Octacalcium phosphate crystals including a higher density dislocation improve its materials osteogenecity

Hamai, Ryo; Sakai, Shizuyoshi; Anada, Takahisa; Tsuchiya, Kaori; Ishimoto, Takuya; Nakano, Takayoshi; Сузукі, Осаму

doi:10.1016/j.apmt.2021.101279

Cited by 17 publications

(19 citation statements)

References 68 publications

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“…All of the aforementioned reasons have pushed the decision to select the hydrolysis pathway of obtaining OCP as a preferential method [ 22 , 23 , 24 ]. Even though hydrolysis is a complex process [ 25 ], involving not only a precipitation control, but also a dissolution control, the existence of only one precursor could make the repeatability of the synthesis with different incorporated drugs more secure. As examples of precursors, α-tricalcium phosphate (α–TCP) and dicalcium phosphate dihydrate (CaHPO 4 ·2H 2 O, DCPD or brushite) have been used in the literature [ 24 , 26 , 27 , 28 ].…”

Section: Introductionmentioning

confidence: 99%

Exploring the Formation Kinetics of Octacalcium Phosphate from Alpha-Tricalcium Phosphate: Synthesis Scale-Up, Determination of Transient Phases, Their Morphology and Biocompatibility

et al. 2023

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Even with decades of research studies behind octacalcium phosphate (OCP), determination of OCP phase formation has proved to be a cumbersome challenge. Even though obtaining a large quantity of OCP is important for potential clinical uses, it still remains a hindrance to obtain high yields of pure OCP. Taking that into consideration, the purpose of this study was to scale-up OCP synthesis for the first time and to use a multi-technique approach to follow the phase transformation pathway at multiple time points. In the present study, OCP has been synthesized from α-tricalcium phosphate (α-TCP), and subsequently scaled-up tenfold and hundredfold (100 mg → 10 g). The hydrolysis mechanism has been followed and described by using XRD and FTIR spectroscopy, as well as Raman and SEM. Gradual transformation into the OCP phase transpired through dicalcium phosphate dihydrate (brushite, DCPD, up to ~36%) as an intermediary phase. Furthermore, the obtained transitional phases and final OCP phases (across all scale-up levels) were tested with human bone marrow-derived mesenchymal stem cells (hBMSCs), in order to see how different phase mixtures affect the cell viability, and also to corroborate the safety of the scaled-up product. Twelve out of seventeen specimens showed satisfactory percentages of cell viability and confirmed the prospective use of scaled-up OCP in further in vitro studies. The present study, therefore, provides the first scale-up process of OCP synthesis, an in depth understanding of the formation pathway, and investigation of the parameters able to contribute in the OCP phase formation.

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Section: Introductionmentioning

confidence: 99%

Exploring the Formation Kinetics of Octacalcium Phosphate from Alpha-Tricalcium Phosphate: Synthesis Scale-Up, Determination of Transient Phases, Their Morphology and Biocompatibility

et al. 2023

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“…8 The CP appears in various phases including Hydroxyapatite (Ca ) and so forth. [9][10][11][12] Among them, hydroxyapatite and tri-calcium phosphate have been widely focused on dental and orthopedic applications. 13 Rather than these two phases, the other translation of CP phases and characteristics of these materials at the nanoscale remains unrevealed yet.…”

Section: Introductionmentioning

confidence: 99%

“…The foremost advantage of enabling hydrothermal synthesis is to provide a phase pure materials with controlled morphology and particle size through high pressure, plus temperature process 8 . The CP appears in various phases including Hydroxyapatite (Ca 10 [PO 4 ] 6 (OH) 2 ), Octacalcium phosphate (Ca 8 H 2 [PO 4 ] 6 .5H 2 O), Monetite (CaHPO 4 ), 8 Brushite (CaHPO 4 .2H 2 O), α and β Tricalcium phosphate (α and β‐Ca 3 [PO 4 ] 2 ), Tetracalcium phosphate (Ca 4 [PO 4 ] 2 O), and Calcium pyrophosphate dihydrate (Ca 2 P 2 O 7 .2H 2 O) and so forth 9–12 . Among them, hydroxyapatite and tri‐calcium phosphate have been widely focused on dental and orthopedic applications 13 .…”

Section: Introductionmentioning

confidence: 99%

Influence of pH in the synthesis of calcium phosphate based nanostructures with enhanced bioactivity and pro‐angiogenic properties

2022

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In synthetic fabrication, the process parameters decide the growth nucleation, phase translation, and the evolution of morphological facets of nanostructured materials. This work demonstrates the formation of different crystallographic phases of calcium phosphate by the influence of pH from acidic to alkaline conditions and also investigated their bone regeneration, protein adsorption, and pro‐angiogenic properties. Present results illustrate that the alteration of pH is the crucial factor for the synthesis of calcium phosphate (CP) phases. The structural analysis reveals the monetite (CaHPO4) phase with a triclinic crystal system for pH 5, dual‐phase of monetite combined with hydroxyapatite at the neutral pH 7, and pure phase of hydroxyapatite (Ca10[PO4]6OH2) with hexagonal structure at pH 10. Microscopic analysis portrays the cubic and rod‐like morphologies by changing the pH values. FTIR and RAMAN spectroscopic analyses confirm the stretching, bending, and vibrational modes of dominant phosphate groups of different CP phases. Further, the biocompatibility of the prepared CP phases was examined by hemolysis assay, which showed less than 2% of lysis and enhanced cell viability. Moreover, the bioactivity study revealed rapid mineralization and a higher protein adsorption rate for the monetite CP phase (M‐CP). Subsequently, the chick embryo angiogenesis assay elucidated 33% higher neovascularization for M‐CP compared with the other two CP phases. The fabricated M‐CP nanostructure constitutes a promising candidate for biomedical applications.

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“…To clarify its capacity for osteoconductivity, the material properties of OCP have been investigated, with focus on the granule size, microstructure, incorporation of ions, and so on 24–26 . OCP shows osteogenic capacity and biodegradability, which has been confirmed to be due to its tendency to hydrolyze to HA in the physiological environment 27–30 . OCP hydrolysis has been shown to be involved in the bone formation process as well as immune response regulation, specifically macrophage behavior modulation, most likely via local microenvironmental changes 31–33 .…”

Section: Introductionmentioning

confidence: 99%

“…[24][25][26] OCP shows osteogenic capacity and biodegradability, which has been confirmed to be due to its tendency to hydrolyze to HA in the physiological environment. [27][28][29][30] OCP hydrolysis has been shown to be involved in the bone formation process as well as immune response regulation, specifically macrophage behavior modulation, most likely via local microenvironmental changes. [31][32][33] The conversion of crystal phase of OCP to its hydrolysate is accompanied by calcium (Ca 2+ ) and inorganic phosphate (Pi) ion exchanges, 22 which have previously been shown to regulate macrophage recruitment to the injury site and inflammatory gene expression in vitro.…”

mentioning

confidence: 99%

Osteogenic capacity of octacalcium phosphate involving macrophage polarization

Xiao

Hamai

Baba

et al. 2022

J Biomedical Materials Res

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Previous research has found that octacalcium phosphate (OCP) increases macrophage accumulation and alters the initial inflammatory response. However, the role of the immune response induced by OCP in osteogenesis remains unknown. This study investigated the behavior of macrophages and bone regeneration capacity during the early inflammatory stage of OCP‐mediated osteogenesis. To assess the change in macrophage polarization and osteogenic capacity, we used a standardized rat defect model filled with OCP or calcium‐deficient hydroxyapatite (CDHA)—a material obtained through the hydrolysis of the original OCP. OCP or CDHA granules were incubated with RAW264 cells for 5 days to investigate the effect of physicochemical characteristics on macrophage cytokine/chemokine expression in vitro. Our in vivo results show that due to the OCP implantation, macrophages in the rat tibial defect area tend to polarize to the M2 phenotype (anti‐inflammatory) and inhibit the formation of the M1 phenotype (pro‐inflammatory). In comparison to CDHA, OCP exhibited superior bone regeneration potential due to its rapid promotion of cortical bone healing and stimulation of macrophage‐related growth factors. Furthermore, our in vitro results have shown that OCP regulates the expression of macrophage chemokines over time. Compared to incubation with CDHA, incubation with OCP caused changes in the ionic microenvironment. These findings suggest that the OCP‐mediated macrophage polarization and secretion profile not only regulate immune function but also positively affect osteogenesis.

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Octacalcium phosphate crystals including a higher density dislocation improve its materials osteogenecity

Cited by 17 publications

References 68 publications

Exploring the Formation Kinetics of Octacalcium Phosphate from Alpha-Tricalcium Phosphate: Synthesis Scale-Up, Determination of Transient Phases, Their Morphology and Biocompatibility

Exploring the Formation Kinetics of Octacalcium Phosphate from Alpha-Tricalcium Phosphate: Synthesis Scale-Up, Determination of Transient Phases, Their Morphology and Biocompatibility

Influence of pH in the synthesis of calcium phosphate based nanostructures with enhanced bioactivity and pro‐angiogenic properties

Osteogenic capacity of octacalcium phosphate involving macrophage polarization

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