Freeze casting of porous hydroxyapatite scaffolds. I. Processing and general microstructure

2008 ◽  
Vol 86B (1) ◽  
pp. 125-135 ◽  
Author(s):  
Qiang Fu ◽  
Mohamed N. Rahaman ◽  
Fatih Dogan ◽  
B. Sonny Bal
Materials ◽  
2017 ◽  
Vol 10 (4) ◽  
pp. 367 ◽  
Author(s):  
Hyun Lee ◽  
Tae-Sik Jang ◽  
Juha Song ◽  
Hyoun-Ee Kim ◽  
Hyun-Do Jung

2019 ◽  
Vol 8 (2) ◽  
pp. 256-264 ◽  
Author(s):  
Zhen Wu ◽  
Zhengren Zhou ◽  
Youliang Hong

2007 ◽  
Vol 61 (11-12) ◽  
pp. 2270-2273 ◽  
Author(s):  
Eun-Jung Lee ◽  
Young-Hag Koh ◽  
Byung-Ho Yoon ◽  
Hyoun-Ee Kim ◽  
Hae-Won Kim

Author(s):  
S. Deville ◽  
P. Miranda ◽  
E. Saiz ◽  
A. P. Tomsia

This work describes two novel techniques for the fabrication of porous hydroxyapatite scaffolds for calcified tissue engineering; robocasting and freeze casting. These techniques allow the fabrication of materials with complex porosity. Both are based on the preparation of concentrated ceramic suspensions with suitable properties for the process. In robocasting, the computer-guided deposition of the suspensions is used to build porous materials with designed three dimensional (3-D) geometries and microstructures. Freeze casting uses ice crystals as a template to form porous lamellar ceramic materials. Preliminary results on the compressive strengths of the materials are also reported.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2864
Author(s):  
Eva Kröll ◽  
Miriana Vadalà ◽  
Juliana Schell ◽  
Simon Stegemann ◽  
Jochen Ballof ◽  
...  

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.


2021 ◽  
Author(s):  
Md Towhidul Islam ◽  
Laura Macri-Pellizzeri ◽  
Virginie Sottile ◽  
Ifty Ahmed

This paper reports on the rapid development of porous hydroxyapatite (HA) microspheres with large external pores and fully interconnected porosity.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wendy E. Brown ◽  
Brian J. Huang ◽  
Jerry C. Hu ◽  
Kyriacos A. Athanasiou

AbstractDespite the prevalence of large (>5 cm2) articular cartilage defects involving underlying bone, current tissue-engineered therapies only address small defects. Tissue-engineered, anatomically shaped, native-like implants may address the need for off-the-shelf, tissue-repairing therapies for large cartilage lesions. This study fabricated an osteochondral construct of translationally relevant geometry with robust functional properties. Scaffold-free, self-assembled neocartilage served as the chondral phase, and porous hydroxyapatite served as the osseous phase of the osteochondral constructs. Constructs in the shape and size of an ovine femoral condyle (31 × 14 mm) were assembled at day 4 (early) or day 10 (late) of neocartilage maturation. Early osteochondral assembly increased the interfacial interdigitation depth by 244%, interdigitation frequency by 438%, interfacial shear modulus by 243-fold, and ultimate interfacial shear strength by 4.9-fold, compared to late assembly. Toward the development of a bioprosthesis for the repair of cartilage lesions encompassing up to an entire condylar surface, this study generated a large, anatomically shaped osteochondral construct with robust interfacial mechanical properties and native-like neocartilage interdigitation.


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