Papers by Keyword: Biphasic Calcium Phosphate (BCP)

Abstract: Biphasic calcium phosphate powders doped with zinc (Zn-doped BCP) were synthesized via sol-gel technique. Different concentrations of Zn have been successfully incorporated into biphasic calcium (BCP) phases namely: 1%, 2%, 3%, 5%, 7%, 10% and 15%. The synthesized powders were calcined at temperatures of 700-900°C. The calcined Zn-doped BCP powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential and thermogravimetric analysis (TG/DTA) and field-emission scanning electron microscopy (FESEM). X-ray diffraction analysis revealed that the phases present in Zn-doped are hydroxyapatite, β- TCP and parascholzite. Moreover, FTIR analysis of the synthesized powders depicted that the bands of HPO4 increased meanwhile O-H decreased with an increase in the calcination temperature. Field emission scanning electron microscopy (FESEM) results showed the agglomeration of particles into microscale aggregates with size of the agglomerates tending to increase with an increase in the dopant concentration.

Abstract: Biphasic calcium phosphate bioceramics were fabricated from the recycling of bone ash which is mostly used as raw materials of bone china. Precursor calcium phosphate powders were prepared by soaking the commercial bone ash in 0.1 M of NaOH solution at 80°C for 4 h. Calcium phosphate powders was obtained by calcination at 800°C for 1 h to completely remove residual organics. Biphasic calcium phosphate bioceramics which is composed of hydroxyapatite and tricalcium phosphate was fabricated by the sintering of pressed compacts at 1200°C for 1 h under moisture protection. The bone ash derived-biphasic calcium phosphate ceramics consists of mostly HA and small amounts of α-tricalcium phosphate, magnesium oxide and calcium oxide. After polishing the HA ceramics, they were immersed in buffered water at 37°C for 3 and 7 days. The bone ash derived- biphasic calcium phosphate ceramics show high biostability in liquid environment with immersion time compared with commercial calcium phosphate ceramics.

Abstract: The main goal of this study was to succeed in the relevant association of well-known osteoconductive biphasic calcium phosphate (BCP) made of Hydroxyapatite (20% HA) and β-Tricalcium Phosphate (80% β-TCP) crystallographic phases and resorbable poly (L-lactide-co-D,L-lactide)(PLDLLA) 3D matrices synthesized by electrospinning. Two types of mineral particles were obtained, BCP new hollow granules, and classical BCP particles. It appeared that hollow shells/PLDLLA composite 3D matrices allowed higher cell adhesion in vitro, thanks to internal concavities and are promising scaffolds in terms of cell carrying.

Abstract: Dermal fillers are injectable implants made of biological materials (collagen, autologous fat and hyaluronic acid animal) or synthetic (PMMA microparticles of hydroxyapatite and non-animal hyaluronic acid), biodegradable or not, that include features such as ideal biocompatibility, durability, non-profile migration and ability to promote a smooth, natural-looking correction. Its main indication is intended to treat contour defects caused by aging, photo damage, disease, trauma or scarification. The fact of biodegradable fillers are absorbed within a year after application resulted in the emergence of products permanent and semi-permanent to offer patients long-lasting effects. Currently, one of the most effective strategies has been the development of scaffolds formed by combining two or more biomaterials seeking the restoration of tissue function. The bioceramic associated with water-soluble polymers have been developed as substitutes for the repair of soft tissues with optimal biological response. The objective of this study was to process and characterize a composite hydrogel in the form of hyaluronic acid (HA) microspheres and biphasic calcium phosphate (BCP) in order injectable applications for repair of soft tissue. The powders of HA and BCP were characterized by Infrared Spectroscopy Fourier Transform (FTIR) and X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The characterization of the hydrogel injectability pure and the composite with different ratios of HA and BCP was performed. The components were characterized compatible for use as dermal fillers. The composite of hyaluronic acid (HA) and biphasic calcium phosphate (BCP) had adequate characterization and injetabilidade proving to be a potential candidate for restoration of soft tissue.

Abstract: The objective of the study was to compare clinical efficiency of the fusion after reconstruction with an anatomically shaped PEEK cage associated with a iliac crest autograft or MBCP in the treatment of cervical disc disease in randomized clinical trial. A multicente randomized, comparative and prospective study on 58 patients, with a 12 months follow up are reported. They underwent anterior cervical decompression and fusion being randomized for autologous graft or MBCP. Patients presenting purely degenerative disc disease were implanted with a PEEK cage filled with iliac crest autograft or MBCP. Pain and functionality as well as patients satisfaction were assessed through VAS, Neck Disability Index (NDI) and Patient Satisfaction index were recorded until 24 month follow-up. Radiological evaluation included plain and dynamic short X-rays at each stage of the follow up. The patients satisfaction rates was of 82% in the autograft group versus 96% in the MBCP group. Pain at the donor site was significantly more important in the autograft group at 3 weeks, 3 months and 1 year follow-up. No implant failures were recorded. Previously goat preclinical study was performed. Micro CT, light microscopy and shistomorphometry were related to the high performance of the MBCP insert for filling cage fusion, completing the clinical assessment of our clinical study. The use of MBCP insert is safe and avoids potential graft site morbidity and pain in comparison with an autologous graft procedure.

Abstract: The development of CaP ceramics involved a better control of the process of resorption and bone substitution. Micro Macroporous Biphasic CaP, (MBCP+) is a concept based on an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases Ca and P ions into the biological medium. The MBCP+ is selected for tissue engineering in a large European research program on osteoinduction and mesenchymal stem cell technology (REBORNE 7^th EU frame work program, Regenerative Bone defects using New biomedical Engineering approaches, www.reborne.org). We have optimized the matrices in terms of their physical, chemical, and crystal properties, to improve cell colonization and to increase kinetic bone ingrowth. The fast cell colonization and resorption of the material are associated to the interconnected macropores structure which enhances the resorption bone substitution process. The micropore content involves biological fluid diffusion and suitable adsorption surfaces for circulating growth factors. The bioceramics developed for this project was fully characterized using X-Ray diffraction, FTIR, X-rays micro tomography, Hg porosimetry, BET specific surface area, compressive mechanical test, and SEM. Preclinical tests on the optimized scaffold were realized in critical size defects in several sites of implantation and animals (rats, rabbits, goats, dogs).The smart scaffold has a total porosity of 73%, constituted of macropores (>100µm), mesopores of 10 to 100µm and high micropores (<10µm) content of more or less 40%. The crystal size is <0.5 to 1 µm and the specific surface area was around 6m²/g. The in vivo experiment indicated higher colonization by osteogenic cells demonstrating suitable matrices for tissue engineering. The HA/TCP ratio of 20/80 was also more efficient for combination with total bone marrow or stem cell cultivation and expansion before to be implanted.

Abstract: Magnesium and strontium both play important roles in the growth of bone and so are desirable ions for substitution into hydroxyapatite (HA) intended for use as bioinstructive bone substitutes. A range of compositions were prepared by a solid state method based on the nominal composition of HA (Ca₁₀(PO₄)₆(OH)₂), with various levels of strontium and/or magnesium substitution: strontium-substituted HA (Ca₈Sr₂(PO₄)₆(OH)₂), magnesium-substituted HA (Ca_9.8Mg_0.2(PO₄)₆(OH)₂ and Ca₉Mg (PO₄)₆(OH)₂), and strontium and magnesium co-substituted HA (Ca_7.8Sr₂Mg_0.2(PO₄)₆(OH)₂ and Ca₇Sr₂Mg (PO₄)₆(OH)₂). Materials were characterised by powder X-ray diffraction, Fourier-transform infrared spectroscopy and Raman spectroscopy. These analyses indicated that the co-substituted materials were composed of mixtures of strontium-substituted hydroxyapatite and magnesium and strontium co-substituted β-tricalcium phosphate. In the magnesium-substituted materials, increased magnesium content was related to increased proportion of β-tricalcium phosphate phase, both with and without strontium co-substitution. The unsubstituted and strontium mono-substituted materials, however, were pure apatite phase, suggesting that magnesium was the destabilising factor in the phase compositions of the magnesium mono-substituted and magnesium and strontium co-substituted materials.

Abstract: In this work, thepreparation and morphology of biphasic calcium phosphate (BCP) have been studied. The biphasic calcium phosphate (BCP) ceramics were prepared by mixing between hydroxyapatite (HA) and Beta-tricalcium phosphate (β-TCP) powderby ball milling technique with different ratios (100:0,80:20,60:40,50:50,40:60, 20:80 and 0:100). After that the mixtures were forming by Gel casting method and then sintered at 1200°C, respectively. The phase formation of the biphasic calcium phosphateceramics were studied by X-ray diffraction (XRD) and their ceramic microstructure,shrinkage and density were investigated.

Abstract: Biphasic calcium phosphate (BCP) ceramic is commonly used in the biomedical applications particularly as a bone substitute due to its biocompatibility and directly bond to bones. However, the mechanical strength is quite poor. Therefore, well known biocompatible and strong ceramics such as SiO₂, ZrO₂ and TiO₂ were added to improve the strength of BCP. BCP powder with HA/TCP ratios of 70/30 (HAP7030) was obtained by controlling the calcining temperature of the mixture between a pure HA and TCP. SiO₂, ZrO₂ and TiO₂ powder with 2, 5 and 10 %wt were mixed with the HAP7030 powder by ball milling in ethanol. The mixtures were dried, pressed and sintered at 1100°C for 2 hrs. XRD and SEM were used to determine crystal structures and morphology of the sintered samples, respectively. Physical properties and flexural strength of samples were measured. Results showed that the bending strength of HAP7030 sample was rather improved by adding TiO₂ than the addition of SiO₂ or ZrO₂. With increasing TiO₂, HAP7030 strength was superior and HAP7030 with 10 %wt of TiO₂ obtained the optimum bending strength around 61 MPa. However, the addition of TiO₂ induced the thermal stability of HA/TCP, in which HA completely decomposed to β-TCP in this study.

Abstract: Biphasic calcium phosphate (BCP) coatings on a medical grade 316L stainless steel substrate were prepared by electrophoretic deposition (EPD) using ethanol as a dispersive medium. The deposition voltage of 30V was applied for 1 min at 25, 40 and 60 °C, respectively. The coated substrates were sintered in a vacuum furnace at 800 °C for 1 h. The surface morphology, structure and phase composition of the coatings was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that by increasing deposition conditions of voltage and temperature, crack occurrence and morphological changes increased in the produced coatings. The optimum condition for crack-free surface was at 30 V at 25 °C.