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Chitosan Nanomaterials for Smart Delivery of Bioactive Compounds in Agriculture
Published in Ramesh Raliya, Nanoscale Engineering in Agricultural Management, 2019
Ram Chandra Choudhary, Sarita Kumari, R.V. Kumaraswamy, Garima Sharma, Ashok Kumar, Savita Budhwar, Ajay Pal, Ramesh Raliya, Pratim Biswas, Vinod Saharan
Nanoemulsions are nanoscale droplets (oil/water system) of size less than ∼ 100 nm (Anton and Vandamme 2011). Nanoemulsions have novel applications in various fields, such as agrochemicals, foods, cosmetics and pharmaceuticals. A typical nanoemulsion contains oil, water and emulsifier. They act as efficient delivery systems for hydrophobic compounds by dispersing the lipid phase as a colloidal dispersion. Nanoemulsions are commercially valuable delivery systems because they have the unique characteristic of small size and high surface area, transparent appearance, optical clarity and reduced rate of gravitational separation and flocculation. These are commonly stabilized by amphiphilic surfactants or emulsifiers which get absorbed between water and oil phases (Fig. 2). The emulsifier plays an important role for the creation of small sized droplets (Kumari et al. 2018). It reduces interfacial tension between oil and water phase and decreases the rate of coalescence of oil droplets by forming a physical, steric and/or electric barrier around them. Generally, synthetic surfactants, such as Tween-20 and Tween-80, are used in emulsion. However, their usage increases the synthetic content in the emulsions, making them unsuitable for agriculture and the food industry, and also bearing environmental consequences.
Formulation Design and Optimization Using Molecular Dynamics
Published in Davide Fissore, Roberto Pisano, Antonello Barresi, Freeze Drying of Pharmaceutical Products, 2019
Roberto Pisano, Andrea Arsiccio
The most common excipients used for protein stabilization during freeze-drying include sugars, such as the disaccharides sucrose, trehalose, and lactose or the monosaccharide glucosepolyols, such as sorbitol and glycerolpolymers, including albumin, dextran, polyvinylpyrrolidone (PVP) or hydroxyethyl cellulose (HEC)amino acids, such as glycine, proline, arginine, etc.surfactants, especially the polysorbates Tween 20 and Tween 80 When designing a freeze-dried formulation, it is important to remember that freezing and drying expose proteins to different stresses; therefore, the mechanisms of protein stabilization by excipients are not the same during the two stages of lyophilization. As a general guideline, those excipients that stabilize a protein in solution also have a protective action during freezing, as in both cases water is present. However, the mechanisms of protein stabilization are different in the dried state, and in this case the ability of the excipients to form a stiff, compact cake that inhibits the protein motions responsible for unfolding and aggregation becomes dominant (Ohtake et al. 2011). In the following, the main mechanisms of cryo- and lyoprotection will be described. The role of surfactants will be discussed in a separate section, as their mechanism is significantly different.
®” Preserves Wet/Living Organisms for Observation in High Resolution under a Scanning Electron Microscope
Published in Akihiro Miyauchi, Masatsugu Shimomura, Industrial Biomimetics, 2019
To mimic ECSs that could create the NanoSuit®, solutions including amphiphilic molecules were then tested. One of the best results obtained at the first stage was a solution of Tween 20, a nontoxic compound commonly used in biological experiments [18]. To test the barrier properties of the NanoSuit® made by this solution, the surfaces of certain animals previously unable to survive SEM exposure were provided exogenous materials by immersion in 1% Tween 20 solution before electron or plasma irradiation. Figure 15.3A–C shows typical results obtained with larvae of the Asian tiger mosquito, Aedes albopictus.
The effects of turmeric on the grain structure and properties of copper electrodeposited composites
Published in Transactions of the IMF, 2020
R. Merrill, L. Wu, J. E. Graves, J. Beddow, E. Fuentes, A. Cobley
To achieve a good quality homogeneous copper deposit of 30 µm at a cathode efficiency of 100%, the following conditions were selected. Direct current (DC) was utilised at a current density of 0.04 A cm−2 at ambient room temperature for 36.5 min. A 35 mm magnetic stirring bar was used throughout deposition at a speed of 200 rev min–1. Previous research had demonstrated that high metal ion concentrations in the electrolyte can cause salting out of the turmeric particles, therefore a low metal ion concentration acid copper electrolyte was used.8 The copper electrolyte was an aqueous solution of 75.0 ± 1.0 g L−1 of CuSO4.6H2O supplied by Fisher Scientific UK Ltd, 1.6 × 10−2 mol L−1 of HCl supplied by Sigma Aldrich UK Ltd, and 3.7 mol L−1 of H2SO4. Tween 20 is a non-ionic surfactant commonly utilised for biochemical applications, and previous research had demonstrated its effectiveness at dispersing turmeric particles in an electrolyte.8 Between 1.0 and 10.0 g L−1 of turmeric with 10.0 ml L−1 of Tween 20 was added to the copper electrolyte. The experimental arrangement is illustrated in Figure 1. Before deposition, the turmeric particles were dispersed using ultrasound from a 20 kHz Sonic Systems sonic processor P100/3-20 horn model GA99893 for 20 min at a power of 11 and 33 W L−1. A brass sheet 0.9 mm thick with a plating area of 25 mm2 was used as the cathode, with a pure copper anode. An aqueous solution of 10% Decon supplied by Sigma Aldrich UK Ltd, at ambient room temperature was used to remove any surface contaminants from the anode and cathode. To remove the oxidation layer the cathode and anode were submerged in a 3.9 M solution of H2SO4 at ambient room temperature for 60 s. DI water was then used to rinse off cathode and anode before electrodeposition.