The Effect of Si(IV) Species Derived from Chitosan-Silicate Hydrogels on Osteoblast Behavior

2011 ◽  
Vol 493-494 ◽  
pp. 698-702 ◽  
Author(s):  
Yuki Shirosaki ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka
Keyword(s):  
Cell Adhesion ◽  
Room Temperature ◽  
Gelation Time ◽  
Osteoblastic Cells ◽  
Amino Groups ◽  
Hybrid Hydrogels ◽  
Methoxy Groups ◽  
Gelation Behavior ◽  
Epoxy Groups ◽  
Phosphate Groups

Chitosan-GPTMS (γ-Glycidoxypropyltrimethoxysilane) hybrid hydrogels were synthesized with β-glycerophosphate (β-GP) as the additive agent. Chitosan-GPTMS sols were fluid at room temperature and transformed to hydrogel at 36.5°C in several min. The gelation time of the hydrogels was shortened by the addition of GPTMS. From NMR experiments, this gelation behavior depended on some factors, namely, electrostatic interaction between the phosphate groups of β-GP and the amino groups of chitosan chains, crosslinking between the epoxy groups of GPTMS and the amino groups of chitosan, and polycondensation of the methoxy groups of GPTMS. The Si(IV) released from the hydrogels promoted the cell adhesion and ALP activity of osteoblastic cells MG63.

scholarly journals Efficacy of Plasma-Polymerized Allylamine Coating of Zirconia after Five Years

2020 ◽  
Vol 9 (9) ◽  
pp. 2776 ◽  
Author(s):  
Nadja Rohr ◽  
Katja Fricke ◽  
Claudia Bergemann ◽  
J Barbara Nebe ◽  
Jens Fischer
Keyword(s):  
Room Temperature ◽  
Storage Period ◽  
Cell Spreading ◽  
Osteoblastic Cells ◽  
Cell Behavior ◽  
Amino Groups ◽  
Differentiation Markers ◽  
Oxidation Processes ◽  
Human Osteoblastic Cells ◽  
Zirconia Implant

Plasma-polymerized allylamine (PPAAm) coatings of titanium enhance the cell behavior of osteoblasts. The purpose of the present study was to evaluate a PPAAm nanolayer on zirconia after a storage period of 5 years. Zirconia specimens were directly coated with PPAAm (ZA0) or stored in aseptic packages at room temperature for 5 years (ZA5). Uncoated zirconia specimens (Zmt) and the micro-structured endosseous surface of a zirconia implant (Z14) served as controls. The elemental compositions of the PPAAm coatings were characterized and the viability, spreading and gene expression of human osteoblastic cells (MG-63) were assessed. The presence of amino groups in the PPAAm layer was significantly decreased after 5 years due to oxidation processes. Cell viability after 24 h was significantly higher on uncoated specimens (Zmt) than on all other surfaces. Cell spreading after 20 min was significantly higher for Zmt = ZA0 > ZA5 > Z14, while, after 24 h, spreading also varied significantly between Zmt > ZA0 > ZA5 > Z14. The expression of the mRNA differentiation markers collagen I and osteocalcin was upregulated on untreated surfaces Z14 and Zmt when compared to the PPAAm specimens. Due to the high biocompatibility of zirconia itself, a PPAAm coating may not additionally improve cell behavior.

scholarly journals Investigation of the curing process of epoxy compositions by developed amine products based on household waste polyethylene terephthalate and polycarbonate

2021 ◽  
pp. 21-24
Author(s):  
M. B. Alikin ◽  
K. D. Alekseeva ◽  
D. A. Panfilov ◽  
N. A. Lavrov ◽  
I. M. Dvorko
Keyword(s):  
Polyethylene Terephthalate ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Aliphatic Amine ◽  
Gelation Time ◽  
Structural Features ◽  
Household Waste ◽  
Curing Process ◽  
Waste Polyethylene ◽  
Epoxy Groups

The objects of research are oligomers-hardeners obtained by aminolysis of secondary polyethylene terephthalate (PET) and polycarbonate (PC) household waste with an aliphatic amine (PEP).The epoxy-diane resin of the ED-20 brand was chosen as the binder cured by the obtained oligomers due to its availability, good properties, acceptable viscosity, and wide applicability. The study of some parameters of the curing of thermosetting resin by industrial and synthesized hardeners is carried out.The gelation times at elevated temperatures (in the range from 50 to 100°C) and the activation energies of epoxy compositions were determined, and the conversion of epoxy groups during curing at room temperature was studied. The analysis of the obtained data showed that the structural features of macromolecules caused by the introduction of PET and PC fragments have a negligible effect on the activation energy and affect only when cured at room temperature and increase the viability of the compositions, while the gelation time at elevated temperatures in the case of all the studied hardeners is almost the same.

scholarly journals The Influence of Mn2+on DNA structure in the presence of Na+ions: A Raman spectroscopic study

2006 ◽  
Vol 20 (5-6) ◽  
pp. 261-268 ◽  
Author(s):  
Cristina M. Muntean ◽  
Rolf Misselwitz ◽  
Heinz Welfle
Keyword(s):  
Conformational Changes ◽  
Room Temperature ◽  
Dna Structure ◽  
Dna Melting ◽  
Physiological Concentration ◽  
Raman Spectroscopic ◽  
Calf Thymus ◽  
Dna Backbone ◽  
Na Ions ◽  
Phosphate Groups

The influence of Mn2+ions on the structure of natural calf thymus DNA was studied by Raman spectroscopy. Measurements were done at room temperature and pH 6.2±0.2, in the presence of the physiological concentration of 150 mM Na+ions, and in the presence of Mn2+concentrations that varied between 0 and 600 mM. No condensation of DNA was observed at any of the Mn2+concentrations. At 5 mM Mn2+and 150 mM Na+no significant influence of Mn2+ions on the DNA structure can be observed. Compared with our previous results obtained at 10 mM Na+ions, binding of Mn2+ions to charged phosphate groups and to DNA bases is inhibited in the presence of 150 mM Na+ions. DNA backbone conformational changes were not observed in the whole concentration range of Mn2+ions as judging from the Raman spectra. No evidence for DNA melting was identified. A high Mn2+affinity for binding to guanine N7 and possibly, in a much lesser extent, to adenine have been found.

scholarly journals Role of the Metal Surface on the Room Temperature Activation of the Alcohol and Amino Groups of p-Aminophenol

2020 ◽  
Vol 124 (36) ◽  
pp. 19655-19665
Author(s):  
Nerea Ruiz del Árbol ◽  
Irene Palacio ◽  
Carlos Sánchez-Sánchez ◽  
Gonzalo Otero-Irurueta ◽  
José I. Martínez ◽  
...  
Keyword(s):  
Metal Surface ◽  
Room Temperature ◽  
Amino Groups ◽  
Temperature Activation

Aminofluorsilane: 1.3-Silylgruppenwanderung und gehinderte Si-N-Bindungsrotation / Aminofluorosilanes: 1.3-Migration of Silyl Groups and Si-N-Rotational Barrier

1980 ◽  
Vol 35 (9) ◽  
pp. 1155-1161 ◽  
Author(s):  
Uwe Klingebiel ◽  
Jutta Neemann
Keyword(s):  
Room Temperature ◽  
Electronic Effects ◽  
Amino Groups ◽  
Structural Isomers ◽  
Hindered Rotation ◽  
Silyl Groups ◽  
Group Migration ◽  
Silyl Group Migration ◽  
Trimethylsilyl Groups ◽  
Coalescence Temperature

Triaminofluorosilanes with bulky amino groups are prepared by the reaction of bis- (organyl-trimethylsilyl)amino-difluorosilanes with lithiated amines. A 1,3-migration of trimethylsilyl groups from bulky alkylamino substituents to arylamino substituents is observed in these reactions. Structural isomers of the new triaminofluorosilanes were isolated. The silyl group migration depends on steric and electronic effects. Further reactions of the triaminofluorosilanes with butyllithium and trifluoroorganylsilanes lead to the formation of difluorosilyl-substituted triaminofluorosilanes and LiF. The symmetric compounds show AB-systems for the fluorine atoms of the difluorosilyl groups in the low temperature 19F NMR Spectra, due to hindered rotation about the Si-N-bond. The coalescence temperature depends on the bulkiness of the substituents and is observed at or about room temperature.

Structural Investigations on a Cell-Wall Lipopolysaccharide from Neisseria sicca

1971 ◽  
Vol 49 (2) ◽  
pp. 243-250 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Lipid A ◽  
Periodate Oxidation ◽  
Amino Groups ◽  
Structural Investigations ◽  
Acid Protein ◽  
A Cell ◽  
Backbone Structure ◽  
Neisseria Sicca ◽  
Fourfold Excess ◽  
Phosphate Groups

Lipopolysaccharide (LPS) prepared from Neisseria sicca in 1.5% yield contained D-glucose, D-glucosamine, D-galactosamine, 3-deoxyoctulosonic acid, protein, lipid A, and phosphate. The molecule was judged to be homogeneous as tested by free boundary electrophoresis. D-Galactosamine was associated exclusively with the polysaccharide portion of the molecule and was in fourfold excess of D-glucosamine. The latter hexosamine was primarily a constituent of the lipid A moiety in which it formed the backbone structure linked glycosidically 1 → 4. To this structure, fatty acids, principally β-hydroxymyristic acid and β-hydroxylauric acid, were linked along with phosphate groups. The D-glucosamine units in the polysaccharide portion of the LPS molecule were also attached by 1 → 4 glycosidic linkages. D-Galactosamine units did not survive the methylation procedures due presumably to the lack of acyl protecting groups on its amino groups. Methylation results showed that approximately one-third of the D-glucose units were nonreducing end groups, approximately one-third were linked α1 → 2, a small proportion was linked 1 → 4, and the remainder was branched through C-3, C-4, and C-6. Periodate oxidation results were in agreement with the structure proposed on the basis of the methylation data. The LPS of N. sicca was considerably simpler than that of N. perflava and lacked heptose, rhamnose, and ethanolamine components.

Samarium doped glass-reinforced hydroxyapatite with enhanced osteoblastic performance and antibacterial properties for bone tissue regeneration

2014 ◽  
Vol 2 (35) ◽  
pp. 5872-5881 ◽  
Author(s):  
Diana Santos Morais ◽  
João Coelho ◽  
Maria Pia Ferraz ◽  
Pedro Sousa Gomes ◽  
Maria Helena Fernandes ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Antibacterial Properties ◽  
Bone Tissue Regeneration ◽  
Osteoblastic Cells ◽  
Sem Images ◽  
Doped Glass

Cell adhesion of MG63 osteoblastic cells seeded over GR-HA_control and Sm doped composites, at day 1 of culture. Low (A) and high (B) CLSM images of cells stained for F-actin cytoskeleton (green) and nuclei (red); (C) SEM images.

scholarly journals Incorporation of 3-Aminobenzanthrone into 2′-Deoxyoligonucleotides and Its Impact on Duplex Stability

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Mark Lukin ◽  
Tanya Zaliznyak ◽  
Francis Johnson ◽  
Carlos R. de los Santos
Keyword(s):  
Dna Adducts ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Helical Structure ◽  
Environmental Pollutant ◽  
Synthetic Approach ◽  
Amino Groups ◽  
Double Helical Structure ◽  
Duplex Stability ◽  
Living Organisms

3-Nitrobenzanthrone (3NBA), an environmental pollutant and potent mutagen, causes DNA damage via the reaction of its metabolically activated form with the exocyclic amino groups of purines and the C-8 position of guanine. The present work describes a synthetic approach to the preparation of oligomeric 2′-deoxyribonucleotides containing a 2-(2′-deoxyguanosin-N2-yl)-3-aminobenzanthrone moiety, one of the major DNA adducts found in tissues of living organisms exposed to 3NBA. The NMR spectra indicate that the damaged oligodeoxyribonucleotide is capable of forming a regular double helical structure with the polyaromatic moiety assuming a single conformation at room temperature; the spectra suggest that the 3ABA moiety resides in the duplex minor groove pointing toward the 5′-end of the modified strand. Thermodynamic studies show that the dG(N2)-3ABA lesion has a stabilizing effect on the damaged duplex, a fact that correlates well with the long persistence of this damage in living organisms.

PLGA-Hydroxyapatite Composite Scaffolds for Osteoblastic-Like Cells

2008 ◽  
Vol 396-398 ◽  
pp. 461-464 ◽  
Author(s):  
André Dutra Messias ◽  
Aguedo Aragones ◽  
Eliana Aparecida de Rezende Duek
Keyword(s):  
Cell Adhesion ◽  
Collagen Synthesis ◽  
Colorimetric Method ◽  
Cellular Responses ◽  
Osteoblastic Cells ◽  
Adhesion Assay ◽  
Polymer Scaffolds ◽  
Composite Scaffolds ◽  
Hydroxyapatite Composite ◽  
Sirius Red

The aim of this work was to investigate the behaviour of rat calvarial osteoblastics cells on porous PLGA/HA composite scaffolds. Cells were submitted to cytotoxicity and cell adhesion assay. In addition, the cells morphology were observed by SEM, and the collagen synthesis measured by Sirius Red colorimetric method. The results showed that the material was not cytotoxic and hydroxyapatite improved cell adhesion. Osteoblastic cells could adhere and spread on the scaffolds as observed. After 14 days the presence of hydroxyapatite increased the synthesis of collagen. This study demonstrates that composite scaffolds presented better cellular responses compared to polymer scaffolds.

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