Synthesis of a Fullerene Derivative of Benzo[18]crown-6 byDiels-Alder Reaction: Complexation Ability, Amphiphilic Properties, and X-Ray Crystal Struc…

1993

A fullerene derivative 1 of benzo[18]crown-6 was obtained by Diels-Alder addition of fullerene[60](C60) to the ortho-quinodimethane prepared in situ from 4,5-bis(bromomethyl)benzo[18]crown-6 (3) with Bu4NI in toluene. Extraction experiments show that the complexation of K+ ions strongly increases the solubility of 1 in protic solvents like MeOH. Using Langmuir-Blodgett techniques, monolayers of the highly amphiphilic fullerene-derived crown ether 1 and its K+ ion complex were prepared. An X-ray crystal structure was obtained from a benzene clathrate of comparison compound 2, synthesized by Diels-Alder reaction of C60 with the ortho-quinodimethane derived from 1,2-bis(bromomethyl)-4,5-dimeth…

Synthesis of a Fullerene[60] Cryptate and Systematic Langmuir-Blodgett and Thin-Film Investigations of Amphiphilic Fullerene Derivatives

1995

The synthesis of the first fullerene cryptate 7 with a sodium ion bound to a benzo[2.2.2]cryptand covalently attached to a methanofullerene[60] is described. The amphiphilic properties of 7 as well as of a variety of other covalent fullerene derivatives with polar functional groups and the ability of these compounds to form Langmuir monolayers at the air-water interface were investigated in a systematic study. Among these derivatives are Diels-Alder adducts of C60 and methanofullerenes, four of which are fullerene C-glycosides. The films at the water surface were characterized by their surface pressure versus molecular area isotherms, compression and expansion cycles, and optical light micr…

Tetraethynylethene molecular scaffolding: Nonlinear optical, redox, and amphiphilic properties of donor functionalized polytriacetylene and expanded …

1997

Photocrosslinkable polysaccharide hydrogel composites based on dextran or pullulan-amylose blends with cytokines for a human co-culture model of huma…

2016

Although a large body of research has been devoted to biomaterial development for bone tissue engineering and related medical disciplines in the last few years, novel and optimized materials especially for bone fractures of critical sizes demand continued development. In this respect, polysaccharide-based hydrogels demonstrate beneficial properties and fulfill the main requirements for a bone tissue scaffold as they are hydrophilic, biocompatible, and biodegradable. The aim of the present study was the development of a natural polysaccharide-based scaffold material that can integrate with the host tissue and support bone regeneration. For this purpose, we prepared and investigated two polym…

Complex Ordering in Thin Films of Di- and Trifunctionalized Hexaalkoxytriphenylene Derivatives

1997

We have used pressure−area isotherms, X-ray diffraction, atomic force microscopy, and infrared dichroism to study Langmuir and Langmuir−Blodgett films of 2,3,6,7,10,11-hexaalkoxytriphenylenes which...

ChemInform Abstract: Synthesis of a Fullerene Derivative of Benzo(18)crown-6 by Diels-Alder Reaction: Complexation Ability, Amphiphilic Properties, a…

2010

A fullerene derivative 1 of benzo[18]crown-6 was obtained by Diels-Alder addition of fullerene[60](C60) to the ortho-quinodimethane prepared in situ from 4,5-bis(bromomethyl)benzo[18]crown-6 (3) with Bu4NI in toluene. Extraction experiments show that the complexation of K+ ions strongly increases the solubility of 1 in protic solvents like MeOH. Using Langmuir-Blodgett techniques, monolayers of the highly amphiphilic fullerene-derived crown ether 1 and its K+ ion complex were prepared. An X-ray crystal structure was obtained from a benzene clathrate of comparison compound 2, synthesized by Diels-Alder reaction of C60 with the ortho-quinodimethane derived from 1,2-bis(bromomethyl)-4,5-dimeth…

Definitionen von Grundbegriffen mit Bezug zu Polymerreaktionen und zu funktionellen polymeren Materialien

2007

Hier werden die Ausdrucke definiert, die im Bereich von Polymerreaktionen und funktionellen Polymeren am gelaufigsten sind. Dabei wurden nur Begriffe aufgenommen, die fur Polymersysteme spezifisch sind. Die Zusammenstellung ist in drei Abschnitte unterteilt: Im ersten werden die Begriffe definiert, die sich auf Polymerreaktionen beziehen. Die Namen spezifischer chemischer Reaktionen wurden nicht aufgenommen, auch nicht in Fallen, in denen die Reaktionen wichtig fur das Gebiet der Polymerreaktionen sind. Im zweiten Abschnitt werden Begriffe zu polymeren Reaktanten und reaktiven polymeren Materialien definiert, und im dritten Begriffe, die funktionelle polymere Materialien beschreiben.

Photocrosslinked Dextran-Based Hydrogels as Carrier System for the Cells and Cytokines Induce Bone Regeneration in Critical Size Defects in Mice

2018

Modified biomaterials have for years been the focus of research into establishing new bone substitutes. In our preceding in vitro study employing different cell cultures, we developed chemically and mechanically characterized hydrogels based on photocrosslinkable dextran derivatives and demonstrated their cytocompatibility and their beneficial effects on the proliferation of osteoblasts and endothelial cells. In the present in vivo study, we investigate photocrosslinked dextran-based hydrogels in critical size defects in mice to evaluate their potential as carrier systems for cells or for a specific angiogenesis enhancing cytokine to induce bone formation. We could demonstrate that, with op…

From Well-Defined Carbon-Rich Precursors to Monodisperse Carbon Particles with Hierarchic Structures

2007

The creation of nanoscale particles with well-defined structures has long been considered as a promising approach to generate materials with novel properties. Carbonaceous nanoparticles (CNPs) with defined architectures, such as carbon nanotubes (CNTs), C60, carbon onions, carbon spheres, and carbon rods are particularly attractive owing to their unique electronic properties and many potential applications. At the same time, when these CNPs are regularly organized, additional functions appear. Such materials are believed to have hierarchic structures, in which the organization of the CNPs forms the first-order structure (FOS) and the configuration of the single CNP forms the secondor higher…

Photocrosslinkable dextran hydrogel films as substrates for osteoblast and endothelial cell growth

2012

Functional hydrogel films on solid supports are versatile materials with large potential for cell growth and tissue engineering. Here, we report on a modular approach to generate functional hydrogel composite films for endothelial and osteoblast cell co-culture. The polymer network of the parent hydrogel was formed by a dextran derivative (BP-CMD), which contained carboxymethyl (CM) groups for further chemical functionalization and benzophenone (BP) moieties as a photocrosslinkable unit. BP-CMD could be synthesized by three different routes, first with the benzophenone unit attached via an amide bond, or second by an ether bond, or third as an ion pair between the benzophenone ammonium salt…

Hydrogel-supported protein-tethered bilayer lipid membranes: a new approach toward polymer-supported lipid membranes

2011

Polymer-supported bilayer lipid membranes offer great opportunities for the investigation of functional membrane proteins. Here we present a new approach in this direction by introducing a thin hydrogel layer as a soft ‘cushion’ on indium–tin oxide (ITO), providing a smooth, functional surface to form the protein-tethered BLM (ptBLM). ITO was used as a transparent electrode, enabling simultaneous implementation of electrochemical and optical waveguide techniques. The hydrogel poly(N-(2-hydroxyethyl)acrylamide-co-5-acrylamido-1-carboxypentyl-iminodiacetate-co-4-benzoylphenyl methacrylate) (P(HEAAm-co-NTAAAm-co-MABP)) was functionalized with the nickel chelating nitrilotriacetic acid (NTA) gr…

Glossar zu Begriffen mit Bezug zu Kinetik, Thermodynamik und Mechanismen von Polymerisationen

2009

Im Folgenden werden empfohlene Definitionen von grundlegenden Begriffen mit Bezug zu Polymerisationsprozessen vorgestellt. Neuere Entwicklungen im Hinblick auf die Kinetik, die Thermodynamik und die Mechanismen von Polymerisationen machen die Einfuhrung neuer Begriffe und einige Revisionen oder Erweiterungen von Begriffen notwendig, die zuvor im “Compendium of Chemical Terminology” oder im “Glossary of Basic Terms in Polymer Science” definiert wurden.

Magnetic Composite Thin Films of FexOy Nanoparticles and Photocrosslinked Dextran Hydrogels

2012

Abstract Magnetic hydrogel composites are promising candidates for a broad field of applications from medicine to mechanical engineering. Here, surface-attached composite films of magnetic nanoparticles (MNP) and a polymeric hydrogel (HG) were prepared from magnetic iron oxide nanoparticles and a carboxymethylated dextran with photoreactive benzophenone substituents. A blend of the MNP and the dextran polymer was prepared by mixing in solution, and after spin-coating and drying the blend film was converted into a stable MNP–HG composite by photocrosslinking through irradiation with UV light. The bulk composite material shows strong mobility in a magnetic field, imparted by the MNPs. By util…