 54 and 71 nm. As a result of oral exposure of animals to NiNPs, an increase in glycemia, triglyceride, LDL, total protein, and its globulin fraction levels was noticed. The intake of NiNPs by the animals caused a decrease in the reserves of reduced liver glutathione and excretion of selenium in the urine, an increase in serum levels of cytokines IL-1b, IL-2, IL-6, IL-12p70, TNF-a, and INF-g with a simultaneous decrease in IL-4 and IL-17A. In the liver of rats exposed to NiNPs, the expression of fibrosis-marking genes, such as MMp2, MMp9, and Timp3, increased. Light-optical microscopy revealed in these animals signs of liver inflammation, leukocyte and eosinophilic infiltration, lamina propria tint, and villus involution in the small intestinal mucosa. The severity of the toxic effects of NiNPs depended on their size and, in some cases, were more pronounced at their low or medium doses than at the highest one. Most of the manifestations of the toxic effect of NiNPs were absent in animals that were subjected to a soluble Ni salt in a metal-equivalent dose. The estimate of LOAEL for NiNPs was less than 0.1 mg/kg of body weight according to the indicators studied. Higher oral toxicity of NiNPs, when compared to the salt form of Ni, is presumably associated with their easier penetration through biological barriers, which requires additional studies.

  • Open access
  • 62 Reads
ZnO Memristive Nanostructures for ReRAM Application

This paper is devoted to the fabrication of ReRAM elements based on TiN/ZnO/TiN/Al2O3 structures using scratching probe nanolithography of the atomic force microscope, as well as to the investigation of the resistive switching of the memristive nanostructures. The regimes of scratching probe nanolithography on the photoresist film were investigated. The memristive nanostructures were shown to exhibit a bipolar resistive switching with the ratio of HRS/LRS ratio up to 78.8 at reading voltage 0.5 V and maintaining a resistive state up to 105 s. The results can be useful for micro- and nanoelectronics elements manufacturing, as well as neuromorphic applications using probe nanotechnologies and nanocrystalline ZnO-based ReRAM elements prototyping.

  • Open access
  • 57 Reads

Pt Supported on CeTi-Modified Hexagonal Mesoporous Silica as Photocatalysts for Degradation of Phenols in Water

Aromatic compounds such as phenol and its derivatives are among the most common organic pollutants released by various industries. Recently, there has been a growing interest in the oxidative photodegradation of organic pollutants from water by coupling two semiconductor particles with different band-gaps and to modify their surface by doping with metal ions. The objective of this work is to evaluate the effect of Pt and CeO2 on photocatalytic properties of Ti-modified SBA-15 mesoporous support. The influence of the synthesis parameters on morphology, ceria-titania interaction, Pt oxidation state as well as photocatalytic activity in degradation of phenol and catechol (2x10-4M) aqueous solution was evaluated. SBA-modified support, with 5% TiO2, was prepared by hydrothermal method in the presence of block copolymer P123 and butanol. The support was impregnated with ceria (1%) and Pt (0.5 and 1%) precursors. The obtained materials were characterized by X-ray diffraction, nitrogen adsorption, SEM and TEM microscopy, XPS, PL and DRS UV-Vis spectroscopy. HO. radicals from the surface were detected by fluorescence technique. The results evidenced a mesoporous ordered structure, high dispersion of titania, ceria and platinum species, interaction of CeOx and Pt0/Pt2+ nanoparticles with well dispersed TiO2 on silica supports, oxygen vacancies and their effect on photocatalytic properties. XPS showed the percentage of Ce3+, stabilized by the presence of Pt0, which significantly influenced the presence of the oxygen vacancies. The lower Pt loading and its high dispersion enhanced the absorption of visible light further by junction between Pt and TiO2. As the photo-excited electrons in the conduction band of TiO2 can migrate to the Pt increasing the sample activity. Under UV light the best results were obtained for samples with Ti and PtTi. The obtained results evidenced the possibility to activate TiO2 in the UV light and to control photocatalytic activity by synthesis method.

  • Open access
  • 49 Reads
A Delve into The Novel Field of Essential Oil-Based Silver Nanoparticles and Its Anti-Inflammatory Potential
,

The overall interest in natural products is ever-increasing which clearly explains the involvement of various essential oils in different aspects of the day-to-day lives of common people. These pharmacologically relevant agents are categorized as secondary metabolites of plants extracted from different tissues of plants. And show pharmacological activities like anti-inflammatory, antioxidant, antimicrobial, larvicidal, etc.

The synthesis of metal nanoparticles has been developed by including different polymers, capping agents, and metal sources in the reaction. With the advancement of research, biological capping agents are being used for synthesizing metal nanoparticles like plant extracts, algae, fungi, etc. Essential oil is a newly added member of this list of capping agents. In the case of other metallic nanoparticles produced from biological capping agents, it was seen that the therapeutic activity of the plant material is also present within the produced nanoparticle. Similarly, for essential oil-derived nanoparticles, the therapeutic efficacy of the oil will be present within the nanoparticle. So, essential oils derived from plants like Eucalyptus, Clove, Lavender, etc. can be used to create nanoparticles that can act as anti-inflammatory agents. With work initiating on cumin oil and other oils like turmeric oil, it can be understood that the field of essential oil-derived nanoparticles is gaining much traction. The poster will present a cumulation of knowledge and show the available literature related to the anti-inflammatory potential of essential oil-mediated silver nanoparticles.

  • Open access
  • 78 Reads
Au/ZnO Nanocomposites Obtained at Different Au Precursor Concentration for Highly Efficient Photo-Degradation of Methylene Blue under UV Light
, , , ,
Published: 24 April 2022 by MDPI in 3rd International Online-Conference on Nanomaterials session Poster

Au/ZnO nanocomposites were successfully synthesized by a facile and low cost methods. ZnO nanoparticles and Au/ZnO samples growth at different Au precursor (HAuCl4) concentrations were obtained by hydrothermal synthesis and chemical reduction method, respectively. The influence of Au content in morphological and optical properties were analyzed by scanning electron microscopy (SEM) with energy dispersive X-ray (EDS) spectrometer, Raman and UV-Vis spectroscopy. Photocatalytic activity of ZnO nanoparticles and Au/ZnO nanocomposites were evaluated in the photo-degradation of methylene blue (MB) solution under UV irradiation. Compared with ZnO nanoparticles, Au/ZnO nanocomposites showed enhanced photocatalytic activity for degradation of MB under UV light irradiation, due to the charge transfer that occurs between ZnO and Au interface. The Au/ZnO sample with lowest HAuCl4 concentration (0.5 mM) showed the best photocatalytic performance, reaching a MB degradation rate of 99.99 % within 60 min, which exhibits an enhancement of 60% compared with ZnO nanoparticles.

  • Open access
  • 107 Reads
Fabrication and Characterization of Perovskite Solar Cells Using Silicon Phthalocyanine Complex

Fabrication and characterization of CH3NH3PbI3 perovskite solar cells using silicon phthalocyanine (SiPc) with decaphenylcyclopentasilane (DPPS) were performed. Effects of hole transport capacity of SiPc on the photovoltaic properties were investigated by changing the concentration of the SiPc. Continuous addition of SiPc and DPPS on the perovskite layer improved the short circuit current density related to the conversion efficiency. The stabilities of conversion efficiency were maintained for 28 days. The photovoltaic performance depended on the (100) crystal orientation and the crystallite size. Photovoltaic properties were also obtained without using spiro-OMeTAD as a hole transport layer.

  • Open access
  • 24 Reads
Straightforward Approach for Electrochemical Deposition and Modification of Conductive Polythiophene Thin Films for Bioreceptor Immobilization

Polythiophene is a prominent example of conductive polymers, which combine the advantages of organic polymers and inorganic conductors. They can easily be electropolymerized and deposited as nanostructured thin films and serve as key material in a wide variety of applications, of which chemical sensors and biosensors are trendsetting examples. Although polythiophene outperforms other conductive polymers, such as polypyrrole and polyaniline regarding conductivity and stability, its utilization for the construction of biosensors can barely be seen. We think this owes to the fact that there is a fundamental lack of fast and easy fabrication procedures for polythiophene-based bioreceptor immobilization platforms. Published protocols almost exclusively employ deeply complex synthesis strategies for functionalized monomers, which require a background in synthesis chemistry and well-equipped laboratories.

In this proceedings paper, we want to communicate two alternative approaches that convince with their simplicity: We investigate a literature-known, carboxylated thiophene monomer and present our newly developed method for electrochemical binding of a carboxylated linker to deposited polythiophene films. Aminated bioreceptors can subsequently be immobilized via EDC/NHS click chemistry. Films were electropolymerized and modified by chronopotentiometry, and characterized by electrochemical impedance spectroscopy (EIS), surface-enhanced Raman spectroscopy (SERS), as well as energy-dispersive X-ray spectroscopy (EDS).

Both of the presented methods offer the opportunity to fabricate a polythiophene-based bioreceptor immobilization platform in a straightforward manner – all it takes is a potentiostat/galvanostat, affordable, low hazard chemicals that can be used as received, as well as only a few minutes of time.

  • Open access
  • 32 Reads
Efficient Biexciton State Preparation in a Semiconductor Quantum Dot Coupled to a Metal Nanoparticle with Linearly Chirped Gaussian Pulses

We consider a hybrid nanostructure composed of a semiconductor quantum dot placed near a spherical metallic nanoparticle, and study the effect of the nanoparticle on the population transfer from the ground state to the biexciton state of the quantum dot, when using linearly chirped Gaussian pulses. For various values of the system parameters (biexciton energy shift, pulse area and chirp, interparticle distance), we calculate the final population of the biexciton state by performing numerical simulations of the nonlinear density matrix equations describing the coupled system as well as its interaction with the applied electromagnetic field. We find that for relatively large values of the biexciton energy shift and not very small interparticle distances, the presence of the nanoparticle improves the biexciton state preparation, since it effectively increases the area of the applied pulse. For smaller biexciton energy shifts and smaller distances between the quantum dot and the nanoparticle, the exciton-plasmon interaction term gains importance leading in general to a degraded performance. But even in these cases we can still find ranges of parameter values where the population transfer to the biexciton state is accomplished with high fidelity, when using linearly chirped Gaussian pulses. We expect that these results may be exploited for the development of novel nanoscale photonic devices or future quantum technologies.

Top