Interfacial biocatalysis in bacteria-stabilized Pickering emulsions for microbial transformation of hydrophobic chemicals

Author(s):  
Haisheng Xie ◽  
Wenyu Zhao ◽  
Daniel Chikere Ali ◽  
Xuehong Zhang ◽  
Zhilong Wang

The Pickering emulsion interface is an exceptional habitat for bacteria to grow by simultaneously utilizing hydrophobic and hydrophilic chemicals.

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1071 ◽  
Author(s):  
Yu-Jin Cho ◽  
Dong-Min Kim ◽  
In-Ho Song ◽  
Ju-Young Choi ◽  
Seung-Won Jin ◽  
...  

A pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA)-based oligoimide (PMDA-ODA) was synthesized by a one-step procedure using water as a solvent. The PMDA-ODA particles showed excellent partial wetting properties and were stably dispersed in both water and oil phases. A stable dispersion was not obtained with comparison PMDA-ODA particles that were synthesized by a conventional two-step method using an organic solvent. Both oil-in-water and water-in-oil Pickering emulsions were prepared using the oligoimide particles synthesized in water, and the size of the emulsion droplet was controlled based on the oligoimide particle concentration. The oligoimide particles were tested to prepare Pickering emulsions using various kinds of oils. The oil-in-water Pickering emulsions were successfully applied to prepare microcapsules of the emulsion droplets. Our new Pickering emulsion stabilizer has the advantages of easy synthesis, no need for surface modification, and the capability of stabilizing both oil-in-water and water-in-oil emulsions.


Soft Matter ◽  
2015 ◽  
Vol 11 (18) ◽  
pp. 3512-3529 ◽  
Author(s):  
Juntao Tang ◽  
Patrick James Quinlan ◽  
Kam Chiu Tam

Pickering emulsions with stimuli-responsive properties have, in recent years, received a considerable amount of attention. This paper provides a concise and comprehensive review of Pickering emulsion systems that possess the ability to respond to an array of external triggers, including pH, temperature, CO2concentration, light intensity, ionic strength, and magnetic field intensity.


2020 ◽  
Vol 19 (2) ◽  
pp. 169-178
Author(s):  
D Prasanthi ◽  
N Varsha Priya ◽  
Amoolya Chennuri ◽  
PK Lakshmi

Emulsifier-free, particle-stabilised emulsions called Pickering emulsions of fluconazole for topical delivery, were studied using Taguchi L9 orthogonal array (OA) design. Formulations were prepared by homogenization method, using bentonite in the concentration range of 2-4% w/v, oil phase (coconut oil, oleic acid, sesame oil). In Taguchi L9 OA experimental design, independent variables (oil phase & concentration of bentonite) effect on dependent variables (drug content & release rate) was studied. All the formulations have shown good physicochemical properties. The PS3 formulation containing sesame oil and 4% bentonite was optimized as particle size was found to be 758.0 nm, zeta potential -48 mv, with Q8 of 166.70±0.15μg/cm2, flux of 17.33±0.02 μg/cm2/hr, permeability coefficient of 3.46±0.015 cm/hr×10-3 and skin content of 4.01±0.24 mg/g. The formulations were stable and non-irritant. Hence pickering emulsion of fluconazole using sesame oil can be used for topical delivery as the drug release was maintained at the localised site. Dhaka Univ. J. Pharm. Sci. 19(2): 169-178, 2020 (December)


RSC Advances ◽  
2020 ◽  
Vol 10 (36) ◽  
pp. 21545-21560
Author(s):  
Ramesh Narukulla ◽  
Umaprasana Ojha ◽  
Tushar Sharma

Schematic for the impact of NaCl on droplet stabilization in Pickering emulsions.


2015 ◽  
Vol 11 ◽  
pp. 2355-2364 ◽  
Author(s):  
Shintaro Kawano ◽  
Toshiyuki Kida ◽  
Mitsuru Akashi ◽  
Hirofumi Sato ◽  
Motohiro Shizuma ◽  
...  

Background: Emulsions stabilized by colloidal particles are known as Pickering emulsions. To date, soft microgel particles as well as inorganic and organic particles have been utilized as Pickering emulsifiers. Although cyclodextrin (CD) works as an attractive emulsion stabilizer through the formation of a CD–oil complex at the oil–water interface, a high concentration of CD is normally required. Our research focuses on an effective Pickering emulsifier based on a soft colloidal CD polymer (CD nanogel) with a unique surface-active property. Results: CD nanogels were prepared by crosslinking heptakis(2,6-di-O-methyl)-β-cyclodextrin with phenyl diisocyanate and subsequent immersion of the resulting polymer in water. A dynamic light scattering study shows that primary CD nanogels with 30–50 nm diameter assemble into larger CD nanogels with 120 nm diameter by an increase in the concentration of CD nanogel from 0.01 to 0.1 wt %. The CD nanogel has a surface-active property at the air–water interface, which reduces the surface tension of water. The CD nanogel works as an effective Pickering emulsion stabilizer even at a low concentration (0.1 wt %), forming stable oil-in-water emulsions through interfacial adsorption by the CD nanogels. Conclusion: Soft CD nanogel particles adsorb at the oil–water interface with an effective coverage by forming a strong interconnected network and form a stable Pickering emulsion. The adsorption property of CD nanogels on the droplet surface has great potential to become new microcapsule building blocks with porous surfaces. These microcapsules may act as stimuli-responsive nanocarriers and nanocontainers.


Holzforschung ◽  
2018 ◽  
Vol 72 (6) ◽  
pp. 489-497 ◽  
Author(s):  
Jun Jiang ◽  
Jinzhen Cao ◽  
Wang Wang ◽  
Haiying Shen

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.


2017 ◽  
Vol 19 (45) ◽  
pp. 30790-30797 ◽  
Author(s):  
Thriveni G. Anjali ◽  
Madivala G. Basavaraj

pH driven detachment of particles from Pickering emulsion droplets.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1990
Author(s):  
Yinghao Li ◽  
Ge Xu ◽  
Weiwei Li ◽  
Lishuang Lv ◽  
Qiuting Zhang

Ultrasound is one of the most commonly used methods to prepare Pickering emulsions. In the study, zein nanoparticles-flaxseed gum (ZNP-FSG) complexes were fabricated through various preparation routes. Firstly, the ZNP-FSG complexes were prepared either through direct homogenization/ultrasonication of the zein and flaxseed gum mixture or through pretreatment of zein and/or flaxseed gum solutions by ultrasonication before homogenization. The Pickering emulsions were then produced with the various ZNP-FSG complexes prepared. ZNP-FSG complexes and the final emulsions were then characterized. We found that the complex prepared by ultrasonication of zein as pretreatment followed by homogenization of the ZNP with FSG ((ZNPU-FSG)H) exhibited the smallest turbidity, highest absolute potential value, relatively small particle size, and formed the most stable complex particles. Meanwhile, complex prepared through direct ultrasonication plus homogenization on the mixture ((ZNP-FSG)HU) showed significantly decreased emulsifying properties and stability. Compared with the complex without ultrasonic treatment, the complex and emulsion, which prepared by ultrasonicated FSG were extremely unstable, and the phase separation phenomenon of the emulsion was observed 30 min after preparation. The above conclusions are also in line with the findings obtained from the properties of the corresponding emulsions, such as the droplets size, microstructure, freeze-thaw stability, and storage stability. It is, therefore, clear that to produce stable Pickering emulsion, ultrasonication should be avoided to apply together at the end of ZNP-FGS complex preparation. It is worth noticing that the emulsions prepared by complex with ultrasonicated zein (ZNPU-FSG)H are smaller, distributed more uniformly, and are able to encapsulate oil droplets well. It was found that the emulsions prepared with ZNPU-FSG remained stable without serum phase for 14 days and exhibited improved stability at low-temperature storage. The current study will provide guidance for the preparation of protein–polysaccharide complexes and Pickering emulsions for future work.


Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1820
Author(s):  
Benoit Fouconnier ◽  
M. Ali Aboudzadeh ◽  
Francisco López-Serrano

In this work, polymerizations of styrene (St) in the presence of divinylbenzene (DVB) as a crosslinking agent and sodium 4-vinylbenzenesulfonate (VBS) have been performed in Pickering emulsions, using silica nanoparticles (SNps) as stabilizing agents and ammonium persulfate as a hydrophilic initiator. In oil-in-water Pickering emulsions with alkaline continuous phase (pH = 9) at 1, 2, and 3 wt% DVB (relative to St), polydisperse spheroid copolymer submicronic nanoparticles were obtained. Comparatively, polymerizations performed in Pickering emulsions with acidic continuous phase (pH = 5) allowed preparing St-co-DVB microspheres with core–shell structures at 1 wt% DVB and St-co-DVB hybrid monoliths with bi-continuous morphologies at 2 and 3 wt% DVB. It is noteworthy that this work reports Pickering emulsion polymerization as a new strategy for preparing hybrid percolated scaffolds with bi-continuous porosity. The proposed mechanisms originated by pH, DVB, and VBS and the drastic impact caused on the final morphology obtained, either hybrid particles or monoliths, are discussed herein.


2016 ◽  
Vol 4 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Lei Ouyang ◽  
Dingyi Li ◽  
Lihua Zhu ◽  
Wenwen Yang ◽  
Heqing Tang

β-CD modified plasmonic Pickering emulsions were synthesized for interfacial reaction monitoring as well as for kinetic study.


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