Crystallization of a Bone-like Apatite from a Milk-Containing Revised Simulated Body Fluid (SBF)

2007 ◽  
Vol 330-332 ◽  
pp. 641-644
Author(s):  
Sergey V. Dorozhkin ◽  
Elena I. Dorozhkina ◽  
S. Salman ◽  
Faik N. Oktar

Revised simulated body fluid (rSBF) was prepared using a conventional route but all the chemicals were dissolved in commercial cow milk instead of de-ionized water. To accelerate crystallization and increase the amount of precipitates, the influence of milk on the crystallization of calcium phosphates was studied in supersaturated solutions equal to 4 times the ionic concentrations of rSBF. The experiments were carried out in physiological conditions, i.e. pH of 7.35–7.40, temperature of 37.0 (± 0.2) °C, and duration of 7 days, using a constant-composition double-diffusion (CCDD) device, which enables slow precipitation in strictly controlled crystallization conditions. Similar experiments with 4 times the ionic concentrations of rSBF using de-ionized water as solvent were carried out as control. For comparison purposes, another set of experiments with 4 times the ionic concentrations of rSBF in de-ionized water also containing 40 g of bovine serum albumin (BSA) per liter was also conducted. The experimental results showed that the behavior of milk was similar to the presence of dissolved BSA. Some components of milk, presumably proteins, co-precipitated with calcium phosphates. This phenomenon had a strong negative influence on the crystallinity of the precipitates.

2020 ◽  
Vol 16 (5) ◽  
pp. 779-792
Author(s):  
Ahlam M. Fathi ◽  
Howida S. Mandour ◽  
Hanaa K. Abd El-Hamid

Background: Increasing the bioactivity of metallic implants is necessary for biomaterial applications where hydroxyapatite (HA) is used as a surface coating. In industry, HA is currently coated by plasma spraying, but this technique has a high cost and produces coating with short-term stability. Objectives: In the present study, electrophoretic deposition (EPD) was used to deposit nano-biphasic calcium phosphate compound (β-tri-calcium phosphate (β-TCP) /hydroxyapatite (HA)) bio-ceramics on the titanium surface. The microstructural, chemical compositions and bioactivity of the β- TCP/HA coatings were studied in a simulated body fluid solution (SBF). Methods: Scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) were used. Additionally, the antibacterial effect was studied by the agar diffusion method. The corrosion behavior of the β-TCP/HA coating on titanium surface (Ti) in the SBF solution at 37oC was investigated by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests. Results: The Ti surface modification increased its biocompatibility and corrosion resistance in the simulated body fluid. The antibacterial inhibition activity of the β-TCP/HA bio-ceramic was enhanced by electroless silver deposition. The enhanced properties could be attributed to the use of nano-sized biphasic calcium phosphates in a low-temperature EPD process. Conclusions: The β-TCP/HA and β-TCP/HA/Ag coatings well protect Ti from the corrosion in SBF and endow Ti with biocompatibility. The β-4-TCP/HA/Ag/Ti substrate shows good antibacterial activity.


1996 ◽  
Vol 6 (0) ◽  
pp. 309-312
Author(s):  
SUNG-BAEK CHO ◽  
YASUSHI SUETSUGU ◽  
JUNZO TANAKA

2019 ◽  
Vol 829 ◽  
pp. 145-150
Author(s):  
Astrie Yumeisa ◽  
Lisda Damayanti ◽  
Taufik Sumarsongko ◽  
Andrie Harmaji ◽  
Arief Cahyanto

Abstract. Various bioactive calcium phosphates such as hydroxyapatite (HA) and carbonate apatite (CO3Ap) have been widely studied due to their biocompatibility and osteoconductivity when implanted into bone defects. CO3Ap has the ability to adapt bone structure and induce bone regeneration; so that it can be categorized as resorbable bioactive materials. CO3Ap induced much stronger response such as cell adhesion and actin ring formation to osteoclast-like cells rather than HA. The aim of this study is to evaluate the bioactivity on zirconia (Y-TZP) coated with CO3Ap using simulated body fluid (SBF). Twenty Y-TZP ZrO2 disks with a 12-mm diameter and 1-mm thickness were employed as the samples. The disks were divided into two groups which the control group without CO3Ap coating and tested group with CO3Ap coating. Disks samples are dipped into CO3Ap suspension for one minute and stored in 37°C incubator for 24 hours. The disks were soaked in SBF for 1, 4, and 7 day(s) at 36.5°C. The obtained apatite crystals were characterized by scanning electron microscopy (SEM). It was found that the apatite formation on the tested group was greater than the control group. The EDS pattern showed the presence of Ca and P on the control and tested group after SBF soaking, which indicate the apatite deposition on the disks’ surface. However, the Ca and P on the tested group was higher compared to the control group. The formation of apatite layer on the disks’ surface is bioactivity indicator of CO3Ap.


2015 ◽  
Vol 21 (1) ◽  
pp. 190-203 ◽  
Author(s):  
M.G. Gandolfi ◽  
P. Taddei ◽  
F. Siboni ◽  
V. Perrotti ◽  
G. Iezzi ◽  
...  

AbstractThe creation of micro-textured dental implant surfaces possessing a stimulating activity represents a challenge in implant dentistry; particularly, the formation of a thin, biologically active, calcium-phosphate layer on their surface could help to strengthen the bond to the surrounding bone. The aim of the present study was to characterize in terms of macrostructure, micro-topography and reactivity in simulated body fluid (SBF), the surface of titanium (Ti) implants blasted with TiO2 particles, acid etched with hydrofluoric acid, and activated with Ca and Mg-containing nanoparticles. Sandblasted and acid-etched implants were analyzed by ESEM-EDX (environmental scanning electron microscope with energy dispersive X-ray system) to study the micromorphology of the surface and to perform elemental X-ray microanalysis (microchemical analyses) and element mapping. ESEM-EDX analyses were performed at time 0 and after a 28-day soaking period in SBF Hank’s balanced salt solution (HBSS) following ISO 23317 (implants for surgery—in vitro evaluation for apatite-forming ability of implant materials). Microchemical analyses (weight % and atomic %) and element mapping were carried out to evaluate the relative element content, element distribution, and calcium/phosphorus (Ca/P) atomic ratio. Raman spectroscopy was used to assess the possible presence of impurities due to manufacturing and to investigate the phases formed upon HBSS soaking. Micro-morphological analyses showed a micro-textured, highly rough surface with microgrooves. Microchemical analyses showed compositional differences among the apical, middle, and distal thirds. The micro-Raman analyses of the as-received implant showed the presence of amorphous Ti oxide and traces of anatase, calcite, and a carbonaceous material derived from the decomposition of an organic component of lipidic nature (presumably used as lubricant). A uniform layer of Ca-poor calcium phosphates (CaPs) (Ca/P ratio <1.47) was observed after soaking in HBSS; the detection of the 961 cm−1 Raman band confirms this finding. These implants showed a micro-textured surface supporting the formation of CaPs when immersed in SBF. These properties may likely favor bone anchorage and healing by stimulation of mineralizing cells.


2013 ◽  
Vol 334-335 ◽  
pp. 297-302 ◽  
Author(s):  
A.L.A. Escada ◽  
João Paulo Barros Machado ◽  
Roberto Zenhei Nakazato ◽  
Ana Paula Rosifini Alves Claro

Titanium and its alloys are widely used as biomaterials due to their mechanical, chemical and biological properties. To enhance the biocompatibility of titanium alloys, various surface treatments have been proposed. In particular, the formation of titanium oxide nanotubes layers has been extensively examined. Among the various materials for implants, calcium phosphates and hydroxyapatite are widely used clinically. In this work, titanium nanotubes were fabricated on the surface of Ti-7.5Mo alloy by anodization. The samples were anodized for 20 V in an electrolyte containing glycerol in combination with ammonium fluoride (NH4F, 0.25%), and the anodization time was 24 h. After being anodized, specimens were heat treated at 450 °C and 600°C for 1 h to crystallize the amorphous TiO2 nanotubes and then treated with NaOH solution to make them bioactive, to induce growth of calcium phosphate in a simulated body fluid. Surface morphology and coating chemistry were obtained respectively using, field-emission scanning electron microscopy (FEG-SEM), AFM and X-ray diffraction (XRD). It was shown that the presence of titanium nanotubes induces the growth of a sodium titanate nanolayer. During the subsequent in-vitro immersion in a simulated body fluid, the sodium titanate nanolayer induced the nucleation and growth of nanodimensioned calcium phosphate. It was possible to observe the formation of TiO2 nanotubes on the surface of Ti-7.5Mo. Calcium phosphate coating was greater in the samples with larger nanotube diameter. These findings represent a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.


2007 ◽  
Vol 330-332 ◽  
pp. 713-716 ◽  
Author(s):  
Celso A. Bertran ◽  
S. Bertazzo ◽  
L.P. Faria

The surface charge of calcium phosphates in Simulated Body Fluid (SBF) may be one of the factors associated with the adhesion of cells and proteins, processes that are related with osteogenesis. For calcium phosphates in SBF, surface charge varies with solution pH due to the adsorption of positive ions and to the reactions that occur at the solid/biological fluid interface. In this work, the variation of the density of protons adsorbed and the surface charge as a function of pH were determined for Hydroxyapatite, CaHPO4, and Bone Mineral.


Author(s):  
S V Dorozhkin ◽  
E I Dorozhkina

A first approach to in vitro simulation of vascular calcification was elaborated. Vascular calcification was simulated by a slow crystallization of a non-stoichiometric poorly crystallized carbonateapatite from Kokubo's revised simulated body fluid (rSBF) on the surface of a porous pellet made of pure cholesterol. To achieve this, the crystallization experiments were performed under strictly controlled conditions (similar to physiological ones) provided by a constant-composition double-diffusion (CCDD) device. To obtain an even closer match to in vivo conditions, rSBF was enriched by the addition of glucose and bovine serum albumin (BSA) in physiological amounts. Precipitation took place on the surface of cholesterol and the precipitates consisted of poorly crystalline non-stoichiometric, sodium-and magnesium-containing carbonateapatite.


2012 ◽  
Vol 16 ◽  
pp. 63-68 ◽  
Author(s):  
A.L.A. Escada ◽  
João Paulo Barros Machado ◽  
Sandra G. Schneider ◽  
Roberto Zenhei Nakazato ◽  
Ana Paula Rosifini Alves Claro

Many materials with different surfaces have been developed for dental and orthopedics implants. Among the various materials for implants, titanium and bioactive ones such as calcium phosphates and hydroxyapatite, are widely used clinically. When these materials are inserted into bone several biological reactions occur. Thes processes can be associated with surface properties (topography, roughness and surface energy). In this work, ingots were obtained from titanium and molybdenum by using an arc-melting furnace. They were submitted to heat treatment at 1100°C for one hour, cooled in water and cold worked by swaging. Titanium nanotubes were fabricated on the surface of Ti-7,5Mo alloy by anodization, and then treated with NaOH solution to make them bioactive, to induce growth of calcium phosphate in a simulated body fluid. . It is shown that the presence of titanium nanotubes induces the growth of a sodium titanate nanolayer. During the subsequent in-vitro immersion in a simulated body fluid, the sodium titanate nanolayer induced the nucleation and growth of nano-dimensioned calcium phosphate. These titanium nanotubes can be useful as a well-adhered bioactive surface layer on Ti implant metals for orthopedic and dental implants.


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