Preparation of Porous Hydroxyapatite-Zirconia Composite Scaffolds by Combination of Gel-Casting and Polymer Sponge Methods

2010 ◽  
Vol 105-106 ◽  
pp. 616-619 ◽  
Author(s):  
Li Li Wang ◽  
Xiu Feng Wang ◽  
Hong Tao Jiang ◽  
Cheng Long Yu
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Porous Structure ◽  
Porous Scaffolds ◽  
Pore Morphology ◽  
Porous Composite ◽  
Composite Scaffolds ◽  
Porous Hydroxyapatite ◽  
Casting Technique ◽  
Gel Casting

Hydroxyapatite (HA) doped with 3%yttria-stabilized 20wt% zirconia (ZrO2) ceramic were developed in order to produce a porous composite biomaterial by integrating the gel-casting technique with polymer sponge method with improved mechanical strength and controllable porous structure. The pore morphology, size, and distribution of the scaffolds were characterized using an electron microscope. The scaffolds prepared have an open, uniform and interconnected porous structure with a pore size of 300~500m. The porosity of the open pores in the scaffold can be controlled by changing HA-ZrO2 composite concentration and it is between 87%~35%. A compressive strength of 12MPa for HA-ZrO2 porous scaffolds with HA-ZrO2 concentration of 55wt% was achieved, which is comparable to that of cortical bone.

Preparation of Porous Hydroxyapatite Scaffolds for Bone Tissue Engineering

2006 ◽  
Vol 510-511 ◽  
pp. 754-757 ◽  
Author(s):  
Sang Ho Min ◽  
Hyeong Ho Jin ◽  
Hoy Yul Park ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Porous Structure ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Porous Scaffolds ◽  
Pore Morphology ◽  
Average Pore ◽  
Porous Hydroxyapatite

Porous hydroxyapatite (HAp) scaffolds were successfully prepared by using the HAp slurry based on the replication of polymer sponge substrate. The effect of HAp content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous scaffolds was investigated. The scaffolds with average pore sizes ranging from 200 to 400 µm had an open, relatively uniform, and interconnected porous structure. As the HAp content increased, the porosity of scaffold decreased while the density increased. These phenomena were attributed to the fact that the pores became interconnected with more dense and thicker pore walls with increasing HAp content in slurry. The results suggest that the density, porosity, and compressive strength of the porous HAp scaffold were significantly affected by the content of the HAp powder in the slurry.

Effect of Reaction Conditions on Pore Configuration and Mechanical Property for Porous Hydroxyapatite Prepared by Polymer Sponge Method

2007 ◽  
Vol 336-338 ◽  
pp. 1567-1570 ◽  
Author(s):  
Sang Ho Min ◽  
Hyeong Ho Jin ◽  
B.S. Jun ◽  
Ik Min Park ◽  
Hong Chae Park ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Porous Structure ◽  
Pore Wall ◽  
Pore Morphology ◽  
Reaction Conditions ◽  
Average Pore ◽  
Porous Hydroxyapatite ◽  
Pore Wall Thickness

Porous HAp scaffolds have been prepared by using the slurry including HAp and magnesia based on the replication of polymer sponge substrate. The influence of HAp and MgO content in slurry on the pore morphology and size, and density, porosity, and mechanical strength of porous HAp scaffolds was investigated. The obtained scaffolds with average pore sizes ranging 150 to 300 μm had open, relatively uniform, and interconnected porous structure regardless of HAp and MgO content. As the MgO content increased, the pore network frame of scaffolds became to be relatively stronger, even though the pore size was not much changed. The compressive strength of the scaffolds increased rapidly with the increase of MgO content at a fixed HAp content because of increasing the pore wall thickness and density of the scaffolds. As a result, the porosity, density, and compressive strength of the porous HAp scaffolds scaffolds prepared by the sponge method were significantly affected by the addition of MgO.

scholarly journals Evaluation of Structural and Mechanical Properties of Porous Artificial Bone Scaffolds Fabricated via Advanced TBA-Based Freeze-Gel Casting Technique

2019 ◽  
Vol 9 (9) ◽  
pp. 1965 ◽  
Author(s):  
Tae-Rim Kim ◽  
Min-Su Kim ◽  
Tae Sik Goh ◽  
Jung Sub Lee ◽  
Yun Hak Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cancellous Bone ◽  
Casting Process ◽  
High Porosity ◽  
Artificial Bone ◽  
Porous Hydroxyapatite ◽  
Casting Technique ◽  
Bone Scaffolds ◽  
Gel Casting

Porous hydroxyapatite (HA) artificial bone scaffolds were prepared via the freeze-gel casting process in order to improve their mechanical strengths. As a porogen, various volumes of poly (methyl methacrylate) (PMMA) powders were added to obtain high porosity, such as in cancellous bone. After fabrication, the porous and mechanical properties of the scaffolds were examined. The HA60 scaffold, with a porosity over 80%, had proper compressive strength and modulus and satisfied the range of properties of cancellous bone. Moreover, it was found that the investigated mechanical properties were affected by the scaffolds’ porosity. However, a section was found where the compressive strength was high despite the increase in the porosity. Specifically, HA30 had a porosity of 62.9% and a compressive strength of 1.73 MPa, whereas the values for HA60 were 81.9% and 3.23 MPa, respectively. The results indicate that there are factors that can preserve the mechanical properties even if the porosity of the scaffold increases. Therefore, in this study, various parameters affecting the porous and mechanical properties of the scaffolds during the manufacturing process were analyzed. It is expected that the improvement in the mechanical properties of the artificial bone scaffold having a high porosity can be applied to tissue engineering.

Porous hydroxyapatite scaffolds containing calcium phosphate glass-ceramics processed using a freeze/gel-casting technique

2014 ◽  
Vol 20 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Tae Wan Kim ◽  
Su Chak Ryu ◽  
Byung Kyu Kim ◽  
Seog Young Yoon ◽  
Hong Chae Park
Keyword(s):  
Calcium Phosphate ◽  
Phosphate Glass ◽  
Glass Ceramics ◽  
Porous Hydroxyapatite ◽  
Casting Technique ◽  
Gel Casting

Preparation and characterization of porous hydroxyapatite/β-cyclodextrin-based polyurethane composite scaffolds for bone tissue engineering

2018 ◽  
Vol 33 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Jingjing Du ◽  
Shuchun Gan ◽  
Qihao Bian ◽  
Duhan Fu ◽  
Yan Wei ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Bone Repair ◽  
Cell Attachment ◽  
Hexamethylene Diisocyanate ◽  
Porous Scaffolds ◽  
Composite Scaffolds ◽  
Porous Hydroxyapatite ◽  
Polyurethane Composite

In this study, novel porous scaffolds containing hydroxyapatite and β-cyclodextrin-based polyurethane were first successfully fabricated by polymerizing β-cyclodextrin with hexamethylene diisocyanate and hydroxyapatite in situ for bone tissue engineering. The physicochemical and mechanical properties as well as cytocompatibility of porous scaffolds were investigated. The results showed that polyurethane reinforced with hydroxyapatite composites had cancellous bone-like porous structure. The mechanical strength of the scaffolds increased with increasing the hydroxyapatite content in scaffolds. Synthesized scaffolds (PU1, PUHA1, PU2, and PUHA2) presented compressive strength values of 0.87 ± 0.24 MPa, 1.81 ± 0.10 MPa, 6.16 ± 0.89 MPa, and 12.95 ± 2.05 MPa, respectively. The pore size and porosity of these scaffolds were suitable for bone regeneration. Cytocompatibility of composite scaffolds was proven via favorable interactions with MC3T3-E1 cells. The addition of hydroxyapatite into CD-based polyurethane scaffolds improved cell attachment, well-spread morphology, and higher proliferation. The hydroxyapatite-polyurethane scaffolds have the potential to be applied in bone repair and regeneration.

Preparation and Characterization of the Porous Hydroxyapatite/Silk Fibroin Composite Scaffolds with Interconnected Ducts

2008 ◽  
Vol 368-372 ◽  
pp. 1190-1193 ◽  
Author(s):  
Jing Wang ◽  
Mu Qin Li ◽  
Xiang Cai Meng ◽  
Guang Wu Wen
Keyword(s):  
Compressive Strength ◽  
Silk Fibroin ◽  
Freeze Drying ◽  
Composite Scaffold ◽  
Drying Process ◽  
X Ray Diffraction ◽  
Composite Scaffolds ◽  
Porous Hydroxyapatite ◽  
X Ray

Porous hydroxyapatite (HA) bioceramic matrix with interconnected ducts was obtained using a porogen burnout technique at 1200°C. The HA/silk fibroin (SF) composite scaffolds were developed with the SF sponges formed inside the pores and ducts of the bioceramics by first introducing HA/SF slurries into the pores and ducts followed by a freeze-drying process. Phase components and morphology of materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Porosity was measured by Archimedean method. Compressive strength was also measured. The simulated body fluids (SBF) experiments were conducted to evaluate bioactivity. The results show that hydroxyapatite is the main phase compositions after sintering at 1200°C. The porosity of composite scaffolds reaches 70%~80%. The sizes of pores and ducts of HA matrix range from 150μm to 400μm and the pore sizes of SF sponges formed inside the macroporous structure of bioceramics are approximately 100μm,a structure favorable for bone tissue in-growth. The compressive strength of the composite scaffolds is greatly improved in comparison with that of HA matrix. In the SBF tests, a layer of randomly oriented apatite crystals form on the scaffold surface after sample immersion in SBF. The cell culture experiments show that the osteoblast cells are attached and proliferated on the surface of the composite scaffold, which suggest good bioactivity and cellular compatibility of the composite material.

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.

Tailoring the in vitro characteristics of poly(vinyl alcohol)-nanohydroxyapatite composite scaffolds for bone tissue engineering

2016 ◽  
Vol 36 (8) ◽  
pp. 771-784 ◽  
Author(s):  
Tejinder Kaur ◽  
Arunachalam Thirugnanam ◽  
Krishna Pramanik
Keyword(s):  
Mechanical Strength ◽  
Vinyl Alcohol ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Poly Vinyl Alcohol ◽  
Apatite Formation ◽  
Composite Scaffolds ◽  
Alizarin Red ◽  
Casting Technique

Abstract Poly(vinyl alcohol) reinforced with nanohydroxyapatite (PVA-nHA) composite scaffolds were developed by varying the nHA (1%, 2%, 3%, 4%, and 5%, w/v) composition in the PVA matrix by solvent casting technique. The developed composite scaffolds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and contact angle measurement. The stability of the composite scaffolds in physiological environment was evaluated by swelling and degradation studies. Further, these composite scaffolds were tested for in vitro bioactivity, hemolysis, biocompatibility, and mechanical strength. SEM micrographs showed a homogenous distribution of nHA (3%, w/v) in the PVA matrix. XRD and ATR-FTIR analysis confirmed no phase contamination and the existence of the chemical bond between PVA-nHA at approximately 2474 cm-1. PVA-nHA composite scaffolds with 3% (w/v) concentration of nHA showed nominal swelling and degradation behavior with good mechanical strength. The mechanical strength and degradation properties of the scaffold above 3% (w/v) of nHA was found to deteriorate, which is due to the agglomeration of nHA. The in vitro bioactivity and hemolysis studies showed improved apatite formation and hemocompatibility of the developed scaffolds. In vitro cell adhesion, proliferation, alkaline phosphatase activity, and Alizarin red S staining confirmed the biocompatibility of the composite scaffolds.

Effect of P2O5 on the Properties of Alite-Calcium Strontium Sulphoaluminate Cement

2011 ◽  
Vol 306-307 ◽  
pp. 961-965
Author(s):  
Chao Nan Yin ◽  
Ling Chao Lu ◽  
Shou De Wang
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Heat Evolution ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sulphoaluminate Cement ◽  
Suitable Amount ◽  
Acceleration Period ◽  
Scanning Electron

The influence of P2O5on the properties of alite-calcium strontium sulphoaluminate cement was researched by means of X-ray diffraction, scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) and petrographic analysis. The results show that the optimal content of P2O5is 0.3% and the compressive strength of the cement at 1, 3, 28d are 27.0, 59.1, 110.9MPa when the calcining temperature is 1350°C. P2O5mainly exists in the belite and a suitable amount of P2O5can promote the formation of C1.5Sr2.5A3and alite. When the content of P2O5is higher than 0.3%, the formation of C1.5Sr2.5A3and alite can be hindered. P2O5can enhance the hydration heat evolution rate in the acceleration period and the hydrate heat of cement containing P2O5increases slightly.

An Experiment for Effects of Different Additives on Strength of Sediment Solidification

2013 ◽  
Vol 357-360 ◽  
pp. 1235-1240 ◽  
Author(s):  
Guan Huan Chen ◽  
Jian Zhong Zhu
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Unconfined Compressive Strength ◽  
Scan Electron Microscope ◽  
Dredged Sediment ◽  
Comparative Tests ◽  
Cement Based Materials

The solidification method is a significant and resultful method for the disposal of dredged sediment. Solidified agents can be employed to improve the unconfined compressive strength (UCS) of sediment solidification. In this work, considering of economy and practicability, three kinds of optimized compound additives are selected and investigated on the effects of UCS of sediment solidification. 7d., 14d.and 28d. solidification stadium were taken to test the UCS of samples. Results showed that the activator had the best effect on increasing the UCS. The comparative tests also indicated that adding any kind of additive into the cement-based materials could improve the UCS of sediment solidification, the highest value of UCS was 11.02MPa (SCAHR). By means of scan electron microscope (SEM) technology, the microstructure images of the raw sample and solidified sample were obtained, which help to understand the development of UCS of the solidified sediments.

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