1. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; 2. Beijing Allgens Medical Science and Technology Co., Ltd., Beijing 100085, China; 3. Institute of Natural Science and Atomic-scale Surface Science Research Center, Yonsei University, Seoul 120-749, Korea; 4. Department of Orthopedics, Renji Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
Dense hydroxyapatite (HA) ceramic is a promising material for hard tissue repair due to its unique physical properties and biologic properties. However, the brittleness and low compressive strength of traditional HA ceramics limited their applications, because previous sintering methods produced HA ceramics with crystal sizes greater than nanometer range. In this study, nano-sized HA powder was employed to fabricate dense nanocrystal HA ceramic by high pressure molding, and followed by a three-step sintering process. The phase composition, microstructure, crystal dimension and crystal shape of the sintered ceramic were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties of the HA ceramic were tested, and cytocompatibility was evaluated. The phase of the sintered ceramic was pure HA, and the crystal size was about 200 nm. The compressive strength and elastic modulus of the HA ceramic were comparable to human cortical bone, especially the good fatigue strength overcame brittleness of traditional sintered HA ceramics. Cell attachment experiment also demonstrated that the ceramics had a good cytocompatibility.
Guo X, Xiao P, Liu J, . Fabrication of nanostructured hydroxyapatite via hydrothermal synthesis and spark plasma sintering. Journal of the American Ceramic Society , 2005, 88(4): 1026-1029
2
Chen I W, Wang X H. Sintering dense nanocrystalline ceramics without final-stage grain growth. Nature , 2000, 404(6774): 168-171
3
Zhao H S, Wang G C, Hu S P, . In vitro biomimetic construction of hydroxyapatite-porcine acellular dermal matrix composite scaffold for MC3T3-E1 preosteoblast culture. Tissue Engineering Part A , 2011, 17(5-6): 765-776
4
Sadighpour L, Geramipanah F, Raeesi B. In vitro mechanical tests for modern dental ceramics. Journal of Dentistry of Tehran University of Medical Sciences , 2006, 3(3): 143-152
5
Nakahira A, Tamai M, Aritani H, . Biocompatibility of dense hydroxyapatite prepared using an SPS process. Journal of Biomedical Materials Research , 2002, 62(4): 550-557
6
Meyers M A, Chen P-Y, Lin A Y-M, . Biological materials: Structure and mechanical properties. Progress in Materials Science , 2008, 53(1): 1-206
7
Gu Y W, Khor K A, Cheang P. Bone-like apatite layer formation on hydroxyapatite prepared by spark plasma sintering (SPS). Biomaterials , 2004, 25(18): 4127-4134
8
Joschek S, Nies B, Krotz R, . Chemical and physicochemical characterization of porous hydroxyapatite ceramics made of natural bone. Biomaterials , 2000, 21(16): 1645-1658
9
Kusmanto F, Walker G, Gan Q, . Development of composite tissue scaffolds containing naturally sourced mircoporous hydroxyapatite. Chemical Engineering Journal , 2008, 139(2): 398-407
10
Deville S, Saiz E, Tomsia A P. Freeze casting of hydroxyapatite scaffolds for bone tissue engineering. Biomaterials , 2006, 27(32): 5480-5489
11
Wen S, Van D. Grain boundary in some nano-materials. Ceramics International , 1995, 21(2): 109-112
12
Suchanek W, Yashima M, Kakihana M, . Hydroxyapatite ceramics with selected sintering additives. Biomaterials , 1997, 18(13): 923-933
13
Aronov D, Karlov A, Rosenman G. Hydroxyapatite nanoceramics: Basic physical properties and biointerface modification. Journal of the European Ceramic Society , 2007, 27(13-15): 4181-4186
14
Yoon B H, Park C S, Kim H E, . In-situ fabrication of porous hydroxyapatite (HA) scaffolds with dense shells by freezing HA/camphene slurry. Materials Letters , 2008, 62(10-11): 1700-1703
15
Omori M, Onoki T, Hashida T, . Low temperature synthesis of hydroxyapatite from CaHPO4·H2O and Ca(OH)2 based on effect of the spark plasma system (SPS). Ceramics International , 2006, 32(6): 617-621
16
Miao X, Tan D M, Li J, . Mechanical and biological properties of hydroxyapatite/tricalcium phosphate scaffolds coated with poly(lactic-co-glycolic acid). Acta Biomaterialia , 2008, 4(3): 638-645
17
He L H, Standard O C, Huang T T Y, . Mechanical behaviour of porous hydroxyapatite. Acta Biomaterialia , 2008, 4(3): 577-586
18
Werner J, Linner-Krcmar B, Friess W, . Mechanical properties and in vitro cell compatibility of hydroxyapatite ceramics with graded pore structure. Biomaterials , 2002, 23(21): 4285-4294
19
Chen B, Zhang T, Zhang J, . Microstructure and mechanical properties of hydroxyapatite obtained by gel-casting process. Ceramics International , 2008, 34(2): 359-364
20
Kumar R, Prakash K H, Cheang P, . Microstructure and mechanical properties of spark plasma sintered zirconia-hydroxyapatite nano-composite powders. Acta Materialia , 2005, 53(8): 2327-2335
21
Fellah B H, Gauthier O, Weiss P, . Osteogenicity of biphasic calcium phosphate ceramics and bone autograft in a goat model. Biomaterials , 2008, 29(9): 1177-1188
22
Kalita S J, Bhatt H A. Nanocrystalline hydroxyapatite doped with magnesium and zinc: Synthesis and characterization. Materials Science and Engineering C , 2007, 27(4): 837-848
23
Chen Q Z, Wong C T, Lu W W, . Strengthening mechanisms of bone bonding to crystalline hydroxyapatite in vivo. Biomaterials , 2004, 25(18): 4243-4254
