De novo determination of mosquitocidal Cry11Aa and Cry11Ba structures from naturally-occurring nanocrystals

Cry11Aa and Cry11Ba are the two most potent toxins produced by mosquitocidal Bacillus thuringiensis subsp. israelensis and jegathesan, respectively. The toxins naturally crystallize within the host; however, the crystals are too small for structure determination at synchrotron sources. Therefore, we applied serial femtosecond crystallography at X-ray free electron lasers to in vivo-grown nanocrystals of these toxins. The structure of Cry11Aa was determined de novo using the single-wavelength anomalous dispersion method, which in turn enabled the determination of the Cry11Ba structure by molecular replacement. The two structures reveal a new pattern for in vivo crystallization of Cry toxins, whereby each of their three domains packs with a symmetrically identical domain, and a cleavable crystal packing motif is located within the protoxin rather than at the termini. The diversity of in vivo crystallization patterns suggests explanations for their varied levels of toxicity and rational approaches to improve these toxins for mosquito control.

“FORMULATION DEVELOPMENT AND SOLUBILITY ENHANCEMENT OF ROSUVASTATIN CALCIUM BY USING HYDROPHILIC POLYMERS AND SOLID DISPERSION METHOD”

Objective: Preparation of Rosuvastatin Calcium by Using Hydrophilic Polymers and Solid Dispersion Method, Rosuvastatin calcium is a Dyslipidaemic agent, which act as a selective competitive inhibitor of HMG CoA educates enzyme and is used in the treatment of hyperlipidemia. Methods: In the present work, Solid Dispersion was prepared by kneading method to increase the solubility of Rosuvastatin Calcium. Results: Solid dispersions were evaluated by determining percentage yield, drug content, solubility, Scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), DSC and in vitro dissolution profile. The prepared solid dispersion are formulated into capsule dosage form and characterized by various parameters i.e. weight variation, content uniformity, disintegration and dissolution. The evaluated parameters of capsule dosage form increase in solubility and dissolution rate of the pure drug. Conclusion: These are various techniques to enhance the solubility of the drug, such as particle size reduction, use of surfactants, solid dispersion etc. Carriers are the major players in these formulations, e. g. Hydroxypropylmethylcellulose, ethylcellulose, Carbopol, Acacia Gum etc. Carbopol and Acacia Gum is one of the most efficient polymers work as a carrier for these drugs to enhance solubility.

EFFECT OF SILICON DIOXIDE NANOPARTICLES ON MECHANICAL PROPERTIES OF CARBON FIBER/UNSATURATED POLYESTER COMPOSITE

This study deals with the effect of silicon dioxide nanoparticles (SiO2NPs) on the mechanical properties of polymer matrix composite (PMC). The nanocomposites were prepared by adding carbon fiber (CF1.5%) to the unsaturated polyester resin, and then different proportions of SiO2 NPs (1 to 4% by weight) were added using the ultrasonic bath machine dispersion method. The results showed that the tensile strength decreases with the increase in the partial weight of SiO2. Impact resistance, bending and compressive strength were improved by (50.67%, 10.2%, and 18.14%) respectively at 2% by weight, then these properties decreased with the increase in weight ratio of (SiO2), and the hardness was improved by (19.7%) at 3% by weight. The present study aims to study the effect of adding silicon dioxide nanoparticles on the mechanical properties (tensile properties, compression, hardness and bending) of carbon fiber reinforced unsaturated polyester composite.

Evaluation of Dispersion Methods and Mechanical Behaviour of Glass Fibre Composites with Embedded Self-Healing Systems

The present paper is focused on evaluating the most suitable dispersion method in the epoxy matrix of two self-healing systems containing dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene (ENB) monomers encapsulated in a urea-formaldehyde (UF) shell, prior to integration, fabrication and impact testing of specimens. Both microstructural analysis and three-point bending tests were performed to evaluate and assess the optimum dispersion method. It was found that ultrasonication damages the microcapsules of both healing systems, thus magnetic stirring was used for the dispersion of both healing systems in the epoxy matrix. Using magnetic dispersion, 5%, 7%, 10%, 12% and 15% volumes of microcapsules were embedded in glass fibre composites. Some of the samples were subjected to thermal cycling between −20 °C and +100 °C for 8 h, to evaluate the behaviour of both healing systems after temperature variation. Impact test results showed that the mechanical behaviour decreases with increasing microcapsule volume, while for specimens subjected to thermal cycling, the impact strength increases with microcapsule volume up to 10%, after which a severe drop in impact strength follows. Retesting after 48 h shows a major drop in mechanical properties in specimens containing 15% MUF-ENB microcapsules, up to total penetration of the specimen.

Formulation and Evaluation of Curcumin Loaded Nanoliposome on Brain Targeted

The present work aimed to produce Curcumin based nanoliposomes that nanoliposome can target the site via the brain in a controlled manner. Nanoliposomes are important in controlling the carriage; Curcumin which is an active constituent of curcuminoids thus also provides an effective treatment for the central nervous system and plays a crucial role. The interaction of the drug was ruled out by FT-IR studies and no incompatibility and lipids and surfactant. To optimize the formulation, factors affecting the physical appearance of Nanoliposomes were investigated. Curcumin-loaded Nanoliposomes were formulated using cholesterol by physical dispersion method and characterized for particle size, drug content, stability, production yield. Prepared nanoliposomes gave the better physical, morphological concerning the concentration of the lipids, surfactant, and ratio of lipid and surfactant. Six different formulations of Nanoliposomes F1-F6 were formulated to obtain the optimized formulation. The TEM (Transmission Electron Microscopy) of Nanoliposomes showed that they were rounded in shape and porous in texture. In-vitro drug release of formulation indicates that formulation F6 was selected as an optimized formulation for incorporation into the nanoliposomes among all the six formulations and liposome showed drug release in a controlled manner at the end of 10 hours. Keywords: Curcumin, Nanoliposomes, Physical Dispersion Method, Brain Targeting, Blood-Brain Barrier, Cholesterol, Bioavailability, In vitro Release.