Production of Prednisolone byPseudomonas oleovoransCells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

In order to rise the yield of prednisolone from hydrocortisone, thePseudomonas oleovoranscells were entrapped into radiation crosslinked poly(vinyl pyrrolidone)/poly(ethylene oxide)(PVP/PEO) hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such aspolymercomposition,polymerblend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition(90:10)and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44) was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilizedPseudomonas oleovoransentrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%.

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Investigation on Structural and Dielectric Properties of Silica Nanoparticles Incorporated Poly(Ethylene Oxide)/Poly(Vinyl Pyrrolidone) Blend Matrix Based Nanocomposites

Journal of Inorganic and Organometallic Polymers and Materials ◽

10.1007/s10904-018-1034-1 ◽

2018 ◽

Vol 29 (2) ◽

pp. 592-607 ◽

Cited By ~ 12

Author(s):

Shobhna Choudhary ◽

R. J. Sengwa

Keyword(s):

Dielectric Properties ◽

Ethylene Oxide ◽

Silica Nanoparticles ◽

Vinyl Pyrrolidone ◽

Poly Ethylene Oxide ◽

Poly Ethylene ◽

Poly Vinyl Pyrrolidone

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Deposition of Bead Arrays With Variable Diameter by Self-Focusing of Electrohydrodynamic Jets

Volume 2: Additive Manufacturing; Materials ◽

10.1115/msec2017-2893 ◽

2017 ◽

Author(s):

Nicolas Martinez-Prieto ◽

Gabriela Fratta ◽

Jian Cao ◽

Kornel Ehmann

Keyword(s):

Low Cost ◽

Three Dimensional ◽

Deposition Process ◽

Direct Writing ◽

Variable Diameter ◽

Self Focusing ◽

Poly Ethylene Oxide ◽

Poly Ethylene ◽

Number Of Passes ◽

Bead Arrays

Electrohydrodynamic processes were used for direct-writing of bead arrays with controllable bead sizes. Experiments were conducted to align layers of bead-on-string structures in an effort to create three-dimensional patterns. The results show that the jet focuses on previously deposited droplets allowing for the selective deposition of material over already deposited patterns. Jet attraction to already deposited solutions on the substrate is attributed to the charge transport at the liquid ink-metal collector interface and the dielectric properties of the water/poly(ethylene oxide) solution under an electric field. The deposition process consists of 3 steps: (1) deposition of a layer of bead-on-string structures, (2) addition of extra volume to the beads by subsequent passes of the jet, and (3) evaporation of the solvent resulting in an array of beads with varying sizes. Patterns with up to 20 passes were experimentally obtained. The beads’ height was seen to be independent of the number of passes. The process reported is a simple, fast, and low-cost method for deposition of bead arrays with varying diameters.

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