scholarly journals The role of CaO/SiO2 ratio and P2O5 content in gel-derived bioactive glass-polymer composites in the modulation of their bioactivity and osteoinductivity in human BMSCs

2020 ◽  
Vol 109 ◽  
pp. 110535
Author(s):  
Krzysztof Łukowicz ◽  
Barbara Zagrajczuk ◽  
Aleksandra Nowak ◽  
Łukasz Niedźwiedzki ◽  
Maria Laczka ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Polymer Composites ◽  
P2o5 Content ◽  
Human Bmscs

Fabrication of poly (1, 8-octanediol-co-Pluronic F127 citrate)/chitin nanofibril/bioactive glass (POFC/ChiNF/BG) porous scaffold via directional-freeze-casting

2020 ◽  
Vol 40 (7) ◽  
pp. 591-599
Author(s):  
Yaling Tian ◽  
Kai Liang ◽  
Yali Ji
Keyword(s):  
Bioactive Glass ◽  
Porous Structure ◽  
Pore Structure ◽  
Porous Scaffold ◽  
Pluronic F127 ◽  
Porous Scaffolds ◽  
Freeze Casting ◽  
Promising Candidate ◽  
Complete Replacement

AbstractThe citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.

Ultralow Wear PTFE-Based Polymer Composites—The Role of Water and Tribochemistry

2019 ◽  
Vol 52 (14) ◽  
pp. 5268-5277 ◽  
Author(s):  
Kasey L. Campbell ◽  
Mark A. Sidebottom ◽  
Cooper C. Atkinson ◽  
Tomas F. Babuska ◽  
Claudia A. Kolanovic ◽  
...  
Keyword(s):  
Polymer Composites

Polymer Heat Exchangers: An Enabling Technology for Water and Energy Savings

2011 ◽  
Author(s):  
Juan G. Cevallos ◽  
Frank Robinson ◽  
Avram Bar-Cohen ◽  
Hugh Bruck
Keyword(s):  
Polymer Composites ◽  
Case Studies ◽  
Heat Exchangers ◽  
Energy Savings ◽  
Embodied Energy ◽  
Enabling Technology ◽  
Current Trends ◽  
Thermoelectric Energy ◽  
Polymer Heat Exchangers

Polymer heat exchangers (PHXs), using thermally-enhanced composites, constitute a “disruptive” thermal technology that can lead to significant water and energy savings in the thermoelectric energy sector. This paper reviews current trends in electricity generation, water use, and the inextricable relationship between the two trends in order to identify the possible role of PHXs in seawater cooling applications. The use of once-through seawater cooling as a replacement for freshwater recirculating systems is identified as a viable way to reduce the use of freshwater and to increase power plant efficiency. The widespread use of seawater as a coolant can be made possible by the favorable qualities of thermally-enhanced polymer composites: good corrosion resistance, higher thermal conductivities, higher strengths, low embodied energy and good manufacturability. The authors use several seawater cooling case studies to explore the potential water and energy savings made possible by the use of PHX technology. The results from three case studies suggest that heat exchangers made with thermally enhanced polymer composites require less energy input over their lifetime than corrosion resistant metals, which generally have much higher embodied energy than polymers and polymers composites. Also, the use of seawater can significantly reduce the use of freshwater as a coolant, given the inordinate amounts of water required for even a 1MW heat exchanger.

scholarly journals The role of thermal diffusion, particle clusters, hydrodynamic and magnetic forces on the flow behaviour of magneto-polymer composites

2021 ◽  
Vol 379 (2205) ◽  
pp. 20200302 ◽  
Author(s):  
William R. Suarez-Fernandez ◽  
Juan D. G. Duran ◽  
Modesto T. Lopez-Lopez
Keyword(s):  
Polymer Composites ◽  
Magnetic Particles ◽  
Hydrodynamic Forces ◽  
Particle Movement ◽  
Dimensionless Numbers ◽  
Anionic Polymer ◽  
Experimental Conditions ◽  
Magnetic Attraction ◽  
Induced Flow

In this paper, we study the shear-induced flow of magneto-polymer composites, consisting of dispersions of magnetic particles in solutions of polymers, as a competition between the colloidal forces amid particles and their bulk transport induced by the hydrodynamic forces. For this aim, we analyse the role of different experimental parameters. Firstly, by using only solutions of a well-known anionic polymer (sodium alginate), we provoke a moderate hindering of particle movement, but keeping the liquid-like state of the samples. On the contrary, a gel-like behaviour is conferred to the samples when a cationic polymer (chitosan) is additionally added, which further reduces the particle movement. We analyse the effect of an applied magnetic field, which is opposed to particle transport by hydrodynamic forces, by inducing magnetic attraction between the particles. We perform the analysis under both stationary and oscillatory shear. We show that by using dimensionless numbers the differences between samples and experimental conditions are emphasized. In all cases, as expected, the transport of particles driven by bulk hydrodynamic forces dominates at high values of the shear rate. This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

Analisa Kekuatan Bahan Komposit Yang Diperkuat Serat Bambu Menggunakan Resin Polyester Dengan Memvariasikan Susunan Serat Secara Acak Dan Lurus Memanjang

2020 ◽  
Vol 2 (1) ◽  
pp. 28-35
Author(s):  
Rokki Manurung ◽  
Sutan Simanjuntak ◽  
Jesayas Sembiring ◽  
Richard A.M. Napitupulu ◽  
Suriady Sihombing
Keyword(s):  
Polymer Composites ◽  
Polyester Resin ◽  
Natural Fibers ◽  
Resin Matrix ◽  
Strength Increase ◽  
Test Results ◽  
The Matrix ◽  
Bamboo Fibers ◽  
Reinforcing Material

Composites are materials which are mixed with one or more different and heterogeneous reinforcement. Matrix materials can generally be polymers, ceramics and metals. The matrix in the composite serves to distribute the load into all reinforcing material. Matrix properties are usually ductile. The reinforcing material in the composite has the role of holding the load received by the composite material. The nature of the reinforcing material is usually rigid and tough. Strengthening materials commonly used so far are carbon fiber, glass fiber, ceramics. The use of natural fibers as a type of fiber that has advantages began to be applied as a reinforcing material in polymer composites. This study seeks to see the effect of the use of bamboo natural fibers in polyester resin matrix on the strength of polymer composites with random and straight lengthwise fiber variations. From the tensile test results it can be seen that bamboo fibers can increase the strength of polymer composites made from polyester resin and the position of the longitudinal fibers gives a significantly more strength increase than random fibers.

Key role of the expression of bone morphogenetic proteins in increasing the osteogenic activity of osteoblast-like cells exposed to shock waves and seeded on bioactive glass-ceramic scaffolds for bone tissue engineering

2014 ◽  
Vol 29 (5) ◽  
pp. 728-736 ◽  
Author(s):  
Giuliana Muzio ◽  
Germana Martinasso ◽  
Francesco Baino ◽  
Roberto Frairia ◽  
Chiara Vitale-Brovarone ◽  
...  
Keyword(s):  
Shock Wave ◽  
Alkaline Phosphatase ◽  
Shock Waves ◽  
Bioactive Glass ◽  
Bone Morphogenetic Protein ◽  
Bone Morphogenetic Proteins ◽  
Glass Ceramic ◽  
Osteogenic Activity ◽  
Morphogenetic Protein

In this work, the role of shock wave-induced increase of bone morphogenetic proteins in modulating the osteogenic properties of osteoblast-like cells seeded on a bioactive scaffold was investigated using gremlin as a bone morphogenetic protein antagonist. Bone-like glass-ceramic scaffolds, based on a silicate experimental bioactive glass developed at the Politecnico di Torino, were produced by the sponge replication method and used as porous substrates for cell culture. Human MG-63 cells, exposed to shock waves and seeded on the scaffolds, were treated with gremlin every two days and analysed after 20 days for the expression of osteoblast differentiation markers. Shock waves have been shown to induce osteogenic activity mediated by increased expression of alkaline phosphatase, osteocalcin, type I collagen, BMP-4 and BMP-7. Cells exposed to shock waves plus gremlin showed increased growth in comparison with cells treated with shock waves alone and, conversely, mRNA contents of alkaline phosphatase and osteocalcin were significantly lower. Therefore, the shock wave-mediated increased expression of bone morphogenetic protein in MG-63 cells seeded on the scaffolds is essential in improving osteogenic activity; blocking bone morphogenetic protein via gremlin completely prevents the increase of alkaline phosphatase and osteocalcin. The results confirmed that the combination of glass-ceramic scaffolds and shock waves exposure could be used to significantly improve osteogenesis opening new perspectives for bone regenerative medicine.

scholarly journals The Regenerative Applicability of Bioactive Glass and Beta-Tricalcium Phosphate in Bone Tissue Engineering: A Transformation Perspective

2019 ◽  
Vol 10 (1) ◽  
pp. 16 ◽  
Author(s):  
Baboucarr Lowe ◽  
Mark P. Ottensmeyer ◽  
Chun Xu ◽  
Yan He ◽  
Qingsong Ye ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bioactive Glass ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Tricalcium Phosphate ◽  
Beta Tricalcium Phosphate ◽  
Engineering Strategy

The conventional applicability of biomaterials in the field of bone tissue engineering takes into consideration several key parameters to achieve desired results for prospective translational use. Hence, several engineering strategies have been developed to model in the regenerative parameters of different forms of biomaterials, including bioactive glass and β-tricalcium phosphate. This review examines the different ways these two materials are transformed and assembled with other regenerative factors to improve their application for bone tissue engineering. We discuss the role of the engineering strategy used and the regenerative responses and mechanisms associated with them.

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