scholarly journals Effect of Ethylenediaminetetraacetic Acid on Unsaturated Poly(Butylene Adipate-Co-Butylene Itaconate) Copolyester with Low-Melting Point and Controllable Hardness

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 611 ◽  
Author(s):  
Chin-Wen Chen ◽  
Te-Sheng Hsu ◽  
Syang-Peng Rwei
Keyword(s):  
Melting Point ◽  
Textile Industry ◽  
Ethylenediaminetetraacetic Acid ◽  
Crosslinking Agent ◽  
Three Dimensional ◽  
Uv Curing ◽  
Plastic Properties ◽  
Smart Textile ◽  
Dimensional Network

A series of copolyesters, poly(butylene adipate-co-butylene itaconate) (PBABI), was synthesized using melt polycondensation from adipic acid (AA), itaconic acid (IA), 1,4-butanediol (1,4-BDO), and ethylenediaminetetraacetic acid (EDTA). 1H-NMR, FT-IR, GPC, DSC, TGA, DMA, XRD, Shore D, and tensile test were used to systematically characterize the structural and composition/physical properties of the copolyesters. It was found that the melting point (Tm) and crystallization temperature (Tc) of the copolyesters were, respectively, between 21.1 to 57.5 °C and −6.7 to 29.5 °C. The glass transition (Tg) and the initial thermal decomposition (Td-5%) temperatures of the PBABI copolyesters were observed to be between −53.6 to −55.8 °C and 313.6 and 342.1 °C at varying ratios of butylene adipate (BA) and butylene itaconate (IA), respectively. The XRD feature peak was identified at the 2θ values of 21.61°, 22.31°, and 23.96° for the crystal lattice of (110), (020), and (021), respectively. Interestingly, Shore D at various IA ratios had high values (between 51.3 to 62), which indicated that the PBABI had soft plastic properties. The Young’s modulus and elongation at break, at different IA concentrations, were measured to be at 0.77–128.65 MPa and 71.04–531.76%, respectively, which could be attributed to a close and compact three-dimensional network structure formed by EDTA as a crosslinking agent. There was a significant bell-shaped trend in a BA/BI ratio of 8/2, at different EDTA concentrations—the ∆Hm increased while the EDTA concentration increased from 0.001 to 0.05 mole% and then decreased at an EDTA ratio of 0.2 mole%. Since the PBABI copolymers have applications in the textile industry, these polymers have been adopted to reinforce 3D air-permeable polyester-based smart textile. This kind of composite not only possesses the advantage of lower weight and breathable properties for textiles, but also offers customizable, strong levels of hardness, after UV curing of the PBABI copolyesters, making its potential in vitro orthopedic support as the “plaster of the future”.

Tough Double-Network Hydrogels as Scaffolds for Tissue Engineering

2012 ◽  
pp. 213-222
Author(s):  
Jing Jing Yang ◽  
Jian Fang Liu ◽  
Takayuki Kurokawa ◽  
Nobuto Kitamura ◽  
Kazunori Yasuda ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
Cartilage Regeneration ◽  
Cell Types ◽  
Embryoid Bodies ◽  
Living Tissue ◽  
Double Network ◽  
Dimensional Network

Hydrogels are used as scaffolds for tissue engineering in vitro & in vivo because their three-dimensional network structure and viscoelasticity are similar to those of the macromolecular-based extracellular matrix (ECM) in living tissue. Especially, the synthetic hydrogels with controllable and reproducible properties were used as scaffolds to study the behaviors of cells in vitro and implanted test in vivo. In this review, two different structurally designed hydrogels, single-network (SN) hydrogels and double-network (DN) hydrogels, were used as scaffolds. The behavior of two cell types, anchorage-dependent cells and anchorage-independent cells, and the differentiation behaviors of embryoid bodies (EBs) were investigated on these hydrogels. Furthermore, the behavior of chondrocytes on DN hydrogels in vitro and the spontaneous cartilage regeneration induced by DN hydrogels in vivo was examined.

Modification of Thai Silk Fibroin Scaffolds by Gelatin Conjugation for Tissue Engineering

2008 ◽  
Vol 55-57 ◽  
pp. 685-688 ◽  
Author(s):  
J. Chamchongkaset ◽  
Sorada Kanokpanont ◽  
David L. Kaplan ◽  
Siriporn Damrongsakkul
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Textile Industry ◽  
Three Dimensional ◽  
Biological Properties ◽  
Salt Leaching ◽  
Biological Compatibility ◽  
Salt Crystals

Silk has been used commercially as biomedical sutures for decades. Recently silk fibroin, especially from Bombyx mori silkworm, has been explored for many tissue engineering applications such as bone and cartilage due to its impressive biological compatibility and mechanical properties. In Thailand, Thai native silkworms have been long cultivated. Distinct characteristics of cocoon Thai silk are its yellow color and coarse filament. There is more sericin in Thai silk than in other Bombyx mori silks. These characteristics provide Thai silk a unique texture for textile industry. It is therefore the aim of this study to develop three-dimensional silk fibroin-based scaffolds from Thai yellow cocoon “Nangnoi-Srisaket” of Bombyx mori silkworms using salt-leaching method. To enhance the biological properties, type A gelatin, the denature form of collagen having good biocompactibility, was used to conjugate with silk fibroin scaffolds. The pore size of salt-leached silk fibroin scaffold structure represented the size of salt crystals used (600-710µm). After gelatin conjugation, gelatin was partly formed fibers inside the pores of silk fibroin scaffolds resulting in fiber-like structure with highly interconnection. Gelatin conjugation enhanced the compressive modulus of silk fibroin scaffolds by 93%. The results on in vitro culture using mouse osteoblast-like cells (MC3T3-E1) showed that gelatin conjugation could promote the cell proliferation in silk fibroin scaffolds. Moreover, the observed morphology of cells proliferated inside the scaffold after 14 days of culture showed the larger spreading area of cells on conjugated gelatin/silk fibroin scaffolds, compared to round-shaped cells on silk fibroin scaffolds. The results implied that Thai silk fibroin looked promising to be applied in tissue engineering and gelatin conjugation on Thai silk fibroin scaffolds could enhance the biological properties of scaffolds.

Evidence for the persistence of a decondensed chromosome scaffold in the interphase nucleus

1986 ◽  
Vol 86 (1) ◽  
pp. 155-171
Author(s):  
A.G. Bekers ◽  
A.C. Pieck ◽  
A.A. Rijken ◽  
F. Wanka
Keyword(s):  
Three Dimensional ◽  
Protein Composition ◽  
Bovine Liver ◽  
Dimensional Network ◽  
Dna Attachment ◽  
Cross Bridges ◽  
Triton X ◽  
Chromosome Scaffold

Nuclei of in vitro cultured bovine liver cells, deprived of the membranes by Triton X-100, were treated with 2 M-NaCl and DNase. Changes in ultrastructure and protein composition were studied at successive steps during treatment. Electron micrographs of nuclei treated with 2 M-NaCl showed a peripheral lamina and an internal system of randomly coiled filaments embedded in a mass of DNA fibres. After partial removal of the DNA the filaments could be seen to serve as backbones for the DNA attachment. Artificial redistribution occurring during fixation with glutaraldehyde suggests that the salt-resistant filaments are not stably cross-bridged into a three-dimensional network. The existence of reversible cross-bridges in vivo cannot be excluded, however. From the available data it is inferred that the filaments represent a decondensed from of the chromosome scaffolds and play a basic role in the organization of the genome throughout the nuclear cycle.

Multiple Approaches to Visualizing Fibrin Clot Structure and Assembly

1997 ◽  
Vol 3 (S2) ◽  
pp. 329-330
Author(s):  
John W. Weisel
Keyword(s):  
Binding Sites ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Fibrin Clot ◽  
Structural Basis ◽  
Physiological Processes ◽  
Dimensional Network ◽  
Clot Structure

Fibrin clot formation is necessary for maintaining the integrity of the vasculature via physiological processes of hemostasis and wound healing and is also involved in pathological processes, such as thrombosis and atherosclerosis. A variety of structural and biophysical approaches has been used to examine intermediates in the formation of clots and to visualize in vitro clots and ex vivo thrombi.Structures at all stages of polymerization have been examined to learn about molecular mechanisms of assembly. Fibrinogen is a polyfunctional, multi-domain protein that is essential for platelet aggregation and for the formation of the three-dimensional network of fibrin fibers which is the structural basis of the clot. Distinctive functions for several of fibrinogen's domains in the fibrin assembly process have been elucidated. Enzymatic removal of the fibrinopeptides exposes binding sites in the central region which then interact with complementary sites at the ends of a neighboring molecule to yield fibrin oligomers.

New Developments in Dynamically Cured PP—EPDM Blends

2001 ◽  
Vol 74 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Miguel A. López-Manchado ◽  
Miguel Arroyo ◽  
José M. Kenny
Keyword(s):  
Mechanical Properties ◽  
Crosslinking Agent ◽  
Three Dimensional ◽  
Mechanical Analysis ◽  
Dynamic Vulcanization ◽  
New Developments ◽  
Dimensional Network ◽  
Polymeric Chains ◽  
Ethylene Propylene Diene Terpolymer ◽  
Vulcanization Process

Abstract Different procedures for preparing thermoplastic vulcanizates (TPVs), based on isotactic polypropylene (iPP) and ethylene—propylene—diene terpolymer rubber (EPDM), are used and analyzed in this work. In order to determine the effect of the vulcanization method on material properties, a rheological study, dynamic-mechanical analysis, mechanical properties and morphological study have been carried out. In all cases, the sulfur is used as crosslinking agent of the elastomeric phase. It has been shown that the dynamically cured blends (referred in the work as V2 and V3) present better properties in relation to those statically cured (V1) and uncrosslinked (V). Thus, the elastic ability, mechanical properties and rheological characteristics of these systems sensibly increase when the samples are dynamically vulcanized. Morphological analysis performed by scanning electron microscopy (SEM) is clearly in agreement with the analyzed properties, showing a better dispersion between both polymeric chains, when the blends are dynamically cured. These results seem to indicate that the dynamic vulcanization process gives rise to the formation of a thermally stable three-dimensional network, and as a consequence of it, a sensible increase of the properties is obtained.

The role of different nonspecific interactions and halogen contacts in the crystal structure organization of 5-chloroisatoic anhydride

2018 ◽  
Vol 74 (3) ◽  
pp. 372-380
Author(s):  
Dorota Pogoda ◽  
Agnieszka Matera-Witkiewicz ◽  
Marcin Listowski ◽  
Jan Janczak ◽  
Veneta Videnova-Adrabinska
Keyword(s):  
Crystal Structure ◽  
Weak Interactions ◽  
Three Dimensional ◽  
Lone Pair ◽  
One Dimensional ◽  
Π Interactions ◽  
Dimensional Network ◽  
Nonspecific Interactions

The crystal structure of 6-chloro-2,4-dihydro-1H-3,1-benzoxazine-2,4-dione (5-chloroisatoic anhydride), C8H4ClNO3, has been determined and analysed in terms of connectivity and packing patterns. The compound crystallizes in the noncentrosymmetric space groupPna21with one molecule in the asymmetric unit. The role of different weak interactions is discussed with respect to three-dimensional network organization. Molecules are extended into one-dimensional helical arrangements, making use of N—H...O hydrogen bonds and π–π interactions. The helices are further organized into monolayersviaweak C—H...O and lone pair–π interactions, and the monolayers are packed into a noncentrosymmetric three-dimensional architecture by C—Cl...π interactions and C—H...Cl and Cl...Cl contacts. A Hirshfeld surface (HS) analysis was carried out and two-dimensional (2D) fingerprint plots were generated to visualize the intermolecular interactions and to provide quantitative data for their relative contributions. In addition, tests of the antimicrobial activity andin vitrocytotoxity effects against fitoblast L929 were performed and are discussed.

scholarly journals Telocytes: ultrastructural, immunohistochemical and electrophysiological characteristics in human myometrium

Reproduction ◽  
2013 ◽  
Vol 145 (4) ◽  
pp. 357-370 ◽  
Author(s):  
Sanda M Cretoiu ◽  
Dragos Cretoiu ◽  
Adela Marin ◽  
Beatrice Mihaela Radu ◽  
Laurentiu M Popescu
Keyword(s):  
Contractile Activity ◽  
Three Dimensional ◽  
Time Lapse ◽  
Human Myometrium ◽  
Dynamic Interactions ◽  
Distinct Cell Type ◽  
Dimensional Network ◽  
Distinct Cell ◽  
Pregnant State

Telocytes (TCs) have been described in various organs and species (www.telocytes.com) as cells with telopodes (Tps) – very long cellular extensions with an alternation of thin segments (podomers) and dilated portions (podoms). We examined TCs using electron microscopy (EM), immunohistochemistry (IHC), immunofluorescence (IF), time-lapse videomicroscopy and whole-cell patch voltage clamp. EM showed a three-dimensional network of dichotomous-branching Tps, a labyrinthine system with homocellular and heterocellular junctions. Tps release extracellular vesicles (mean diameter of 160.6±6.9 nm in non-pregnant myometrium and 171.6±4.6 nm in pregnant myometrium), sending macromolecular signals to neighbouring cells. Comparative measurements (non-pregnant and pregnant myometrium) of podomer thickness revealed values of 81.94±1.77 vs 75.53±1.81 nm, while the podoms' diameters were 268.6±8.27 vs 316.38±17.56 nm. IHC as well as IF revealed double c-kit and CD34 positive results. Time-lapse videomicroscopy of cell culture showed dynamic interactions between Tps and myocytes. In non-pregnant myometrium, patch-clamp recordings of TCs revealed a hyperpolarisation-activated chloride inward current with calcium dependence and the absence of L-type calcium channels. TCs seem to have no excitable properties similar to the surrounding smooth muscle cells (SMCs). In conclusion, this study shows the presence of TCs as a distinct cell type in human non-pregnant and pregnant myometrium and describes morphometric differences between the two physiological states. In addition, we provide a preliminaryin vitroelectrophysiological evaluation of the non-pregnant state, suggesting that TCs could influence timing of the contractile activity of SMCs.

Contribution of Rat Endothelial Progenitor Cells on Three-Dimensional Network Formation In Vitro

2009 ◽  
Vol 15 (9) ◽  
pp. 2727-2739 ◽  
Author(s):  
Masaki Koga ◽  
Ryo Sudo ◽  
Yoshinori Abe ◽  
Kimiko Yamamoto ◽  
Joji Ando ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Network Formation ◽  
Three Dimensional ◽  
Endothelial Progenitor ◽  
Dimensional Network

scholarly journals Three-Dimensional Supermacroporous Carrageenan-Gelatin Cryogel Matrix for Tissue Engineering Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Archana Sharma ◽  
Sumrita Bhat ◽  
Tanushree Vishnoi ◽  
Vijayashree Nayak ◽  
Ashok Kumar
Keyword(s):  
Tissue Engineering ◽  
Crosslinking Agent ◽  
Three Dimensional ◽  
Natural Polymers ◽  
Cell Matrix ◽  
Polymeric Scaffold ◽  
Original Length ◽  
Original Size ◽  
Interconnected Pores

A tissue-engineered polymeric scaffold should provide suitable macroporous structure similar to that of extracellular matrix which can induce cellular activities and guide tissue regeneration. Cryogelation is a technique in which appropriate monomers or polymeric precursors frozen at sub-zero temperature leads to the formation of supermacroporous cryogel matrices. In this study carrageenan-gelatin (natural polymers) cryogels were synthesized by using glutaraldehyde and 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride andN-hydroxysuccinimide (EDC-NHS) as crosslinking agent at optimum concentrations. Matrices showed large and interconnected pores which were in the range of 60–100 μm diameter. Unconfined compression analysis showed elasticity and physical integrity of all cryogels, as these matrices regained their original length after 90% compressing from the original size. Moreover Young’s modulus was found to be in the range of 4–11 kPa for the dry cryogel sections. These cryogels also exhibited goodin vitrodegradation capacity at 37 °C within 4 weeks of incubation. Supermacroporous carrageenan-gelatin cryogels showed efficient cell adherence and proliferation of Cos-7 cells which was examined by SEM. PI nuclear stain was used to observe cell-matrix interaction. Cytotoxicity of the scaffolds was checked by MTT assay which showed that cryogels are biocompatible and act as a potential material for tissue engineering and regenerative medicine.

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