STRUCTURAL FEATURES AND MECHANICAL PROPERTIES OF PLLA/PEARL POWDER SCAFFOLDS

2013 ◽  
Vol 13 (01) ◽  
pp. 1350020 ◽  
Author(s):  
Y. S. LIU ◽  
Q. L. HUANG ◽  
Q. L. FENG ◽  
N. M. HU ◽  
O. ALBERT
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Lactic Acid ◽  
Yield Strength ◽  
Porous Structure ◽  
Freeze Drying ◽  
Structural Features ◽  
Drying Method ◽  
Composite Scaffolds ◽  
Powder Content

In order to improve the mechanical properties of scaffolds for bone tissue engineering, the present study aims to bring calcium carbonate (CaCO3) with signaling molecules, namely pearl powder, into poly(L-lactic acid) (PLLA). PLLA/aragonite and PLLA/vaterite scaffolds were successfully fabricated by the freeze-drying method. Both composite scaffolds had a similar porous structure but a different saturated content of pearl powders. For both scaffolds, the porosity decreases and yield strength increases as pearl powder content increases. Introducing pearl powders into PLLA can improve the mechanical properties of the scaffolds. The porous structure plays a crucial role in the yield strength of pure PLLA scaffolds, whereas the yield strength of PLLA/pearl powder scaffolds mostly relies on pearl powder content.

Microstructural and Mechanical Properties of Polymer-Based Scaffolds Reinforced by Hydroxyapatite

2007 ◽  
Vol 544-545 ◽  
pp. 765-768 ◽  
Author(s):  
Hyeong Ho Jin ◽  
Won Ki Lee ◽  
Hong Chae Park ◽  
Seog Young Yoon
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Yield Strength ◽  
Pore Size ◽  
Compressive Modulus ◽  
Precipitation Method ◽  
Pore Morphology ◽  
Composite Scaffolds ◽  
Co Precipitation

Various polymer-based scaffolds reinforced by the hydroxyapatite (HAp) for bone tissue engineering were successfully synthesized by in-situ co-precipitation method. The influence of HAp in composite scaffolds on the pore morphology, microstructure, and mechanical properties was investigated. The polymer-based scaffolds appeared to be macroporous and an interconnected open pore microstructure with pore size around 200 μm. The pore structure of the composite scaffolds was not much changed by the presence of HAp but the pore size of the composite scaffolds decreased with adding the HAp. The compressive modulus and yield strength of the polymer-based scaffolds improved by the presence of HAp.

Preparation of PLLA/HAP/β-TCP Composite Scaffold for Bone Tissue Engineering

2014 ◽  
Vol 513-517 ◽  
pp. 143-146 ◽  
Author(s):  
Xue Jun Wang ◽  
Tao Lou ◽  
Jing Yang ◽  
Zhen Yang ◽  
Kun Peng He
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Lactic Acid ◽  
Phase Separation ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Composite Scaffold ◽  
Thermally Induced Phase Separation ◽  
Composite Scaffolds ◽  
Thermally Induced

In this study, a nanofibrous poly (L-lactic acid) (PLLA) scaffold reinforced by Hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP) was fabricated using the thermally induced phase separation method. The composite scaffold morphology showed a nanofibrous PLLA matrix and evenly distributed β-TCP/HAP particles. The composite scaffold had interconnective micropores and the pore size ranged 2-10 μm. Introducing β-TCP/HAP particles into PLLA matrix significantly improved the mechanical properties of the composite scaffold. In summary, the new composite scaffolds show a great deal promise for use in bone tissue engineering.

Development and Characterization of Poly(ε-caprolactone) Reinforced Porous Hydroxyapatite for Bone Tissue Engineering

2012 ◽  
Vol 529-530 ◽  
pp. 447-452 ◽  
Author(s):  
Yos Phanny ◽  
Mitsugu Todo
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Freeze Drying ◽  
Secondary Phase ◽  
Potential Candidate ◽  
Drying Method ◽  
Drying Process ◽  
Composite Scaffolds ◽  
Porous Hydroxyapatite

Hydroxyapatite (HA) scaffold was fabricated using template method. Secondary phase of poly (ε-caprolactone) (PCL) was then introduced into the porous structure of the HA scaffold by the freeze drying method or the room drying process. Compression test and SEM were done to examine the mechanical properties and the microstructural morphology of the composite scaffolds. It was found that the compressive strength and modulus tend to increase with increasing PCL concentration. HA/PCL scaffolds fabricated under the room drying process exhibited higher compression strength and modulus than HA/PCL scaffolds prepared by the freeze drying method because the porous HA surfaces were completely covered by PCL in the room drying scaffolds. XRD test was also used to study the phase stability of the scaffolds. It was confirmed that there was no chemical reaction between PCL and HA. On overall, the results indicated that the introduction of secondary PCL phases into the porous HA scaffold can improve the low strength and toughness of the pure HA scaffold and the HA/PCL composite scaffolds might be a potential candidate in bone tissue engineering.

Construction of a CsPbBr3 modified porous g-C3N4 photocatalyst for effective reduction of CO2 and mechanism exploration

2021 ◽  
Author(s):  
Yunqi Wang ◽  
Zhixiang Liu ◽  
Xu Tang ◽  
Pengwei Huo ◽  
Zhi Zhu ◽  
...  
Keyword(s):  
High Temperature ◽  
Porous Structure ◽  
Freeze Drying ◽  
Drying Method ◽  
Full Spectrum ◽  
Effective Reduction ◽  
Reduction Of Co2 ◽  
High Temperature Calcination

A P-CN/CsPbBr3 photocatalyst with a lamellar porous structure was prepared by a high temperature calcination and freeze drying method, and it exhibited superior CO2 reduction performance under the conditions of full spectrum irradiation.

Preparation and Characterization of a Novel γ-PGA/β-Tricalcium Phosphate Composite for Tissue Engineering

2014 ◽  
Vol 900 ◽  
pp. 306-311 ◽  
Author(s):  
Xiu Lin Shu ◽  
Qing Shan Shi ◽  
Xiao Bao Xie ◽  
Xiao Mo Huang ◽  
Yi Ben Chen
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Porous Structure ◽  
Water Absorption ◽  
Tricalcium Phosphate ◽  
Absorption Rate ◽  
Swelling Ratio ◽  
Composite Scaffolds

In order to improvedβ-TCP biocompatibility and cell growth, was chosen to modify β-TCP matrices to produce a γ-PGA/β-TCP composite biomaterial. Then, the morphology, water uptake and retention abilities,in vitrodegradation property in the simulated medium, cytotoxicity of this novel γ-PGA/β-TCP composite is investigated. SEM shows that the γ-PGA/β-TCP composite has a porous structure. By increasing the percentage ofγ-PGA from 0% to 50%, the swelling ratio of the composite s was enhanced from 9.0%to 297%. These data suggested that the surface hydrophilicity, water absorption rate, and swelling ratio were improved by adding γ-PGA to the composite. In the cytocompatibility test, the density of MC3T3-E1 preosteoblasts cells on the PTCP1:1 leachates was almost 110% higher than that on the controls on day 3. Therefore, the γ-PGA/β-TCP composite scaffolds, due to their better hydrophilicity, cytocompatibility, and porous structure, are very promising biomaterials for tissure engineering applications.

scholarly journals Effect of Melt-Derived Bioactive Glass Particles on the Properties of Chitosan Scaffolds

2019 ◽  
Vol 10 (3) ◽  
pp. 38 ◽  
Author(s):  
Hamasa Faqhiri ◽  
Markus Hannula ◽  
Minna Kellomäki ◽  
Maria Teresa Calejo ◽  
Jonathan Massera
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Bioactive Glass ◽  
Pore Size ◽  
Glass Content ◽  
Micro Computed Tomography ◽  
Glass Composite ◽  
Composite Scaffolds ◽  
Bioactive Glasses

This study reports on the processing of three-dimensional (3D) chitosan/bioactive glass composite scaffolds. On the one hand, chitosan, as a natural polymer, has suitable properties for tissue engineering applications but lacks bioactivity. On the other hand, bioactive glasses are known to be bioactive and to promote a higher level of bone formation than any other biomaterial type. However, bioactive glasses are hard, brittle, and cannot be shaped easily. Therefore, in the past years, researchers have focused on the processing of new composites. Difficulties in reaching composite materials made of polymer (synthetic or natural) and bioactive glass include: (i) The high glass density, often resulting in glass segregation, and (ii) the fast bioactive glass reaction when exposed to moisture, leading to changes in the glass reactivity and/or change in the polymeric matrix. Samples were prepared with 5, 15, and 30 wt% of bioactive glass S53P4 (BonAlive ®), as confirmed using thermogravimetric analysis. MicrO–Computed tomography and optical microscopy revealed a flaky structure with porosity over 80%. The pore size decreased when increasing the glass content up to 15 wt%, but increased back when the glass content was 30 wt%. Similarly, the mechanical properties (in compression) of the scaffolds increased for glass content up to 15%, but decreased at higher loading. Ions released from the scaffolds were found to lead to precipitation of a calcium phosphate reactive layer at the scaffold surface. This is a first indication of the potential bioactivity of these materials. Overall, chitosan/bioactive glass composite scaffolds were successfully produced with pore size, machinability, and ability to promote a calcium phosphate layer, showing promise for bone tissue engineering and the mechanical properties can justify their use in non-load bearing applications.

Computational Design and Optimization of Nerve Guidance Conduits for Improved Mechanical Properties and Permeability

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Shuo Zhang ◽  
Sanjairaj Vijayavenkataraman ◽  
Geng Liang Chong ◽  
Jerry Ying Hsi Fuh ◽  
Wen Feng Lu
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Mechanical Strength ◽  
Tensile Modulus ◽  
Computational Design ◽  
Structural Features ◽  
Nerve Tissue ◽  
High Porosity ◽  
Engineering Research ◽  
Design And Optimization

Nerve guidance conduits (NGCs) are tubular tissue engineering scaffolds used for nerve regeneration. The poor mechanical properties and porosity have always compromised their performances for guiding and supporting axonal growth. Therefore, in order to improve the properties of NGCs, the computational design approach was adopted to investigate the effects of different NGC structural features on their various properties, and finally, design an ideal NGC with mechanical properties matching human nerves and high porosity and permeability. Three common NGC designs, namely hollow luminal, multichannel, and microgrooved, were chosen in this study. Simulations were conducted to study the mechanical properties and permeability. The results show that pore size is the most influential structural feature for NGC tensile modulus. Multichannel NGCs have higher mechanical strength but lower permeability compared to other designs. Square pores lead to higher permeability but lower mechanical strength than circular pores. The study finally selected an optimized hollow luminal NGC with a porosity of 71% and a tensile modulus of 8 MPa to achieve multiple design requirements. The use of computational design and optimization was shown to be promising in future NGC design and nerve tissue engineering research.

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