Reconstruction of resected mandibles using a hydroxyapatite veterinary bone graft

Kobayashi

J Biomedical Materials Res

et al. 2009

Bone ingrowth enhancement by the surface induced charges of the electrically polarized hydroxyapatite (HA)/beta-tricalcium phosphate (beta-TCP) ceramics was histologically investigated to clarify the early stage events of ossification. The HA/beta-TCP specimens with a relatively low porosity of 45% for bone ingrowth were polarized in a dc electric field at 400 degrees C for 1 h. The large preserved charges of 8 muC cm(-2) significantly promoted the bone ingrowth process of the porous ceramics implanted in femoral diaphyses of New Zealand white rabbits. The bone formation in the pores of the polarized HA/beta-TCP specimens was observed within 1 week after surgery. The bone occupancy of the polarized HA/beta-TCP pores reached more than 90% at as early as 2 weeks and significantly higher than that of the nonpolarized. The electrical polarization was proved to be effective for bone penetration improvement of low porosity ceramics. The electrically polarized HA/beta-TCP bone grafts with a lower porosity and a higher mechanical strength combined high osteoconductivity generated by the induced surface charges.

Section: Resultsmentioning

confidence: 99%

Electrostatic surface charge acceleration of bone ingrowth of porous hydroxyapatite/β‐tricalcium phosphate ceramics

Kobayashi

J Biomedical Materials Res

et al. 2009

“…Hydroxyapatite (HA) ceramics have been used extensively as substitutes in bone grafts32–35, because the crystalline phase of natural bone is HA. However, recent clinical evidence has revealed that the pores in conventional HA bone substitute are not replaced with new bone for a substantial period, probably due to the limited interconnection of the pores36, 37. However, the developed IP‐CHA, with a fully interconnected porous structure, overcame these disadvantages and showed excellent bone conductivity.…”

Section: Discussionmentioning

confidence: 99%

Mechanistic Insights into CN Coupling Catalyzed by 1,3‐Diketonate‐Ligated Copper: Unprecedented Activation of Aryl Iodide

et al. 2010

The mechanism of CN cross‐coupling reactions catalyzed by CuI associated to a 1,3‐diketonate ligand L− is investigated by cyclic voltammetry and 1H NMR spectroscopy up to the formation of the key anionic complex [LCuINHCy]−. Its reaction with PhI, shown experimentally, proceeds via an unusual iodide activation, and the transition states are investigated by density functional calculations.

“…HAp [5,6,7] is broadly used, as well as bioabsorbable polymer [8]. HAp is used as an artificial bone to make up for bone defect sites due to its strength, bone conduction ability, and their similarity to the mineral component of bone [9,10]. Unidirectional porous HAp (UDPHAp) [11] has been developed for orthopedic applications as a bone void filler with 75% porosity and penetrating oval pores that range in diameter from 100 to 300 µm.…”

Section: Introductionmentioning

confidence: 99%

Physico-Chemical, In Vitro, and In Vivo Evaluation of a 3D Unidirectional Porous Hydroxyapatite Scaffold for Bone Regeneration

et al. 2017

Abstract:The unidirectional porous hydroxyapatite HAp (UDPHAp) is a scaffold with continuous communicated pore structure in the axial direction. We evaluated and compared the ability of the UDPHAp as a three-dimensional (3D) bone tissue engineering scaffold to the interconnected calcium porous HAp ceramic (IP-CHA). To achieve this, we evaluated in vitro the compressive strength, controlled rhBMP-2 release behavior, adherent cell morphology, cell adhesion manner, and cell attachment of UDPHAp. As a further in vivo experiment, UDPHAp and IP-CHA with rhBMP-2 were transplanted into mouse calvarial defects to evaluate their bone-forming ability. The Results demonstrated that the maximum compressive strengths of the UDPHAp was 7.89 ± 1.23 MPa and higher than that of IP-CHA (1.92 ± 0.53 MPa) (p = 0.0039). However, the breaking energies were similar (8.99 ± 2.72 vs. 13.95 ± 5.69 mJ, p = 0.055). The UDPHAp released rhBMP-2 more gradually in vivo. Cells on the UDPHAp adhered tightly to the surface, which had grown deeply into the scaffolds. A significant increase in cell number on the UDPHAp was observed compared to the IP-CHA on day 8 (102,479 ± 34,391 vs. 32,372 ± 29,061 estimated cells per scaffold, p = 0.0495). In a mouse calvarial defect model, the percentages of new bone area (mature bone + trabecular bone) in the 2x field were 2.514% ± 1.224% for the IP-CHA group and 7.045% ± 2.055% for the UDPHAp group, and the percentage was significantly higher in the UDPHAp group (p = 0.0209). While maintaining the same strength as the IP-CHA, the UDPHAp with 84% porosity showed a high cell number, high cell invasiveness, and excellent bone formation. We believe the UDPHAp is an excellent material that can be applied to bone regenerative medicine.