Synthesis and functions of water-soluble and thermosensitive copolymers having phosphonium groups from acryloyloxyethyl trialkyl phosphonium chloride,N-isopropylacrylamide, and without/with butylmethacrylate

2003 ◽  
Vol 90 (4) ◽  
pp. 1139-1147 ◽  
Author(s):  
Takamasa Nonaka ◽  
Hua Li ◽  
Kaku Makinose ◽  
Tomonari Ogata ◽  
Seiji Kurihara
2011 ◽  
Vol 7 ◽  
pp. 204-209 ◽  
Author(s):  
Sabrina Gingter ◽  
Ella Bezdushna ◽  
Helmut Ritter

In the present work we report the enantioselective recognition of water soluble stimuli-responsive polymers bearing phenylalanine moieties via host-guest interaction with β-cyclodextrin and randomly-methylated-β-cyclodextrin (RAMEB-CD). We synthesised N-acryloyl-D/L-phenylalanine monomers (2 D , 2 L ) which were then copolymerised under free radical conditions with N-isopropylacrylamide (NIPAAm). The resulting copolymers 3 D and 3 L exhibit a lower critical solution temperature (LCST) of 25 °C. As a further benefit, the presence of a free carboxylic group in the copolymer system gives a high sensitivity to the pH value in respect to the LCST value. The enantioselective recognition of the side groups of copolymers 3 D and 3 L and their solubility behaviour were investigated by dynamic light scattering and 2D NMR spectroscopy, respectively.


Author(s):  
V. R. Duflot ◽  
A. V. Gaivoronsky ◽  
E. I. Lobanova

Objectives. Due to the increasing number of oncological diseases, active research into developing new radiopharmaceuticals is underway. Thermosensitive copolymers have valuable physicochemical properties that can be harnessed to develop therapeutic radiopharmaceuticals for treating solid tumors. The aim of this study was to develop a method for producing thermosensitive copolymers that can find use as radionuclide carriers to create therapeutic radiopharmaceuticals for treating solid tumors.Methods. Using radical copolymerization in polar solvents, we synthesized water-soluble copolymers based on N-isopropyl acrylamide and 2-aminoethyl methacrylate hydrochloride. The resulting copolymers were characterized in terms of molecular composition and hydrodynamic properties using gel permeation chromatography, IR spectroscopy, potentiometry, and viscometry. Changes in optical density during temperature scanning helped determine the phase transition temperature (PTT) of aqueous copolymer solutions.Results. We developed a method for preparing copolymers of N-isopropylacrylamide with 2-aminoethyl methacrylate using radical copolymerization in water and isopropanol with a content of 2-aminoethyl methacrylate hydrochloride in a copolymer up to 23 mol %. We studied how the second comonomer affected the PTT of the aqueous copolymer solutions. An increase in the content of 2-aminoethyl methacrylate in the copolymer caused the PTT to increase. We found that the change in the PTT depending on the content of 2-aminoethyl methacrylate units in the copolymer had a straightforward relationship with its content up to 17 mol %. The use of physiological saline as a solvent led to a temperature decrease of the phase transition by two degrees.Conclusions. The method of producing thermosensitive copolymers by radical copolymerization in isopropanol does not allow creating a radionuclide carrier. Solutions of the obtained lowmolecular weight oligomers form coacervate solutions, which will inevitably cause the radionuclide to spread throughout the body. The copolymers obtained by radical copolymerization in water with the content of the second comonomer 2-aminoethyl methacrylate from 10–17 mol % can be used as a radionuclides carrier provided that a physiological solution of sodium chloride is used as a solvent. 


Author(s):  
J. G. Robertson ◽  
D. F. Parsons

The extraction of lipids from tissues during fixation and embedding for electron microscopy is widely recognized as a source of possible artifact, especially at the membrane level of cell organization. Lipid extraction is also a major disadvantage in electron microscope autoradiography of radioactive lipids, as in studies of the uptake of radioactive fatty acids by intestinal slices. Retention of lipids by fixation with osmium tetroxide is generally limited to glycolipids, phospholipids and highly unsaturated neutral lipids. Saturated neutral lipids and sterols tend to be easily extracted by organic dehydrating reagents prior to embedding. Retention of the more saturated lipids in embedded tissue might be achieved by developing new cross-linking reagents, by the use of highly water soluble embedding materials or by working at very low temperatures.


Author(s):  
J. D. McLean ◽  
S. J. Singer

The successful application of ferritin labeled antibodies (F-A) to ultrathin sections of biological material has been hampered by two main difficulties. Firstly the normally used procedures for the preparation of material for thin sectioning often result in a loss of antigenicity. Secondly the polymers employed for embedding may non-specifically absorb the F-A. Our earlier use of cross-linked polyampholytes as embedding media partially overcame these problems. However the water-soluble monomers used for this method still extract many lipids from the material.


Author(s):  
D.R. Mattie ◽  
J.W. Fisher

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.


Author(s):  
H. J. Arnott ◽  
M. A. Webb ◽  
L. E. Lopez

Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.


Author(s):  
B. J. Grenon ◽  
A. J. Tousimis

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.


2020 ◽  
Vol 56 (65) ◽  
pp. 9332-9335
Author(s):  
Sandra Estalayo-Adrián ◽  
Salvador Blasco ◽  
Sandra A. Bright ◽  
Gavin J. McManus ◽  
Guillermo Orellana ◽  
...  

Two new water-soluble amphiphilic Ru(ii) polypyridyl complexes were synthesised and their photophysical and photobiological properties evaluated; both complexes showed a rapid cellular uptake and phototoxicity against HeLa cervical cancer cells.


2020 ◽  
Vol 44 (15) ◽  
pp. 5762-5773 ◽  
Author(s):  
Tatiyana V. Serebryanskaya ◽  
Mikhail A. Kinzhalov ◽  
Vladimir Bakulev ◽  
Georgii Alekseev ◽  
Anastasiya Andreeva ◽  
...  

Water soluble Pd(ii) and Pt(ii)–ADC species synthesized via the metal-mediated coupling of isocyanides and 1,2-diaminobenzene have demonstrated antitumor potential.


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