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.

Structure and properties of nano-hydroxyapatite/poly(butylene succinate) porous scaffold for bone tissue engineering prepared by using ethanol as porogen

2018 ◽  
Vol 33 (6) ◽  
pp. 776-791 ◽  
Author(s):  
Gang Li ◽  
Shuhao Qin ◽  
Xiaonan Liu ◽  
Daohai Zhang ◽  
Min He
Keyword(s):  
Tissue Engineering ◽  
Pore Structure ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Porous Scaffold ◽  
Degradation Products ◽  
Porous Scaffolds ◽  
Butylene Succinate ◽  
Uniform Dispersion ◽  
Polybutylene Succinate

Biodegradable polymers, because their degradation products are small molecules that do not cause immune system rejection, have been increasingly used by researchers to explore the preparation of scaffold with excellent mechanical properties, biocompatibility and biodegradability. In this study, nano-hydroxyapatite and polybutylene succinate were mixed by solution-blending to prepare a porous scaffold that could be used in the biomedical industry. Based on the viewpoint of bionics, porous scaffold with well pore structure and uniform dispersion of nano-hydroxyapatite particles was prepared using ethanol as a porogen. When ethanol was used as a porogen to prepare the porous scaffold, the effects of different mass ratios of nano-hydroxyapatite and polybutylene succinate on the porosity and pore structure of the porous scaffold were investigated under the same amount of ethanol. The mercury intrusion tests showed that the porosity of the 30 nano-hydroxyapatite/polybutylene succinate porous scaffold was 38.987%. The experiment results of in vitro mineralization and cell culture showed that the porous scaffolds have good osteogenic capacity and cell compatibility, including attachment and proliferation. All experiment results indicated that ethanol can be used as a porogen to prepare nano-hydroxyapatite/polybutylene succinate porous scaffold, and it has great potential as a scaffold for bone tissue engineering.

Calcium Phosphate Open Porous Scaffold Bioceramics

2005 ◽  
Vol 284-286 ◽  
pp. 349-352 ◽  
Author(s):  
J.P. Gittings ◽  
I.G. Turner ◽  
A.W. Miles
Keyword(s):  
Calcium Phosphate ◽  
Pore Structure ◽  
Size Range ◽  
Porous Scaffold ◽  
Total Porosity ◽  
Porous Scaffolds ◽  
Structure Property ◽  
Wide Range ◽  
Microcrack Formation ◽  
Relationship Of

Calcium phosphate (CaP) ceramics possessing an interconnecting porosity network in the appropriate size range for vascularisation offer the possibility of providing a structural matrix for replacement of diseased or damaged bone. Such bioceramics must possess sufficient mechanical strength to avoid failure whilst offering a bioactive surface for bone regeneration. The objective of the current study was to produce a hydroxyapatite/tricalcium phosphate (HA/TCP) bioceramic that imitated the orientated trabecular structure found in cancellous bone. The structure-property relationship of these bioceramics was then analysed. It was hypothesised that the mechanical properties would be linked to the shape of the pore structure due to the orientation of the open porous scaffolds (OPS) produced. OPS bioceramics possessed an interconnected macroporosity network of 40-70% by volume with bending strengths of 0.30MPa ± 0.01MPa and apparent densities of 0.35g/cm3 ± 0.05g/cm3. Typically, pore sizes in the range of 150-300µm were produced. The fabrication of CaP OPS resulted in a wide range of macroporosity in the correct size range for osseointegration to occur. Elongating the pore structure did not affect the total porosity of the bioceramics. Strengths were low due to microcrack formation on sintering and not due to the shape of the pores present in the scaffold as initially hypothesised.

scholarly journals Attachment and Proliferation of Human-Adipose-Tissue-Derived Stem Cells on Bioactive Glass/PVA Hybrid Scaffolds

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Viviane Gomide ◽  
Alessandra Arcoverde Cavalcanti Zonari ◽  
Natalia Martins Breyner ◽  
Alfredo Miranda de Goes ◽  
Marivalda M. Pereira
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Adipose Tissue ◽  
Bioactive Glass ◽  
Pore Structure ◽  
Bone Repair ◽  
Sol Gel ◽  
Human Adipose Tissue ◽  
Porous Scaffolds

Bioactive glass/polymer hybrids are promising materials for biomedical applications because they combine the bioactivity of bioceramics with the flexibility of polymers. These advantages may be used in porous scaffolds for tissue-engineering applications. In previous works, hybrid foams bioactive glass/polyvinyl alcohol (PVA) were prepared by the sol-gel process. The hybrid foam 50% PVA/50% bioactive glass was chosen in the composition range studied as the scaffold with better compromise in terms of pore structure and mechanical behavior. The aim of the present study was to evaluate the adhesion, viability, and growth behavior of human-adipose-tissue-derived stem cells on bioactive glass/PVA foams in vitro and their potential as scaffold for application in bone-tissue engineering. The pore structure of the hybrid samples used in the study was analyzed by microcomputed tomography, showing a modal pore diameter of 284 μm and modal interconnect diameter of 138 μm. We found that cells are capable of adhesion, proliferation, growth, and ECM production on the scaffolds tested. The results show that the hybrid bioactive glass/PVA is a promising material for bone repair, providing a good environment for the adhesion and proliferation of human-adipose-tissue-derived stem cells in vitro.

scholarly journals On Various Porous Scaffold Fabrication Methods

2017 ◽  
Vol 16 (4) ◽  
pp. 47-52 ◽  
Author(s):  
D Elamparithi ◽  
V Moorthy
Keyword(s):  
Porous Structure ◽  
Biomedical Applications ◽  
Therapeutic Potential ◽  
Porous Scaffold ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Preparation Methods ◽  
Advantages And Disadvantages ◽  
And Migration ◽  
Preparation Techniques

Three-dimensional scaffolds can be fabricated by various methods. These scaffold constructs showed a major impact on various biomedical applications. The bioactive porous scaffolds should have an excellent three-dimensional architecture and interconnected porous structure for cells adhesion and migration to enhance the therapeutic potential. The porosity and interconnected porous structure can be optimized using various scaffold preparation methods. In this mini review, we discussed the advantages and disadvantages of various commonly used scaffold preparation techniques.

scholarly journals Physicochemical and Microstructural Characterization of Injectable Load-Bearing Calcium Phosphate Scaffold

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mazen Alshaaer ◽  
Mohammed H. Kailani ◽  
Hanan Jafar ◽  
Nidaa Ababneh ◽  
Abdalla Awidi
Keyword(s):  
Calcium Phosphate ◽  
Porous Scaffold ◽  
Setting Time ◽  
Microstructural Characterization ◽  
Porous Scaffolds ◽  
Promising Candidate ◽  
Load Bearing ◽  
Injectable Scaffolds ◽  
Valid Solution

Injectable load-bearing calcium phosphate scaffolds are synthesized using rod-like mannitol grains as porogen. These degradable injectable strong porous scaffolds, prepared by calcium phosphate cement, could represent a valid solution to achieve adequate porosity requirements while providing adequate support in load-bearing applications. The proposed process for preparing porous injectable scaffolds is as quick and versatile as conventional technologies. Using this method, porous CDHA-based calcium phosphate scaffolds with macropores sizes ranging from 70 to 300 μm, micropores ranging from 5 to 30 μm, and 30% open macroporosity were prepared. The setting time of the prepared scaffolds was 15 minutes. Also their compressive strength and e-modulus, 4.9 MPa and 400 MPa, respectively, were comparable with those of the cancellous bone. Finally, the bioactivity of the scaffolds was confirmed by cell growth with cytoplasmic extensions in the scaffolds in culture, demonstrating that the scaffold has a potential for MSC seeding and growth architecture. This combination of an interconnected macroporous structure with pore size suitable for the promotion of cell seeding and proliferation, plus adequate mechanical features, represents a porous scaffold which is a promising candidate for bone tissue engineering.

Role of Flavonoids in Neurodegenerative Disorders with Special Emphasis on Tangeritin

2019 ◽  
Vol 18 (8) ◽  
pp. 581-597 ◽  
Author(s):  
Ambreen Fatima ◽  
Yasir Hasan Siddique
Keyword(s):  
Medicinal Plants ◽  
Mechanism Of Action ◽  
Neurodegenerative Disorders ◽  
Treatment Strategies ◽  
Dietary Supplementation ◽  
Plant Polyphenols ◽  
Promising Candidate ◽  
Naturally Occurring ◽  
The Brain

Flavonoids are naturally occurring plant polyphenols found universally in all fruits, vegetables and medicinal plants. They have emerged as a promising candidate in the formulation of treatment strategies for various neurodegenerative disorders. The use of flavonoid rich plant extracts and food in dietary supplementation have shown favourable outcomes. The present review describes the types, properties and metabolism of flavonoids. Neuroprotective role of various flavonoids and the possible mechanism of action in the brain against the neurodegeneration have been described in detail with special emphasis on the tangeritin.

scholarly journals Yttrium Oxide Freeze-Casts: Target Materials for Radioactive Ion Beams

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2864
Author(s):  
Eva Kröll ◽  
Miriana Vadalà ◽  
Juliana Schell ◽  
Simon Stegemann ◽  
Jochen Ballof ◽  
...  
Keyword(s):  
Pore Structure ◽  
Yttrium Oxide ◽  
Ion Beam ◽  
Isotope Separation ◽  
Target Material ◽  
Ion Beams ◽  
Radioactive Isotopes ◽  
Solid Loading ◽  
Radioactive Ion Beams ◽  
Freeze Casting

Highly porous yttrium oxide is fabricated as ion beam target material in order to produce radioactive ion beams via the Isotope Separation On Line (ISOL) method. Freeze casting allows the formation of an aligned pore structure in these target materials to improve the isotope release. Aqueous suspensions containing a solid loading of 10, 15, and 20 vol% were solidified with a unidirectional freeze-casting setup. The pore size and pore structure of the yttrium oxide freeze-casts are highly affected by the amount of solid loading. The porosity ranges from 72 to 84% and the crosslinking between the aligned channels increases with increasing solid loading. Thermal aging of the final target materials shows that an operation temperature of 1400 °C for 96 h has no significant effect on the microstructure. Thermo-mechanical calculation results, based on a FLUKA simulation, are compared to measured compressive strength and forecast the mechanical integrity of the target materials during operation. Even though they were developed for the particular purpose of the production of short-lived radioactive isotopes, the yttria freeze-cast scaffolds can serve multiple other purposes, such as catalyst support frameworks or high-temperature fume filters.

Pore structure dependent activity and durability of mesoporous rhodium nanoparticles towards the methanol oxidation reaction

2020 ◽  
Vol 56 (32) ◽  
pp. 4448-4451 ◽  
Author(s):  
Yan Guo ◽  
Shuai Chen ◽  
Yuan Li ◽  
Yunwei Wang ◽  
Houbing Zou ◽  
...  
Keyword(s):  
Porous Structure ◽  
Pore Structure ◽  
Methanol Oxidation ◽  
Oxidation Reaction ◽  
Structure Effect ◽  
Methanol Oxidation Reaction ◽  
Rhodium Nanoparticles ◽  
Dependent Activity

A significant porous structure effect of mesoporous rhodium nanoparticles on the electrocatalytic methanol oxidation reaction was reported.

scholarly journals Facile Synthesis of Sponge-Like Porous Nano Carbon-Coated Silicon Anode with Tunable Pore Structure for High-Stability Lithium-Ion Batteries

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3211
Author(s):  
Shugui Song ◽  
Jingcang Li ◽  
Anqi Zheng ◽  
Yongqiang Yang ◽  
Kuibo Yin
Keyword(s):  
Porous Structure ◽  
Pore Structure ◽  
High Stability ◽  
Cycling Stability ◽  
Silicon Anode ◽  
Slow Heating ◽  
Facile Synthesis ◽  
Silicon Anodes ◽  
Carbon Coated ◽  
Nano Carbon

To address the challenge of the huge volume expansion of silicon anode, carbon-coated silicon has been developed as an effective design strategy due to the improved conductivity and stable electrochemical interface. However, although carbon-coated silicon anodes exhibit improved cycling stability, the complex synthesis methods and uncontrollable structure adjustment still make the carbon-coated silicon anodes hard to popularize in practical application. Herein, we propose a facile method to fabricate sponge-like porous nano carbon-coated silicon (sCCSi) with a tunable pore structure. Through the strategy of adding water into precursor solution combined with a slow heating rate of pre-oxidation, a sponge-like porous structure can be formed. Furthermore, the porous structure can be controlled through stirring temperature and oscillation methods. Owing to the inherent material properties and the sponge-like porous structure, sCCSi shows high conductivity, high specific surface area, and stable chemical bonding. As a result, the sCCSi with normal and excessive silicon-to-carbon ratios all exhibit excellent cycling stability, with 70.6% and 70.2% capacity retentions after 300 cycles at 500 mA g−1, respectively. Furthermore, the enhanced buffering effect on pressure between silicon nanoparticles and carbon material due to the sponge-like porous structure in sCCSi is further revealed through mechanical simulation. Considering the facile synthesis method, flexible regulation of porous structure, and high cycling stability, the design of the sCCSi paves a way for the synthesis of high-stability carbon-coated silicon anodes.

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