Dispersion study of clay nanoparticles in vinylester resin

2016 ◽  
Vol 23 ◽  
pp. E51-E57
Author(s):  
M. Praveen ◽  
M. Pramod ◽  
Swati Neogi
Keyword(s):  
Vinylester Resin ◽  
Clay Nanoparticles

Harnessing clay nano-particles for stem-cell driven tissue regeneration, EPSRC

Impact ◽  
2018 ◽  
Vol 2018 (3) ◽  
pp. 26-28
Author(s):  
Jonathan Dawson ◽  
Richard Oreffo
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Blood Vessels ◽  
The Body ◽  
Biological Molecules ◽  
Nano Particles ◽  
Clay Particles ◽  
Clay Nanoparticles ◽  
Signalling Molecules ◽  
The Right

Gels made from clay could provide an environment able to stimulate stem-cells due to their ability to bind biological molecules. That molecules stick to clay has been known by scientists since the 1960s. Doctors observed that absorption into the blood stream of certain drugs was severely reduced when patients were also receiving clay-based antacid or anti-diarrhoeal treatments. This curious phenomenon was realized to be due to binding of the drugs by clay particles. This interaction is now routinely harnessed in the design of tablets to carefully control the release and action of a drug. Dr Dawson now proposes to use this property of clay to create micro-environments that could stimulate stem cells to regenerate damaged tissues such as bone, cartilage or skin. The rich electrostatic properties of nano (1 millionth of a millimetre) -scale clay particles which mediate these interactions could allow two hurdles facing the development of stem-cell based regenerative therapies to be overcome simultaneously. The first challenge - to deliver and hold stem cells at the right location in the body - is met by the ability of clays to self-organise into gels via the electrostatic interactions of the particles with each other. Cells mixed with a low concentration (less than 4%) of clay particles can be injected into the body and held in the right place by the gel, eliminating, in many situations, the need for surgery. Clay particles can also interact with large structural molecules (polymers) which are frequently used in the development of materials (or 'scaffolds'), designed to host stem cells. These interactions can greatly improve the strength of such structures and could be applied to preserve their stability at the site of injury until regeneration is complete. While several gels and scaffold materials have been designed to deliver and hold stem cells at the site of regeneration, the ability of clay nanoparticles to overcome a second critical hurdle facing stem-cell therapy is what makes them especially exciting. Essential to directing the activity of stem-cells is the carefully controlled provision of key biological signalling molecules. However, the open structures of conventional scaffolds or gels, while essential for the diffusion of nutrients to the cells, means their ability to hold the signalling molecules in the same location as the cells is limited. The ability of clay nano-particles to bind biological molecules presents a unique opportunity to create local environments at a site of injury or disease that can stimulate and control stem-cell driven repair. Dr Dawson's early studies investigated the ability of clay gels to stimulate the growth of new blood vessels by incorporating a key molecular signal that stimulates this process, vascular endothelial growth factor (VEGF). In a manner reminiscent of the observations made in the 60s, Dr Dawson and colleagues observed that adding a drop of clay gel to a solution containing VEGF caused, after a few hours, the disappearance of VEGF from the solution as it became bound to the gel. When placed in an experimental injury model, the gel-bound VEGF stimulated a cluster of new blood vessels to form. These exciting results indicate the potential of clay nanoparticles to create tailor-made micro-environments to foster stem cell regeneration. Dr Dawson is developing this approach as a means of first exploring the biological signals necessary to successfully control stem cell behaviour for regeneration and then, using the same approach, to provide stem cells with these signals to stimulate regeneration in the body. The project will seek to test this approach to regenerate bone lost to cancer or hip replacement failure. If successful the same technology may be applied to harness stem cells for the treatment of a whole host of different scenarios, from burn victims to those suffering with diabetes or Parkinson's.

scholarly journals Kinetic Modeling and Degradation Study of Liquid Polysulfide Resin-Clay Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 635
Author(s):  
Mohamadreza Shakiba ◽  
Arash Kakoei ◽  
Iman Jafari ◽  
Erfan Rezvani Ghomi ◽  
Mohammadreza Kalaee ◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Modeling ◽  
Degradation Kinetics ◽  
Nitrogen Atmosphere ◽  
Gravimetric Analysis ◽  
Degradation Kinetic ◽  
Kinetic Evaluation ◽  
Degradation Study ◽  
Clay Nanoparticles ◽  
Conversion Rates

Kinetic modeling and degradation study of liquid polysulfide (LPS)/clay nanocomposite is possible through Ozawa–Flynn–Wall (OFW) and Kissinger methods. Comparing the results of these models with experimental data leads to provide an accurate degradation kinetic evaluation of these materials. To this aim, the morphology and distribution of clay nanoparticles (CNPs) within the LPS matrix were investigated using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD). To evaluate the interaction between the LPS and the CNPs, the Fourier transform infrared (FTIR) identification was utilized. Furthermore, to investigate the kinetics of degradation, the thermal gravimetric analysis (TGA) and derivative thermogravimetry (DTG) of the samples were used in the nitrogen atmosphere with the help of Kissinger and Ozawa–Flynn–Wall (OFW) models. The characterization results confirmed the homogenous dispersion of the CNPs into the LPS matrix. In addition, the presence of CNPs increased the thermal stability and activation energy (Ea) of the samples at different conversion rates. Moreover, the OFW method was highly consistent with the experimental data and provided an appropriate fit for the degradation kinetics.

scholarly journals Clay nanoparticles co-deliver three antigens to promote potent immune responses against pathogenic Escherichia coli

2018 ◽  
Vol 292 ◽  
pp. 196-209 ◽  
Author(s):  
Weiyu Chen ◽  
Huali Zuo ◽  
Barbara Rolfe ◽  
Mark A. Schembri ◽  
Rowland N. Cobbold ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Clay Nanoparticles ◽  
Pathogenic Escherichia Coli

scholarly journals Tuning the Thermogelation and Rheology of Poly(2-Oxazoline)/poly(2-Oxazine)s Based Thermosensitive Hydrogels for 3D Bioprinting.

2021 ◽  
Author(s):  
Malik Salman Haider ◽  
Taufiq Ahmad ◽  
Mengshi Yang ◽  
Chen Hu ◽  
Lukas Hahn ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Stem Cells ◽  
Gel Strength ◽  
Adipose Derived Stem Cells ◽  
3D Bioprinting ◽  
Thermosensitive Hydrogel ◽  
Clay Nanoparticles ◽  
Hydrogel Matrix ◽  
Thermosensitive Hydrogels ◽  
3D Printed

As one kind of smart material, thermogelling polymers find applications in biofabrication, drug delivery and regenerative medicine. Here, we reported on a novel thermosensitive hydrogel which can be 3D printed using extrusion based printing. Gel strength was found around 3kPa storage modulus with pronounced shear thinning and rapid recovery after stress. Addition of clay nanoparticles (Laponite XLG) improved the rheological profile further. Human adipose derived stem cells were added to the hydrogel matrix, which remained fully viable after printing. Therefore, the presented materials adds to the available material toolbox for 3D bioprinting. <br>

Valorization of Post-consumer PP by (Un)modified Tunisian Clay Nanoparticles Incorporation

2018 ◽  
Vol 11 (5) ◽  
pp. 2285-2296 ◽  
Author(s):  
K. Zdiri ◽  
A. Elamri ◽  
M. Hamdaoui ◽  
O. Harzallah ◽  
N. Khenoussi ◽  
...  
Keyword(s):  
Clay Nanoparticles
Sign in / Sign up

Export Citation Format

Share Document