Synthetic approaches towards the preparation of water-soluble fulleropyrrolidines

Carbon ◽  
2000 ◽  
Vol 38 (11-12) ◽  
pp. 1551-1555 ◽  
Author(s):  
Véronique Tomberli ◽  
Tatiana Da Ros ◽  
Susanna Bosi ◽  
Maurizio Prato
2022 ◽  
Author(s):  
Afshin Nabiyan ◽  
Johannes B. Max ◽  
Felix H. Schacher

Double hydrophilic copolymers consist of two chemically different but water-soluble segments. We present synthetic approaches and both established as well as emerging applications such as photocatalysis or sensing.


2018 ◽  
pp. S293-S303 ◽  
Author(s):  
L. KOTRCHOVÁ ◽  
L. KOSTKA ◽  
T. ETRYCH

In this review we summarize several synthetic approaches to the advanced synthesis of star-like polymer-based drug carriers. Moreover, their application as nanomedicines for therapy or the diagnosis of neoplastic diseases and their biodistribution are reviewed in detail. From a broad spectrum of star-like systems, we focus only on fully water-soluble systems, mainly based on poly(ethylene glycol) or N-(2-hydroxypropyl)methacrylamide polymer and copolymer arms and polyamidoamine dendrimers serving as the core of the star-like systems.


2019 ◽  
Vol 59 (7) ◽  
pp. 37-42
Author(s):  
Anton O. Pozdeev ◽  
◽  
Alexander M. Koroteev ◽  
Sofia N. Pimankina ◽  
Mikhail P. Koroteev ◽  
...  

The flavonoid dihydroquercetin and its esterified derivatives possess various biological activities and are widely used as dietary supplements and in pharmacology. A significant disadvantage of this flavonoid is its low solubility in water at ordinary temperatures of up to 0.03%, which negatively affects its biological activity. Nature overcomes this problem by glycosylation, sulfation, and phosphorylation. In chemistry and pharmacology to overcome this problem, there are several synthetic approaches. For dihydroquercetin (DHQ) is the inclusion of DHQ in the cyclodextrin matrix or the formation of a complex of DHQ with basic natural amino acids. In this paper, a method is proposed for obtaining water-soluble morpholinium salts based on chloroacylated derivatives of DHQ. The acylation reaction was carried out in dioxane, pyridine was used as an acceptor of choric hydrogen. The target compounds were obtained with a yield of 68-79%. As a result, chlorinated derivatives based on DHQ and its acyl and benzyl derivatives were synthesized. These derivatives in the interaction with morpholine form its salts, which, as it turned out, have a high water solubility. Pentamorpholine salt of DHQ had the highest solubility in water, up to 6.5% at room temperature, which is 200 times more soluble than the original DHQ. The proposed synthetic approach to increase the water solubility of acyl derivatives of DHQ can be extended using other nitrogenous bases and other haloacyl derivatives of DHQ.


2014 ◽  
Vol 15 (3-4) ◽  
Author(s):  
Xiao-Hua Qin ◽  
Aleksandr Ovsianikov ◽  
Jürgen Stampfl ◽  
Robert Liska

AbstractHydrogels are extensively explored as scaffolding materials for 2D/3D cell culture and tissue engineering. Owing to the substantial complexity of tissues, it is increasingly important to develop 3D biomimetic hydrogels with user-defined architectures and controllable biological functions. To this end, one promising approach is to utilize photolithography-based additive manufacturing technologies (AMTs) in combination with photosensitive hydrogels. We here review recent advances in photolithography-based additive manufacturing of 3D hydrogels for tissue engineering applications. Given the importance of materials selection, we firstly give an overview of water-soluble photoinitiators for single- and two-photon polymerization, photopolymerizable hydrogel precursors and light-triggered chemistries for hydrogel formation. Through the text we discuss the design considerations of hydrogel precursors and synthetic approaches to polymerizable hydrogel precursors of synthetic and natural origins. Next, we shift to how photopolymerizable hydrogels could integrate with photolithography-based AMTs for creating well-defined hydrogel structures. We illustrate the working-principles of both single- and two-photon lithography and case studies of their applications in tissue engineering. In particular, two-photon lithography is highlighted as a powerful tool for 3D functionalization/construction of hydrogel constructs with μm-scale resolution. Within the text we also explain the chemical reactions involved in two-photon-induced biofunctionalization and polymerization. In the end, we summarize the limitations of available hydrogel systems and photolithography-based AMTs as well as a future outlook on potential optimizations.


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.


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