Mixture Of Phosphate Research Articles

A Comparative Study of the Respiratory Neonatal Outcomes Utilizing Dexamethasone Sodium Phosphate versus a Mixture of Betamethasone Dipropionate and Betamethasone Sodium Phosphate as an Antenatal Corticosteroid Therapy.

ObjectiveThe aim of this study is to compare the respiratory neonatal outcomes utilizing antenatal dexamethasone sodium phosphate (DSP) versus a mixture of betamethasone dipropionate and betamethasone sodium phosphate (B-DP/SP) for preterm births.Patients and MethodsAll neonatal intensive care unit (NICU) admissions for prematurity were retrospectively identified at our center in the period between September 2016 and September 2018. Pregnant women expected to give preterm birth and received steroid injections whether it is DSP or B-DP/SP were included in the study. Maternal and obstetrical data along with the corresponding respiratory neonatal outcomes were extracted and analyzed. The population was categorized according to the gestational age into extremely preterm (less than 28 weeks), very preterm (28 up to 32 weeks) and moderate or late preterm (32 up to 37 weeks) in which the repository outcomes were compared in each sub-group.ResultsA total of 650 premature neonates were included in the analysis. B-DP/SP illustrated a significant reduction in the occurrence of respiratory distress syndrome (RDS) among moderate or late preterm neonates (P = 0.003) compared to DSP. In contrast, a non-significant difference was observed between B-DP/SP and DSP regarding apnea of prematurity and transient tachypnea of the newborn. The number of neonates developed chronic lung disease has been remarkably reduced when using DSP in extremely (P = 0.038) and very (P = 0.046) preterm neonates when compared to B-DP/SP.ConclusionThe dual acting B-DP/SP formulation could possess a significant potential in reducing RDS in moderate or late preterm neonates, while DSP groups exhibit a favorable result in the development of chronic lung disease in extreme and very preterm cohorts. Such findings emphasize the need of further clinical trials, pharmacokinetics, pharmacodynamics and cost effectiveness studies to evaluate the durability of these findings.

Osteoinductive Moldable and Curable Bone Substitutes Based on Collagen, BMP-2 and Highly Porous Polylactide Granules, or a Mix of HAP/β-TCP.

In dentistry, maxillofacial surgery, traumatology, and orthopedics, there is a need to use osteoplastic materials that have not only osteoinductive and osteoconductive properties but are also convenient for use. In the study, compositions based on collagen hydrogel were developed. Polylactide granules (PLA) or a traditional bone graft, a mixture of hydroxyapatite and β-tricalcium phosphate (HAP/β-TCP), were used for gel filling to improve mechanical osteoconductive properties of compositions. The mechanical tests showed that collagen hydrogels filled with 12 wt% highly porous PLA granules (elastic modulus 373 ± 55 kPa) or 35 wt% HAP/β-TCP granules (elastic modulus 451 ± 32 kPa) had optimal manipulative properties. All composite components were cytocompatible. The cell’s viability was above 90%, and the components’ structure facilitated the cell’s surface adhesion. The bone morphogenetic protein-2 (BMP-2) provided osteoinductive composition properties. It was impregnated directly into the collagen hydrogel with the addition of fibronectin or inside porous PLA granules. The implantation of a collagen hydrogel with BMP-2 and PLA granules into a critical-size calvarial defect in rats led to the formation of the most significant volume of bone tissue: 61 ± 15%. It was almost 2.5 times more than in the groups where a collagen-fibronectin hydrogel with a mixture of HAP/β-TCP (25 ± 7%) or a fibronectin-free composition with porous PLA granules impregnated with BMP-2 (23 ± 8%) were used. Subcutaneous implantation of the compositions also showed their high biocompatibility and osteogenic potential in the absence of a bone environment. Thus, the collagen-fibronectin hydrogel with BMP-2 and PLA granules has optimal biocompatibility, osteogenic, and manipulative properties.

Composite Drug Delivery System Based on Amorphous Calcium Phosphate-Chitosan: An Efficient Antimicrobial Platform for Extended Release of Tetracycline.

One major warning emerging during the first worldwide combat against healthcare-associated infections concerns the key role of the surface in the storage and transfer of the virus. Our study is based on the laser coating of surfaces with an inorganic/organic composite mixture of amorphous calcium phosphate–chitosan–tetracycline that is able to fight against infectious agents, but also capable of preserving its activity for a prolonged time, up to several days. The extended release in simulated fluids of the composite mixture containing the drug (tetracycline) was demonstrated by mass loss and UV–VIS investigations. The drug release profile from our composite coatings proceeds via two stages: an initial burst release (during the first hours), followed by a slower evolution active for the next 72 h, and probably more. Optimized coatings strongly inhibit the growth of tested bacteria (Enterococcus faecalis and Escherichia coli), while the drug incorporation has no impact on the in vitro composite’s cytotoxicity, the coatings proving an excellent biocompatibility sustaining the normal development of MG63 bone-like cells. One may, therefore, consider that the proposed coatings’ composition can open the prospective of a new generation of antimicrobial coatings for implants, but also for nosocomial and other large area contamination prevention.

Porous silicon nitride–based drug delivery carrier

AbstractTetracalcium phosphate/monetite biocement was modified with the addition of 30 wt% highly porous silicon nitride/α‐tricalcium phosphate (α‐TCP) microgranules. The volume ratio of Si3N4 and α‐TCP in microgranules was 1:1 and showed good in vitro simulated body fluid bioactivity with precipitation of hydroxyapatite particles. The intention of addition of microgranules to the biocement was to have a carrier of drug, which can be released into the body in due time. Granules prepared by the freeze granulation of starting mixture of silicon nitride and calcium phosphate and subsequent sintering at 1100°C have a suitable pore structure for the foreseen use. The pore volume was almost 1000 mm3/g with the open porosity of 77 vol%. This porosity and the biocompatible composition of silicon nitride–based granules gave a chance to fabricate a suitable composite cement for dexamethasone (DMZ) drug release into the human body. An accelerated release of dexamethasone from composite cement was observed and the full amount of DMZ was released from the composite biocement after 10 days. The presented results are a good base to adjust the total drug release time by the mixing of an appropriate amount of drug infiltrated ceramic granules with the tetracalcium phosphate/monetite cement.

Enhanced degradation of organic compounds through the interfacial transfer of electrons in the presence of phosphate and Nitrogen-cobalt doped graphitic carbon

Peroxymonosulfate (PMS) has been activated for the generation of reactive oxygen species by nitrogen-doped carbonaceous material. However, the influence of phosphate on the degradation performance has not been reported. In this study, phosphate ions accelerate PMS decomposition and degradation of target organic compounds such as carbamazepine, atrazine, sulfamethoxazole, and benzoic acid. It was revealed that the physical mixture of phosphate with Co and N doped graphitic carbon (GcN/Co) demonstrates the occurrence of P C, P N, and P O – C bonds. Essentially, the graphitic N or graphitic N P increased in the presence of phosphate. This was correlated with the lower electrical transfer resistance, improved electrical conductivity, and higher electron morbidity confirmed by different electrochemical tests. Moreover, due to the strong buffering capacity of phosphate at neutral pH, bicarbonate was used to confirm the negligible influence of pH. The presence of phosphate helps to recover the scavenging effect of Cl– but has no effect on the presence of HCO3– and CO32–. Nevertheless, GcN/Co demonstrates good reusability for three reaction cycles, however, in order to maintain a high catalytic performance phosphate needs to be replenished after each cycle.

Effect of pentasodium triphosphate concentration on physicochemical properties, microstructure, and formation of casein fibrils in model processed cheese

The effects of varying the concentration of pentasodium triphosphate (PP) emulsifying salt [0, 0.6, 1.2, 1.5, and 1.8%, plus 0.9% of a mixture of citric acid (CA) and disodium phosphate (DSP) to adjust cheese pH to 5.85] on rheological, textural, physicochemical, and microstructural properties were studied in a processed cheese model system containing ~20% micellar casein concentrate, ~20% sunflower oil, and ~59% water. Special emphasis was placed on the unique casein fibrils recently described in a comparable processed cheese model system. Our results show that during processing (90°C, 17.37 rpm over 270 min) the apparent viscosity increased more and faster for formulations containing higher concentrations of PP, in analogy to the so-called creaming reaction, a general thickening of the molten cheese mass with prolonged processing. We found that 1.2% PP (plus 0.9% CA-DSP) appeared to be the threshold for the creaming reaction to take place. With increasing PP concentrations, cheese hardness increased in a sigmoidal fashion, and insoluble (protein-bound) calcium concentration decreased exponentially. Light micrographs of samples taken at the end of processing indicated initially large and dense casein aggregates within the matrix that disappeared with higher levels of PP, in parallel with the development of a finer emulsion. With transmission electron microscopy analysis on the same samples, the highly complex restructuring of the casein matrix was evident; casein fibrils had formed de novo at the periphery of the loosening casein aggregates. With higher levels of PP, amorphous areas were observed in place of the dense casein aggregates that appeared progressively void of protein, whereas fibril concentration increased throughout the rest of the matrix. Fibrils progressively attached to the surface of fat globules, thereby emulsifying them. Reverse-phase HPLC analysis of insoluble and soluble fractions indicated κ-casein to be the most likely constituent of the newly formed fibrils. The results of this study suggest that PP induced a concentration-dependent dissociation of caseins (through increased calcium chelation) and further led to their spatial separation. In essence, their chaperone activity was hindered, which resulted in amorphous aggregation on the one hand and fibril formation on the other.

Producing Superphosphate with Sewage Sludge Ash: Assessment of Phosphorus Availability and Potential Toxic Element Contamination

Recovering and recycling phosphorus (P) from sewage sludge ash (SSA) for the purpose of P fertilizer production contributes to reducing the input of mined phosphate-minerals and closing of the P cycle. However, direct use of SSA as fertilizer is often a questionable strategy due to its low nutrient use efficiency. In addition, the environmental risk potential of utilizing SSA in agriculture is still unclear, in particular potential toxic element (PTE) contamination. In this study, a mixture of SSA and rock phosphate was used at lab-scale superphosphate (SP) production. P availability of the final product and PTE contamination (Cd, Cr, Cu, Zn, Pb, Ni) in soil and crop was investigated through maize (Zea mays L.) cultivation. Results showed that the application of SP that was produced by 25% SSA replacement did not affect the growth, P uptake, and PTE content in aboveground maize compared to the application of SP produced without SSA replacement. However, significant inputs of SP with SSA replacement may decrease the solid-soil solution partitioning of Cu, Ni and Pb in the long-term. Separation of municipal/industrial sludge and PTE removal technology are necessary to be implemented prior to the use of SSA as a secondary raw material in P-fertilizer production.

Effect of heat treatment on the synthesis of hydroxyapatite from Indian clam seashell by hydrothermal method

Hydroxyapatite (HA) powder has been successfully synthesized from low-cost Indian clam seashells by using hydrothermal method. The mixture of tri-calcium phosphate [Ca3(PO4)2], heat-treated ball-milled clam seashell, and demineralized water are heat-treated at several temperatures (700 °C, 800 °C, 900 °C, 1000 °C, and 1100 °C) for various time periods (1 h, 2 h, and 3 h) to perform the hydrothermal reactions. The phases and microstructure of the solid-state reaction products are analyzed through X-ray diffraction (XRD) method and field emission scanning electron microscopy (FESEM) respectively. The crystallite size of all the synthesized powders is calculated by using Scherrer's model. Mainly HA phase is obtained in all the different reaction products. However, these HAs are found to be non-stoichiometric in nature. As per the literature, non-stoichiometric HA is a more biologically active material compared to the stoichiometric one. Almost pure HA is formed with any selected reaction temperature applied for 2 h time duration. The crystallinity and Ca/P ratio of the synthesized pure HA are estimated by using standard model and energy-dispersive X-ray spectroscopy (EDS) analysis, respectively. The highest amount of near stoichiometric crystalline HA has been obtained at 900 °C of reaction temperature applied for 2 h time duration. With raising reaction temperature, the grain size of pure HA is found to be increased. Needle/rod shaped nano grains are noticed to form at lower reaction temperature whereas; beyond 1000 oC of temperature globular/spherical shaped grains are also observed to form. At 3 h reaction time agglomeration of grains is found to occur in all the synthesized powders.

Regarding the Formation of Wood Material Fire Protection and the Mechanism of its Action

The theoretical aspects of wood material fire protection formation by esterification reactions are considered in the article. The reactivity of polysaccharides and polymers from which wood material is composed has been confirmed by the FTIR method. The IR spectra of the original standard samples of lignin and microcrystalline cellulose were taken and after treatment with solutions with concentrations of 10% of the mass. orthophosphoric (Н3РО4) and oxyethylene diphosphonic (CH3C(OH)(H2PO3)2) acids. Electron scanning microscopy revealed the crystallization of inorganic salts on the wood material surface, which play the role of flame retardants, as well as a film of organopolymer (polyhexamethylene guanidine polyphosphate), which forms a foamed layer of coke when heated. Thermogravimetric analysis (TGA) and gas chromatography (GC) methods show the mechanism of action of fire protection provided to wood material. The formation of foamed coke is visually shown and the results on the effectiveness of fire protection on the example of wood material treatment with a mixture of diammonium phosphate and ammonium sulfate are obtained.

Research of Mechanism of Fire Protection with Wood Lacquer

The results of researches of wood burning parameters and influence of fire-retardant substances on them are given. Studies have shown that the process of heat insulation of a wooden structure is the formation of soot-like products on the surface of natural combustible material. Under the action of the burner flame on the protected sample treated with impregnating solutions based on a mixture of ammonium phosphate with antiseptic, the temperature of gaseous combustion products was 230 oC, and weight loss did not exceed 9%, while wood treated with a composition of urea and phosphoric acids and starch showed temperature of 160 oС with a weight loss of 3.6%. It is established that fire protection by coatings provides a low rate of burnout of wood samples and with increasing temperature exposure and translates into a non-flammable material that does not spread the flame on the surface.

Highly conductive organic-ionogels with excellent hydrophobicity and flame resistance

Very different from electronic conductors, ionic conductors usually possess some unique functions such as stretchability, transparency and ionic conductivity, thus exhibiting a great promise in the flexible wearable electronic devices. Herein, we develop a novel stretchable transparent organic-ionogel (OIG-TBP-50) via a rapid photo-curing process, in which we select the mixture of tributyl phosphate (TBP) and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)amine ([BMMIm][NTf2]) as fireproof and conductive solvent, respectively. Just benefiting from the good synergistic effect of TBP and [BMMIm][NTf2], our-designed OIGs demonstrate excellent hydrophobicity and flame resistance as well as perfect stretchability (757%), high transparency (93%) in visible region, good environmental stability, wide temperature tolerance range (from −55 °C to 180 °C) and high ionic conductivity (1.73 × 10-3 S cm−1 at room temperature). In addition, our stretchable transparent OIGs even could light LED lamps under an alternating current field when directly used as the flexible conductive substrate. Further applying such OIGs as ionic conductor to assemble flexible sensor and touch screen, both of them could transport rapid signal response under slight touch stress.

Galvanic Deposition of Hydroxyapatite/Chitosan/Collagen Coatings on 304 Stainless Steel

The galvanic deposition method was used to deposit Hydroxyapatite/Chitosan/Collagen coatings on 304 stainless steel. Galvanic deposition is an alternative and valid way to fabricate bio-coatings with high biocompatibility and good anticorrosion properties. Physical-chemical characterizations were carried out to investigate chemical composition and morphology of the samples. Coatings consist of a mixture of calcium phosphate (Brushite and Hydroxyapatite) with chitosan and collagen. Corrosion tests were performed in the simulated body fluid (SBF) after different aging times. Results show that, in comparison with bare 304 stainless steel, coating shifts corrosion potential to anodic values and reduces corrosion current density. Nevertheless, the aging in SBF led to a completely conversion of brushite into hydroxyapatite. The release of metal ions, measured after 21 days of aging in SBF solution, is very low due to the presence of coating that slow-down the corrosion rate of steel.

3D-Printed Barrier Membrane Using Mixture of Polycaprolactone and Beta-Tricalcium Phosphate for Regeneration of Rabbit Calvarial Defects.

Background: Polycarprolactone and beta tricalcium phosphate (PCL/β-TCP) are resorbable biomaterials that exhibit ideal mechanical properties as well as high affinity for osteogenic cells. Aim: Objective of this study was to evaluate healing and tissue reaction to the PCL/β-TCP barrier membrane in the rabbit calvaria model for guided bone regeneration. Materials and Methods: The PCL/β-TCP membranes were 3D printed. Three circular defects were created in calvaria of 10 rabbits. The three groups were randomly allocated for each specimen: (i) sham control; (ii) PCL/β-TCP membrane (PCL group); and (iii) PCL/β-TCP membrane with synthetic bone graft (PCL-BG group). The animals were euthanized after two (n = 5) and eight weeks (n = 5) for volumetric and histomorphometric analyses. Results: The greatest augmented volume was achieved by the PCL-BG group at both two and eight weeks (p < 0.01). There was a significant increase in new bone after eight weeks in the PCL group (p = 0.04). The PCL/β-TCP membrane remained intact after eight weeks with slight degradation, and showed good tissue integration. Conclusions: PCL/β-TCP membrane exhibited good biocompatibility, slow degradation, and ability to maintain space over eight weeks. The 3D-printed PCL/β-TCP membrane is a promising biomaterial that could be utilized for reconstruction of critical sized defects.

Effects of Phosphorus on Nitrification Process in a Fertile Soil Amended with Urea

While the effects of carbon on soil nitrogen (N) cycle have been extensively studied, it is not clearly understood how co-existing macronutrients, such as phosphorus (P), affect the N cycle in agroecosystems. In this study, P amendment effects on nitrification in a fertile agricultural soil were investigated under a typical N-P amendment rate. In a laboratory incubation study, soils were amended with urea, monopotassium phosphate and a mixture of urea and monopotassium phosphate at the same rate. In soils that received no amendments (control), P only, urea only, and urea plus P amendment, nitrification occurred within the first five days, with an average net nitrification rate of 5.30, 5.77, 16.66 and 9.00 mg N kg−1d−1, respectively. Interestingly, nitrification in urea-treated soils was retarded by P addition where a N:P ratio seemed to be a key factor impeding nitrification. This was also supported by the response of ammonia-oxidizing bacteria (AOB), which was more sensitive to P addition than ammonia-oxidizing archaea (AOA). The outcome of this study showed that application of P fertilizer suppressed the nitrification process in urea amended soil, suggesting that a synergistic aspect of N and P nutrient management should be further explored to retard N losses from agricultural systems.

Mutual chemical effect of autograft and octacalcium phosphate implantation on enhancing intramembranous bone regeneration

ABSTRACT This study examined the effect of a mixture of octacalcium phosphate (OCP) and autologous bone on bone regeneration in rat calvaria critical-sized defect (CSD). Mechanically mixed OCP and autologous bone granules (OCP+Auto), approximately 500 to 1000 μm in diameter, and each individual material were implanted in rat CSD for 8 weeks, and subjected to X-ray micro-computed tomography (micro-CT), histology, tartrate-resistant acid phosphatase (TRAP) staining, and histomorphometry for bone regeneration. Osteoblastic differentiation from mesenchymal stem cells (D1 cells) was examined in the presence of non-contacting materials by alkaline phosphatase (ALP) activity for 21 days. The material properties and medium composition before and after the incubation were determined by selected area electron diffraction (SAED) under transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and chemical analysis. The results showed that while bone formation coupled with TRAP-positive osteoclastic resorption and cellular ALP activity were the highest in the Auto group, a positive effect per OCP weight or per autologous bone weight on ALP activity was found. Although the OCP structure was maintained even after the incubation (SAED), micro-deposits were grown on OCP surfaces (TEM). Fibrous tissue was also exposed on the autologous bone surfaces (SEM). Through FT-IR absorption, it was determined that bone mineral-like characteristics of the phosphate group increased in the OCP + Auto group. These findings were interpreted as a structural change from OCP to the apatitic phase, a conclusion supported by the medium degree of saturation changes. The results demonstrate the mutual chemical effect of mixing OCP with autologous bone as an active bone substitute material.

Evaluation of Mixed Corrosion Inhibitors in Cooling Water System

The effect of mixed corrosion inhibitors in cooling system was evaluated by using carbon steel specimens and weight loss analysis. The carbon steel specimens which immersed in mixture of sodium phosphate ( Na2HPO4 ) used as corrosion inhibitor and sodium glocunate ( C6 H11 NaO7 ) as scale dispersant at different concentrations (20,40, 60, 80 ppm) and at temperature 25°C for (1-5) days. The corrosion inhibitors efficiency was calculated by using uninhibited and inhibited water to give 98.1%. The result of these investigation indicate that the corrosion rate decrease with increase the corrosion inhibitors concentration at 80 ppm and for 5 days, (i.e. corrosion rate= 0.042 gmd).&#x0D;

Population pharmacodynamic modeling of intramuscular and oral dexamethasone and betamethasone effects on six biomarkers with circadian complexities in Indian women

Population pharmacokinetic/pharmacodynamic (PK/PD) analysis was performed for extensive data for differing dosage forms and routes for dexamethasone (DEX) and betamethasone (BET) in 48 healthy nonpregnant Indian women in a partial and complex cross-over design. Single doses of 6 mg dexamethasone phosphate (DEX-P), betamethasone phosphate (BET-P), or 1:1 mixture of betamethasone phosphate and acetate (BET-PA) were administered orally (PO) or intramuscularly (IM) where each woman enrolled in a two-period cross-over study. Plasma concentrations collected over 96 h were described with a two-compartment model with differing PO and IM first-order absorption inputs. Overall, BET exhibited slower clearance, similar volume of distribution, faster absorption, and longer persistence than DEX with BET acetate producing extremely slow absorption but full bioavailability of BET. Six biomarkers were assessed over a 24-h baseline period with four showing circadian rhythms with complex baselines. These baselines and the strong responses seen after drug dosing were fitted with various indirect response models using the Laplace estimation methods in NONMEM 7.4. Both the PK and six biomarker responses were well-described with modest variability likely due to the homogeneous ages, weights, and ethnicities of the women. The drugs either inhibited or stimulated the influx processes with some models requiring joint inclusion of drug effects on circadian cortisol suppression. The biomarkers and order of sensitivity (lowest IC50/SC50 to highest) were: cortisol, T-helper cells, basophils, glucose, neutrophils, and T-cytotoxic cells. DEX sensitivities were generally greater than BET with corresponding mean ratios for these biomarkers of 2.86, 1.27, 1.72, 1.27, 2.69, and 1.06. Overall, the longer PK (e.g. half-life) of BET, but lesser PD activity (e.g. higher IC50), produces single-dose response profiles that appear quite similar, except for the extended effects from BET-PA. This comprehensive population modeling effort provides the first detailed comparison of the PK profiles and six biomarker responses of five commonly used dosage forms of DEX and BET in healthy women.

Performance of Nano-Hydroxyapatite/Beta-Tricalcium Phosphate and Xenogenic Hydroxyapatite on Bone Regeneration in Rat Calvarial Defects: Histomorphometric, Immunohistochemical and Ultrastructural Analysis.

BackgroundSynthetic biomaterials have played an increasingly prominent role in the substitution of naturally derived biomaterials in current surgery practice. In vitro and in vivo characterization studies of new synthetic biomaterials are essential to analyze their physicochemical properties and the underlying mechanisms associated with the modulation of the inflammatory process and bone healing.PurposeThis study compares the in vivo tissue behavior of a synthetic biomaterial nano-hydroxyapatite/beta-tricalcium phosphate (nano-HA/ß-TCP mixture) and deproteinized bovine bone mineral (DBBM) in a rat calvarial defect model. The innovation of this work is in the comparative analysis of the effect of new synthetic and commercially xenogenic biomaterials on the inflammatory response, bone matrix gain, and stimulation of osteoclastogenesis and osteoblastogenesis.MethodsBoth biomaterials were inserted in rat defects. The animals were divided into three groups, in which calvarial defects were filled with xenogenic biomaterials (group 1) and synthetic biomaterials (group 2), or left unfilled (group 3, controls). Sixty days after calvarial bone defects filled with biomaterials, periodic acid Schiff (PAS) and Masson’s trichrome staining, immunohistochemistry tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase-9 (MMP-9), and electron microscopy analyses were conducted.ResultsHistomorphometric analysis revealed powerful effects such as a higher amount of proteinaceous matrix and higher levels of TNF-α and MMP-9 in bone defects treated with alloplastic nano-HA/ß-TCP mixture than xenogenicxenogic biomaterial, as well as collagen-proteinaceous material in association with hydroxyapatite crystalloids.ConclusionThese data indicate that the synthetic nano-HA/ß-TCP mixture enhanced bone formation/remodeling in rat calvarial bone defects. The nano-HA/ß-TCP did not present risks of cross-infection/disease transmission. The synthetic nano-hydroxyapatite/beta-tricalcium phosphate mixture presented adequate properties for guided bone regeneration and guided tissue regeneration for dental surgical procedures.

Influence of polyacrylic acid (PAA)/Na2HPO4 mixture on biphasic calcium phosphate cement: Enhancing strength and cell viability

AbstractThis study has investigated the effect of combination of new liquid phase mixture of disodium hydrogen phosphate (Na2HPO4) and polyacrylic acid (PAA) on the compressive strength, setting time, bioactivity, and cytotoxicity of biphasic calcium phosphate cement. The PAA was known as one of water‐soluble and biocompatible polymers to improve the mechanical performances of the bone cement, but it usually inhibits the phase conversion to hydroxyapatite after the cement has already set. The aim of this work was to evaluate the incorporation of the mixture of PAA and Na2HPO4 into biphasic cement. We have found the crucial concentration for adding PAA/Na2HPO4 at 30:70 v/v% to enhance the mechanical strength, cell viability, and maintain bioactivity. The phase composition and crosslinking reaction between PAA and alpha‐tricalcium phosphate (α‐TCP) powder were detected by XRD and FTIR techniques. The beta‐tricalcium phosphate (β‐TCP) was added in the formula to achieve the biphasic cement, which composed of β‐TCP and apatite/calcium deficient‐hydroxyapatite (CD‐HA) in the final product. The biphasic granule commercial product was used as comparison in the cell viability test. This work had been confirmed that the cement was a nontoxic material. Therefore, our results suggest that the PAA/Na2HPO4 could be beneficial for further clinical applications.

Ultrasound-assisted of alkali chloride separation using bulk ionic liquid membrane

An ultrasonic-assisted separation of alkali chloride (LiCl, NaCl, and KCl) salts have been carried out using of an hydrophobic ionic liquid membrane (ILM). The ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate and tributyl phosphate mixture have been used as ILM. An ultrasonic probe with different frequencies (25, 100, and 250) kHz have been applied as source of ultrasound generator with different times of sonication (2, 5, and 10) min in three phases system containing feed, ILM, and receiver in osmotic U-shaped tube. Also, 250, 500, and 1000 ppm of the feed (alkali chloride) concentration have been used to separate. The frequency of 250 kHz with higher sonication time provides optimum condition for separation of LiCl with lower feed concentration. The thermodynamic properties such as density and speed of sound and the related thermodynamic properties have been calculated to optimize ILM composition (xIL = 0.45) for ultrasound-separation.