Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems.

For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble protein from wheat and corn; legumin is a casein-like protein from leguminous seeds such as peas; lectins are glycoproteins naturally occurring in many plants that recognize specific carbohydrate residues. NPs formed from these proteins show good biocompatibility, possess the ability to enhance solubility, and provide sustained release of drugs and reduce their toxicity and side effects. The effects of preparation methods on the size and loading capacity of these NPs are also described in this review.

Smart micro/nanoparticles in stimulus-responsive drug/gene delivery systems.

New achievements in the realm of nanoscience and innovative techniques of nanomedicine have moved micro/nanoparticles (MNPs) to the point of becoming actually useful for practical applications in the near future. Various differences between the extracellular and intracellular environments of cancerous and normal cells and the particular characteristics of tumors such as physicochemical properties, neovasculature, elasticity, surface electrical charge, and pH have motivated the design and fabrication of inventive "smart" MNPs for stimulus-responsive controlled drug release. These novel MNPs can be tailored to be responsive to pH variations, redox potential, enzymatic activation, thermal gradients, magnetic fields, light, and ultrasound (US), or can even be responsive to dual or multi-combinations of different stimuli. This unparalleled capability has increased their importance as site-specific controlled drug delivery systems (DDSs) and has encouraged their rapid development in recent years. An in-depth understanding of the underlying mechanisms of these DDS approaches is expected to further contribute to this groundbreaking field of nanomedicine. Smart nanocarriers in the form of MNPs that can be triggered by internal or external stimulus are summarized and discussed in the present review, including pH-sensitive peptides and polymers, redox-responsive micelles and nanogels, thermo- or magnetic-responsive nanoparticles (NPs), mechanical- or electrical-responsive MNPs, light or ultrasound-sensitive particles, and multi-responsive MNPs including dual stimuli-sensitive nanosheets of graphene. This review highlights the recent advances of smart MNPs categorized according to their activation stimulus (physical, chemical, or biological) and looks forward to future pharmaceutical applications.

Novel anode catalyst for direct methanol fuel cells.

PtRu catalyst is a promising anodic catalyst for direct methanol fuel cells (DMFCs) but the slow reaction kinetics reduce the performance of DMFCs. Therefore, this study attempts to improve the performance of PtRu catalysts by adding nickel (Ni) and iron (Fe). Multiwalled carbon nanotubes (MWCNTs) are used to increase the active area of the catalyst and to improve the catalyst performance. Electrochemical analysis techniques, such as energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS), are used to characterize the kinetic parameters of the hybrid catalyst. Cyclic voltammetry (CV) is used to investigate the effects of adding Fe and Ni to the catalyst on the reaction kinetics. Additionally, chronoamperometry (CA) tests were conducted to study the long-term performance of the catalyst for catalyzing the methanol oxidation reaction (MOR). The binding energies of the reactants and products are compared to determine the kinetics and potential surface energy for methanol oxidation. The FESEM analysis results indicate that well-dispersed nanoscale (2-5 nm) PtRu particles are formed on the MWCNTs. Finally, PtRuFeNi/MWCNT improves the reaction kinetics of anode catalysts for DMFCs and obtains a mass current of 31 A g(-1) catalyst.

Comparison of the classic TVT and TVT-Secur.

BACKGROUND AND AIMS: Tension-free vaginal tape (TVT) is a well-established surgical procedure for the treatment of female stress urinary incontinence (SUI) and TVT-Secur was designed to reduce the undesired complications and to minimize the operative procedure as much as possible. AIM: To present the authors' experience in using the classic TVT and TVT-Secur and to evaluate and compare complications and short- and long-term results. MATERIALS AND METHODS: A retrospective study and analysis of 230 patients presented with SUI at King Abdulaziz University Hospital (KAUH) and United Doctor Hospital (UDH) from March 1, 2007 until July 3, 2010. Classical TVT and TVT-Secur with or without associated operation were performed. All patients were controlled at six months and complications, as well as objective results, have been reported. The study was approved by ethical committee of KAUH. RESULTS: All patients with SUI admitted to KAUH and UDH for sub-urethral tape were analyzed (230 patients); 149 had classical TVT and 81 had TVT-Secur. Their age ranged from 30 years to 73 years with a mean of 49.8 years and std of 9.4. Their parity ranged from two to 15 with a mean of 6.2 and std of 2.4. One hundred eighty patients had SUI and 50 patients had mixed incontinence. The type of anesthesia used was general anesthesia in 69.6% (160) of cases and regional anesthesia in form of epidural or spine in 30.4% (70) of cases. Operative complications revealed a bladder perforation in 3.5% (eight) of cases and 2.2% had bleeding of more than 200 ml, and 53 patients which contribute to 23% had retention and required a catheter for 48 hours or more. After three months, it was observed that erosion of the mesh occurred in three cases. Fourteen cases (7%) continue to have SUI failure rate. CONCLUSION: The classical TVT and TVT-Secur were found to be very effective, easy, and safe procedures and with excellent results.

Biogenic platinum from agricultural wastes extract for improved methanol oxidation reaction in direct methanol fuel cell.

Platinum is the most commonly used catalyst in fuel cell application. However, platinum is very expensive, thus limits the commercialisation of fuel cell system due to the cost factor. This study introduces a biosynthesis platinum from plant extracts that can reduce the cost of platinum production compared to the conventional method and the hazardous during the production of the catalyst. The biogenic platinum was tested on a Direct Methanol Fuel Cell. Advanced biogenic of Pt nano-cluster was synthesized through a novel and facile of one-pot synthesis bio-reduction derived from natural source in the form of plant extracts as reducing agent. Several selected plant extracts drawn from agricultural waste such as banana peel, pineapple peels and sugarcane bagasse extracts were comparatively evaluated on the ability of phytochemical sources of polyphenols rich for the development of single-step synthesis for Pt NPs. Notably, the biogenic Pt NPs from sugar cane bagasse has superior electro-catalytic activity, the enhanced utilization efficiency of Pt and appreciable stability towards methanol oxidation reaction, whose ECSA value approximates 94.58 m2g-1, mass activity/specific activity (398.20 mAmg-1/0.8471 mA/cm2 Pt) which greater than commercial Pt black (158.12 mAmg-1/1.41 mA/cm2 Pt).

Nanostructured Pd-Based Electrocatalyst and Membrane Electrode Assembly Behavior in a Passive Direct Glycerol Fuel Cell.

The aim of this study was to synthesize, characterize, and observe the catalytic activity of Pd1Au1 supported by vapor-grown carbon nanofiber (VGCNF) anode catalyst prepared via the chemical reduction method. The formation of the single-phase compounds was confirmed by X-ray diffraction (XRD) and Rietveld refinement analysis, which showed single peaks corresponding to the (111) plane of the cubic crystal structure. Further analysis was carried out by field emission scanning emission microscopy (FESEM), energy dispersive X-ray analysis (EDX), nitrogen adsorption/desorption measurements, and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was examined by cyclic voltammetry tests. The presence of mesoporous VGCNF as support enables the use of a relatively small amount of metal catalyst that still produces an excellent current density (66.33 mA cm-2). Furthermore, the assessment of the kinetic activity of the nanocatalyst using the Tafel plot suggests that Pd1Au1/VGCNF exerts a strong electrocatalytic effect in glycerol oxidation reactions. The engineering challenges are apparent from the fact that the application of the homemade anode catalyst to the passive direct glycerol fuel cell shows the power density of only 3.9 mW cm-2. To understand the low performance, FESEM observation of the membrane electrode assembly (MEA) was carried out, examining several morphological defects that play a crucial role and affect the performance of the direct glycerol fuel cell.

Molecular dynamics simulations of sodium alginate/sulfonated graphene oxide membranes properties.

The influence of methanol as a solvent on the properties of sodium alginate/sulfonated graphene oxide (SA/SGO) membranes was explored in water-methanol mixed conditions with various methanol concentrations and temperatures through molecular dynamics simulations. The methanol uptake of the membrane showed an isolation phase determined from the simulation results. The distance between the sulfonic acid groups increased in higher methanol concentrations, as observed from S-S RDFs. Furthermore, the distance between the SA-chain RDFs and the solvent molecules was analysed to determine a) the affinity of water towards the sulfonic acid groups and b) the affinity of the aromatic backbone of the SA towards methanol molecules. A decrease in water molecule diffusion led to an increase in methanol diffusion and uptake. SA/SGO membranes exhibited a smaller diffusion coefficient than that for the Nafion membranes, as calculated from simulation results and compared to the experimental work. Additionally, the diffusion ability increased at higher temperatures for all permeants. The interaction information obtained is useful for DMFC applications.

Enhanced Proton Conductivity and Methanol Permeability Reduction via Sodium Alginate Electrolyte-Sulfonated Graphene Oxide Bio-membrane.

The high methanol crossover and high cost of Nafion® membrane are the major challenges for direct methanol fuel cell application. With the aim of solving these problems, a non-Nafion polymer electrolyte membrane with low methanol permeability and high proton conductivity based on the sodium alginate (SA) polymer as the matrix and sulfonated graphene oxide (SGO) as an inorganic filler (0.02-0.2 wt%) was prepared by a simple solution casting technique. The strong electrostatic attraction between -SO3H of SGO and the sodium alginate polymer increased the mechanical stability, optimized the water absorption and thus inhibited the methanol crossover in the membrane. The optimum properties and performances were presented by the SA/SGO membrane with a loading of 0.2 wt% SGO, which gave a proton conductivity of 13.2 × 10-3 Scm-1, and the methanol permeability was 1.535 × 10-7 cm2 s-1 at 25 °C, far below that of Nafion (25.1 × 10-7 cm2 s-1) at 25 °C. The mechanical properties of the sodium alginate polymer in terms of tensile strength and elongation at break were improved by the addition of SGO.

Penile measurements in normal adult Jordanians and in patients with erectile dysfunction.

The purpose of this work was to determine penile size in adult normal (group one, 271) and impotent (group two, 109) Jordanian patients. Heights of the patients, the flaccid and fully stretched penile lengths were measured in centimeters in both groups. Midshaft circumference in the flaccid state was recorded in group one. Penile length in the fully erect penis was measured in group two. In group one mean midshaft circumference was 8.98+/-1.4, mean flaccid length was mean 9.3+/-1.9, and mean stretched length was 13.5+/-2.3. In group two, mean flaccid length was 7.7+/-1.3, and mean stretched length was 11.6+/-1.4. The mean of fully erect penile length after trimex injection was 11.8+/-1.5. In group 1 there was no correlation between height and flaccid length or stretched length, but there was a significant correlation between height and midpoint circumference, flaccid and stretched lengths, and between stretched lengths and midpoint circumference. In group 2 there was no correlation between height and flaccid, stretched, or fully erect lengths. On the other hand, there was a significant correlation between the flaccid, stretched and fully erect lengths. Comparing group 1 and group 2, the patients in group 1 were slightly older than in group 2 (P=0.035), but there was no significant difference in their height. However, there was a significant difference regarding the mean flaccid length 9.3 vs 7.7 (P=0.001), and the mean stretched length 13.5 vs 11.6 (P=0.000). We divided both groups into those who are less than 40 y of age, and over 40 y old. There was no statistical difference in the stretched and flaccid lengths between the younger and older individuals in each group. However, when we compared the stretched and flaccid lengths in those of less than 40 y old in group 1 and 2, a significant difference was noticed. Similarly, a significant difference in the stretched and flaccid lengths in those patients over 40 y of age was also present.