Phosphate-based Materials Research Articles

An Overview of Antibacterial Dental Restorative Materials

Antibacterial dental restorative materials (ADRM) have been developed to prevent or treat dental caries and other infections. Glass ionomer cements (GICs), composite resins, calcium hydroxide-based materials, mineral trioxide aggregate (MTA), bioactive glasses, silver-containing materials, quaternary ammonium compounds (QACs), chlorhexidine, nanoparticles, and photodynamic therapy (PDT) are common types of ADRMs. They have antibacterial properties due to the release of fluoride ions, QACs, silver nanoparticles, calcium and hydroxyl ions. ADRMs can prevent tooth decay, promote healing of pulp tissue and regenerate damaged tissues. Researchers are exploring new agents like nanoparticles and antimicrobial peptides to improve the antibacterial properties of ADRMs. PDT is a promising technology for improving the antibacterial properties of dental restorative materials. Antibacterial bioactive dental materials like bioactive glasses, calcium phosphate-based materials, hydroxyapatite-based materials, antibacterial peptides, and silver-containing materials have been developed to provide an additional layer of protection against infection and improve the longevity of dental restorations.

High strength bioinspired calcium phosphate-based material for bone repair applications

Owing to the increasing demand for bone repair strategies, several biomaterials have been developed. Among the materials available for this purpose, hydroxyapatite stands out for its osteoinduction capacity, since it possesses a chemical composition similar to that of inorganic bone constituents. In comparison to bones, the mechanical properties of substitute structures incorporating hydroxyapatite still remain a great challenge for scientists. This study thus presents the synthesis of hydroxyapatite incorporated with a natural bioceramic and a metallic phase of excellent biocompatibility to obtain dense biomaterials with improved mechanical strength. The mechanical responses of the synthesized biomaterials are presented and discussed. The results obtained indicate that the hydroxyapatite-natural ceramic systems fulfils the general mechanical property requirements for some bone repair applications. Separately, the synthesis of titanium-based systems was shown to be much more challenging, but promising. Therefore, recommendations for suppressing the issues with the metal-ceramic interfacial bonding strength were provided. • A simple method of synthesising hydroxyapatite composites for biomedical applications is presented. • Titanium-reinforced composites with calcium phosphate content close to natural bone were developed. • Waste seashells were used for extraction and recovery of valuable calcium oxide compounds. • Hydroxyapatite-based calcium oxide composites with high mechanical performance were synthesised.

Curing Characteristics Based on the Mixing Ratio of MKP and Retardant in Phosphate-Based Rapid Hardening Repair Materials

Potholes in asphalt are phenomena in which a part or all of the surface layer is lost due to water, traffic load, and/or changes in temperature, which can lead to traffic accidents. Emergency repair materials used in pothole emergency repair work require different qualities such as suitable curing properties and fluidity, early strength development, high durability and adhesion strength, and moderate heat generation properties. Chemically bonded phosphate ceramic composites made of phosphate and magnesium oxide as main materials are recognized as rapidly hardening materials. This study evaluates the fluidity, hardenability, and mechanical properties of asphalt based on the magnesium oxide and phosphate ratio and retardant used to develop pothole repair materials. Experiments attempted to derive the optimal combination of phosphate and magnesium oxide, where the mixing ratio of phosphate and magnesium oxide and the curing time and curing characteristics based on increases in the contents of the retardant mixture were considered.

Na3CoZr(PO4)3 as high-voltage cathode material for sodium-ion batteries

Phosphate-based electrode materials are sustainable, abundant, low cost and exhibit stable structures. We report Na3ZrCo(PO4)3 cathode material synthetized through a sol-gel method, that shows high electrochemical performances. The electrochemical activity of Co3+/Co+2 redox couple is reversibly accessed in Na3ZrCo(PO4)3, providing thus high discharge voltage plateaus at 4.05 V. Furthermore, a discharge capacity of 85 mAh g−1 was measured, which is about 80% of the theoretical capacity (106 mAh g−1). These results were obtained with small variations of the lattice parameters and a small volume change of 3.8%, as was confirmed by Operando XRD. These results provide guidelines to improve the electrochemical performance of high-voltage Na3ZrCo(PO4)3 cathode materials for the next generation sodium-ion batteries.

Surgical Bone Adhesives with Potential Maxillofacial Applications A Systematic Review

The reduction and stabilisation of fractured bone fragments have always been a challenging task for thesurgeon. A micro-platesystem for maxillofacial fracture treatment provides excellent results. However, plates and screws are difficult toadapt to the thin bone, and small fragments often lead to the weakening of bone causing secondary fractures. Surgical bone adhesives promise as a viable alternative for issues with micro-plates, but a lotremains desired for successful usefor clinical application. The present systematic review aims to identify the bone adhesive materials available at various stages in animal or human models in the last decade and enumerate their characteristics for potential use in non-load bearing maxillofacial fractures. PubMed electronic database searched using a combination of keywords to identify English language articles between January 2011 and December 2020 yielded a total of 1204 records, of which 15 were included for final review after applying PRISMA guidelines. Cyanoacrylate was the commonly used adhesive material followed by fibrin glue and calcium phosphate-based materials. Although encouraging, results with each material still lack human randomised control trials thus presenting inconclusive evidence. Studies on these lines are suggested along with the development of newer materials to overcome the shortcomings in the currently available systems.

Unravelling the regulating role of graphene coating on improving the electrochemical performance of pyrophosphate cathode material: A first-principles study

Pyrophosphate (Li2FeP2O7, LFPO) is proposed as a promising cathode material for Li-ion batteries on account of the high voltage and the two-dimensional lithium ions diffusion channel. Graphene coating could effectively improve the inherent poor ionic and electronic conductivities of Li2FeP2O7 material, however, the interfacial interaction and regulating role of the graphene coating on the graphene/Li2FeP2O7 (G/LFPO) composite structures are lack of research at the atomic scale. With the aid of first-principles calculations and ab initio molecular dynamics (AIMD) simulations, the interaction mechanism of graphene on the LFPO cathode material has been systematically investigated in terms of the geometrical structure, thermodynamical stability, interfacial charge distribution and electronic property. The analysis of electron localization function (ELF), charge density differences, and density of states strongly suggest the G/LFPO(001) and G/LFPO(010) heterostructures exhibit high electrochemical performance. The AIMD simulations show that the parallel and perpendicular G/LFPO(001) and G/LFPO(010) heterostructures have high thermodynamical stabilities and electronic conductivities. The diffusion coefficients of Li+ ions in the G/LFPO heterostructures are noticeably enhanced. Our present work would not only provide a fundamental understanding of interfacial interaction and electrochemical properties of G/LFPO composite, but also shed light on the regulating mechanism for the potential phosphate-based cathode material with high electrochemical performance.

Computational Investigation of a NASICON-Type Solid Electrolyte Material LiGe2(PO4)3

Phosphate-based electrolyte materials are of great interest in the field of Li-ion batteries due to their rigid structural integrity. LiGe2(PO4)3 is a NASICON-type phosphate material with high thermal and electrochemical stability. Computational simulation techniques were employed to study the defects, diffusion, and dopant properties of LiGe2(PO4)3. Furthermore, the reaction energies for the formation of LiGe2(PO4)3 and the incorporation energies for the insertion of additional Li into this material were calculated. The calculations revealed that the Li Frenkel is the lowest-energy defect. The second most favorable defect is the Ge-P anti-site defect cluster. A low Li migration energy of 0.44 eV implies high Li ionic conductivity. The most favorable isovalent dopants on the Li and Ge sites are Na and Si, respectively. The formation of Li interstitials and oxygen vacancies can be facilitated through the doping of Ga on the Ge site. The doping of Ga slightly enhances the Li ionic conductivity. Li incorporation (up to four Li) is thermodynamically feasible.

Assessment of Zinc-Bound Phosphate-Based Glass-Coated Denture-Relining Material with Antifungal Efficacy for Inhibiting Denture Stomatitis.

This study investigated the surface properties, biocompatibility, and antifungal activity against Candida albicans of a denture-relining material coated with zinc-bound phosphate-based glass. First, zinc-bound phosphate-based glass was fabricated. A polymerized denture-relining disk was coated with zinc-bound phosphate-based glass (2%, 4%, and 6%). The surface properties of the control and experimental groups were measured, including the wettability, microhardness, color difference, and gloss. The biocompatibility was evaluated using the MTT assay according to ISO 10993-5. The antifungal activity was investigated by counting the number of colony-forming units of Candida albicans. The results were analyzed using a one-way ANOVA and Tukey’s test (p = 0.05). The results of this study indicate that, despite the antimicrobial effect of zinc-bound phosphate-based glass, a coated denture-relining material does not degrade the surface properties and biocompatibility. Therefore, this novel material is considered promising for use as a dental material with antimicrobial properties that can potentially prevent denture stomatitis.

Calcium-magnesium phosphate biphasic microspheres with nutrient microchannels promote angiogenesis and osteogenic differentiation

Vascularisation and mineralisation are indispensable conditions for bone repair materials. The introduction of magnesium ions into calcium phosphate-based materials can give them angiogenic and mineralising capabilities. However, the optimum calcium to magnesium ratio has yet to be determined. Microspheres have received much attention from researchers due to their flexibility, non-agglomeration and other advantages. We prepared calcium-magnesium phosphate biphasic microspheres (CMBS) using the water-in-oil emulsion cross-linking method to achieve osteogenic differentiation and vascularisation. The simultaneous use of the sacrificial template method and heat treatment endow the microspheres with a rich micro-pore structure. In addition, we investigated the compounding ratio of calcium phosphate to magnesium phosphate and determined the optimal compounding ratio (Ca/Mg = 3/1–1/1) for this material. The prepared microspheres promoted the attachment, proliferation and directed differentiation of bone marrow mesenchymal stromal cells (BMSCs) and human umbilical vein cells (HUVECs). CMBS-I (Ca/Mg = 3/1) and CMBS-II (Ca/Mg = 1/1) microspheres showed the best promotion effect among all groups. These microspheres were implanted under the skin of Sprague- Dawley (SD) rats, and the composite microspheres significantly induced vascular regeneration compared to pure phase microspheres.

Tunable Behavior in Solution of Amorphous Calcium Ortho/Pyrophosphate Materials: An Acellular In Vitro Study.

Amorphous calcium phosphate-based materials are of major interest in the field of bone substitution. Very recently, the low-temperature synthesis of a new family of amorphous calcium phosphate containing both orthophosphate and pyrophosphate ions in controlled proportions has been reported. Despite their interest, especially due to the biochemical role and the hydrolysis of pyrophosphate occurring in vivo, the behavior of such materials when interacting with aqueous media has never been described. Consequently, we herein report the in vitro acellular evolution of three compositions of mixed calcium ortho- and pyrophosphate amorphous materials including a different orthophosphate proportion. As a first step to assess the physicochemical reactivity of these amorphous materials, they were tested in two different media at 37 °C, acidified water and simulated body fluid solution, from 1 h up to 15 days. The results demonstrated that they were quite stable and that they progressively released part of their constitutive ions, highlighting their potential for controlled delivery of bioactive ions (calcium, orthophosphate, and pyrophosphate ions). In addition to these properties, we showed that the material with the highest ortho/(ortho + pyro) phosphate ratio started to crystallize into nanocrystalline apatite analogous to bone mineral within 2 days or 2 weeks depending on the medium. For the other material compositions, no layer of apatite was detected at their surface with SBF testing despite the favorable supersaturation indexes, crystallization being probably inhibited by pyrophosphate ions released in the medium. This varying apatite-forming ability emphasizes the key role of the ortho/(ortho + pyro) phosphate ratio of these materials in their in vitro reactivity and bioactivity, which paves the way for the development of this promising family of amorphous calcium phosphate materials with tunable physicochemical and biological properties.

Novel β-TCP/HA biphasic calcium phosphate microspheres with porous surface structure prepared via a calcium carbonate template

Calcium phosphate-based materials have been considered and widely developed as a promising candidate for bone repair and regeneration. With an aim to allow a better balance between resorption and degradation, novel beta-tricalcium and hydroxyapatite (β-TCP/HA) biphasic calcium phosphate (BCP) microspheres with different surface topographies were successfully prepared in this study. Results revealed that the surface topography structure of prepared BCP microspheres could be adjusted by tuning phosphoric acid concentrations and pH values. In vitro cytocompatibility has also been evaluated by CCK-8 and live/dead staining. Moreover, the potential applications of the obtained BCP microspheres as drug delivery were investigated by using the doxycycline as a model drug. All the results have demonstrated that utilizing the spherical calcium carbonate as a hard template is an effective strategy for synthesizing advanced β-TCP/HA BCP microspheres with controllable surface topography, which holds tremendous promise for bone regeneration and drug delivery applications.

A novel and efficient concentration of pomegranate juice with enhanced antioxidant activity

In the present study we investigated the performance of a panel of 13 solid sorbents comprising layered double hydroxides, zirconium phosphate-based materials, and phyllosilicates as heterogeneous supports for the concentration of pomegranate (Punica granatum L.) juice. Mg-containing clays exhibited an almost complete bleaching capacityof pomegranate juice and more interestingly provided blends with an increased antioxidant capacity (around 1.5-fold) respect to the parent juice when assayed for the Trolox equivalent antioxidant capacity (TEAC) coupled to ABTS decolorization test. Such an activity remained practically unaltered after 4 days during which the pomegranate concentrated preparations remained supported on clays. The approach investigated herein and used for the concentration of pomegranate juice and the discovery of the preservation for long periods of the antioxidant activities of pomegranate extracts when supported on solid sorbents have been reported herein for the first time in the literature to the best of our knowledge.

Assessment of Streptococcus mutans biofilm formation on calcium phosphate ceramics: The role of crystalline composition and microstructure.

Streptococcus mutans is one of the bacteria that initiates the colonization of the pellicle at the tooth surface. It forms a plaque, together with other bacteria, which gradually dissolves the pellicle and leaves the tooth surface unprotected against the acidic oral environment. Calcium phosphate ceramics are excellent synthetic materials for the study of biofilm formation in dentistry because they are comparable to teeth in chemical composition and structure. Calcium phosphates can be processed to achieve a variety of crystalline compounds with biologically relevant ionic substitutions and structures that allow study of the effect of the surface chemistry and the topography independently. In this article, we describe the preparation and characterization of three types of calcium phosphate-based materials as a suitable surface for the formation of the S. mutans biofilm: beta-tricalcium phosphate (β-TCP); sintered hydroxyapatite (SHA); and calcium-deficient hydroxyapatite (CDHA). The densest biofilms were formed on the surfaces of SHA and CDHA, with no significant differences due to the stoichiometry or microstructure. In contrast, β-TCP showed a lower susceptibility to S. mutans biofilm formation, suggesting that the crystalline structure is the controlling parameter. Subsequently, SHA was selected to develop a dental biofilm model that allowed study of S. mutans biofilm susceptibility to chlorhexidine and ethanol.

Experimental Study on the Properties of Phosphate-Based Materials for Rapid Repair of Concrete Cracks

This article studies rapid repair materials by mainly carrying out macro- and micro-performance impact tests. The static volumetric method was used to conduct pore volume-aperture analysis and prove the impact of the durability and repair performance of materials. The results show that 1) material impermeability can be effectively improved by increasing the ratio of active ingredients A:B and reducing the water-to-binder ratio. Adding an appropriate amount of fine aggregate can enable one to adjust the microstructure of the repair material, improve the compactness of the material, and effectively improve the impermeability. 2) An increase in the proportion of active ingredient A, water-binder ratio, sand-cement ratio and fly ash content will reduce the self-shrinkage of the specimen; with increasing NS and silica fume content, shrinkage increases. 3) Through analysis of pore size and pore volume, the total pore volume of the repair material is found to be reduced by 16.0% compared with cement mortar. Within a pore diameter range of 2.00–10.00 nm, the volume of the repair material increases by 78.9% compared to that for cement mortar. The total volume of the mesopores (2–50 nm) in the repair material accounts for 87.7% of the total volume, and the total volume of the mesopores in the cement mortar accounts for 81.23% of the total volume, which further illustrates the excellent macroscopic properties of the repair material.

Investigating triple superphosphate for lead removal from aqueous solutions

The aim of this research is to investigate monocalcium phosphate monohydrate [Ca(H2PO4)2. H2O] also called triple superphosphate (TSP) for the removal of lead (Pb) from aqueous solutions. In this study, TSP was selected amongst various phosphate-based materials and fertilizers to act as the source of orthophosphate (PO4 3-) which is a powerful tool for metal fixation in soil and water. Thermodynamic equilibrium dissolution-precipitation relationships for the systems of Pb-H2O and Pb-PO4 3--H2O were drawn with the aid of Eh-pH stability diagrams to determine the predominance areas of different species. The lead phosphate compounds, identified through the stability area diagrams, were verified with the batch precipitation tests performed with standard solutions of lead and TSP at different conditions. It was observed that, depending upon solution conditions, TSP can precipitate 99.9% of the lead from the solution. Lead precipitates, analyzed by x-ray diffraction, showed the formation of lead phosphate compounds. The mechanism of TSP for the removal of lead from aqueous solutions is discussed.

A micron-size carbon-free K3V2O2(PO4)2F cathode with high-rate performance for potassium-ion batteries

(Fluoro)phosphate-based polyanionic materials have been considered as promising cathode candidates for sodium/potassium-ion batteries (SIBs/PIBs) due to their excellent structure stability and high reaction potential. However, compared with the rapid Na+ storage of (fluoro)phosphates, the potassium analogues still exhibit poor rate capability for K+ storage. Herein, we demonstrate a micron-size fluorophosphate-based polyanionic cathode K3V4+2O2(PO4)2F (KVOPF) without needing extra carbon coating for realizing high-capacity and high-rate K+ storage. This KVOPF cathode is reported for the first time, which can deliver 105 mAh g−1 at 100 mA g−1 and 62 mAh g−1 at 2000 mA g−1, and the rate capability is comparable with its analogue Na3V2O2(PO4)2F for Na+ storage. The energy storage mechanism of KVOPF is revealed by in situ XRD: it undergoes a solid solution process followed by two continuous phase transitions during charging process, and the discharging process is opposite, exhibiting its high reversibility. In addition, a full cell was constructed by coupling with hard carbon anode. This work provides a promising cathode candidate for constructing high power-high energy PIBs.

New Phosphate Zn2Fe(PO4)2 Cathode Material for Nonaqueous Zinc Ion Batteries with Long Life Span.

Phosphate-based cathode materials attract much more attention and are widely used as energy storage materials based on their high economic efficiency and eco-friendly property, their stable potential plateau, and their high thermodynamic stability. A new phosphate family member, Zn2Fe(PO4)2 (ZFP), was successfully explored and synthesized by the scalable high-temperature annealing method, followed by coating a thin carbon layer to optimize the electrotonic conductivity. This obtained ZFP featuring with a tunnel structure can be utilized as a cathode material for Zn2+ ion extraction and insertion, in which Zn2+ ion diffusion behaviors primarily contribute the specific capacity. Based on the actual reversible capacity of ZFP@C of 73 mA h g-1, the application for zinc ion batteries (ZIBs) has potential due to its long life span. The electrochemical performance is primarily contributed from the high Zn2+ ion diffusion rate and low apparent activation energy. This new explored ZFP can accelerate the development of realizing ZIBs with long life span.

Phosphate-based cathode materials to boost the electrochemical performance of sodium-ion batteries

Emerging sodium ion battery technology is superior with highly thermal and structurally stable, having high redox potential polyanionic compounds-based cathode materials among transition metal oxides, Prussian blue analogues and organic compounds.

Calcium phosphate-based materials regulate osteoclast-mediated osseointegration

Calcium phosphate-based materials (CaP) have been widely used as bone graft substitutes with a decent osseointegration. However, the mechanism whereby cells function and repair the bone defect in CaP micro-environment is still elusive. The aim of this study is to find the mechanism how osteoclast behaviors mediate bone healing with CaP scaffolds. Recent reports show that behaviors of osteoclast are closely related with osteogenesis, thus we make a hypothesis that active osteoclast behaviors induced by CaP facilitate bone healing. Here, we found a new mechanism that CaP can regulate osteoclast-mediated osseointegration. Calcium phosphate cement (CPC) is selected as a representative CaP. We demonstrate that the osteoclast-mediated osseointegration can be strongly modulated by the stimulation with CaP. An appropriate Ca/P ratio in CaP can effectively promote the RANKL-RANK binding and evoke more activated NF-κB signaling transduction, which results in vigorous osteoclast differentiation. We observe significant improvement of bone healing in vivo, owing to the active coupling effect of osteoclasts. What is more noteworthy is that the phosphate ions released from CaP can be a pivotal role regulating osteoclast activity by changing Ca/P ratio readily in materials. These studies suggest the potential of harnessing osteoclast-mediated osteogenesis in order to develop a materials-manipulated approach for improving osseointegration.

Recent progress in phosphate based luminescent materials: A case study

The uses of phosphate based luminescent materials are presented in this study in different fields of luminescence. There are different types of luminescent phosphors are available in the field of luminescence such as borates, sulphates, fluorides, sulphides, phosphates etc. From all these phosphors, phosphate-based phosphors shows their potential in almost every field of luminescence in last few years and it becomes a key material in the luminescence especially in photoluminescence, thermoluminescence and mechanoluminescence. These rare earths activated phosphate-based luminescence materials are synthesized with different techniques by means of wet chemical method, combustion technique, sol gel analysis and solid-state diffusion technique etc. which are described in the present article. Consequently, this article chiefly dealing the overview of different phosphate based luminescent materials and modern development and progression in the field of luminescence.