scholarly journals Encapsulation of Lactobacillus casei (ATCC 393) by Pickering-Stabilized Antibubbles as a New Method to Protect Bacteria against Low pH

2020 ◽  
Vol 4 (3) ◽  
pp. 40
Author(s):  
Vida Mardani Ghahfarokhi ◽  
Paolo P. Pescarmona ◽  
Gert-Jan W. Euverink ◽  
Albert T. Poortinga
Keyword(s):  
Aqueous Phase ◽  
Lactobacillus Casei ◽  
Silica Particles ◽  
Low Ph ◽  
New Method ◽  
Liquid Droplets ◽  
Freeze Dried ◽  
Oil In Water

Pickering-stabilized antibubbles were used as a new method to encapsulate Lactobacillus casei. Antibubbles consist of one or more liquid droplets within a shell of gas. The antibubbles were prepared from a water-in-oil-in-water (W/O/W) emulsion stabilized by silica particles, which was then freeze-dried to remove the water and oil phases, before being subsequently reconstituted in water. Different oil phases and aqueous phase compositions were tested for their effect on the survival of the bacteria. The survival of L. casei after encapsulation using decane was 29.8 ± 2.1% in antibubbles containing 10% (w/v) maltodextrin plus 8% (w/v) sucrose, which is comparable to the survival when bacteria were freeze-dried without being encapsulated. Encapsulation within antibubbles led to a 10 to 30 times higher survival of L. casei at pH 2 in comparison with unencapsulated bacteria. This study shows that probiotics can be encapsulated within a shell of gas through the use of antibubbles and that this protects probiotics against a low pH.

scholarly journals HYDROPHOBIZATION OF SILICA PARTICLES WITH VARIOUS CATIONIC SURFACTANTS

2021 ◽  
Vol 64 (3) ◽  
pp. 41-45
Author(s):  
Alla V. Nushtaeva ◽  
Natalia G. Vilkova
Keyword(s):  
Contact Angle ◽  
Aqueous Phase ◽  
Volume Fraction ◽  
Saturated Hydrocarbon ◽  
Vertical Surface ◽  
Contact Angles ◽  
Silica Particles ◽  
Sessile Droplet ◽  
Phase Volume Fraction ◽  
Oil In Water

Silica particles with a radius of 3-7 nm (Ludox and Aerosil) and 270 nm (synthesized by the Stöber method), modified with cetyltrimethylammonium bromide (CTAB) and hexylamine, were used to stabilize emulsions. The hysteresis angles θ of the particle selective wetting were measured by the sessile droplet method on the vertical surface or by the pulling a ball method at using a glass substrate modified by contact coagulation of silica. The contact angle at the boundary between the aqueous phase and the saturated hydrocarbon (octane, decane) reached the values θrec = 53 ± 2 ° and θadv = 116 ± 4 ° (the aqueous phase receding and advancing angle, respectively) with an increase in the initial concentration of long-chain CTAB to (1.4–9.5)·10–2 mmol/g of silica. With a further increase in CTAB concentration, a second reoriented layer was formed, which lowered the contact angle. Accordingly, using CTAB, only oil-in-water emulsions were obtained with the oil phase volume fraction Øoil = 0.5. The amount of short-chain hexylamine required to start stabilizing the emulsions turned out to be 2-3 orders of magnitude higher than the amount of CTAB. At using hexylamine, it was possible to increase the contact angle up to the values θrec ≈ θadv = 163 ± 12 ° at a concentration of 7-21 mmol/g. This is due to the fact that hexylamine is not characterized by formation of micelle or reoriented layers. Apparently, the adsorption of hexylamine is possible not only on dissociated silanol groups Si–OH, but also on siloxane groups Si–O–Si≡, which makes it possible to make the silica surface superhydrophobic. The measured contact angles were correlated with the region of stable oil-in-water and water-in-oil emulsions.

Nanoemulsions- A better Approach for Anti Diabeticdrugs Delivering

2020 ◽  
Vol 17 ◽  
Author(s):  
V. Manimaran ◽  
Ponnurengam Malliappan Sivakumar ◽  
J. Narayanan ◽  
Shanmugam Parthasarathi ◽  
Pranav Kumar Prabhakar
Keyword(s):  
Aqueous Phase ◽  
Therapeutic Agent ◽  
Antidiabetic Drugs ◽  
Optical Behaviour ◽  
Antimicrobial Drugs ◽  
Drug Degradation ◽  
Oil In Water ◽  
Drug Technology ◽  
Human Use ◽  
Poor Absorption

: Conventional delivery of antidiabetic drugs faces many problems like poor absorption, low bioavailability, and drug degradation. Nanoemulsion is a unique drug technology which is very suitable for the delivery of antidiabetic drugs. In recent years the flaws of delivering anti-hypoglycaemic drugs have been overcome by choosing nanoemulsion drug technology. They are thermodynamically stable and also deliver the therapeutic agent for a longer duration. Generally, Nanoemulsions are made up of either oil-in-water or water-in-oil and size of the droplets is from fifty to thousand nanometer. Surfactants are critical substances which are added in the manufacturing of nanoemulsions. Only the surfactants which are approved for human use can be utilized in the manufacturing of nanoemulsions. Generally, the preparation of emulsions includes mixing of the aqueous phase and organic phase and using surfactant with proper agitation. Nanoemulsions are used for antimicrobial drugs, and they are also used in the prophylaxis of cancer, diabetics. Reduction in the droplet size may cause variation in the elastic and optical behaviour of nanoemulsions.

Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

Interactions between Pluronics (F127 and F68) and Bile Salts (NaTDC) in the Aqueous Phase and the Interface of Oil-in-Water Emulsions

Langmuir ◽  
2013 ◽  
Vol 29 (8) ◽  
pp. 2520-2529 ◽  
Author(s):  
Amelia Torcello-Gómez ◽  
Julia Maldonado-Valderrama ◽  
Ana Belén Jódar-Reyes ◽  
Timothy J. Foster
Keyword(s):  
Aqueous Phase ◽  
Bile Salts ◽  
Oil In Water

Fungal exudates

1978 ◽  
Vol 24 (10) ◽  
pp. 1173-1181 ◽  
Author(s):  
Nicholas Colotelo
Keyword(s):  
Osmium Tetroxide ◽  
Sclerotium Rolfsii ◽  
Claviceps Purpurea ◽  
Liquid Droplets ◽  
Colloidal Solutions ◽  
Membranous Structure ◽  
Freeze Dried ◽  
Myrothecium Roridum ◽  
Biochemical Analyses ◽  
Membranous Material

The exudates or liquid droplets on various structures of a number of fungi were examined. The droplets were enveloped in membranous material and were associated with actively growing mycelia, including fruiting structures. Osmium tetroxide vapour-fixed droplets of Claviceps purpurea, Myrothecium roridum, Sclerotinia sclerotiorum, Sclerotium rolfsii, and Thanathephorus cucumeris did not dry to a powder but remained intact as spheres when freeze-dried. Fractured spheres, examined with the scanning electron microscope, showed the presence of a membranous structure similar to that of rapidly frozen colloidal solutions with the ice crystals removed by sublimation. Locules or cavities within the freeze-dried droplets are thought to be due to the entrapment of air when droplets coalesce. Biochemical analyses of the exudates showed that acid phosphatase, β-glucosidase, acid and alkaline protease, RNase polygalacturonase and cellulase enzymes as well as oxalic acid and ammonia were present.

Effect of electrolyte in silicone oil-in-water emulsions stabilised by fumed silica particles

2007 ◽  
Vol 9 (48) ◽  
pp. 6398 ◽  
Author(s):  
Tommy S. Horozov ◽  
Bernard P. Binks ◽  
Torsten Gottschalk-Gaudig
Keyword(s):  
Fumed Silica ◽  
Silicone Oil ◽  
Silica Particles ◽  
Oil In Water

Preparation of a synergistically stabilized oil-in-water paraffin Pickering emulsion for potential application in wood treatment

Holzforschung ◽  
2018 ◽  
Vol 72 (6) ◽  
pp. 489-497 ◽  
Author(s):  
Jun Jiang ◽  
Jinzhen Cao ◽  
Wang Wang ◽  
Haiying Shen
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Size Distribution ◽  
Droplet Size ◽  
Surface Hardness ◽  
Pickering Emulsion ◽  
Silica Particles ◽  
Morphological Properties ◽  
Pickering Emulsions ◽  
Oil In Water

AbstractPickering emulsions (emulsions stabilized by solid-state additives) are attractive as they have strong similarities with traditional surfactant-based emulsions. In this study, an oil-in-water (O/W) paraffin Pickering emulsion system with satisfying stability and small droplet size distribution was developed by hydrophilic silica particles and traditional surfactants as mixed emulsifiers. The droplet morphology and size distribution were observed by optical microscopy and a laser particle analyzer. The emulsion stability was improved and the droplet size was reduced after addition of a suitable amount of silica particles. The silica concentration of 1% showed the optimal effect among all the levels observed (0.1, 0.5, 1 and 2%). Wood was impregnated with the prepared emulsion, and the chemical and morphological properties of the product were investigated by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) combined with energy-dispersed X-ray analysis (SEM-EDXA). Moreover, the hydrophobicity, thermal properties, surface hardness, axial compression strength (CS) and dynamic mechanical properties were tested. The silica was evenly distributed in the wood cell wall and thus there was a synergistic positive effect from the paraffin and silica in the cell wall leading to better hydrophobicity, improved surface hardness and mechanical properties including the thermal stability.

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