Comparing the physicochemical properties of dicalcium phosphate dihydrate (DCPD) and polymeric DCPD (P‐DCPD) cement particles

Abstract

We developed a new and injectable poly‐dicalcium phosphate dihydrate (P‐DCPD) forming cement. The key structural difference between P‐DCPD and classical DCPD is that P‐DCPD is composed of interconnected P‐DCPD crystals by interlocking to the polyphosphate chains. In contrast, DCPD is composed of a package of DCPD crystals with weak mutual ionic bonding. The purpose of this continuing study was to compare the physicochemical properties between P‐DCPD and DCPD cement particles. Data collected from SEM, X‐ray diffraction, and Raman Spectroscopy approaches demonstrated that P‐DCPD has a more stable chemical structure than DCPD as evidenced by much less transformation to hydroxyapatite (HA) during setting. Nanoindentation showed a similar hardness while the elastic modulus of P‐DCPD is much lower than DCPD that might be due to the much less HA transformation of P‐DCPD. P‐DCPD has much lower zeta potential and less hydrophilicity than DCPD because of its entangled and interconnected polyphosphate chains. It is expected that superhydrophilic DCPD undergoes faster dissolution than P‐DCPD in an aqueous environment. Another interesting finding is that the pH of eluent from P‐DCPD is more neutral (6.6–7.1) than DCPD (5.5–6.5). More extensive experiments are currently underway to further evaluate the potential impacts of the different physiochemical performance observed of P‐DCPD and DCPD cement particles on the biocompatibility, degradation behavior and bone defect healing efficacy both in vivo and in vitro.

The effects of electrodeposition temperature on morphology and corrosion resistance of calcium phosphorus coatings on magnesium alloy: comparative experimental and molecular dynamics simulation studies

“…37 Besides, the peak at 527 cm −1 is confirmed the bending mode of O–P–O group. 38 Both the FTIR and the Raman spectra confirm that the CaP compound uniformly covering on the surface of the AZ31 substrate is DCPD (CaHPO 4 ·2H 2 O), which is consistent with the XRD results.…”

A slow and sustained release of methotrexate (MTX) from a new polymeric dicalcium phosphate dehydrate cement (P-DCPD)

“…DCPD is biodegradable and known to possess the highest solubility among all CPCs at physiological conditions. 49 Many studies have demonstrated that the degradation rate of DCPD was within a period of 8-52 weeks both in vitro and in vivo based on experiment settings. [50][51][52][53] We 49 currently demonstrated that P-DCPD has a more stable chemical structure than DCPD as evidenced by much less transformation to HA during setting and evolution.…”

The Effect of Polymer Elastic Particles Modified with Nano-Silica on the Mechanical Properties of Oil Well Cement-Based Composite Materials

“…However, all these polymer particles need to be hydrophilically modified, mainly due to the hydrophobic groups on the surface of the polymer particles, which have a lower interfacial adhesion force and lower co-crosslinking level. When applied to water-based mixed systems, this can cause a decrease in the stability, strength, toughness, and other physical properties of the mixed system [ 12 , 13 , 14 , 15 ]. Cheng et al [ 16 ], He et al [ 17 ], and Zhong et al [ 18 ] found that unmodified rubber powder cannot be dispersed when soaked in water, and when added to cement-based composite materials, its compressive strength is low, which can easily lead to a poor stability of the cement paste and the deterioration of its mechanical properties.…”