scholarly journals Magnetic Graphene Oxide Nanocarrier for Targeted Delivery of Cisplatin: A Perspective for Glioblastoma Treatment

2019 ◽  
Vol 12 (2) ◽  
pp. 76 ◽  
Author(s):  
Sami A. Makharza ◽  
Giuseppe Cirillo ◽  
Orazio Vittorio ◽  
Emanuele Valli ◽  
Florida Voli ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Room Temperature ◽  
Release Profile ◽  
7 Tesla ◽  
Fe2o3 Nanoparticles ◽  
Magnetic Graphene Oxide ◽  
Maximum Value ◽  
Magnetite Fe3o4 ◽  
U87 Cells ◽  
Fractional Release

Selective vectorization of Cisplatin (CisPt) to Glioblastoma U87 cells was exploited by the fabrication of a hybrid nanocarrier composed of magnetic γ-Fe2O3 nanoparticles and nanographene oxide (NGO). The magnetic component, obtained by annealing magnetite Fe3O4 and characterized by XRD measurements, was combined with NGO sheets prepared via a modified Hummer’s method. The morphological and thermogravimetric analysis proved the effective binding of γ-Fe2O3 nanoparticles onto NGO layers. The magnetization measured under magnetic fields up to 7 Tesla at room temperature revealed superparamagnetic-like behavior with a maximum value of MS = 15 emu/g and coercivity HC ≈ 0 Oe within experimental error. The nanohybrid was found to possess high affinity towards CisPt, and a rather slow fractional release profile of 80% after 250 h. Negligible toxicity was observed for empty nanoparticles, while the retainment of CisPt anticancer activity upon loading into the carrier was observed, together with the possibility to spatially control the drug delivery at a target site.

scholarly journals Formulation of Quaternized Aminated Chitosan Nanoparticles for Efficient Encapsulation and Slow Release of Curcumin

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 449
Author(s):  
Ahmed M. Omer ◽  
Zyta M. Ziora ◽  
Tamer M. Tamer ◽  
Randa E. Khalifa ◽  
Mohamed A. Hassan ◽  
...  
Keyword(s):  
Slow Release ◽  
Sodium Tripolyphosphate ◽  
Chitosan Nanoparticles ◽  
Gastric Fluid ◽  
Release Profile ◽  
Simulated Gastric Fluid ◽  
Maximum Value ◽  
Structure Surface ◽  
Drug Encapsulation Efficiency

An effective drug nanocarrier was developed on the basis of a quaternized aminated chitosan (Q-AmCs) derivative for the efficient encapsulation and slow release of the curcumin (Cur)-drug. A simple ionic gelation method was conducted to formulate Q-AmCs nanoparticles (NPs), using different ratios of sodium tripolyphosphate (TPP) as an ionic crosslinker. Various characterization tools were employed to investigate the structure, surface morphology, and thermal properties of the formulated nanoparticles. The formulated Q-AmCs NPs displayed a smaller particle size of 162 ± 9.10 nm, and higher surface positive charges, with a maximum potential of +48.3 mV, compared to native aminated chitosan (AmCs) NPs (231 ± 7.14 nm, +32.8 mV). The Cur-drug encapsulation efficiency was greatly improved and reached a maximum value of 94.4 ± 0.91%, compared to 75.0 ± 1.13% for AmCs NPs. Moreover, the in vitro Cur-release profile was investigated under the conditions of simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. For Q-AmCs NPs, the Cur-release rate was meaningfully decreased, and recorded a cumulative release value of 54.0% at pH 7.4, compared to 73.0% for AmCs NPs. The formulated nanoparticles exhibited acceptable biocompatibility and biodegradability. These findings emphasize that Q-AmCs NPs have an outstanding potential for the delivery and slow release of anticancer drugs.

Superhydrophobic Silicon Surface with Micro/Nanocomposite Structure Formed by 2-Step Wet Etching

2013 ◽  
Vol 747 ◽  
pp. 542-546 ◽  
Author(s):  
Kensuke Nishioka ◽  
Takatoshi Yasui
Keyword(s):  
Potassium Hydroxide ◽  
Silicon Surface ◽  
Room Temperature ◽  
Isopropyl Alcohol ◽  
Alcohol Solution ◽  
Wet Etching ◽  
Nanocomposite Structure ◽  
Maximum Value ◽  
O 11 ◽  
Stain Etching

The micro/nanocomposite structure on silicon surface was formed by a simple 2-step chemical etching with a potassium hydroxide anisotropic etching and a stain etching in order to obtain a superhydrophobic silicon surface. Micro-sized pyramids structure was formed in a mixture of 3 wt.% potassium hydroxide with 8 vol.% isopropyl alcohol solution at 80C for 60 min. The formation of the nanosized structure was performed by stain etching at room temperature using nitric acid (HNO3) / hydrofluoric acid (HF) aqueous solutions. The silicon surface had the superhydrophobic surface. The contact angle was measured and the maximum value was 167o for the condition of second etching with HF : HNO3 : H2O = 11 : 1 : 3.

Kinetics and Mechanism of Platinum Pressure-Cyanide Dissolution

2014 ◽  
Vol 522-524 ◽  
pp. 424-428
Author(s):  
J.S. Zhao ◽  
J.H. Dai
Keyword(s):  
Oxygen Pressure ◽  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Direct Dissolution ◽  
Increasing Temperature

A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of metal platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, temperature and oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.

THE MERCURY PHOTOSENSITIZED REACTIONS OF BENZENE AT HIGH TEMPERATURES

1951 ◽  
Vol 29 (3) ◽  
pp. 233-242 ◽  
Author(s):  
E. J. Y. Scott ◽  
E. W. R. Steacie
Keyword(s):  
High Temperatures ◽  
Room Temperature ◽  
Main Product ◽  
Main Reaction ◽  
Kcal Mole ◽  
Detailed Mechanism ◽  
Maximum Value ◽  
Secondary Reactions

An investigation has been made of the mercury photosensitized decomposition of benzene at high temperatures. Practically no reaction occurs at room temperature. At higher temperatures the main product is diphenyl although even at 400°C. the maximum value of [Formula: see text] is 0.1. Ediphenyl has been found to be 13 kcal. mole−1. There is evidence that an activated molecule mechanism occurs. The secondary reactions are complex and it is not possible to arrive at a detailed mechanism, but the probable main reaction steps have been pointed out.

Study on Pressure-Cyanide Dissolution of Metal Platinum Powder

2012 ◽  
Vol 554-556 ◽  
pp. 541-545
Author(s):  
L. Yan ◽  
J.S. Zhao
Keyword(s):  
Oxygen Pressure ◽  
Room Temperature ◽  
Research Study ◽  
Elevated Temperatures ◽  
Rotation Speed ◽  
Sodium Cyanide ◽  
Cyanide Solution ◽  
Platinum Group Metals ◽  
Maximum Value ◽  
Increasing Temperature

A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Metal Platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 20°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased. The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution was independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and was well below chemical reaction-limited for cyanide and oxygen.

In vitro and in vivo assessment of the abuse potential of PF614, a novel BIO-MD™ prodrug of oxycodone

2017 ◽  
Vol 13 (1) ◽  
pp. 39 ◽  
Author(s):  
D. Lynn Kirkpatrick, PhD ◽  
William K. Schmidt, PhD ◽  
Ricardo Morales, BSc ◽  
John Cremin, PhD ◽  
Julie Seroogy, BSc ◽  
...  
Keyword(s):  
Room Temperature ◽  
Extended Release ◽  
Ex Vivo ◽  
Liver Microsomes ◽  
Release Profile ◽  
Opioid Agonist ◽  
Pharmacologically Active ◽  
Household Chemicals

Objective: The need for pain medication which will not lead to abuse is well recognized. Ensysce has designed prodrug analogs of the commonly used pain medications including hydromorphone, oxycodone (OC), hydrocodone, and morphine that limit their use to oral delivery, two of which are in clinical development. This study was undertaken to demonstrate that PF614, an extended-release prodrug of OC, allows the release of OC as designed when delivered orally, yet it resists ex vivo extraction with household chemicals and is pharmacologically inactive when administered by nonoral routes (nasal and parenteral), thereby substantially reducing its intravenous (IV) and intranasal abuse potential.Methods: In vitro and in vivo methods were used to determine release of OC from PF614 and to show potential μ-opioid receptor activity. Plasma and cerebral spinal fluid levels of OC were evaluated following in vivo IV administration of PF614 in rats. In vitro extraction of OC from PF614 was explored using enzymes, common solvents, and household chemicals at room temperature and elevated temperature over time to determine release of OC from the prodrug.Results: PF614 was stable with in vitro exposure to human plasma, saliva, and liver microsomes or culinary enzyme preparations. PF614 was stable (≥90 percent remaining as intact prodrug) under all room temperature conditions evaluated for 24 hours. At 80 °C for 1 hour, no OC was released. Incubation at 80 °C for 24 hours in vinegar or vodka produced a conversion to OC of 6 percent. Incubation with trypsin at 37 °C converted PF614 approximately stoichiometric to OC with half-life of 4 hours. PF614's penetration of the central nervous system was 83-fold lower than OC and it had a 6.5-fold reduced potency as a μ-opioid agonist. Finally, oral PF614 delivers OC into plasma with an extended-release profile in dogs (reduced Cmax; delayed Tmax).Conclusions: The Bio-Activated Molecular Delivery prodrug design limits the use of PF614 to the intended oral route of delivery with reduced potential for IV or nasal abuse, as it cannot be activated intravenously or nasally to provide an active opioid. Unlike existing opioid formulations, the extended-release profile of PF614 cannot be accelerated by chewing or ex vivo extraction to pharmacologically active substances.

Synthesis and Characterization of Iron Oxides Nanoparticles

2006 ◽  
Vol 306-308 ◽  
pp. 1115-1120 ◽  
Author(s):  
Bee Chin Ang ◽  
Iskandar Idris Yaacob
Keyword(s):  
Iron Oxides ◽  
Room Temperature ◽  
Magnetic Particles ◽  
Aqueous Salt Solution ◽  
Gas Absorption ◽  
Microemulsion System ◽  
X Ray Diffraction ◽  
Weight Losses ◽  
Magnetite Fe3o4

Magnetic iron oxides nanoparticles were synthesized at room temperature using water in oil microemulsion process. This microemulsion system was prepared using HTAB (surfactant), noctane (oil), 1-butanol (cosurfactant) and aqueous salt solution of Fe2+ and OH-. The microemulsions were used as microreactors for controlling the growth of the particles. The nanoparticles were characterized using TGA, XRD, TEM, BET, DLS and AGM. X-ray diffraction analysis revealed that the magnetic nanoparticles could be directly formed at room temperature. It also showed that the particles were either maghemite (γ-Fe2O3) or magnetite (Fe3O4). TGA thermogram showed two significant weight losses at around 100°C and 250° C, which were caused by dehydration and burn off of the surfactant. The surface area of the magnetic particles measured using gas absorption and desorption technique was 105.43m2/g, which indicated the presence of particles of 21nm in length. The size measured by TEM and DLS was 105nm and 107.9nm respectively due to the formation of large aggregated clusters. The sample also showed strong magnetic properties with the value of Ms of 11.2 emu/g.

Thermoelectric Properties of Binary-Phased Nanocomposites

2014 ◽  
Vol 809-810 ◽  
pp. 3-8
Author(s):  
Peng Xian Lu
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Hot Press ◽  
Point Temperature ◽  
Disordered Structure ◽  
Maximum Value ◽  
Hot Press Process

In order to increase the electrical conductivity greatly but maintain a large Seebeck coefficient and a low thermal conductivity simultaneously, the binary-phased LaCeFe3CoSb12-Sb nanocomposites composed of LaCeFe3CoSb12skutterudite nanospheres and semimetal Sb microsized ribbons were fabricated via a hydro/solvo thermal route. The results suggest that the Sb powders result in a disordered structure during a hot-press process at its melting-point temperature and the disordered structure has been partly preserved into the room-temperature materials successfully. The Sb microsized ribbons enhance the electrical conductivity of the binary-phased materials largely, meanwhile the disordered structure increases the Seebeck coefficient obviously even though the thermal conductivity is also increased slightly. Consequently, the figure of merit of the binary-phased materials is improved significantly and the maximum value of 1.54 at 773 K has been realized for the LaCeFe3CoSb15material.

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