Teriparatide with octacalcium phosphate collagen composite stimulates osteogenic factors

Octacalcium phosphate (OCP) is widely used in biomaterial fabrication by virtue of its unique crystal structure and low environmental loading. Although various ion and molecule substitution methods into the OCP unit lattice have been introduced, it remains unclear which factors and mechanisms dominate the substitution process. Experimental studies have indicated that Na alkali metal ions are substituted at the P3 PO4 conjugated site in acidic to weakly acidic conditions and the P5 PO4 conjugated site in neutral to weak basic conditions. Ionic species calculation methods have indicated that the pair ratios of Na and HPO42− (NaHPO4−) are small in acidic reacting solutions but large under weakly basic conditions. Consequently, the roles played by NaHPO4− and ionic pair formation processes are thought to dominate ion and molecule substitution into the OCP unit lattice. Such ionic pair formation strongly inhibits dicarboxylic acid substitution into the OCP unit lattice due to the replacement of the Ca ion, which conjugates P5 PO4 as an anchor of dicarboxylic acid.

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Coherent surface structure induces unique epitaxial overgrowth of metastable octacalcium phosphate on stable hydroxyapatite at critical fluoride concentration

Acta Biomaterialia ◽

10.1016/j.actbio.2021.02.024 ◽

2021 ◽

Vol 125 ◽

pp. 333-344

Author(s):

Kazuo Onuma ◽

Mari M. Saito ◽

Yasuo Yamakoshi ◽

Mayumi Iijima ◽

Yu Sogo ◽

...

Keyword(s):

Surface Structure ◽

Fluoride Concentration ◽

Octacalcium Phosphate

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Involvement of distant octacalcium phosphate scaffolds in enhancing early differentiation of osteocytes during bone regeneration

Acta Biomaterialia ◽

10.1016/j.actbio.2021.05.017 ◽

2021 ◽

Author(s):

Shizu Saito ◽

Ryo Hamai ◽

Yukari Shiwaku ◽

Tomoka Hasegawa ◽

Susumu Sakai ◽

...

Keyword(s):

Bone Regeneration ◽

Octacalcium Phosphate ◽

Early Differentiation

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Microwave-Assisted Fabrication of Mesoporous Silica-Calcium Phosphate Composites for Dental Application

Polymers ◽

10.3390/polym13010053 ◽

2020 ◽

Vol 13 (1) ◽

pp. 53

Author(s):

Adrian Szewczyk ◽

Adrianna Skwira ◽

Marta Ginter ◽

Donata Tajer ◽

Magdalena Prokopowicz

Keyword(s):

Calcium Phosphate ◽

Mesoporous Silica ◽

Octacalcium Phosphate ◽

Precipitation Method ◽

X Ray Diffraction ◽

Coating Solution ◽

X Ray ◽

Microwave Assisted ◽

Calcium Orthophosphates ◽

Different Types

Herein, the microwave-assisted wet precipitation method was used to obtain materials consisting of mesoporous silica (SBA-15) and calcium orthophosphates (CaP). Composites were prepared through immersion of mesoporous silica in different calcification coating solutions and then exposed to microwave radiation. The composites were characterized in terms of molecular structure, crystallinity, morphology, chemical composition, and mineralization potential by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). The application of microwave irradiation resulted in the formation of different types of calcium orthophosphates such as calcium deficient hydroxyapatite (CDHA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP) on the SBA-15 surface, depending on the type of coating solution. The composites for which the progressive formation of hydroxyapatite during incubation in simulated body fluid was observed were further used in the production of final pharmaceutical forms: membranes, granules, and pellets. All of the obtained pharmaceutical forms preserved mineralization properties.

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Effect of pH of coating solution on the adhesion strength and corrosion resistance of hydroxyapatite and octacalcium phosphate coated WE43 alloy

Journal of Biomaterials Applications ◽

10.1177/08853282211012525 ◽

2021 ◽

pp. 088532822110125

Author(s):

Tuyet Thi Anh Ngo ◽

Sachiko Hiromoto ◽

Linh Chi Do ◽

Hanh Hong Pham ◽

Le Hanh

Keyword(s):

Corrosion Resistance ◽

Adhesion Strength ◽

Corrosion Current ◽

Xrd Analysis ◽

Octacalcium Phosphate ◽

Solution Deposition ◽

Chemical Solution Deposition Method ◽

Before And After ◽

Coating Layers ◽

We43 Alloy

Hydroxyapatite (HAp) and octacalcium phosphate (OCP) layers were formed on Mg- 4mass% Y- 3mass% rare earth (WE43) alloy by a chemical solution deposition method at various pH values of pH 5.5, 6.2, 7.5, and 8.6. Adhesion strength of HAp and OCP layers was evaluated before and after immersing in a medium for 14 days by a pull-off test. The corrosion resistance of these coatings was measured by polarization tests performed in a simulated body fluid (SBF). XRD analysis demonstrated that HAp coating layers were formed at pH 7.5 and 8.6, while OCP coating layers were formed at pH 5.5 and 6.2. Adhesion test results showed that the as-coated pH7.5-HAp layer had the highest adhesion strength of 8.6 MPa, which was attributed to the very dense structure of the coating layer. The as-coated pH8.6-HAp layer showed the adhesion strength of 6.5 MPa. The adhesion strength of the as-coated pH5.5- and pH6.2-OCP layers was 3.9 and 7.1 MPa, respectively, that was governed by the thick and fragile property of the layers. After immersing in the medium for 14 days, the adhesion strength of pH7.5- and pH8.6-specimens decreased to 5.8 and 5.6 MPa, respectively. The pitting corrosion and formation of Mg(OH)2 under the HAp layers were responsible for the decrease of adhesion strength. The polarization tests in SBF at 37 °C showed that the corrosion current density decreased with the HAp and OCP coatings, indicating the improvement of the corrosion resistance of WE43 alloy. The HAp coatings improved the corrosion resistance more efficiently than the OCP coatings.

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Mineralogical-geochemical study of the anionic competition effect on the octacalcium phosphate reaction into fluorapatite

Heliyon ◽

10.1016/j.heliyon.2021.e06882 ◽

2021 ◽

Vol 7 (5) ◽

pp. e06882

Author(s):

Alfredo Idini ◽

Franco Frau

Keyword(s):

Octacalcium Phosphate ◽

Competition Effect ◽

Geochemical Study

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Cemp1-p3 Peptide Promotes the Transformation of Octacalcium Phosphate into Hydroxyapatite Crystals

Crystals ◽

10.3390/cryst10121131 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1131

Author(s):

Maricela Santana ◽

Gonzalo Montoya ◽

Raúl Herrera ◽

Lía Hoz ◽

Enrique Romo ◽

...

Keyword(s):

Electron Microscopy ◽

Octacalcium Phosphate ◽

Sequence Motifs ◽

Simple Method ◽

Transmission Electron ◽

Precursor Phase ◽

Mineralized Tissues ◽

Potent Growth

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.

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