Effects of pullulan on the biomechanical and anti-collapse properties of dicalcium phosphate dihydrate bone cement

In this work, a modified dicalcium phosphate dihydrate (DCPD) bone cement with unique biodegradable ability in a calcium phosphate cement system was prepared by the hydration reaction of monocalcium phosphate monohydrate and calcium oxide and integration with pullulan (Pul), a non-toxic, biocompatible, viscous, and water-soluble polysaccharide that has been successfully used to improve defects in DCPD bone cement, especially its rapid solidification, fragile mechanical properties, and easy collapse. The effect of different contents of Pul on the structure and properties of DCPD were also studied in detail. The modified cement was characterised by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, ultraviolet–visible absorption, X-ray photoelectron spectroscopy analysis, and rheological property measurements. The results indicated that Pul promoted the hydration formation of DCPD, and interface bonding occurred between Pul and DCPD. With increasing content of Pul, the setting time of the DCPD bone cement increased from 2.6 min to 42.3 min, the compressive strength increased from 0 MPa to 20.4 MPa, and the anti-collapse ability also improved owing to the strong interface bonding, implying that the DCPD bone cement improved by Pul has better potential for application in the field of non-loading bone regenerative medicine compared to unmodified DCPD bone cement.

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Analysis on the Setting of Brushite Bone Cement after Storage in the Humid Environment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.696.32 ◽

2016 ◽

Vol 696 ◽

pp. 32-35

Author(s):

Tai Joo Chung ◽

Kyung Sik Oh

Keyword(s):

Bone Cement ◽

Tricalcium Phosphate ◽

Driving Force ◽

Activation Barrier ◽

Setting Time ◽

Dicalcium Phosphate ◽

Dicalcium Phosphate Dihydrate ◽

Major Phase ◽

Phosphate Dihydrate ◽

Humid Environment

The cause of the degradation was analyzed by applying the highly humid conditions during the storage of cement composed of β-tricalcium phosphate (β-TCP) and monocalcium phosphate monohydrate (MCPM). For the β-TCP and MCPM stored separately under the humid environment, the mild increase in the setting time was observed, and the product after the setting was entirely dicalcium phosphate dihydrate (CaHPO42H2O: DCPD). However, for the β-TCP and MCPM stored mixed under the same condition, the setting time significantly increased with the period of storage, and the product contained dicalcium phosphate (CaHPO4: DCP) as major phase, resulting in the loss of setting ability. The formation of DCP could be because of the weak driving force for setting, caused by a feeble supply of water from moisture. As the formation of DCPD requires stronger driving force to overcome the activation barrier, sufficient amount of water is essential. Humid environment during the storage decreased the driving force by the formation of DCP, and the driving force to produce DCPD was lost during the actual setting.

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Rheological Properties of an Injectable Calcium Phosphate Bone Cement and their Relationship with the Phase Evolution

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1658 ◽

2007 ◽

Vol 336-338 ◽

pp. 1658-1661

Author(s):

Jian Dong Ye ◽

Xiu Peng Wang ◽

Ying Jun Wang

Keyword(s):

Calcium Phosphate ◽

Bone Cement ◽

Yield Stress ◽

Invasive Surgery ◽

Phase Evolution ◽

Hydration Reaction ◽

Dicalcium Phosphate Dihydrate ◽

Non Invasive ◽

Phosphate Dihydrate ◽

Calcium Phosphate Bone Cement

An injectable calcium phosphate bone cement was prepared by combining amorphous calcium phosphate (ACP) and dicalcium phosphate dihydrate (DCPD) for use in non-invasive surgery in this work. The effect of the conserving time on the viscosity, yield stress and injectability of the calcium phosphate cement (CPC) pastes were studied. The results showed that as the conserving time of the pastes prolonged, the viscosity and the yield stress of the pastes increased exponentially, and the injectability of the pastes decreased. This resulted from the transformation of DCPD and ACP into hydroxyapatite via hydration reaction. The results also indicated that the pastes still exhibited good injectability in even 15 min after preparation of the CPC pastes.

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Preparation of Calcium Phosphate Cement Utilizing Dicalcium Phosphate Dihydrate and Calcium Carbonate

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.608.280 ◽

2014 ◽

Vol 608 ◽

pp. 280-286

Author(s):

Nudthakarn Kosachan ◽

Angkhana Jaroenworaluck ◽

Sirithan Jiemsirilers ◽

Supatra Jinawath ◽

Ron Stevens

Keyword(s):

Calcium Carbonate ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Raw Materials ◽

Setting Time ◽

Dicalcium Phosphate ◽

Dicalcium Phosphate Dihydrate ◽

Cement Pastes ◽

Setting Times ◽

Phosphate Dihydrate

Calcium phosphate cement has been widely used as a bone substitute because of its chemical similarity to natural bone. In this study, calcium phosphate cement was prepared using dicalcium phosphate dihydrate (CaHPO4.2H2O) and calcium carbonate (CaCO3) as starting raw materials. The cement pastes were mixed and the chemistry adjusted with two different aqueous solutions of sodium hydroxide (NaOH) and disodium hydrogen phosphate (Na2HPO4). Concentrations of the solution were varied in the range 0.5 to 5.0 mol/L with the ratio of solid/liquid = 2 g/ml. The cement paste was then poured into a silicone mold having a diameter of 10 mm and a height 15 mm. Setting times for the cement were measured using a Vicat apparatus. XRD, FT-IR, and SEM techniques were used to characterize properties and microstructure of the cement. From the experimental results, it is clear that different concentrations of Na2HPO4 and NaOH have affected the setting times of the cement. The relationship between concentration of NaOH and Na2HPO4 and setting time, including final properties of the cement, is discussed.

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SOME EFFECTS OF MOISTURE AND TEMPERATURE ON TRANSFORMATION OF MONOCALCIUM PHOSPHATE IN SOIL

Canadian Journal of Soil Science ◽

10.4141/cjss62-031 ◽

1962 ◽

Vol 42 (2) ◽

pp. 229-239 ◽

Cited By ~ 9

Author(s):

W. C. Hinman ◽

J. D. Beaton ◽

D. W. L. Read

Keyword(s):

Water Soluble ◽

Dicalcium Phosphate ◽

Dicalcium Phosphate Dihydrate ◽

Inorganic P ◽

Monocalcium Phosphate ◽

Liesegang Rings ◽

Phosphate Dihydrate ◽

The Mean ◽

Surrounding Soil

Pre-weighed monocalcium phosphate pellets, containing about 15 milligrams of P, were placed in 200 grams of soil and stored for 2 weeks at four moisture tensions and three temperatures. Pellet residues were then removed and the amount of phosphorus remaining was determined. Small cores containing pellet residues and the surrounding soil contacted by fertilizer solution were removed for determination of water-soluble and total inorganic P. Phosphate phases present at the granule sites and the surrounding soil were identified by their optical properties.The mean amount of phosphorus remaining at the granule sites was 20.2 per cent. Although both moisture tension and temperature significantly affected the quantity of phosphorus retained, no consistent trend was apparent. Residues remaining at the site of application were found to be mixtures of anhydrous and dihydrated dicalcium phosphate, with the latter predominating. Moisture tension and temperature did not greatly alter the proportion of the two phases.Periodic precipitates or Liesegang rings of dicalcium phosphate were formed in the soil surrounding monocalcium phosphate pellets. Dicalcium phosphate dihydrate was the predominant phase. The proportion of dihydrated to anhydrous dicalcium phosphate increased as the temperature decreased and as the moisture tension increased.Water-soluble P increased significantly with increased moisture tension and was significantly greater at 5 °C. than at either 16 or 27 °C. The mean of all treatments was 5.6 per cent. Increased amounts of dicalcium phosphate dihydrate in the surrounding soil seemed to be responsible for the increase in water solubility.Between 89.5 and 99.2 per cent of the added phosphorus was recovered in the water and acid extracts of soil cores containing about 1.4 cm.3 of soil.

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