Papers by Keyword: Tricalcium Phosphate

Abstract: Hydroxyapatite (HAp) derived from bovine bone waste is extensively explored for biomedical applications due to its close chemical resemblance to natural bone. However, its intrinsic brittleness and thermal instability remain critical limitations. In this study, HAp–titanium (5–20 wt.%) composites were synthesized using the self-propagating high temperature synthesis (SHS) method within the range of 750–950°C. X-ray diffraction (XRD) analysis confirmed the in-situ formation of CaTiO₃ at 850°C, which significantly improved densification and microstructural consolidation. At higher temperature (950°C), partial decomposition of HAp to tricalcium phosphate (TCP) was observed, consistent with phase evolution trends reported in the literature. Scanning electron microscopy (SEM) revealed distinct grain morphology transitions across the processing window, supporting the identified phase transformations. The results demonstrate a clear correlation between phase evolution and microstructural development: CaTiO₃ formation enhances densification, while TCP contributes to favorable bioresorbability. These findings highlight the tunability of SHS-derived HAp–Ti composites and their promising potential as bone substitute materials with adjustable bioactivity.

Abstract: In this study, we used Stereolithography to develop tricalcium phosphate-based scaffolds. The feedstock for the process consisted of a UV-curable resin, synthetic tricalcium phosphate, and silicon oxide. The viscosity and curability of the resins are carefully controlled to enable the fabrication of complex-shaped scaffolds. Following stereolithography, the ceramic-resin scaffolds were heat treated. The first step was debinding process followed by a sintering step. The resulting sintered samples underwent microstructure, chemical, and mechanical analysis to assess their properties. The optimized samples were then subjected to biodegradability and cytotoxicity tests to evaluate their suitability for use as tissue engineering scaffolds.

Abstract: Calcium-silicate cement mainly based on dicalcium-silicate (C₂S) was synthesized by the mean of solid state reaction. Beta-C₃P was added to C₂S to obtain C₂S-C₃P. Zinc oxide and bismuth oxide was incorporated to prepare radioc cement. In this work, the bioactivity and the mechanical strength of the synthesized cement were investigated. The in vitro test was carried out by immersion of cement pastilles in the artificial saliva in different periods from 4 hours to 30 days. Whereas the mechanical strength of some samples was operated at 28 and 72 days. The specimens are characterized by X-ray diffraction , Infrared spectroscopy and scanning electron microscopy. The finding results indicated that hydroxyapatite may appear after 24 hours of soaking; it was also shown that the presence of C₃P with a small amount of the cement can enhance the bioactivity and develop more resistance strength of cement. Moreover, the addition of zinc oxide and bismuth oxide increase the radiopacity of the cement. However, the mechanical strength enhances with the incorporation of the zinc oxide while decrease with bismuth oxide. It was concluded then that there is possibility of combining addition of C₃P (10%) and an agent radiopacifiers ZnO/Bi₂O₃ (15%) with small amounts on C₂S to obtain a cement with excellent bioactivity, good mechanical strength and significante radiopacity that makes this material a great candidate as a biomaterial for biomedical use.

Abstract: Porous Tricalcium Phosphate (TCP) is recognized as a good biomaterial having excellent biocompatibility, biodegrability and bioresorbability. Some of the techniques to produce porous β-TCP, are replica technique (polymeric sponge method), sacrificial template method and direct forming method, however, these methods are complicated and can be costly. In this study, solid state sintering was adopted to form porous TCP as a new approach to overcome these problems. TCP bioceramic was prepared by mixing calcium hydrogen phosphate dihydrate and calcium carbonate. The powders were pressed into pellet form with four different pressures; 10, 20, 30 and 40 MPa. Then, the pellets were sintered at 1100°C to 1400°C and subsequently characterized by X-ray diffraction (XRD), density and porosity measurement, diametral tensile strength test (DTS) and scanning electron microscopy (SEM) evaluation. β-TCP phase was maintained at 1100°C and 1200°C whilst α-TCP phase had formed as second phase above 1300°C. The highest apparent porosity (60.93%) was obtained at 10 MPa and 1100°C sintering temperature, with the density of 1.12 g/cm³. The DTS values were in the range of 0.31 to 3.78 MPa in with lower DTS values were obtained at low compaction pressure and sintering temperature. Interconnected pores with high level porosity were observed at the fracture surfaces of the sintered pellets. Intraporosity was also observed. In conclusion, TCP bioceramics with interconnected pores were produced via solid state reaction; however, more work is required to improve the level of porosity.

Abstract: Hydroxyapatite (HA) is produced from animal sources like bovine-sheep bones and from human sources with different techniques. Nowadays, it is very crucial utilizing higher valued products from waste materials. Especially, fish bones become major sources for HA production. We have used the waste bone of "Atlantic Bonito" (Sarda sarda), which is a very characteristic fish species. It lives through Atlantic Ocean, the Mediterranean Sea and up to the Black Sea, where it is regarded as a point commercial fish. In this study, the fish bones of "Atlantic Bonito" (Sarda sarda) were collected and cleaned from flesh and greasy parts with distilled boiling water. It was washed again with distilled water, dried and calcinated for 4 hours at 850 °C. Afterwards the material was analysed by X-ray diffraction (XRD) and scanning electron microscope (SEM). XRD analysis revealed the obtained bioceramic material is made of 66.7% HA and 33.3% TCP. The fish bone of “Atlantic Bonito” (Sarda sarda) can be easily trandformed to bioceramic material and it can be used in applications where partly resorbable and economic biomaterials with low carbon footprint needed.

Abstract: The development of the calcium phosphate ceramics (CPC) using natural materials such as coral, eggshell, bovine bone, fish bone etc., from Indian origin have been reviewed. The CPCs from natural sources has the benefit that they inherit some of the properties of the raw materials such as the macro-and micro-pore structure, optimal composition, similar morphology etc., as well as the advantage of unlimited world wide availability at a very low raw material cost. Hydroxyapatite (HA), carbonated HA and fluorapatite from natural coral genus "Goniopora” has been obtained. Growth factor loaded coralline HA has been found to significantly accelerate early-stage bone formation in in vivo rabbit model studies. Sea shells have been tested as the source of calcium for electrochemical deposition of HA on titanium implants. Deproteinized hydroxyl carbonate apatite phase was formed by heating adult bovine tibia at 500o C. As eggshell could be easily procured, a great deal of effort has been made to utilize this resource as value-added CPCs including nanocrystalline HA (OHA), calcium deficient HA (CDHA), TCP, tetracalcium phosphate (TTCP) etc., which are the most widely used bone substitutes. Also OHA showed higher antibiotic delivery and more controlled protein release profile compared to the synthetic apatites. Eggshell derived CPCs were also found to have minor amount of Mg, Sr, Si and Na ions inherited from the eggshell. As these ions are crucial for bio-mineralization of eggshell, the influence of multi-ions substituted CPCs as a potential bioceramic for bone regenerative applications has been emphasised.

Abstract: In the case of patients suffering from medial compartment osteoarthritis of the knee, a high tibial osteotomy is the preferred treatment for preserving the knee articulation and correcting the knee biomechanical axis. Nowadays, the open wedge high tibial osteotomy is the preferred surgical technique for treating patient with varus knee angulation. The procedure consists in creating a medial gap in the proximal tibial metaphysis that is filled with autologus bone graft or bone substitutes. Synthetic bone substitutes made by bioceramics like hydroxyapatite or tricalcium phosphate are becoming more popular. Tricalcium phosphate (TCP) used as a bone substitute has shown to have osteoconductive properties and it is resorbable. We describe our experience in Orthopaedics III Department of the Clinical Emergency Hospital Bucharest, where we treated a total of 26 patients suffering from medial compartment osteoarthritis of the knee with high tibial open wedge osteotomy, between 2011 and 2015. TCP wedge implants were successfully used as bone substitutes for the tibial medial osteotomy in conjunction with a proximal tibia plate and screws. Open wedge high tibia osteotomy used for correcting the biomechanical axis of the lower limb is a safe surgical procedure that preserves the anatomical knee joint.

Abstract: Scaffolds with mechanical properties that mimic the tissue to be restored are critical to maintain the morphology and function of a scaffold after implantation and during tissue regeneration. Silk fibroin (SF), a protein from the Bombyx mori silk worm cocoon, is currently employed in the biomedical field and tissue engineering. The objective of this study was to construct three-dimensional porous silk fibroin/alpha tricalcium phosphate scaffolds for bone tissue engineering application. The scaffolds were fabricated using a solvent casting and salt leaching technique. The hybrid strain of degummed Thai silk fibroin, Nangnoi Srisaket 1 x Mor, was dissolved in hexafluoroisopropanol at 16% (w/v). Alpha tricalcium phosphate (α-TCP) was incorporated to produce 4, 8, 12, and 16 wt% solution and sucrose (particle size 250-450 μm; sucrose/silk fibroin = 8.5/1 w/w) was used as a porogen. The microstructure and pore size, calcium and phosphorus contents, and compressive modulus were evaluated. The scanning electron microscope images revealed the microstructure of scaffolds to be square shaped with continuous interconnected pores. The average pore size of the scaffolds was 265.70 + 67.45 μm. The scaffolds containing 8% (w/w) α-TCP exhibited the highest compressive modulus (64.84 + 16.65 kPa) and the highest calcium content. The results suggested that the scaffolds containing α-TCP may be a potential candidate for application in bone tissue engineering applications.

Abstract: The use of bioceramics for orthopedic and dental application nowadays increases due to their good biocompatibility and osteoconductivity. β-tricalcium phosphate (β-TCP) bioceramics which have excellent biodegradation properties have been in use quite extensively. This paper reports the synthesis of β-TCP bioceramics from precipitation of calcined chicken’s eggshells and phosphoric acid (H₃PO₄). Chicken’s eggshells were calcined at 1000°C for 5 hours to form calcium oxide (CaO). Various molarities of CaO and H₃PO₄, between 0.4 M and 2.4 M, were used in this experiment with the Ca:P ratio was kept 1.5:1. After precipitation, the samples were filtered and heated at a sintering temperature of 1000°C for 7 hours. The X Ray Diffraction profile showed that the patterns were affected by the molarity. The patterns of 1.2 M CaO/0.8 M H₃PO₄ samples showed pure β-TCP, while those of 0.6 M CaO/0.4 M H₃PO₄ and 2.4 M CaO/1.6 M H₃PO₄ samples showed the presence of hydroxyapatite and octa calcium phosphate. These findings were also supported by Fourier transform infrared spectra. The purity of the samples shown by the atomic absorption spectroscopy resulted in Ca:P ratio of 1.48:1 which is very closed to that of standard β-TCP bioceramics.

Abstract: This proposal aims to develop a newly, stable, excellent and environmental process of manufacturing scaffolds with virtually identical biphasic calcium phosphate compositions. Calcium phosphate cements (CPCs), which combines calcium orthophosphate powders with a liquid leading to a paste that hardens spontaneously at low temperatures, have potential to be used as a porous template for dental bone grafting substitutes [1,2]. Such newly developed sintering processes having the bone grafts with properties of bioactivity or even bioresorbability would be applied in many clinical setting. Template materials combine calcium orthophosphate powders with a liquid leading to a paste that hardens spontaneously at low temperatures. Hence, CPCs could be applied as scaffolds to support cell/tissue growth [3, 4]. This paper studies CPC scaffolds processing by foaming cement's paste state in which was added phasic stabilizer of magnesia and foaming agent of sucrose. The X-ray diffraction was performed to identify the phases of bone grafting substitutes, and we also used scanning electron microscope to observe the structure and pores of bone grafting substitutes. The cell viability about biocompatibility of developed bone grafting substitutes was examined. The results showed that our bone grafting substitutes produced steady final biphasic products consisting of hydroxyapatite (HA) and beta-tricalcium phosphates (β-TCP). We observed interconnected pores and highly porosity in microstructure of the bone grafting substitutes. The cell viability was over 70 % to make sure that the bone grafting substitutes has excellent biocompatibility. In conclusion, using the slurry of calcium phosphate cements (CPCs) and pores forming agent set into a porous template would be a useful process for manufacturing bone graft substitutes.