scholarly journals ASAXS Study on Spatial Distribution of Hydrophobic Compounds in Polymer Micelles

2014 ◽  
Vol 70 (a1) ◽  
pp. C1580-C1580
Author(s):  
Isamu Akiba ◽  
Ryosuke Nakanishi ◽  
Masaki Kugimoto ◽  
Daisuke Kugimoto ◽  
Yusuke Sanada ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Hydrophobic Core ◽  
Polymer Micelle ◽  
Polymer Micelles ◽  
Small Droplet ◽  
Chemical Structures ◽  
Hydrophobic Compounds ◽  
Drug Compounds ◽  
Resonant Term ◽  
Highly Hydrophobic

In drug delivery system (DDS) using polymer micelles as drug carrier, DDS properties are related to spatial distribution of drug compounds in the micelles [1]. Because the spatial distribution of drug compounds should strongly depend on interactions and solubility of drug compounds in the micelles, elucidation of the relation between chemical structures of drug compounds and their spatial distribution in the micelle is much important. Thus, in this study, we examine to elucidate the relation between chemical features and spatial distribution of drug compounds in polymer micelles by using anomalous small-angle X-ray scattering (ASAXS). To apply the ASAXS near bromine K-edge for analysis [2] of spatial distribution of drug compounds in polymer micelles, we employ 4 different bromine-labeled hydrophobic compounds as model drug compounds and polymer micelles composed of poly(dimethylaminoethyl methacrylate)-block-poly(methyl methacrylate) (PDMAEMA-b-PMMA). Figure shows SAXS and resonant term obtained from ASAXS near bromine K-edge for the polymer micelles containing 9-bromofluorene (BrF). The domain size estimated from the resonant term is much smaller than that of hydrophobic PMMA core of the micelle. Therefore, When BrF, which is highly hydrophobic and scarcely dissolved in hydrophobic PMMA, is incorporated in the polymer micelle, BrF forms small droplet in the hydrophobic core composed of PMMA. For the micelles incorporating bromobenzene, which as similar properties of BrF, similar result is obtained. On the other hand, 4-bromobenzyl alcohol and ethyl 2-bromoethyl propionate, which are miscible with PMMA, are homogeneously dispersed in the PMMA core of the micelles. These results indicate that highly hydrophobic compounds forms small droplet in hydrophobic core, and introduction of polarity to the compounds causes expansion of the area existing the hydrophobic compounds in polymer micelle.

scholarly journals Effect of Molecular Architecture on Associating Behavior of Star-Like Amphiphilic Polymers Consisting of Plural Poly(ethylene oxide) and One Alkyl Chain

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Daisuke Kugimoto ◽  
Aoi Taniguchi ◽  
Masaki Kinoshita ◽  
Isamu Akiba
Keyword(s):  
Ethylene Oxide ◽  
Average Molecular Weight ◽  
Amphiphilic Polymers ◽  
Hydrophobic Core ◽  
Molecular Architecture ◽  
Polymer Micelles ◽  
The Core ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Associating behavior of star-like amphiphilic polymers consisting of two or three poly(ethylene oxide) (PEO) chains and one stearyl chain (C18) was investigated. Although the aggregation number (Nagg) of linear analogue of amphiphilic polymers monotonically decreased with increasing number-average molecular weight of PEO (Mn,PEO), the Nagg of micelles of star-like amphiphilic polymers with Mn,PEO = 550 g/mol was smaller than that with Mn,PEO = 750 g/mol, whereas that with Mn,PEO ≥ 750 g/mol showed general Mn,PEO dependence. Small-angle X-ray scattering analyses revealed that the occupied area of one PEO chain on the interface between hydrophobic core and corona layer in the micelles of star-like polymers was much narrower than that in the linear amphiphilic polymers. This result indica ted the PEO chains of star-like polymers partially took unfavorable conformation near the core–corona interface in polymer micelles. The effect of local conformation of PEO chains near the interface on the associating behavior became significant as Mn,PEO decreased. Therefore, in polymer micelles of star-like amphiphilic polymers containing PEO with Mn,PEO = 550 g/mol, the enlargement of occupied area of PEO on the core–corona interface should be caused to avoid the formation of unfavorable conformations of partial PEO chains, resulting in a decrease in Naggs.

scholarly journals Enzymatic synthesis of hydrophobic compounds integrated with membrane separation

2016 ◽  
Vol 37 (1) ◽  
pp. 15-27
Author(s):  
Andrzej Noworyta ◽  
Anna Trusek-Holownia
Keyword(s):  
Mass Transfer ◽  
Enzymatic Synthesis ◽  
Membrane Separation ◽  
Batch Processes ◽  
Operating Parameters ◽  
Membrane Contactor ◽  
Hydrophobic Compounds ◽  
Highly Hydrophobic ◽  
Describe Mass Transfer ◽  
Good Agreement

Abstract The enzymatic synthesis of a highly hydrophobic product (dipeptide precursor) in which the reaction is accompanied by the mass transfer of the reaction product to the organic phase and the substrates to the water phase is considered. Equations describing both continuous and batch processes are formulated. The range of variability in the operating parameters of such a bioreactor is specified, and the correlations reported in the literature to describe mass transfer in the membrane contactor are validated. The proposed process was verified experimentally, and good agreement between the determined and calculated concentrations was obtained in both phases.

Polymer Micelles with Hydrophobic Core and Ionic Amphiphilic Corona. 2. Starlike Distribution of Charged and Nonpolar Blocks in Corona

Langmuir ◽  
2012 ◽  
Vol 28 (34) ◽  
pp. 12663-12670 ◽  
Author(s):  
Evgeny A. Lysenko ◽  
Alevtina I. Kulebyakina ◽  
Pavel S. Chelushkin ◽  
Artem M. Rumyantsev ◽  
Elena Yu. Kramarenko ◽  
...  
Keyword(s):  
Hydrophobic Core ◽  
Polymer Micelles

Core hyper-cross-linked star polymers from block polymer micelle precursors

2020 ◽  
Vol 11 (45) ◽  
pp. 7178-7184
Author(s):  
Jongmin Park ◽  
Stefan J. D. Smith ◽  
Colin D. Wood ◽  
Xavier Mulet ◽  
Myungeun Seo
Keyword(s):  
Star Polymers ◽  
Cross Linking ◽  
Polymer Micelle ◽  
Polymer Micelles ◽  
Block Polymer

Hyper-cross-linking of a core of block polymer micelles produces core cross-linked polymer with a spacious hyper-cross-linked core, which is solution-processible.

scholarly journals Use of Silica-Encapsulated Pseudomonas sp. Strain NCIB 9816-4 in Biodegradation of Novel Hydrocarbon Ring Structures Found in Hydraulic Fracturing Waters

2014 ◽  
Vol 80 (16) ◽  
pp. 4968-4976 ◽  
Author(s):  
Kelly G. Aukema ◽  
Lisa Kasinkas ◽  
Alptekin Aksan ◽  
Lawrence P. Wackett
Keyword(s):  
Hydraulic Fracturing ◽  
Full Range ◽  
Ring Systems ◽  
Content Type ◽  
Ring Compounds ◽  
Hydrophobic Compounds ◽  
Ring Structures ◽  
Fundamental Ring ◽  
Silica Encapsulation ◽  
Highly Hydrophobic

ABSTRACTThe most problematic hydrocarbons in hydraulic fracturing (fracking) wastewaters consist of fused, isolated, bridged, and spiro ring systems, and ring systems have been poorly studied with respect to biodegradation, prompting the testing here of six major ring structural subclasses using a well-characterized bacterium and a silica encapsulation system previously shown to enhance biodegradation. The direct biological oxygenation of spiro ring compounds was demonstrated here. These and other hydrocarbon ring compounds have previously been shown to be present in flow-back waters and waters produced from hydraulic fracturing operations.Pseudomonassp. strain NCIB 9816-4, containing naphthalene dioxygenase, was selected for its broad substrate specificity, and it was demonstrated here to oxidize fundamental ring structures that are common in shale-derived waters but not previously investigated with this or related enzymes.Pseudomonassp. NCIB 9816-4 was tested here in the presence of a silica encasement, a protocol that has previously been shown to protect bacteria against the extremes of salinity present in fracking wastewaters. These studies demonstrate the degradation of highly hydrophobic compounds by a silica-encapsulated model bacterium, demonstrate what it may not degrade, and contribute to knowledge of the full range of hydrocarbon ring compounds that can be oxidized usingPseudomonassp. NCIB 9816-4.

Evaluation of the Efficacy and Performance of a New Nano-Drug Carrier in the Treatment of Recurrent Oral Ulcerper

2021 ◽  
Vol 21 (2) ◽  
pp. 1107-1117
Author(s):  
Yuqi He ◽  
Zhiqiang Xu ◽  
Zhuwen Qiu ◽  
Dechun Zheng ◽  
Liting Xie
Keyword(s):  
High Efficiency ◽  
Drug Carrier ◽  
Rapid Development ◽  
Drug Carriers ◽  
Surface Proteins ◽  
Diagnosis And Treatment ◽  
Research Progress ◽  
Hydrophobic Core ◽  
Polymer Micelle ◽  
Oral Ulcers

Recurrent oral ulcer is a common oral mucosal disease. Due to its periodic and recurrent characteristics, the onset of burning pain is unbearable, which brings great inconvenience to the patient’s life and seriously affects the patient’s quality of life. There are certain limitations to conventional drug therapy. With the rapid development of nanotechnology, the obvious advantages of nanotechnology such as targeting, controlled release, biocompatibility is obviously shown. The combination of nanotechnology and medical research has led to the emergence of polymer nanoparticles and ligands. Nano-drugs for gene therapy, and many other new nano-drug carriers, polymer micelle is a new type of nano drug carrier that has appeared in recent years. It has both a hydrophilic shell and a hydrophobic core, and has a variety of excellent properties, such as higher stability in vivo and in vitro, and poorly soluble drugs. In this paper, a new method for treating recurrent oral ulcers based on a new nano-drug carrier was studied. Because of the hydrophilicity and biocompatibility of oral cell surface proteins, the research progress of nanopharmaceutical carrier in the treatment of recurrent oral ulcers is reviewed. The experimental results show that the method has good reproducibility and high efficiency in the treatment of recurrent oral ulcers. It is used to explore the application and progress of nanotechnology in the diagnosis and treatment of recurrent oral ulcers, and to provide new ideas for the clinical diagnosis and treatment of recurrent oral ulcers. This new technical method has wide practical application value.

Anomalous Small-Angle X-ray Scattering Study of Structure of Polymer Micelles Having Bromines in Hydrophobic Core

2012 ◽  
Vol 45 (15) ◽  
pp. 6150-6157 ◽  
Author(s):  
Isamu Akiba ◽  
Atsuro Takechi ◽  
Megumi Sakou ◽  
Masashi Handa ◽  
Yuya Shinohara ◽  
...  
Keyword(s):  
Small Angle ◽  
Hydrophobic Core ◽  
Polymer Micelles ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

scholarly journals Plasticized PVC Membrane Modified Electrodes: Voltammetry of Highly Hydrophobic Compounds

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 202 ◽  
Author(s):  
Ernő Lindner ◽  
Marcin Guzinski ◽  
Bradford Pendley ◽  
Edward Chaum
Keyword(s):  
Chemical Sensor ◽  
Modified Electrodes ◽  
Pvc Membrane ◽  
Plasticized Pvc ◽  
Hydrophobic Compounds ◽  
Voltammetric Measurement ◽  
Electrochemically Active ◽  
Highly Hydrophobic ◽  
Electrically Charged ◽  
Voltammetric Measurements

In the last 50 years, plasticized polyvinyl chloride (PVC) membranes have gained unique importance in chemical sensor development. Originally, these membranes separated two solutions in conventional ion-selective electrodes. Later, the same membranes were applied over a variety of supporting electrodes and used in both potentiometric and voltammetric measurements of ions and electrically charged molecules. The focus of this paper is to demonstrate the utility of the plasticized PVC membrane modified working electrode for the voltammetric measurement of highly lipophilic molecules. The plasticized PVC membrane prevents electrode fouling, extends the detection limit of the voltammetric methods to sub-micromolar concentrations, and minimizes interference by electrochemically active hydrophilic analytes.

Separation of highly hydrophobic compounds in MEKC with an ionic polymer

1995 ◽  
Vol 18 (7) ◽  
pp. 443-445 ◽  
Author(s):  
Shenyuan Yang ◽  
Jefferson G. Bumgarner ◽  
Morteza G. Khaledi
Keyword(s):  
Ionic Polymer ◽  
Hydrophobic Compounds ◽  
Highly Hydrophobic
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