Papers by Keyword: β-Tricalcium Phosphate

Abstract: The aim of this study was to compare the difference in bone formation between hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) ceramics with similar porous structure. Porous HAp and β-TCP ceramics (total porosity: ~70%) with highly-interconnected structure were fabricated by firing calcium-phosphate fiber mixed with carbon beads (~150 μm). The size of highly-interconnected pores was measured by mercury intrusion technique. Each sample (ϕ4 mm × 8 mm) was implanted into the tibial bone defect (ϕ4.2 mm × 8 mm) of a pig (2 years old, male). After 6 weeks of implantation, undecalcified section was prepared and stained with hematoxylin and eosin (HE) stain. New bone area and remaining material area were evaluated.Interconnection sizes of HAp and β-TCP ceramics were 23.0 µm and 15.6 µm, respectively. New bone area of β-TCP ceramics was significantly higher compared to HAp ceramics. Remaining material ratio was 77.1 ± 3.3% for β-TCP ceramics whereas HAp ceramics remained stable. Bone formation in HAp ceramics was inhomogeneous compared to β-TCP ceramics in HE stained section. Although the β-TCP ceramics interconnection size was smaller, higher resorption may have played a positive role in homogeneous bone formation. According to the result of the study, it is suggested that highly-interconnected porous ceramics made by β-TCP could be a suitable material for bone regeneration.

Abstract: Fish processing by-products, such as fish bone waste is usually considered as waste and will be disposed without fully utilizing it. Indeed, this by-product can serve as a cheap bio-resource for the production of high-value product, for instance, as an inexpensive source of calcium phosphate material. In this research, Lutjanus johnii and Lutjanus sebae bones were subjected to thermal calcination to yield different calcium phosphate products. XRD, FTIR and HRTEM-SAED results revealed that biphasic HAp/β-TCP mixture was obtained by heat treatment of Lutjanus johnii bone while a single-phase HAp was prepared from Lutjanus sebae bone. In addition, it was shown that both Lutjanus johnii and Lutjanus sebae bones had a merit in producing B-type carbonated composition that is advantageous for biomedical application. EDX result further corroborated the existence of inorganic elements such as Mg, Na and Sr. With their unique composition, the calcined products deriving from Lutjanus johnii and Lutjanus sebae bones can be further employed to form bioceramic scaffolds for bone engineering applications.

Abstract: The aim of this study is to investigate the effect of soaking time on the compositional and morphological changes of dicalcium phosphate dihydrate (DCPD)-coated β-tricalcium phosphate (β-TCP) bioceramic. In this study, an established method from our research group was used to prepare the β-TCP bioceramic pellets and expose them to acidic calcium phosphate solution for 2, 4, 6, and 8 hours to obtain DCPD coated layer on β-TCP pellets through dissolution-precipitation reaction. Characterization methods such as x-ray diffraction analysis (XRD) and scanning electron microscope (SEM) were carried out on the specimen. XRD and SEM analyses indicated that the peak intensity and density of DCPD crystal precipitated on the pellets were increased when increasing the soaking time. Therefore, it was confirmed that the DCPD coated layer formation on the β-TCP pellet surfaces depended on the exposure time to acidic calcium phosphate solution.

Abstract: Reconstruction of bone defect due to a disease or a trauma can use autograft, allograft, xenograft or synthetic bonegraft as the bone substitute material. However, in particular cases, it is required a material that has a specific resorption characteristic, beside owning excellent bioactive properties, such as β-tricalcium phosphate (β-TCP). In this study, we report the synthesis of β-TCP particles with mesopores structure by using chitosan and aloe vera as templates. A solution of (NH₄)₂HPO₄ was added dropwise into solution of Ca(NO₃)₂·4H₂O and the template at 85°C for 2 hours, and subsequently aged for 3 hours. Then, the formed precipitate was washed and centrifuged repeatedly prior to drying at 80°C for 24 hours. Finally, the dried precipitate was calcined at 900°C for 1 hour to obtain β-TCP powder. Phase identification and mesopores structure were analyzed using X-ray diffraction (XRD), while the existence of functional groups was identified by Fourier-transform infrared (FTIR) spectroscopy. Microstructure and particle size distribution were characterized by scanning electron microscopy (SEM) and particle size analyzer (PSA), respectively. XRD analysis shows that β-TCP is dominant with the presence of small amount of impurities. Furthermore, low angle peak in XRD analysis indicates the formation of mesopores structure. From the SEM and PSA analysis, the morphology of both TCP-K and TCP-KA particles showed more large agglomerates and more heterogeneous particle size distribution due to the addition of the biopolymers in the synthesis of β-TCP.

Abstract: Porous β-tricalcium phosphate (β-TCP) foam granular cements was obtained by exposing different range size of β-TCP foam granular (300-600 μm and 600-1000 μm) with 1.4 mol/L of saturated acidic calcium phosphate solution at various setting reaction times. It was found that large amount of dicalcium phosphate dihydrate (DCPD) was formed in the set specimens after exposing small size of β-TCP foam granular with saturated acidic calcium phosphate solution. Morphological observation shows that the bridging of DCPD platelet-like crystals between β-TCP foam granular surfaces were detected as early as 10 mins after exposing 300-600 μm of β-TCP foam granules with saturated acidic calcium phosphate solution. In fact, the amount of DCPD formed in the specimens obtained from small size of β-TCP foam granules is higher than large sized foam granules. These results demonstrated that small size of β-TCP foam granules induced fast setting reaction of β-TCP foam granules to produce porous β-TCP foam granular cements.

Abstract: A nanosized magnesium substituted beta-tricalcium phosphate (Mg:β-TCP) was synthesized by an aqueous precipitation method, at room temperature, in one single step. In the present study, the novel and stable Mg:β-TCP resulted in a crystalline and spherical nanoparticles (diameter of approximately 20 nm) with mesoporous structures and a high specific surface area (about 574 m²/g). These special characteristics make this novel crystalline mesoporous Mg: β-TCP nanoparticles ideal candidates for drug delivery system and a promising non-viral vector for gene therapy.

Abstract: In this present work, an original 3D bioprinting method has been developed by modifying an exceptional 3D printer. Using a composite material, bioprinting was carried out to create the ideal scaffold material to contribute regeneration of the certain amount of tissue types in humans. After bypassing the extruder and heating system of the 3D printer, instead of using solid filaments, polymer-ceramic composite was dissolved using an organic agent and bioprinting was conducted. During the bioprinting, dissolving agent was evaporated quickly and solidification process was completed. Despite of the traditional 3D printing, which benefits from the glass transition temperature of the materials, regardless of the temperature, rapid prototyping technology has been merged with controlled flow rate of the composite solution and evaporation of the solvents were adjusted meticulously for proper solidification and layer by layer bioprinting of the scaffolds.

Abstract: The zinc (Zn) substituted hydroxyapatite were synthesized using a chemical precipitation method. The chemical precursors were prepared from di-ammonium hydrogen orthophosphate, calcium oxide (CaO) derived from chicken eggshell and zinc nitrate (Zn(NO₃)₂). The Zn(NO₃)₂ contents in the prepared samples were varied from 1 to 25 %wt of CaO. The Zn substituted hydroxyapatite were heated at the various temperatures from 200 to 1300 °C in the furnace with an incremental temperature of 100 °C. The crystal structure, function group and morphology of sample were analyzed by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM), respectively. The results show that the hydroxyapatite doped Zn was a hydroxyapatite phase as well as pure hydroxyapatite. The crystalline size of sample decreased with increasing the Zn content. And, the crystallinity of hydroxyapatite phase was increased following by increasing heat treatment temperature. However, the amount of Zn has the effect on phase transformation of hydroxyapatite phase after heat treatment. Zn concentration accelerates hydroxyapatite transforms to β-tricalcium phosphate phase.

Abstract: The injection behavior of β-tricalcium phosphate (Ca₃(PO₄)₂: β-TCP) based cement was improved through the granulation of β-TCP. Dense β-TCP granules were obtained by heat treatment after spray drying. The fraction of injected paste under loaded mass in the syringe was measured while varying the granular fraction of β-TCP and the heat treatment temperature. The increase in granular fraction and heating treatment temperature reduced the amount of setting agent required to wet the granules. As the surplus setting agent could be used in the powdery β-TCP to reduce the viscosity, improved injectability was achieved. Inappropriate setting by the excessive setting agent was not observed and the cements tested exhibited normal setting behavior by forming a brushite phase.

Abstract: The bone remodeling process plays an essential part of the calcium homeostatic system and provides a crucial mechanism for adaptation to physical stress, the repair of damaged bone and the removal of old bone. We reported previously that sustainable release of simvastatin (SIM) from poly (lactic-co-glycolic acid) (PLGA) formulations could induce bone formation. The aim of this study was to develop a simvastatin-releasing PLGA/β-TCP composite microspheres (β-SPMs) sintered scaffolds (β-SPMSS) as a synthetic bone substitute, and investigate the influence of the dissolution medium on the drug release capabilities of these device based on a physicochemical model for bone remodeling. X-ray diffraction analysis (XRD) results showed β-TCP and SIM could be encapsulated into the PLGA microspheres. The β-SPMs and the β-SPMSS were able to produce sustained release of SIM for 1 month in simulated body fluid (SBF), whereas these composites released SIM for 10 days in acetate buffer (AB). The release rate of SIM from β-SPMSS in AB was faster than in SBF, indicating that the β-SPMSS could control drug release with bone cells activity response, and could be used as a scaffold in bone remodeling area. These results suggested that the β-SPMSS could release SIM sustainably, with bone cells activity response, and could be used as a scaffold in bone remodeling area.