Apatite-Forming Ability of Polyglutamic Acid Gel in Simulated Body Fluid: Effect of Cross-Linking Agent

2007 ◽  
Vol 330-332 ◽  
pp. 683-686 ◽  
Author(s):  
Atsushi Sugino ◽  
Toshiki Miyazaki ◽  
Chikara Ohtsuki
Keyword(s):  
Simulated Body Fluid ◽  
Heterogeneous Nucleation ◽  
Body Fluid ◽  
Organic Polymer ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Apatite Formation ◽  
Organic Substrates ◽  
Polyglutamic Acid ◽  
Acid Gel

Development of the organic-inorganic hybrids composed of apatite crystals and organic polymer is expected to be an attractive material that has mechanical properties similar to natural bone as well as bone-bonding ability, i.e. bioactivity. It is reported that the carboxyl groups (-COOH) on the surfaces of the organic substrates act as a catalyst for induction of heterogeneous nucleation of apatite. The present authors previously showed that the apatite was successfully deposited on the polyglutamic acid gels containing abundant carboxyl groups through the biomimetic process, when they were priorly treated with calcium chloride solution. In this study, we fabricated the polyglutamic acid gels with different degree of cross-linking. Effect of the cross-linking on their ability of the apatite formation was examined in simulated body fluid (SBF). It was suggested that the apatite deposition on the polyglutamic acid gels is governed not only by the amount of –COOH that induces the heterogeneous nucleation of the apatite, but also by swelling property that controls local increase in degree of supersaturation with respect to the apatite.

Apatite Deposition on Polypeptides Derived from Plants in a Solution Mimicking Body Fluid

2006 ◽  
Vol 309-311 ◽  
pp. 671-674
Author(s):  
Toshiki Miyazaki ◽  
Chikara Ohtsuki ◽  
Shinichi Ogata ◽  
Masahiro Ashizuka
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Mechanical Performance ◽  
Extracellular Fluid ◽  
Organic Polymer ◽  
Carboxyl Groups ◽  
Organic Substrates ◽  
Ion Concentrations ◽  
Inorganic Ion ◽  
Apatite Deposition

Organic-inorganic hybrids composed of organic polymer and apatite is quite attractive as novel bone-repairing materials since it has mechanical performance analogous to those of natural bone as well as bone-bonding ability, i.e. bioactivity. To fabricate such an apatite-polymer hybrid, biomimetic process has been recently paid much attention. In this process, bone-like apatite is deposited on the surfaces of organic substrates in simulated body fluid (SBF, Kokubo solution) having ion concentrations analogous to those of human extracellular fluid or more concentrated solutions. Previous studies showed that the apatite deposition is triggered by a catalytic effect of carboxyl groups (COOH) on the surfaces of the organic substrates. In this study, we examined apatite deposition on natural polypeptides derived from crops in a biomimetic solution. We selected gluten derived from wheat and zein derived from corn. Both of gluten and zein formed bone-like apatite on their surfaces in a solution that has inorganic ion concentrations 1.5 times those of simulated body fluid, when they were treated with 1 mol/L calcium chloride solution. High content of acidic amino acids such as glutamic acid and aspartic acid in gluten and zein would give large amount of carboxyl groups effective for the apatite nucleation.

Comparison of Apatite Formation on Polyamide Films Containing Carboxyl and Sulfonic Groups in a Solution Mimicking Body Fluid

2006 ◽  
Vol 309-311 ◽  
pp. 477-480
Author(s):  
Chikara Ohtsuki ◽  
Takahiro Kawai ◽  
Masanobu Kamitakahara ◽  
Masao Tanihara ◽  
Toshiki Miyazaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Crystal Growth ◽  
Simulated Body Fluid ◽  
Calcium Ions ◽  
Body Fluid ◽  
Functional Group ◽  
Carboxyl Groups ◽  
Apatite Formation ◽  
Ion Concentrations ◽  
Polyamide Film

Apatite formation on polyamide films containing either carboxyl or sulfonic groups was compared in 1.5SBF, whose ion concentrations are 1.5 times those of a simulated body fluid (SBF). The sulfonic groups induced the apatite nucleation earlier than the carboxyl groups. In contrast, the rate of crystal growth depended not on the kind of functional group, but on the degree of supersaturation of the surrounding solution. The more ready association of sulfonic groups with calcium ions may lead to earlier apatite nucleation than that of carboxyl groups. Adhesive strength of the apatite layer to polyamide film containing sulfonic groups was significantly lower than that with carboxyl groups depending on the chemical interactions as well as on the mechanical properties of the polyamide film.

Effects of Heat Treatment on Apatite Formation of CaO-SiO2-PEEK Composites

2012 ◽  
Vol 529-530 ◽  
pp. 436-440 ◽  
Author(s):  
S.B. Cho ◽  
E.M. An ◽  
Sujeong Lee ◽  
H.D. Jang ◽  
Ill Yong Kim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Sol Gel ◽  
Spherical Particles ◽  
Organic Polymer ◽  
Apatite Formation ◽  
Ceramic Filler ◽  
Induction Periods ◽  
Sol Gel Process

Osteoconductive bone-repairing materials with mechanical properties analogous to those of human bone can be prepared through the combination of an osteoconductive ceramic filler with an organic polymer. Osteoconduction is archived from apatite formation on substrates. Previously, we reported that novel osteoconductive spherical particles in a binary CaO-SiO2 system were produced through a sol-gel process as ceramic filler for the fabrication of composites. In this study, we fabricated the composites consisting of polyetheretherketone (PEEK) and 30CaO·70SiO2 (CS) spherical particles and evaluated the effects of heat treatment in the range of 320-360 °C on apatite formation of the composites in a simulated body fluid. The prepared composites of PEEK and CS particles form hydroxyapatite on their surfaces in the simulated body fluid. The induction periods of hydroxyapatite on the composites decreased with increasing the amount of CS particles and decreasing the temperature for heat treatment. The apatite formation was affected by exposure of ceramic filler on the polymer matrix.

Apatite-Forming Ability of Organic-Inorganic Hybrids Prepared from Calcium Silicate and Glucomannan

2007 ◽  
Vol 361-363 ◽  
pp. 567-570
Author(s):  
Yasuyuki Morita ◽  
Toshiki Miyazaki ◽  
Eiichi Ishida ◽  
Chikara Ohtsuki
Keyword(s):  
Calcium Silicate ◽  
Body Fluid ◽  
Organic Polymer ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Living Body ◽  
Bioactive Ceramics ◽  
Previously Treated

So-called bioactive ceramics are used for bone-repairing owing to attractive features such as direct bone-bonding in living body. However, there is limitation on clinical applications due to their inappropriate mechanical properties performances such as higher brittleness and lower fracture toughness than natural bone. To overcome this problem, hybrid materials have been developed by modification of calcium silicate, that is basic component of bioactive ceramics, with organic polymer. It is known that bioactive ceramics bond to bone through bone-like apatite layer which is formed on their surfaces by chemical reaction with body fluid. We attempted preparation of bioactive organic-inorganic hybrids from Glucomannan that is a kind of complex polysaccharide, and calcium silicate. Hybrids were prepared from glucomannan and tetraethoxysilane (TEOS). They were treated with 1M (=mol·m-3) CaCl2 aqueous solution for 24 hours. Then ability of apatite formation on the hybrids was examined in vitro using simulated body fluid (SBF, Kokubo solution). Surface structure of the specimens was examined by thin-film X-ray diffraction (TF-XRD), scanning electron microscopic (SEM) observation. The hybrids with TEOS:Glucomannan= 1:1 to 4:1 in mass ratio formed the apatite in SBF within 3 or 7 d, when they were previously treated with CaCl2 solution.

The apatite formation ability of CaF 2 doping tricalcium silicates in simulated body fluid

2009 ◽  
Vol 4 (4) ◽  
pp. 045005 ◽  
Author(s):  
Qing Lin ◽  
Yanbao Li ◽  
Xianghui Lan ◽  
Chunhua Lu ◽  
Yixin Chen ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Apatite Formation

scholarly journals Bioactivity Behavior Evaluation of PCL-Chitosan-Nanobaghdadite Coating on AZ91 Magnesium Alloy in Simulated Body Fluid

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 231
Author(s):  
Farzad Soleymani ◽  
Rahmatollah Emadi ◽  
Sorour Sadeghzade ◽  
Fariborz Tavangarian
Keyword(s):  
Simulated Body Fluid ◽  
Corrosion Rate ◽  
Composite Coating ◽  
Body Fluid ◽  
Composite Coatings ◽  
Phosphate Buffer Solution ◽  
Az91 Alloy ◽  
Apatite Formation ◽  
Az91 Magnesium Alloy ◽  
Sbf Solution

Polymer–ceramic composite coatings on magnesium-based alloys have attracted lots of attention in recent years, to control the speed of degradability and to enhance bioactivity and biocompatibility. In this study, to decrease the corrosion rate in a simulated body fluid (SBF) solution for long periods, to control degradability, and to enhance bioactivity, polycaprolactone–chitosan composite coatings with different percentages of baghdadite (0 wt.%, 3 wt.%, and 5 wt.%) were applied to an anodized AZ91 alloy. According to the results of the immersion test of the composite coating containing 3 wt.% baghdadite in a phosphate buffer solution (PBS), the corrosion rate decreased from 0.45 (for the AZ91 sample) to 0.11 mg/cm2·h after seven days of immersion. To evaluate the apatite formation capability of specimens, samples were immersed in an SBF solution. The results showed that the samples were bioactive as apatite layers formed on the surface of specimens. The composite coating containing 3 wt.% baghdadite showed the highest apatite-formation capability, with a controlled release of ions, and the lowest corrosion rate in the SBF.

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