Papers by Keyword: β-Tricalcium Phosphate (β-TCP)

Abstract: Nanosized β-tricalcium phosphate (TCP) material was produced in this study using a wet precipitation method and characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Human ovarian sarcoma SKOV-3 cells were cultured and the influence of nanoscale β-TCP particles on SKOV-3 cell behavior was studied in vitro. As a result, β-TCP nanoparticles with average size of 100 nm were obtained. Cell growth of SKOV-3 cells was noticeably declined in the presence of β-TCP nanoparticles (200ng/ml). The distribution of cell cycle for SKOV-3 cells cultured with and without β-TCP nanomaterials was quite different. In G1 phase of cell cycle, the percentage of SKOV-3 cells cultured in the absence of β-TCP nanoparticles was significantly lower than that cultured in the presence of β-TCP nanoparticles (p<0.01). In S phase of cell cycle, on the other hand, the percentage of SKOV-3 cells cultured without β-TCP nanoparticles was noticeably increased compared with that cultured with β-TCP nanoparticles (p<0.01). Moreover, the expression of proliferating cell nuclear antigen (PCNA) in SKOV-3 cells cultured in medium containing 200ng/ml β-TCP nanopaticles was significantly lower than that in the cells cultured without β-TCP nanoparticles (p<0.01). In conclusion, the nanoscale β-TCP material synthesized in this study can exert anti-tumor effects on SKOV-3 cells through mechanisms of cell growth inhibition, downregulation of PCNA expression and cell cycle arrest at G1 phase.

Abstract: In the present work, apatite powders were synthesized at pH 10, pH 11 and pH 12 in order to give rise to biphasic and triphasic bioceramics after sintering. A modified gelcasting process, including polyethylene wax spheres addition to the suspension, is proposed in comparison to the original gelcasting method. The aim of the addition is the creation of uniform, open and interconnected pores in the body of samples.

Abstract: This paper describes the use of micro-computed tomography for determining in vitro degradation of calcium-phosphate ceramic materials. Samples were immersed in a simulated body fluid and scanned at the initial and final timepoints. Analysis indicates degradation of material density as well as changes in mineral content and mineral density. Findings are confirmed with known methods of materials characterization (SEM, mass analysis, and Archimedes’s density calculations), indicating changes in surface morphology, mass, and pore volume.

Abstract: The Tissue Engineering appears with a modern proposal for the treatment of damages or diseases. The study of materials and methods for tissues and organs regeneration by the patient cells culture had been developed on the last years but still couldn’t be used for all different tissues. In this multidisciplinary research field, the present work joins the biodegradability of poly(ε-caprolactone) (PCL) with the osteoconductive properties of β-tricalcium phosphate (β-TCP) in order to create a composite which acts as a temporary support for cell culture without a second surgery to remove the biomaterial. This work evaluates three membranes types, obtained by casting in chloroform, on the biocompatibility and differentiation on mesenquimal stem cells (hMSC). These analyses showed cell viability with the rezasurin method and the alkaline phosphatase activity (ALP). DMA analyses, MEV and OPM were performed.

Abstract: Spherical beta-tricalcium phosphate (b-TCP) granules synthesized using a unique dropping slurry method expressed good osteoconductivity with prominent bone apposition and bioresorbability when implanted into the rat femur (Gonda et al., Key Eng. Mater. 361-363:1013-1016, 2008). The spherical b-TCP granules were implanted into the bone defect created in the distal end of the right femur of each 8-week-old female Wistar rat. To analyze performance of the spherical b-TCP granules as bone substitute in the bone with reduction in osteogenic potential, the right sciatic neurectomy was performed after implantation and the right hind limb was kept unloaded for 2 weeks before euthanization. Four weeks after implantation, some spherical b-TCP granules with resorption in part were surrounded by newly formed bone. Eight and 12 weeks after implantation, most of the residual b-TCP granules were embedded in newly formed bone, and total volume of the implant and newly formed bone was more than the other portions of the bone or the bone of control animals. Osteoclast activity in the implanted area was also higher than the other portions of the bone or the bone of control animals. Replacement of the intraosseous residual b-TCP granules for bone progressed at 12 weeks after implantation compared to those at 8 weeks after implantation. These data suggested that the spherical b-TCP granules stimulated osteogenesis and osteoclast activity of the unloaded bone.

Abstract: Beta-tricalcium phosphate(β-TCP) coating layer is known to be resorbed much faster than hydroxyapatite(HA), however, there has been no report to explain the exact reason of these results. Eighty titanium discs, coated with HA(n=40) or β-TCP(n=40) by dip and spin coating method, were divided into 2 subgroups respectively; Dissolution(D, n=20) and osteoclast culture(C, n=20). The coated discs in D group were immersed in the cell culture media for 5 days, whereas, in C group, osteoclasts were seeded on the specimens and cultured for 5 days. After simple dissolution test, β-TCP coating layer showed much more cracks and denudation as compared to HA. In osteoclast culture group, mean area fraction of resorption pits in HA-C group was 11.62%, which was significantly higher than that of 0.73% in β-TCP-C group(p=0.001). In conclusion, the resorption mechanisms of HA and β-TCP coating layers were different each other in vitro study. The coated β-TCP was degraded mainly by dissolution and separation from implant, on the other hand, the HA coating layer was resorbed by osteoclastic activity.

Abstract: In this study, the PLA plied yarn was fabricated by twisting four of PLA yarns together, then PLA plied yarn was used a 16-spindle braid machine to produce the PLA braids. PLA braids were immersed in the suspension of β-tricalcium phosphate (β-TCP), and heat treatment to improve the adhesion of β-TCP particles. PLA/β-TCP composite braids were immersed in simulated body fluid (SBF) to promote bonelike apatite production. The morphology of PLA braids were investigated by scanning electron microscopy (SEM), and the results shown that when twist coefficient was 3 of PLA plied yarn, the concentration of β-TCP suspension was 0.15 wt % and heat treatment at 175 °C for 9 min, we can obtain the optimal conditions of β-TCP particles adhesion.

Abstract: In this study the degradation behaviour of pure hydroxyapatite (HA), pure tricalcium phosphate (β-TCP) and four biphasic calcium phosphate ceramics was studied to gain information about the influence of the phase composition on this property with the aim to tailor individually adapted bone substitute materials. The chemical dissolution of each ceramic composition was measured by its release of calcium ions into a buffered solution. With decreasing HA content in the ceramics the degradation rate increased. Cell experiments were carried out with stimulated osteoclast-like RAW 264.7 cells. Using biochemical, genetic and microscopic analysis, the differentiation of the cells on the ceramic samples was studied. The monocytic precursor cells differentiated into osteoclast-like cells on all ceramics. The strongest cell differentiation into osteoclast-like cells was found on ceramics with HA/β-TCP ratios of 80/20, 60/40 and 40/60. Cells on these ceramics had many nuclei and the largest cell size. As a result of resorption, lacunas were found on all ceramics except β-TCP. All these experimental results proved the influence of the phase composition on degradation and resorption of calcium phosphate ceramics. Biphasic calcium phosphate ceramics with HA/β-TCP ratios of 80/20 and 60/40 exhibited the most promising properties to serve as synthetic bone substitute materials because for integration in the physiological bone remodeling process the implanted bone substitute materials should have optimized dissolution and resorption properties.

Abstract: The aim of this study is to investigate in vivo local BMP-2 PK and bone induction in two bioceramics blocks (HAp, β-TCP), based on different composition and surface structures. We estimated the in vivo release profile of 125I–labeled BMP-2 and bone induction of hard tissues histologically. β-TCP is more effective for both BMP-2 retention and bone induction, compared to HAp, in the ectopic model.

Abstract: Several kinds of biomaterials are known to possess osteoinductive ability without bone inductive substances in ectopic implantation. β-TCP is one such material that has been reported to exhibit this ability in a canine model. In addition, prostaglandin E2 has been proved to accelerate osteogenesis in a rodent model, and one of its receptors EP4 has been considered to play a particularly important role. We examined that the EP4 agonist accelerates β-TCP-induced osteoinduction in a canine model. The results suggested that the EP4 agonist accelerated not only osteoinduction but also osteoclastogenesis prior to bone formation.