Primary osteoblasts adhesion onto RGD-functionalized and cross-linked polyelectrolyte multilayer films

2004 ◽  
Vol 823 ◽  
Author(s):  
Catherine Picart ◽  
Ludovic Richert ◽  
René Elkaim ◽  
Pierre Schaaf ◽  
Jean-Claude Voegel ◽  
...  
Keyword(s):  
Mechanical Stimulus ◽  
Water Soluble ◽  
Cross Linking ◽  
Chemical Stimulus ◽  
Polyelectrolyte Multilayer ◽  
Amino Acid Peptide ◽  
Long Term Effect ◽  
Carboxylic Groups ◽  
Short Time ◽  
Functionalized Films

AbstractThe adhesion of primary osteoblastic cells on top of biocompatible polyelectrolyte multilayer (PEM) films was investigated for native films and after changing the films properties either with a chemical stimulus (film functionalization), with a mechanical stimulus (film cross-linking), or with both stimuli combined. For the functionalization, a 15 amino acid peptide containing a –RGD- (-Arg-Gly-Asp) sequence was grafted to poly(L-glutamic) acid and deposited on top of poly(L-lysine)/poly(L-glutamic) (PLL/PGA), PLL/Poly(alginic), and PLL/Poly(galacturonic) films. The film buildup and the adsorption of the PGA-RGD was followed by Optical Waveguide Lightmode Spectroscopy and by Atomic Force Microscopy. The mechanical stimulus was achieved by crosslinking the films with a water soluble carbodiimide (EDC) in combination with N-hydroxysulfo-succinimide (sulfo-NHS) to induce amide formation. Fourier Transform Infrared Spectroscopy evidenced the conversion of amine and carboxylic groups into amide groups.The alkaline phosphatase (ALP) activity test was used to assess osteoblast adhesion and proliferation on top of the different films over a period of eight days in culture. Whereas the native films are poorly adherent, the RGD-functionalized films exhibit an increased short time adhesion. The native films could also be successfully cross-linked thereby dramatically enhancing cell proliferation. The cells did not react similarly on the different types of films investigated : the cross-linked (PLL/Palg) and (PLL/Pgal) films were much more efficient than the native or functionalized films in terms of proliferation. On the other hand, for the (PLL/PGA) films, functionalization and film cross-linking had a similar long term effect. Very interestingly, for these latter films, both stimuli could be combined.

A Novel Versatile Process for the Production of Polymer Foams

1998 ◽  
Vol 550 ◽  
Author(s):  
V.P. Shastri ◽  
I. Martin ◽  
R. Langer
Keyword(s):  
Water Soluble ◽  
Wound Dressings ◽  
High Porosity ◽  
Polymer Foams ◽  
Polymer Foam ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Great Utility ◽  
Wide Range ◽  
Short Time

AbstractPorous polymeric media are used in several applications such as solid supports for separations and catalysis, as well as biomedical applications such as vascular grafts and wound dressings. We have developed a novel versatile process to produce polymeric cellular solids. This process which is based on a phase extraction-co-polymer precipitation is applicable to a wide range of polymer systems including water soluble polymers. It is capable of yielding polymer foams of high porosity (> 90%) and excellent mechanical characteristics in a very short time (less than 2 hours) without limitations in foam thickness. Polymer foam with such characteristics have great utility in tissue engineering applications. We have successfully explored polymer foams of biocompatible polymers produced by the presented approach for bone and cartilage engineering using bone marrow stromal cells.

scholarly journals Improvements of glycol methacrylate. I. Its use as an embedding medium for electron microscopic studies.

1977 ◽  
Vol 25 (3) ◽  
pp. 163-174 ◽  
Author(s):  
R C Spaur ◽  
G C Moriarty
Keyword(s):  
Electron Beam ◽  
Water Soluble ◽  
Cross Linking ◽  
Electron Microscopic ◽  
Glycol Methacrylate ◽  
Ultrastructural Studies ◽  
Tissue Morphology ◽  
Methacrylate Monomer ◽  
Microscopic Studies ◽  
Embedding Medium

The technique for using the water-soluble embedding medium glycol methacrylate has been improved for ultrastructural studies by the simplification of the method of formation of prepolymers used in embedding the tissue, by the addition of a cross-linking agent so that sections are stable in the electron beam, and by improving the softness of the blocks by the addition of a plasticizing agent. The preservation of tissue morphology has been improved by complete dehydration in glycol methacrylate monomer prior to infiltration with the prepolymer. Preservations of tissue morphology is further enhanced by complete dehydration in ethanols and embedding in the improved glycol methacrylate medium.

Chitosan Cross-Linking with a Water-Soluble, Blocked Diisocyanate. 2. Solvates and Hydrogels

2003 ◽  
Vol 4 (5) ◽  
pp. 1357-1361 ◽  
Author(s):  
Eric R. Welsh ◽  
Ronald R. Price
Keyword(s):  
Water Soluble ◽  
Cross Linking

scholarly journals Molecular Distributions of Soluble Oxidation Products from Coals Characterized by Mass Spectrometers

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xing Fan ◽  
Fei Wang
Keyword(s):  
Mass Spectrometry ◽  
Direct Analysis ◽  
Water Soluble ◽  
Oxidation Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Mass Spectrometers ◽  
Polycarboxylic Acids ◽  
Alkanoic Acids ◽  
Carboxylic Groups ◽  
Soluble Species

Oxidation of three coals with rank from lignite to anthracite in NaOCl aqueous solution was investigated in this study. The oxidation products were characterized by using gas chromatography/mass spectrometry and direct analysis in real-time mass spectrometry. The results showed that most of organic compounds in coals were converted into water-soluble species under mild conditions, even the anthracite. Benzene polycarboxylic acids (BPCAs) and chloro-substituted alkanoic acids (CSAAs) were major products from the reactions. The products from lower rank coals consist of considerable CSAAs and most products from high rank coals are BPCAs. As coal rank increases, the yield of BPCAs with more carboxylic groups increases.

Rheology of latex films bonded to wood: influence of cross-linking

Holzforschung ◽  
2006 ◽  
Vol 60 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Francisco López-Suevos ◽  
Charles E. Frazier
Keyword(s):  
Phenol Formaldehyde ◽  
Adhesive Layer ◽  
Wood Adhesive ◽  
Water Soluble ◽  
Cross Linking ◽  
Sample Type ◽  
Master Curves ◽  
Latex Films ◽  
Adhesive Interaction ◽  
Tan Δ

Abstract Parallel-plate rheological analysis was conducted on two types of cross-linking poly(vinyl acetate) latex films: dry freestanding films, and dry films bonded directly to wood (composites). For each sample type, three levels of cross-linking were used: (1) little or no cross-linking of unaltered latex; (2) substantial cross-linking through AlCl3 catalysis of N-methylolacrylamide co-monomer; and (3) greater cross-linking from a phenol-formaldehyde resol additive, in addition to AlCl3 catalysis. Simple thermal scans revealed a strong wood/adhesive interaction; wood increased the base polymer T g by ∼5°C in all adhesives. Relative to the simple thermal scans, time-temperature master curves provided more insight and information about the wood/adhesive interaction. Storage modulus and tan δ master curves both indicated that wood retarded adhesive cross-linking. Using time-temperature superposition, a segmental coupling analysis demonstrated that wood actually narrowed the breadth of the glass transition, or reduced segmental coupling. Cross-linking influenced segmental coupling, but in a fashion that was dependent on the presence or absence of wood. Wood-induced reductions in cross-linking and in segmental coupling were attributed to the diffusion of water-soluble reactive compounds away from the adhesive layer and into the bulk wood. Time/temperature equivalence provides a sensitive means to detect interactions between wood and viscoelastic adhesives.

scholarly journals Current Progress in Cross-Linked Peptide Self-Assemblies

2020 ◽  
Vol 21 (20) ◽  
pp. 7577
Author(s):  
Noriyuki Uchida ◽  
Takahiro Muraoka
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Water Soluble ◽  
Cross Linking ◽  
Physical And Chemical Properties ◽  
Cell Scaffold ◽  
Scaffold Materials ◽  
Physical And Chemical ◽  
And Chemical Properties

Peptide-based fibrous supramolecular assemblies represent an emerging class of biomaterials that can realize various bioactivities and structures. Recently, a variety of peptide fibers with attractive functions have been designed together with the discovery of many peptide-based self-assembly units. Cross-linking of the peptide fibers is a key strategy to improve the functions of these materials. The cross-linking of peptide fibers forming three-dimensional networks in a dispersion can lead to changes in physical and chemical properties. Hydrogelation is a typical change caused by cross-linking, which makes it applicable to biomaterials such as cell scaffold materials. Cross-linking methods, which have been conventionally developed using water-soluble covalent polymers, are also useful in supramolecular peptide fibers. In the case of peptide fibers, unique cross-linking strategies can be designed by taking advantage of the functions of amino acids. This review focuses on the current progress in the design of cross-linked peptide fibers and their applications.

scholarly journals Combination of Different Approaches to Infer Local or Regional Contributions to PM2.5 Burdens in Graz, Austria

2020 ◽  
Vol 10 (12) ◽  
pp. 4222
Author(s):  
Bernadette Kirchsteiger ◽  
Magdalena Kistler ◽  
Thomas Steinkogler ◽  
Christopher Herzig ◽  
Andreas Limbeck ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Source Apportionment ◽  
Water Soluble ◽  
The European Union ◽  
Limit Value ◽  
Soluble Ions ◽  
Local Sources ◽  
Polycyclic Aromatic ◽  
Accumulation Of Pollutants ◽  
Short Time

In early 2017 high particulate matter (PM) levels were observed across mid-Europe, including Austria. Here we characterize PM pollution in the city of Graz during January to March 2017, a period with substantial exceedances (34 days) of the European Union (EU) PM10 short time limit value. This study evaluates whether the observed exceedances can be attributed to the accumulation of pollutants emitted by local sources or to a larger scale pollution episode including transport. The analyses are based on the ratios of PM10 concentrations determined at an urban and background site, and the analyses of chemical composition of PM2.5 samples (i.e., water soluble ions, organic and elemental carbon, anhydro-sugars, humic-like substances, aluminum, and polycyclic aromatic hydrocarbons). Source apportionment was realized using a macro-tracer model. Overall, the combination of different approaches (PM10 ratios, chemical composition, and macro-tracer derived source apportionment) enabled a conclusive identification of time periods characterized by the accumulation of emissions from local sources or regional pollution episodes.

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