Phosphate Complexes Research Articles

Competitive adsorption geometries for the arsenate As(V) and phosphate P(V) oxyanions on magnetite surfaces: Experiments and theory

Abstract In the present study, the competitive adsorption geometries for arsenate and phosphate on magnetite surfaces over a pH range of 4–9 were investigated using in situ attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) and two-dimensional correlation analysis (2D-COS). The adsorption energies and infrared vibrational frequencies of these surface complexes were also calculated by first-principles simulations. Arsenate and phosphate have different preferences for the magnetite surface in the presence of aqueous solvent at both acid and alkaline pH. For the adsorption of phosphate, mono-protonated monodentate mononuclear (MMM) complexes dominated at acid pH, while non-protonated bidentate binuclear (NBB) complexes were dominant at alkaline pH. Arsenate mainly formed bidentate binuclear (BB) complexes with some outer-sphere species, both of which were more prevalent at acid pH. The pre-absorbed inner-sphere arsenate species were scarcely affected by the introduction of phosphate. However, the pre-absorbed phosphate oxyanions, especially the MMM complexes, were significantly substituted by BB arsenate at the magnetite surfaces. The adsorption affinity of phosphate and arsenate species for magnetite surface was found to increase in the following order: MMM phosphate complex < NBB phosphate complex < BB arsenate complex, which was consistent with the calculated adsorption energies. The simulated infrared vibrational frequencies for the most favorable adsorption modes of each oxyanion display distinctive patterns, and their trends are in excellent agreement with experimental data. The effects of pH, adsorption sequence, and mineral species on the competitive adsorption between arsenate and phosphate oxyanions are also discussed, and their different competing ability and stability on the magnetite surfaces can be ascribed to the variations in adsorption geometry and strength of binding. To the best of our knowledge, this is the first study aiming to distinguish the stability of the different phosphate and arsenate complexes on magnetite by employing a combined approach of in situ spectroscopy and DFT simulations. Our results provide molecular-level insight into the geometries and relative stabilities of the adsorption of phosphate and arsenate on magnetite surfaces, which is useful for interpretation of the mobility and bioavailability of these anions.

A potential new therapeutic option for the treatment of nonmuscle invasive bladder cancer: Combination of intravesical oncotherad immunotherapy and platelet rich plasma (PRP).

461 Background: Effective intravesical therapies remain lacking for non-muscle invasive bladder cancer (NMIBC) when Bacillus Calmette-Guerin fails. OncoTherad is a nanostructured inorganic phosphate complex associated with glycosidic protein, developed by the University of Campinas/Brazil, which triggers immunomodulatory and antitumor activities. Previous studies have shown that Platelet Rich Plasma (PRP) acts on immune activation and exerts antitumor effects. This study characterized the effects of the OncoTherad associated with PRP in the treatment of NMIBC chemically induced in mice and the modulation promoted in the Toll-like receptors (TLRs) signaling pathway. Methods: Forty-two C57BL/6J mice were divided into groups: Control; Cancer (N-ethyl-N-nitrosourea carcinogen, 50 mg/ml); PRP (0.1 ml); OncoTherad (20 mg/ml); OncoTherad+PRP 10 mg/ml and OncoTherad+PRP 20 mg/ml. The intravesical doses (0.1 ml) were instilled once a week for 6 weeks after induction. Results: The NMIBC induction decreases (p<0.05) body weight, although after treatments the body weight was recovered similarly to the healthy mice. The treatments did not significantly alter the biochemical patterns of the urine and food and water consumption. There was no acute toxicity or kidney damage, and the presence of hydroureter was variable. The urinary bladders of mice treated with Oncotherad associated or not with PRP showed hyperemia associated with the inflammatory condition. The thickening of the urinary bladder wall in the Cancer group was more evident than in the treated groups, in which there were bladders without thickening or macroscopic lesions. Flat carcinoma in situ (pTis) was present in 100% of the mice in the Cancer group and the intensity of immunoreactivities for TLR2, IL-6, TLR4, and IRF-3 was significantly weaker in comparison with the Control, indicating suppression of the immune system in the tumor microenvironment. When treated intravesically with PRP only, mice showed 28.6% of tumor progression inhibition rate; with OncoTherad 85.7% and with OncoTherad+PRP 10 mg/ml or 20 mg/ml 71.4%. Intravesical treatments led to distinct activation of TLRs 2 and 4-mediated innate immune system in the interleukins (MyD88-dependent) and interferons (TRIF-dependent) signaling pathways. The combined treatment of OncoTherad+PRP increased (p<0.05) the percentage of positive TLR4 urothelial cells and the intensity of immunoreaction for TLR4 compared to the isolated treatments and the immunoreactivities of NF-kB, IL-6, TLR4, IRF-3, and IFN-γ in comparison to the Cancer. Conclusions: Intravesical treatment with OncoTherad plus PRP promoted significant inhibition of tumor progression, possibly due to immunomodulatory activity involving the TLR pathway. This association can constitute a therapeutic strategy for refractory NMIBC patients.

Cultivation and application of Scenedesmus sp. strain UKM9 in palm oil mill effluent treatment for enhanced nutrient removal

Palm oil mill effluent (POME) contains nutrients such as carbon, nitrogen and phosphorus, and poses a threat to the environment especially if released untreated into water bodies. The phylum Chlorophyta contains microalgae from the genus Scenedesmus which are utilised as bioremediation agents. This study was conducted to evaluate the performance of Scenedesmus sp. UKM9 to remove chemical oxygen demand (COD) and nutrients (NH4+ and PO43−) from anaerobic POME by considering photoperiods and pollutant loading rates as environmental parameters. The results showed that the removal of COD (57% removal) and NH4+ (100% removal) was the highest in a 12h:12h (light:dark) photoperiod and a pollutant loading rate of 61.67 mg L−1 day−1 COD. Removal of PO43− (91% removal) was highest in a 16h:8h (light:dark) photoperiod and a pollutant loading rate of 11.67 mg L−1 day−1 COD. The removal of COD, nitrogen and phosphate occurred via the actions of microalgae through assimilation, bacteria through oxidation and precipitation through the formation of calcium phosphate complexes. These findings suggest that Scenedesmus sp. strain UKM9 is a potential bioremediation agent for treating POME.

Utilization of high internal phase emulsion stabilized by egg yolk-modified starch complex for the delivery of lutein

The purpose of this study was to evaluate the physicochemical stability and potential gastrointestinal fate of the lutein-enriched high internal phase emulsions (LE-HIPE) stabilized by egg yolk-modified starch complex. Results showed that the physical stability and lutein retention of the LF-HIPE stabilized by egg yolk-hydroxypropyl distarch phosphate (EY-HPDSP) or egg yolk-octenyl succinic anhydride starch (EY-OSA) complex were both significantly improved at 4 °C. However, the LE-HIPE stabilized by EY-HPDSP complex showed better physical stability, lower lipid oxidation and higher lutein retention during storage at 37 °C than that stabilized by EY-OSA complex, which was related with the results of smaller droplets, more restricted water and oil protons for the former. In vitro digestion results showed that high level of HPDSP in LE-HIPE was beneficial to the improvement of the bioaccessibility of lutein. These results could be useful in the development of nutrient delivery system based on egg yolk-modified starch complex stabilized HIPE.

Detoxification of heavy metals attributed to biological and non–biological complexes in soils around copper producing areas throughout China

Previously risk evaluation did not consider soil composition and the in–situ existing forms for heavy metals in soils would be altered during sequential extraction. It necessitates exploring the detoxification pathways of heavy metals using real soil biological/non–biological components and then linking them to risk evaluation of heavy metals. In this study, we focused on the potential health risks associated with heavy metals, enzyme/extracellular polymeric substances (EPS)–producing bacteria associated with heavy metal resistance, and non–biological compositions in soils from typical copper producing areas throughout China. This study showed that 83% of the monitored regions in 7 provinces throughout China posed unacceptable health risks using prediction models. Details include Pb (1.21) and Hg (3.60) with unacceptable non–cancer hazards, As (1.44E-04) with unacceptable cancer risks, and highly unacceptable risks associated with groundwater ingestion from soil leaching. The production processes and periods as well as ore composition accounted for the distributions of heavy metals in soils through principal component analysis. Linkage between heavy metals, soil biological and non–biological components were built using redundancy models. Based on the results, two possible existing forms were revealed for detoxification of heavy metals. First, the ternary complex of heavy metal, phosphate and Fe (hydr)oxide were formed for multiple metals, where the urease and catalase were up–regulated. Second, the bacterial EPS complexed with Fe (hydr)oxides was formed in soils with Cr of low risks and high total N/total P ratios. Therefore, we recommended insight into pollution sources and existing forms of heavy metals to control risks. • Up to 83% of typical Cu producing areas pose unacceptable risks to workers in China. • Pollution sources and complicate soil composition account for risks of heavy metals. • Ternary complex of heavy metal, PO 4 3− and Fe (hydr)oxide detoxify multiple metals. • Urease and catalase along with ternary complex reduce high risks of multiple metals. • EPS complexed with Fe (hydr)oxides reduce risks of Cr in soils with high N/P ratio.

Neptunium – Tri-n-butyl phosphate complexes in room temperature ionic liquids: Extraction and spectroelectrochemical studies

The extraction of Np4+ and NpO22+ was investigated from nitric acid feeds using solutions of tri-n-butyl phosphate (TBP) in two room temperature ionic liquids viz. 1-butyl-3-methylimidazolium bis(trifluoromethane)sulfonamide (C4mim•NTf2) and 1-methyl-3-octylimidazolium bis(trifluoromethane)sulfonamide (C8mim•NTf2). For comparison purposes, the extraction of Pu4+ and UO22+ were also studied in select cases in view of their similarity with the tetra- and hexavalent neptunium ions. The nature of the extracted species was ascertained by slope analysis and two-phase extraction constants were determined. While the Np4+ ion bearing species of the type Np(NO3)3(TBP)2+ and Np(NO3)3(TBP)+ were extracted into C4mim•NTf2 and C8mim•NTf2, respectively, species of the type NpO2(NO3)2∙TBP were obtained for NpO22+ ion in both the ionic liquids. The extraction data were compared with those reported before in other solvent systems. Cyclic voltammetric studies were carried out using the Np(IV)-TBP extract in both the ionic liquid medium and the conversion to the penta-valent state (NpO2+) was confirmed by UV–visible spectrophotometric analysis of the extract.

New insights for titanium(iv) speciation in acidic media based on UV-visible and 31P NMR spectroscopies and molecular modeling.

Titanium chemistry in aqueous acidic media has been extensively investigated over the last decades. Hydrolyzed species such as Ti(OH)3+, TiO2+, Ti(OH)22+ or Ti(OH)3+ have been identified and their equilibria have been studied in nitric and perchloric acid. A predominance of the divalent cations was found for low pH (i.e., pH <2). Nonetheless, recent literature reports the existence of small titanium oxo-clusters in aqueous acidic media for large titanium(iv) concentration (typically., >0.1 mol L−1), as stable precursors for the formation of condensed titanium dioxide. The present paper reconsiders firstly previous knowledge about the speciation of titanium(iv) in non-complexing acidic media by giving evidence for the presence of polynuclear hydrolyzed species, even at very low Ti(iv) concentration (i.e., typically <0.1 mmol L−1). UV-visible absorbance spectra recorded for diluted nitric acid solutions (a model of non-complexing acidic medium) containing titanium(iv) were compared to time-dependent density functional theory (TD-DFT) predicted excitation energies. Experimental and predicted maximal absorbance wavelengths showed significantly improved matches when polynuclear species were considered in TD-DFT calculation. Then, 0.1–12.7 mol L−1 phosphoric acid solutions containing titanium(iv) were studied by means of spectroscopic techniques (UV-visible, NMR) in order to identify qualitatively the presence of titanium(iv) complexes and to link this speciation to the acid concentration. Two different titanium(iv) orthophosphate complexes, potentially polynuclear, were detected, and the presence of free titanium(iv) is also expected for low phosphoric acid concentration (i.e., <0.1 mol L−1). A general complexation scheme for a large range of H3PO4 concentration was thus formulated.

Adsorption of phosphate and cadmium on iron (oxyhydr)oxides: A comparative study on ferrihydrite, goethite, and hematite

Iron (oxyhydr)oxides participate in a variety of geochemical processes, and hence control the cycling of elements and quality of soils. The present work provides information about the macroscopic adsorption behaviors and microscopic mechanisms of typical cations and oxyanions (i.e., cadmium and phosphate) on three omnipresent iron (oxyhydr)oxides (i.e., ferrihydrite (Fh), goethite (Gt), and hematite (Hm)) in single- and double-solute systems, which can not only help in understanding the different adsorption behaviors of iron (oxyhydr)oxides, but also be important in developing robust and accurate surface complexation models. In both adsorption systems, Fh exhibited the strongest capacity in the uptake of phosphate and cadmium, followed by Gt and Hm; specifically, the adsorbed amounts of ions by Fh were ~ 6 times higher than those by Gt and Hm. Phosphate and cadmium can be synergistically adsorbed by the minerals. In situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra combining with the two-dimensional correlation spectroscopic (2D-COS) analysis were employed to unravel the bonding modes of phosphate on minerals. In the single-solute adsorption systems, although the primary species on Hm and Gt were similar, i.e., protonated and non-protonated bidentate phosphate complexes, more protonated complexes were found on Hm than on Gt; whereas the complexation modes of phosphate on Fh were diversified due to the complex nature of the surfaces, including monoprotonated bidentate, non-protonated bidentate, and outer-sphere complexes. The synergistic adsorption mechanisms of phosphate and cadmium on the three minerals were analogous, including electrostatic interaction, as well as the formation of phosphate-bridged ternary complexes and surface precipitation; nevertheless, the relative contributions of the mechanisms on the minerals were distinct: electrostatic attraction was the predominant co-adsorption mechanism for ions on Gt, while surface precipitation was the most significant on Fh among the three minerals. This study can be enlightening to understand the interaction between the soil constituents, which is crucial to evaluate the fate and transport of the environmentally important substances in different geological settings.

Understanding effect of phosphorus-based additive on ash deposition characteristics during high-sodium and high-calcium Zhundong coal combustion in drop-tube furnace

Zhundong coal as a high quality steam coal has not been widely utilized due to severe fouling and slagging problems during combustion. To promote clean utilization of Zhundong coal, combustion experiments of Zhundong coal were carried out in the drop tube furnace (DTF). The influence of novel phosphorus-based additive on ash deposition characteristics of Zhundong coal was studied. The appearance and phase composition of the raw coal and mixed coal ash deposits at different flue gas temperatures were researched respectively. The new prediction index of slagging tendency containing phosphorus was proposed, and the balance calculation were performed by FactSage thermodynamic software in different flue gas temperatures, including experimental temperatures selected. The results showed that the values of new indexes for predicting slagging tendency had obvious changes, and the phosphorus-based additive had a significant effect on the ash deposition behavior during the combustion process of Zhundong coal in DTF. Compared with the raw coal, the mixed coal with additive had higher ash fusion points and were in the form of loose, crisp, and porous powder, which was beneficial for soot blowing. When the flue gas temperature was 1000 °C or 1150 °C, there was much phosphate complex salt as the skeleton in the ash deposits of the mixed coal, such as Na2CaMg7(PO4)6. Phosphate captured Na and Ca, and effectively inhibited the low temperature eutectic mixtures of Ca with Si and Al, indicating that phosphorus-based additive had good effect on improving ash deposition characteristics of Zhundong coal.

Preparation of Responsive Zwitterionic Diblock Copolymers Containing Phosphate and Phosphonate Groups

In this study, novel zwitterionic diblock copolymers, namely poly(2-(N-morpholino)ethyl methacrylate))-block-poly(2-(methacryloyloxy)ethyl phosphate) (PMEMA-b-PMOEP) and poly(2-(N-morpholino)ethyl methacrylate))-block-poly ((methacryloyloxy)methyl phosphonic acid) (PMEMA-b-PMOMP), were synthesized via reversible addition-fragmentation chain transfer controlled radical polymerization. Solution properties of these phosphorus-based diblock copolymers were investigated using dynamic light scattering, transmission electron microscopy and proton nuclear magnetic resonance spectroscopy. Since the PMEMA block has both salt- and thermo-responsive properties, PMEMA-b-PMOEP and PMEMA-b-PMOMP diblock copolymers formed core-shell micelles in basic aqueous media as the PMEMA block formed insoluble micelle core with the addition of Na2SO4 or an increase in temperature in basic solution. Additionally, PMEMA-b-PMOMP diblock copolymers interacted strongly with calcium cations and yielded reverse micellar structures via complexation of phosphate with metal cation in aqueous media.

Biological activities of siRNA-loaded lanthanum phosphate nanoparticles on colorectal cancer

Lanthanum can reduce absorption of phosphate by forming lanthanum phosphate complexes after oral administration of lanthanum carbonate tablets (FOSRENOL®) in patients. Based on the pH-responsive interaction of phosphate and lanthanum ions, the chitosan coated siRNA-loaded lanthanum phosphate nanoparticles (CS/LaP/siRNA NPs) were prepared for improving cancer treatment, in which polysaccharide chitosan was used as the outer shell to control the excessive growth of lanthanum phosphate complexes, and enable intestinal mucoadhesion. The CS/LaP/siEGFR NPs exhibited significant biological activities in human colorectal cancer HT-29 cells by the synergistic effects of siEGFRs and lanthanum ions, such as downregulation of EGFR and upregulation of miR-34a. Furthermore, significant tumor growth inhibition was observed in both transgenic C57BL/6-ApcMinC/Nju cancer mouse model and AOM/DSS chemically induced orthotopic colorectal cancer mouse model after intestinal instillation administration of CS/LaP/siEGFR NPs. Therefore, the lanthanum-based siRNA delivery system would provide a potential and efficient strategy for the treatment of colorectal cancers.

Changes in Sedimentary Phosphorus Burial Following Artificial Eutrophication of Lake 227, Experimental Lakes Area, Ontario, Canada

AbstractLake 227 of the Experimental Lakes Area (ELA) in Ontario, Canada, has been fertilized with phosphorus (P) since 1969, which resulted in a rapid transition from oligotrophic to eutrophic conditions. Sediment cores collected from the oxygenated epilimnion, and the mostly anoxic hypolimnion of this unique lake contain a historical record of the changes in sediment P speciation and burial rates across the trophic transition. To elucidate these changes, results of chemical extractions were combined with 210Pb sediment dating, and with 31P NMR, Mössbauer, and XANES spectroscopies. Prior to 1969, organic P (POrg) was the major sedimentary P sink in Lake 227. Eutrophication of the lake coincided with marked increases in the burial rate of total P (TP), as well as in the relative contribution of the NaHCO3‐extractable P pool (humic‐bound P, PHum). Together, PHum and POrg account for ≥70% of total P burial in the sediments deposited since artificial fertilization started. The PHum fraction likely comprises phosphate complexes with humic substances. The strong linear correlation between P and iron (Fe) extracted by NaHCO3 implies a close association of the two elements in the humic fraction. Mössbauer and XANES spectra further indicate that most Fe in the post‐1969 sediments remained in the Fe (III) oxidation state, which is attributed to the stabilization of reducible Fe by organic matter, in part via the formation of phosphate‐Fe (III)‐humic complexes. Importantly, our results show that the eutrophication experimentation of Lake 227 caused the accumulation of a large reservoir of reactive sediment P, which may continue to fuel internal P loading to the water column once artificial fertilization is terminated.

Combination of phosphorus mobilizing and solubilizing fungi with phosphoric rocks and volcanic materials for growth promotion of lettuce (Lactuca sativa L.) plants

Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote the solubilization of insoluble phosphate complexes, together benefiting plant nutrition. The use of these organisms in combination with minerals or rocks that provide nutrients is another alternative to maintain crop productivity. The objective of this work was to combine AMF and S with pyroclastic materials (ashes and pumicites) from the Puyehue volcano and phosphoric rocks (PR) from the Río Chico Group (Chubut) and to evaluate the performance of these mixtures as substrates for potted production of Lactuca sativa. To formulate the substrates, a mixture of Ter-rafertil® with ashes was used as a base. Penicillium thomii was the S and spores of the fungus Rhizophagus intraradices (AEGIS® Irriga) served as the source of AMF. Various combinations of microorganisms and the addition or not of RP were evaluated. The treatments were: (1) substrate; (2) substrate + AMF; (3) substrate + S; (4) substrate + AMF + S; (5) substrate: PR; (6) substrate: PR + AMF; (7) substrate: PR + S, and (8) substrate: PR + AMF + S. There were 3 replicates per treatment. The parameters evaluated were total and assimilable P content in the substrate, P in plant tissue and dry biomass. All of them were significantly higher in the plants grown in the substrate added with PR and inoculated with S and AMF. This work confirms that the S/AMF combination with volcanic ashes from Puyehue and PR from Grupo Río Chico formulated with a commercial substrate promote the growth of L. sativa. Thus, it is possible to increase the added value of geomaterials of national origin.

Phosphorus application improved the yield of citrus plants grown for three years in an acid soil in the Three Gorges Reservoir Area

The objectives of the current study were to investigate the effects of nitrogen (N), phosphorus (P), and potassium (K) application rates on yield and quality of citrus fruits, and soil nutrient availability. The experiment was carried out using 8-year-old ‘Navelina’ navel orange (Citrus sinensis L. Osbeck) trees in an acid yellow sandy soil over three consecutive growing years in Zigui County in the Three Gorges Reservoir Area. This experiment consisted of 14 treatments with three factors (N, P, and K) and four levels of each factor. N application doses were 0, 66, 132, and 198 kg hm−2; P application doses were 0, 16.5, 33.0, and 49.5 kg hm−2; K application doses were 0, 27, 54, and 81 kg hm−2. P application at 49.5 kg hm−2 increased the yield of citrus by 32.6 % attributed to the increase in fruit number rather than mean fruit weight. P application did not affect total soluble solids of fruits when compared with the treatment without P application. Soil receiving 198 kg hm-2 of N rate revealed the lowest soil pH, which likely increased the toxicity of aluminum and then reduced citrus yield compared with the treatment without N fertilization. N and P application did not affect available N and available P in soils compared with treatments without N and P applications, respectively. We speculate that the increased fruit yield response of citrus trees by P fertilization is possibly due to aluminum detoxification as a result of phosphate complex with aluminum ions.

Synergistic effect between histidine phosphate complex and hazelnut shell for flammability reduction of low-smoke emission epoxy resin

A novel intumescent fire retardant (FR) system based on ground hazelnut shell (HS) and L-histidinium dihydrogen phosphate-phosphoric acid (LHP) was introduced into the epoxy resin (EP) in order to verify their effectiveness as fire retardant. The burning behaviour and smoke emission were assessed with cone calorimeter (CC) and UL-94 tests. Furthermore, the analysis of volatile products evolved during both the thermal decomposition and burning was conducted with the use of thermogravimetric analysis (TGA/FT-IR) and steady-state tube furnace (Purser/FT-IR), both combined with FT-IR with the use of a transfer line. It was found that the system containing 5 wt% of HS and 15 wt% of LHP lead to in the formation of a swollen char with numerous closed cells, which reduced the burning process as well as smoke emission. The obtained results confirm the occurrence of a synergistic effect between the components.

Complexation of Injectable Biphasic Calcium Phosphate with Phosphoserine-Presenting Dendrons with Enhanced Osteoregenerative Properties.

Injectable biphasic calcium phosphates have been proposed as a solution in the treatment of a range of clinical applications including as fillers in the augmentation of osteoporotic bone. To date, various biodegradable natural or synthetic organics have been used as a polymer component of bone materials to increase their cohesiveness. Herein, a novel bone material was developed combining osteoconductive biphasic calcium phosphate (BCP) nanoparticles with phosphoserine-tethered generation 3 poly(epsilon-lysine) dendron (G3-K PS), a class of hyperbranched peptides previously shown to induce biomineralization and stem cell osteogenic differentiation. Strontium was also incorporated into the BCP nanocrystals (SrBCP) to prevent bone resorption. Within 24 h, an antiwashout behavior was observed in G3-K PS-integrated pure BCP group (BCPG3). Moreover, both in vitro tests by relevant cell phenotypes and an in vivo tissue regeneration study by an osteoporotic animal bone implantation showed that the integration of G3-K PS would downregulate Cxcl9 gene and protein expressions, thus enhancing bone regeneration measured as bone mineral density, new bone volume ratio, and trabecular microarchitectural parameters. However, no synergistic effect was found when Sr was incorporated into the BCPG3 bone pastes. Notably, results indicated a concomitant reduction of bone regeneration potential assessed as reduced Runx2 and PINP expression when bone resorptive RANKL and CTX-I levels were reduced by Sr supplementation. Altogether, the results suggest the potential of injectable BCPG3 bone materials in the treatment of osteoporotic bone defects.

Imine Amidation Catalyzed by a Chiral VAPOL Calcium Phosphate.

Over the last 16 years, chiral phosphoric acids (CPAs) have been shown to be excellent asymmetric catalysts, very effectively used in constructing chiral molecules with high enantiocontrol. In 2010, Ishihara et al. discovered that chiral metal phosphate complexes (or salts) could be found in substantial quantities, as contaminates, in some reported CPA-catalyzed reactions (Hatano, M.; Moriyama, K.; Maki, T.; Ishihara, K. Angew. Chem., Int. Ed. 2010, 49, 3823-3826). These metal phosphates were shown to actually catalyze the reactions in addition to CPAs. In this work, we have investigated in depth a reaction first reported to be catalyzed by CPAs based on a vaulted bis-phenanthrol (VAPOL) backbone. We have found that VAPOL metal phosphates were, in fact, superior catalysts for this reaction. Upon optimization, a wide substrate scope, low catalyst loading, and mild conditions could provide intermolecular imine amidation reactions producing chiral N,N'-aminal products in high yields and with excellent ee values (up to >99% yield, >99% ee).

Oncotherad immunotherapy elicits promising responses in Bacillus Calmette-Guérin-unresponsive non–muscle invasive bladder cancer: Results from phase I/ II study.

e17048 Background: Standard treatment for high-grade non-muscle-invasive bladder cancer (HGNMIBC) is transurethral resection of the bladder tumor followed by intravesical Bacillus Calmette-Guérin (BCG) immunotherapy. Up to 40% of patients with HGNMIBC will fail intravesical BCG therapy. A promising therapeutic perspective is represented by OncoTherad immunotherapy. OncoTherad is a nanostructured inorganic phosphate complex associated to glycosidic protein developed by University of Campinas/Brazil that exhibits antitumor properties. The aims of this study were to evaluate the efficacy and safety of OncoTherad immunotherapy for BCG-refractory or relapsed HGNMIBC. Methods: We conducted a prospective, single-center (Municipal Hospital of Paulinia, São Paulo, Brazil), single-arm phase I/ II study of OncoTherad immunotherapy in 29 (18 male, 11 female) patients with BCG-unresponsive HGNMIBC (≥ 1 previous course of BCG intravesical therapy). The schedule was initiated with weekly intravesical (120 mg/mL) and intramuscular (25 mg/mL) OncoTherad treatment for 6 weeks, followed by one every other week application for 3 months and, one monthly application until the end of the treatment (24 months). Follow-up was performed with systematic mapping biopsies of the bladder, cystoscopy and ultrasound. The primary endpoint was pathological complete response (pCR) and recurrence-free survival (RFS). The recurrence was defined as histology proven tumor recurrence (any grade) and monitored at 3-month intervals. Secondary endpoints were time to disease recurrence and safety response. Results: The median age of the 29 patients was 64 years (range 34-94). At baseline pTis, pTaG2-3, pT1G2-3 occurred in 10%, 59% and 31% of patients respectively. OncoTherad treatment showed pCR rates (95% CI) of 100% at 3, 6 and 9 months, 89,6% (26/29) at 12 months and, 89,6% (26/29) at 24 months. A 24-months RFS rate in all patients was 79,3%. Also, the median time to disease recurrence for patients was 459 days (15,3 months; 95% CI) at 24-months follow-up. 95% of adverse events were Grade 1 or 2. The most commonly reported treatment-related adverse events were dysuria (51,7%), cystitis (34,5%), pruritus (44,8%), rash (27,6%), arthralgia (27,6%) and fatigue (27,6%). Conclusions: In conclusion, OncoTherad seems a safe and effective treatment option for BCG-unresponsive HGNMIBC patients and may provide benefit for preventing tumor recurrence. Clinical trial information: RBR-6swqd2.

Synthesis, crystal structure, physical and catalytic oxidation studies of a new hybrid phosphate [(N2H5)2Co(HPO4)2

A new one-dimensional coordination polymer [(N2H5)2Co(HPO4)2] was synthesized by slow evaporation method and characterized by means of single-crystal X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Its catalytic activity was tested using UV–visible absorption measurements. The compound crystallizes in the monoclinic system (S.G: P21/c) with the cell parameters (Å, °): a = 5.3665(3), b = 11.1271(6), c = 7.7017(4), β = 104.843(4), V = 444.55(4) Å3 and Z = 2. The crystal structure, consisting of a linear chain, is made of rings of [CoN2O4] octahedra and [PO3(OH)] tetrahedra sharing vertices via oxygen atoms coordinated to cobalt centers. The rings are linked to chains running along [100] and form thereby polymeric chains that are connected by hydrogen bonds in a three-dimensional arrangement. The FTIR spectroscopy shows the expected bands of hydrazine and phosphate groups. The thermal behavior consists mainly of the loss of hydrazine moieties leading thus to the formation of anhydrous cobalt phosphate. The phosphate complex exhibits efficiency in catalytic oxidation and degradation of methylene blue dye. The ac magnetic susceptibility shows a peak indicating antiferromagnetic order with a Néel temperature of 5.5 K. Fitting the Curie-Weiss equation to the ac magnetic susceptibility above 50 K gives the average Curie-Weiss Constant to be −11.8 K.

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate on Fracture Resistance of Reattached Tooth Fragments Using Conventional and Self-Adhesive Bioactive Flowable Composite.

Objectives The present study aimed to investigate the effect of casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) complex and the type of flowable composite (conventional or self-adhesive bioactive) on the fracture resistance of fractured incisors restored through reattachment technique. Materials and Methods In this experimental in vitro study, 60 extracted bovine central mandibular incisors were randomly divided into six groups ( n = 10) according to the reattachment technique. Their incisal edges were cut off to represent an enamel–dentin fracture. The fragment edges were reattached as follows: Group 1—selective etching and bonding followed by conventional flowable composite; Group 2—selective etching and bonding followed by bioactive flowable composite; Group 3 was like Group 2 but without applying bonding; Groups 4, 5, and 6 were similar to Groups 1, 2, and 3, respectively, but both tooth fragments were pretreated with CPP-ACP-containing paste for 3 minutes. Fracture resistance was assessed by a universal testing machine. Statistical Analysis Data were analyzed by SPSS—Statistical Package for the Social Sciences—software using one-way analysis of variance and Tukey post-hoc tests (α= 0.05). Results The highest and lowest fracture resistance was recorded in Groups 5 (15.96 MPa) and Group 6 (1.95 MPa), respectively, being significantly different from the other groups. The mean fracture resistance of Groups 3 and 6 was significantly lower than the other groups ( p < 0.05). However, Groups 1, 2, and 4 showed no difference in fracture resistance. Conclusion Bioactive composite was not superior to conventional composite for fragment reattachment, but using it in self-adhesive mode reduced the fracture strength significantly. Yet, pretreatment with CPP-ACP, followed by application of adhesive, improved the fracture resistance of bioactive composite.