Carbon Nanotubes-Chitosan-Molecularly Imprinted Polymer Nano-Carriers Synthesis for Nanomedicine Application

Carbon nanotube-natural biopolymer nanovectors have important potential applications in delivery system for drugs and biomolecules. In this work, the use of multi-wall CNTs as nanoreserviors for drug loading and controlled release is demonstrated .We synthesized CNT-based Drug delivery systems; MWCNT-CS nanoparticles based on an ionotropic gelation method as a sustained-release systems for the delivery of Tenofovir (hydrophilic anti-retroviral drug). Molecularly imprinted polymer used as shell for encapsulating the synthesized polymer to reduce the toxicity of CNT and improved theit application in Drug Delivery System. The prepared nanoparticles were characterized by FTIR spectroscopy. TGA was applied to study the thermal stabilities, and SEM to investi-gate the morphology. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3521

Development of a Novel Thermally Stable Inhibitor Based on Furfuryl Alcohol for Mild Steel Corrosion in a 15% HCl Medium for Acidizing Application

Although corrosion inhibitors are widely used as a practical method for inhibiting metal corrosion in a variety of industries, their efficiency decreases dramatically at high temperatures. We present a thorough experimental and theoretical investigation into the inhibitory power of a novel thermally stable corrosion inhibitor based on furfuryl alcohol (FACI). The open-circuit potential, linear polarization resistance, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques were used for the first time to evaluate FACI inhibition performance at 293, 313, 333, and 353 K. All electrochemical methods clearly indicated that FACI effectively suppressed corrosion of mild steel (MS) in the 15% HCl environment via a mixed-type mechanism at all temperatures investigated. The highest inhibition efficiencies of 95.4 and 90.8 at 333 and 353 K, respectively, were obtained in the solution containing 136 × 10-5 M FACI. FACI inhibited both the anodic and cathodic corrosion reactions of MS, but its main effect was on the cathodic hydrogen evolutions. The results of the Langmuir adsorption isotherm confirmed that the predominantly chemical adsorption of FACI molecules occurred on the MS surface. The experimental results were also validated using a combined DFT

A theoretical and experimental study of castor oil-based inhibitor for corrosion inhibition of mild steel in acidic medium at elevated temperatures

© 2020 Elsevier Ltd The castor oil as a cheap and environmentally friendly source was used to prepare a novel green corrosion inhibitor for mild steel in acidic medium. The poor performance at high temperatures and low biodegradability are two important challenges of corrosion inhibitors that castor oil-based corrosion inhibitor (COCI) is designed to overcome them. The inhibition performance of COCI was evaluated by weight loss, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and polarization techniques. The morphology of MS was examined by field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX) and atomic force microscopy (AFM). Furthermore, a comprehensive computational study was done to clarify the anticorrosive mechanism of COCI by molecular dynamics (MD) simulation, density functional based tight-binding (DFTB) approach and density functional theory (DFT). Maximum inhibition efficiency of 85 % and 91 % were achieved at 80 °C using 140 μM of COCI in EIS and polarization tests, respectively. COCI acted as a mixed type inhibitor and the adsorption of the inhibitor on the mild steel surface was chemisorption. The obtained results demonstrate that the COCI has a considerable ability to suppress acidic corrosion at all concentrations were studied here, particularly at high temperatures. Given the fact that several articles were reported a significant reduction in performance of corrosion inhibitors by increasing temperature, in this study was found out not only was there no decrease in inhibition efficiency of COCI at higher temperatures, but it depicted good performance at 80 °C. In addition, the high adsorption energy of COCI confirmed a strong interaction between Fe surface and inhibitor molecules and showed a significant effect of the urethane bonds and the triglyceride groups on molecular activity. The Fermi energy state indicated that the chemical adsorption occurred in the interaction of COCI-Fe surface by electron transition from inhibitor to Fe 3d band state. We expect the results of this work provide new opportunities for the design and synthesis of efficient corrosion inhibitors based on vegetable oils

Hybrid hydrogels based on agarose, halloysite nanotubes and polyvinyl alcohol: An excellent nanocarrier for controlled release of 5-fluorouracil

Nanotechnology, rather than traditional medicinal procedures like chemotherapy, now helps to reduce adverse effects. There is a great demand for a biocompatible nanocarrier with a long half-life, high bioavailability, and capable of imaging cells and targeting them selectively. A procedure known as water-in-oil-in-water (W/O/W) emulsification was employed to produce hybrid nanohydrogels containing agarose, polyvinyl alcohol, halloysite nanotubes, and 5-fluorouracil (AGA-PVA-HNT@5-Fu) which can be highly effective for decreasing the particle size of nanohydrogels and improving their uniformity. These hydrogels were produced to specifically target and administer the 5-Fu anti-cancer drug for the treatment of breast cancer. Following the evaluation of physicochemical characteristics, both a substantial drug loading and efficient trapping were accomplished. The nanohydrogels displayed a zeta potential of −38.4 mV indicative of a good stability due to the usage of span 80. Based on the drug release profile conducted in vitro, it was observed that AGA-PVA-HNT@5-Fu released the medication in a regulated way. By using MTT and flow cytometry analysis, it was found that AGA-PVA-HNT@5-Fu could effectively eliminate tumor cells, while the blank nanoparticles proved to be biocompatible. The results indicate that hybrid nanohydrogels based on AGA-PVA-HNT@5-Fu can be utilized as nanohydrogels for treating breast cancer

In vitro/in vivo study of novel anti-cancer, biodegradable cross-linked tannic acid for fabrication of 5-fluorouracil-targeting drug delivery nano-device based on a molecular imprinted polymer

Using biodegradable material in medicinal applications is known as an important factor. On the other hand, the delivery of drugs directly to the target site is a promising field of research especially for anti-cancer drug delivery systems. The present research aimed to evaluate an effective anti-cancer device for treatment of tumors. In this respect, a novel fluorescent multi core–shell structure of magnetic molecular imprinted polymer nanoparticles based on biodegradable materials was designed as a carrier for targeted, sustained and controlled release of 5-fluorouracil (5-FU). Herein, tannic acid as a biodegradable polyphenol with potential anti-cancer performance was used to fabricate a cross-linker agent. Then, a mini-emulsion polymerization technique was performed in the presence of magnetic fluorescent cores for preparing the carrier. The structure of samples was fully characterized using various kinds of analyses. Afterwards, the performance of the product as an anti-cancer carrier was examined through different in vivo and in vitro analyses including small animal body imaging, the MTT viability assay and high performance liquid chromatography (HPLC). The biodegradable structure of samples was also investigated in various environments similar to the human body. Furthermore, in vitro analyses on Michigan Cancer Foundation-7 (MCF-7) cells provided evidence for the multiple anti-cancer performances of the carrier. Based on the obtained results, this novel drug carrier with outstanding properties can perform an effective and obvious roll in the cancer-therapy field

TiO2 nanoarrays modification by a novel Cobalt-heteroatom doped graphene complex for photoelectrochemical water splitting: An experimental and theoretical study

Different graphene structures have received much attention due to their unique chemical and electron properties. In this report, we use heteroatom-doped graphene to coordinate Co2+ for use in photoelectrochemical cells. Flower-like TiO2 photoelectrode morphology was used as a semiconductor. Its surface was covalently modified with Co2+ coordinated nitrogen and sulfur-doped graphene quantum dot (S, N-GQD). S, N-GQD was used to improve visible light absorption and electron transport properties. Also, cobalt ions were coordinated with pyridinic nitrogen in the GQD structure and, like the cobalt-bipyridine complexes, acted as a catalyst for the water oxidation reaction. The modified photoelectrode significantly improved cell performance and resulted in a photocurrent density of 1.141 mA/cm2. To study the electronic structure of the compounds in more detail, we also used density functional theory (DFT) calculations. The obtained results confirmed the effective interactions of cobalt and S, N-GQD, and showed the energy levels and band gaps in agreement with the experimental results. This study led to the presentation of a new and robust strategy to improve the optical and catalytic performance of TiO2 nanoarrays in photoelectrochemical cells

Exploration of Sunflower Oil As a Renewable Biomass Source to Develop Scalable and Highly Effective Corrosion Inhibitors in a 15% HCl Medium at High Temperatures

The feasibility study of utilizing sunflower oil as renewable biomass source to develop highly effective inhibitors for mild steel corrosion (MS) in the 15% HCl medium was done by weight loss, potentiodynamic polarization (PDP), dynamic electrochemical impedance spectroscopy (DEIS), and electrochemical impedance spectroscopy (EIS), supported with energy-dispersive X-ray (EDX), atomic force microscopy (AFM), and field-emission scanning electron microscope (FESEM) techniques. Moreover, a complementary theoretical investigation was carried out to clarify the inhibition mechanism of inhibitors by density functional theory (DFT), density functional based tight-binding (DFTB), and molecular dynamics (MD) simulation approaches. The obtained results confirm that sunflower-oil-based corrosion inhibitor (SFOCI) has a significant anticorrosion property toward the dissolution of MS in 15% HCl solution in the temperature range 20-80 °C. In addition, the results show that SFOCI could provide an inhibition efficiency of 98 and 93% at 60 and 80 °C, respectively. The inhibition mechanism of SFOCIs was mixed-type and their adsorption on the surface of MS was mainly chemisorption. The FESEM and EDX studies proved the presence of SFOCI molecules on the surface of MS. In addition, the adsorption energy of SFOCI indicated an intense interaction between the inhibitor and surface of Fe. The results of this study could open a new window for the design and development of scalable and effective eco-friendly vegetable-oil-based corrosion inhibitors for highly corrosive solutions at high temperatures