scholarly journals Bone-Mimicking Injectable Gelatine/Hydroxyapatite Hydrogels

2019 ◽  
Vol 33 (3) ◽  
pp. 325-335
Author(s):  
Anamarija Rogina ◽  
Nikolina Šandrk ◽  
Laura Teruel-Biosca ◽  
Maja Antunović ◽  
Marica Ivanković ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Storage Modulus ◽  
Hek293 Cells ◽  
Injectable Hydrogels ◽  
Composite Hydrogels ◽  
Natural Bone ◽  
Hydroxyapatite Crystal ◽  
Prepared Composite

Bioactive synthetic hydrogels have emerged as promising materials because they<br /> can provide molecularly tailored biofunctions and adjustable mechanical properties. To<br /> mimic the mineralogical and organic components of the natural bone, hydroxyapatite and<br /> a tyramine conjugate of gelatine were combined in this study. The effect of various amounts of in situ synthesized hydroxyapatite in gelatine-tyramine on the morphology<br /> and physical properties of injectable hydrogels was investigated. Mineralogical identification confirmed successful precipitation of in situ formed hydroxyapatite. Better distribution of hydroxyapatite crystal agglomerates within modified gelatine was found at 5 % of hydroxyapatite, which could be responsible for increased storage modulus with respect to pure gelatine hydrogel. Prepared composite hydrogels are non-toxic and support<br /> the proliferation of Hek293 cells.

CHARACTERIZATION AND APPLICATION OF CONDUCTING POLYMER COATED TEXTILES

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1241-1247 ◽  
Author(s):  
LIJING WANG ◽  
TONG LIN ◽  
XUNGAI WANG
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Conducting Polymer ◽  
Physical And Mechanical Properties ◽  
Fibrous Materials ◽  
Conductive Coating ◽  
Coating Durability

This paper reports on some physical properties of a conducting polymer, polypyrrole, coated textiles. Polypyrrole was coated on textiles chemically through in-situ solution or vapor polymerisation to produce conducting textiles. The effects of the conductive coating on the physical and mechanical properties of the fibrous materials are presented. The coating durability and conductivity of the textiles have also been examined.

scholarly journals Melanocyte pigmentation stiffens murine cardiac tricuspid valve leaflet

2009 ◽  
Vol 6 (40) ◽  
pp. 1097-1102 ◽  
Author(s):  
Kantesh Balani ◽  
Flavia C. Brito ◽  
Lidia Kos ◽  
Arvind Agarwal
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Tricuspid Valve ◽  
Viscoelastic Properties ◽  
Mechanical Analysis ◽  
Current Work ◽  
Valve Leaflet ◽  
Stiffness Measurement ◽  
Proper Functioning

Pigmentation of murine cardiac tricuspid valve leaflet is associated with melanocyte concentration, which affects its stiffness. Owing to its biological and viscoelastic nature, estimation of the in situ stiffness measurement becomes a challenging task. Therefore, quasi-static and nanodynamic mechanical analysis of the leaflets of the mouse tricuspid valve is performed in the current work. The mechanical properties along the leaflet vary with the degree of pigmentation. Pigmented regions of the valve leaflet that contain melanocytes displayed higher storage modulus (7–10 GPa) than non-pigmented areas (2.5–4 GPa). These results suggest that the presence of melanocytes affects the viscoelastic properties of the mouse atrioventricular valves and are important for their proper functioning in the organism.

scholarly journals Regenerated Antheraea pernyi Silk Fibroin/Poly(N-isopropylacrylamide) Thermosensitive Composite Hydrogel with Improved Mechanical Strength

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 302 ◽  
Author(s):  
Boxiang Wang ◽  
Song Zhang ◽  
Yifan Wang ◽  
Bo Si ◽  
Dehong Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silk Fibroin ◽  
In Situ Polymerization ◽  
Crosslinking Agent ◽  
Composite Hydrogel ◽  
Raw Material ◽  
Antheraea Pernyi ◽  
Composite Hydrogels ◽  
Polymerization Method

At present, Antheraea pernyi silk fibroin (ASF) has attracted research efforts to investigate it as a raw material for fabrication of biomedical devices because of its superior cytocompatibility. Nevertheless, native ASF is not easily processed into a hydrogel without any crosslinking agent, and a single hydrogel shows poor mechanical properties. In this paper, a series of ASF/poly (N-isopropylacrylamide) (PNIPAAm) composite hydrogels with different ASF contents were manufactured by a simple in situ polymerization method without any crosslinking agent. Meanwhile, the structures, morphologies and thermal properties of composite hydrogels were investigated by XRD, FTIR, SEM, DSC and TGA, respectively. The results indicate that the secondary structure of silk in the composite hydrogel can be controlled by changing the ASF content and the thermal stability of composite hydrogels is enhanced with an increase in crystalline structure. The composite hydrogels showed similar lower critical solution temperatures (LCST) at about 32 °C, which matched well with the LCST of PNIPAAm. Finally, the obtained thermosensitive composite hydrogels exhibited enhanced mechanical properties, which can be tuned by varying the content of ASF. This strategy to prepare an ASF-based responsive composite hydrogel with enhanced mechanical properties represents a valuable route for developing the fields of ASF, and, furthermore, their attractive applications can meet the needs of different biomaterial fields.

Rheology, morphology and mechanical properties of LLDPE/PS blends catalyzed by combined Lewis acids

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Yan-Long Liu ◽  
Li-Gang Yin ◽  
Zhuo Ke ◽  
Qiang Shi ◽  
Jing-Hua Yin
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Lewis Acids ◽  
Low Frequency ◽  
Complex Viscosity ◽  
Reactive Blending ◽  
Izod Impact ◽  
Rheological Experiments ◽  
And Storage

AbstractThe rheological, morphological and mechanical properties of LLDPE/PS blends with a combined catalyst, Me3SiCl and InCl3·4H2O, were studied in this work. The higher complex viscosity and storage modulus at low frequency were ascribed to the presence of graft copolymers, which were in situ formed during the mixing process. From the rheological experiments, the complex viscosity and storage modulus of reactive blends were higher than the physical blends. The dispersion of LLDPE particles of reactive blending becomes finer than that of physical blends, consistent with the rheological results. As a result of increased compatibility between LLDPE/PS, the mechanical properties of reactive blends show much higher tensile and Izod impact strength than those of physical blends.

scholarly journals Assessment of AlN/Mg–8Al Composites Reinforced with In Situ and/or Ex Situ AlN Particles

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 52
Author(s):  
Tong Gao ◽  
Zengqiang Li ◽  
Kaiqi Hu ◽  
Yihan Bian ◽  
Xiangfa Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Ex Situ ◽  
Prepared Composite ◽  
Particle Chains

In this paper, 8.2AlN/Mg–8Al composites reinforced with in situ and/or ex situ AlN particles have been synthesized. The in situ-formed AlN particles are nano-sized, performing as particle chains. It has been clarified that the in situ AlN particles are more efficient than ex situ particles for the enhancement of mechanical properties. The in situ-prepared composite exhibits improved density, hardness and compressive strength compared to the ex situ ones. This work may be referred to for designing particle-reinforced Mg composites by various methods.

scholarly journals An in situ Gelling BMSC-laden Collagen/Silk Fibroin Double Network Hydrogel for Cartilage Regeneration

2021 ◽  
Author(s):  
Yajie Zhang ◽  
Min Liu ◽  
Renjun Pei
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cartilage Tissue Engineering ◽  
Cartilage Regeneration ◽  
Cartilage Tissue ◽  
Injectable Hydrogels ◽  
Double Network ◽  
Good Biocompatibility ◽  
In Situ Gelling

Collagen (Col)-based injectable hydrogels are desirable scaffolds for cartilage tissue engineering. However, fabrication of Col-based injectable hydrogels with short gelation times, good biocompatibility and high mechanical properties still faces great...

Mechanical Properties and Biocompatibility of in Situ Enzymatically Cross-Linked Gelatin Hydrogels

2017 ◽  
Vol 40 (4) ◽  
pp. 159-168 ◽  
Author(s):  
Nada Z. Alarake ◽  
Patrick Frohberg ◽  
Thomas Groth ◽  
Markus Pietzsch
Keyword(s):  
Mechanical Properties ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Cross Linking ◽  
Adipose Derived Stem Cells ◽  
Swelling Ratio ◽  
Connective Tissues ◽  
Injectable Hydrogels ◽  
Cross Linker

Objectives Gelatin, a degraded collagen, has been widely used as a scaffolding material in tissue engineering applications. In this work, we aimed at the development of in situ, cross-linking, cytocompatible hydrogels by the use of transglutaminase as a cross-linker for potential application in the regeneration of tissues. Methods Hydrogels were prepared from gelatin of different concentrations and bloom degree (175 (G175) or 300 (G300) bloom gelatin) and cross-linked with various amounts of microbial transglutaminase (mTG) at 37°C. Mechanical properties and cross-linking degree were studied by rheology and swelling experiments. Four hydrogels with different stiffness were selected for studies with embedded human adipose-derived stem cells (hASCs). Results Hydrogels were obtained with storage modulus (G’) values between 11 (±1) Pa and 1,800 (±200) Pa with gelation times between 80 (±6) and 450 (±36) seconds. G300 cross-linked gelatin hydrogels displayed higher gel stiffness, lower swelling ratio and gelled more rapidly compared to the hydrogels prepared from G175. Stiffer hydrogels (50 and 200 Pa) showed greater ability to support the proliferation of hASCs than softer ones (11 and 30 Pa). The highest cell proliferation was observed with a hydrogel of 200 Pa modulus. Conclusions Overall, transglutaminase cross-linked gelatin hydrogels might be suitable as injectable hydrogels for the engineering of musculoskeletal and other types of connective tissues.

Dynamic Mechanical Properties and Phase Structure of Polyethylene/Montmorillonite Nanocomposites Prepared by In Situ Polymerization

2013 ◽  
Vol 457-458 ◽  
pp. 293-296
Author(s):  
Min Li ◽  
Li Guang Xiao ◽  
Hong Kai Zhao
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Polymer Matrix ◽  
Phase Structure ◽  
In Situ Polymerization ◽  
Conformational Transitions ◽  
Dynamic Mechanical Properties ◽  
Strong Interactions ◽  
Dynamic Mechanical

Polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by in situ polymerization. The dynamic mechanical properties and phase structure of PE/MMT nanocomposites at different MMT concentrations (from 0.1 to 1.2 wt %) were studied. The storage modulus of PE/MMT nanocomposites is higher than that of the polymer matrix. And the motions of molecular relaxations and conformational transitions both in non-crystalline and crystalline phases are confined by the strong interactions between polymer and MMT. Otherwise, the spherulite size gradually decreases with the increasing content of MMT.

A pH and Electric Responsive Graphene Oxide Based Composite Hydrogel

2012 ◽  
Vol 430-432 ◽  
pp. 327-330 ◽  
Author(s):  
Yong Qiang He ◽  
Hua Bin Chen ◽  
Hong Sun ◽  
Xiao Dong Wang ◽  
Jian Ping Gao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Electric Field ◽  
Structure And Properties ◽  
Composite Hydrogels ◽  
External Stimuli ◽  
Scanning Electron

The pH and electric responsive composite hydrogels were prepared byin situpolymerization in the presence of graphene oxide (GO). Their structure and properties were characterized by scanning electron microscopy, Raman microscopy and mechanical testing. The results indicate that the GO is evenly dispersed in the composite hydrogels and the mechanical properties of the GO based composite hydrogels are significantly improved. Most importantly, the composite hydrogels were responsive to external stimuli such as pH and electric field.

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