Strontium Substitution Research Articles

Effect of Sr2+ substitution on structural, morphological, electrical and dielectric properties of Ca2MgSi2O7 ceramic

Despite the excellent properties of ceramic materials for electronic devices, this study systematically investigates the significant effects of strontium (Sr2⁺) substitution on the structural, morphological, electrical, and dielectric behavior of Ca2-xSrxMgSi2O7 (x = 0, 0.2, 0.4, 0.6) ceramics. The composite was prepared via a solid-state route and characterized using techniques such as FESEM-EDAX, BET, XRD, Hall Effect measurements, and an LCR meter, respectively. The surface morphology of the structure was initiated to be smooth, compact, dense, island-shaped and porous. It is noted that the grain size reduced (from 1.10 μm to 0.72 μm) while the surface area enlarged (from 90 m2/g to 122 m2/g) with Sr substitution. XRD study showed that all the ceramics samples, after sintering at 1250 °C for 5 h. Higher amount of Sr, enhanced the crystallinity, as validated by the peak intensification. Correspondingly, the electrical resistivity and dielectric permittivity of Ca2-xSrxMgSi2O7 was decreased with Sr substitution. Particularly, the Ca1.6Sr0.4MgSi2O7 unveiled the lowermost electrical resistivity (76 Ω cm) and dielectric permittivity (εr = 848) but the uppermost dielectric loss (tan δ = 1.06) at 1 kHz. The attained outcomes exhibited the appropriateness of these samples for use in capacitor and antennas design.

Synthesis and Properties of CaMgSi2O6 - SrO Bioceramics for Enhanced Hydroxyapatite Formation and Cell Viability in Bone Regeneration

This study aims to synthesize and evaluate the properties of diopside (CaMgSi2O6) and strontium modified diopside (CaMgSi2O6-SrO) bioceramics for potential bone regeneration applications. The substitution of strontium for calcium leads to the formation of solid solutions: Sr-CaMgSi2O6, Ca-SrMgSi2O6, and a single phase of SrMgSi2O6, along with secondary phases of Ca-Sr2MgSi2O7 and Sr2MgSi2O7. This study is the first to examine the physical and biological properties of SrMgSi2O6 and its solid solutions. Microstructural analysis reveals that the pure diopside exhibits uniformly packed fine particles, while the SrO substitution results in lattice distortion and structural damage, thus weakening the mechanical properties and biodegradation resistance. The in vitro hydroxyapatite (HAp) formation ability of CaMgSi2O6-SrO bioceramics is comprehensively investigated, revealing that the re-adsorption of Mg2+/Sr2+ is a crucial factor. Pure diopside and Sr0.25 demonstrate effective HAp formation after immersion in simulated body fluid (SBF), with Sr0.25 showing finer particles and more uniform distribution due to appropriate Sr2+ re-adsorption. In contrast, SrO-rich samples show reduced HAp formation due to excessive re-adsorption of Mg2+ and Sr2+ ions, hindering HAp nuclei development. The cell viability test reveals that SrO substitution enhances cell viability due to increased surface area and the release of beneficial ions. Overall, Sr0.25 demonstrates excellent potential for bone regeneration applications by promoting HAp uniformity.

Investigation of the effect of strontium substitution in bismuth ferrites for enhanced structural and optical properties using experimental and DFT approaches

BiFeO3 doped with Sr, having the composition Bi1-xSrxFeO3 (0.00 ≤ x ≤ 0.20), was synthesized using the auto-combustion method. Various characterization techniques were employed to investigate the structural, morphological, and optical properties. X-ray diffraction (XRD) patterns confirmed that the materials exhibit a distorted rhombohedral structure with the space group R3c. The average crystallite size was determined to be in the range of 18–28 nm. A decrease in the lattice parameters was observed due to the contraction of the unit cell volume (373.83–371.49 Å) caused by Sr doping. Scanning electron microscopy (SEM) images revealed a reduction in grain size, suggesting the suppression of grain growth with Sr doping. Fourier-transform infrared (FTIR) studies identified two strong peaks at 552 cm−1 and 449 cm−1, confirming the perovskite structure of the materials. The optical band gap was found to decrease from 2.14 eV to 2.05 eV with increasing Sr concentration. Theoretical calculations of electronic and optical properties using density functional theory (DFT) were conducted. The calculated direct optical band gaps (2.0 eV, 2.22 eV, 2.1 eV, and 2.09 eV) for Bi1-xSrxFeO3 samples at doping levels x = 0.0, 0.10, 0.15, and 0.20, respectively, were in good agreement with the experimental results. These findings provide valuable insights into the tunability of electronic and optical properties in Sr-doped BiFeO3, making them promising candidates for various technological applications.

Enhanced magnon thermal transport in yttrium-doped spin ladder compounds Sr14−xYxCu24O41

Magnons are quasiparticles of spin waves, carrying both thermal energy and spin information. Controlling magnon transport processes is critical for developing innovative magnonic devices used in data processing and thermal management applications in microelectronics. The spin ladder compound Sr14Cu24O41 with large magnon thermal conductivity offers a valuable platform for investigating magnon transport. However, there are limited studies on enhancing its magnon thermal conductivity. Herein, we report the modification of magnon thermal transport through partial substitution of strontium with yttrium (Y) in both polycrystalline and single crystalline Sr14−xYxCu24O41. At room temperature, the lightly Y-doped polycrystalline sample exhibits 430% enhancement in thermal conductivity compared to the undoped sample. This large enhancement can be attributed to reduced magnon-hole scattering, as confirmed by the Seebeck coefficient measurement. Further increasing the doping level results in negligible change and eventually suppression of magnon thermal transport due to increased magnon-defect and magnon-hole scattering. By minimizing defect and boundary scattering, the single crystal sample with x = 2 demonstrates a further enhanced room-temperature magnon thermal conductivity of 19Wm−1K−1, which is more than ten times larger than that of the undoped polycrystalline material. This study reveals the interplay between magnon-hole scattering and magnon-defect scattering in modifying magnon thermal transport, providing valuable insights into the control of magnon transport properties in magnetic materials.

Co-relation between Rietveld analysis, dielectric studies and impedance spectroscopy of the Ba1−xSrxTiO3 ceramics

Barium strontium titanate (BST), with varying Sr doping levels (x = 0, 0.05, 0.075, 0.1, 0.15, 0.3), was successfully synthesized using the solid-state reaction technique. The aim was to investigate the microstructural, dielectric, and impedance properties as Sr doping increases. X-ray diffraction analysis revealed a tetragonal phase structure for these materials, belonging to the P4mm space group, confirmed via Rietveld refinement using the Fullprof suite. SEM analysis indicated the decrement in grain sizes ranging from 0.198 to 0.0582 μm as doping concentration increases. The temperature and frequency dependencies of the dielectric constant were examined, with the Curie temperature observed in the range of 295 to 351 K with decreasing trend with substitution of strontium in pure barium titanate, showing an increase in dielectric constant with rising temperatures and non-relaxor behavior. P–E loops of BST samples illustrated bulk ferroelectric behavior, with maximum values of retentivity and coercivity reaching 1.56 and 13.97, respectively, in the highly doped BST sample. Various analytical techniques, including Nyquist plots, real and imaginary components of impedance, conductivity measurements, modulus formalism, and determination of charge carrier activation energy, were employed to elucidate the relationships between microstructure and electrical properties. Temperature-dependent resistivity demonstrated the negative temperature coefficient of resistance (NTCR) behavior in Sr-doped barium titanate. Impedance studies revealed semicircular arcs in Nyquist plots, indicating contributions from both grains and grain boundaries. The formation of well-defined grains in the BST samples was further confirmed through modulus spectroscopy.

Tailoring structural and optical properties of LaGaO3 perovskite through strontium (sr) substitution: Insights and applications

In this groundbreaking research, we investigate the nuanced impact of controlled strontium (Sr) substitution on LaGaO3 perovskite, specifically exploring La1-xSrxGaO3 (x = 0; 0.1; 0.2) composites. Through meticulous synthesis and detailed characterization using X-ray diffraction, UV–Visible diffuse reflectance spectroscopy (UV–Vis DRS), and Photoluminescence Spectroscopy (PL), our study unravels the intricacies of dopant-induced modifications. The X-ray diffraction (XRD) analysis reveals the emergence of secondary phases, shedding light on the structural modifications induced by Sr2+ substitution. UV–Vis DRS measurements show shifts in band gaps, indicative of changes in the optical properties of the composites. The results Photoluminescence Spectroscopy illuminated the intricate spectral changes induced by dopants, offering insights into the interactions between impurity ions and color centers. This work not only advances our fundamental understanding of the complex relationship between dopants and perovskite materials but also highlights the potential applications of these composites. The ability to engineer both structural and optical properties through controlled Sr2+ substitution holds promise for innovations in optoelectronics, catalysis, and beyond. As materials science continues to push the boundaries of interdisciplinary research, this study contributes to the evolving landscape of advanced materials with tailored properties for emerging technologies.

Synthesis and characterization of strontium substituted monetite coatings via mild phosphate chemical conversion

Strontium (Sr) substitution into calcium phosphate (CaP) materials has gained acceptance in research into the enhancement of physiochemical and osteogenic potential. Conventional synthesis of metal cationic substitution into CaP coatings on metal substrate usually takes relatively high temperature (﹥100 °C) and hours of processing time. Herein, a mild phosphate chemical conversion method was developed for preparing Sr-substituted CaP coatings on surface of titanium (Ti) in the presence of increasing amount of Sr (40–60 mol%). The results indicated that the complete and even coatings could be produced on the whole surface of Ti only within 50–60 % Sr and the coatings represented a unique lamellar texture in micro/nano-scale. As Sr concentration increased, the phases of coatings were predominantly indexed to monetite and SrHPO4, which presented a highly oriented crystal alignment. With high content of Sr, monetite, instead of brushite, was deposited in the coatings. The possible mechanism of coating formation was proposed that α-SrHPO4 and α-monetite were co-deposited in the acidic phosphating solution and finally a compound of (CaxSr1-x)HPO4 was produced on surface of Ti. Results revealed that coatings formed at high degree of Sr substitution exhibited relative improved mechanical and electrochemical properties. The coatings enhanced the cell focal adhesion and proliferation of BMSCs compared with that of the bare Ti.

New Solid-Solutions of Substitution Strontium (Sr) for Lead (Pb) in Apatite Structure

Strontium substitution for lead in Pb(8-x)SrxNa2(PO4)6 was analyzed using XRD, SEM, and Rietveld refinement techniques. All samples were synthesized using ceramic and semi-ceramic technologies. Pure apatite was formed in the composition from x=0.00 up to x=2.75. The results indicate that the samples’ collected compositions agree with the values calculated.

Microwave shock motivating the Sr substitution of 2D porous GdFeO3 perovskite for highly active oxygen evolution

The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity. Conventional methods for A-site substitution typically involve prolonged high-temperature processes. While these processes promote the development of unique nanostructures with highly exposed active sites, they often result in the uncontrolled configuration of introduced elements. Herein, we present a novel approach for synthesizing two-dimensional (2D) porous GdFeO3 perovskite with A-site strontium (Sr) substitution utilizing microwave shock method. This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step, capitalizing on the advantages of rapid heating and cooling (temperature ∼1100 K, rate ∼70 K s−1). The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure. For electrocatalytic oxygen evolution reaction application, the synthesized 2D porous Gd0.8Sr0.2FeO3 electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm−2 and a small Tafel slope of 55.85 mV dec−1 in alkaline electrolytes. This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.

Insights into the Reactivity of Gd2−xSrxFe2O7 (x = 0 ÷ 0.4) in CO Radical Hydrogenation

The effect of strontium substitution in the structure of the complex oxide Gd2SrFe2O7 on the production of light olefins by CO hydrogenation was investigated. Perovskite-type oxides Gd2−xSr1+xFe2O7 (x = 0; 0.1; 0.2; 0.3; 0.4) were synthesized by sol–gel technology and characterized by XRD, Mössbauer spectroscopy, BET specific area, acidity testing, and SEM. The experimental data revealed a correlation between the state of iron atoms, acidity, and catalytic performance. It was found that with an increase in the content of Sr2+ in the perovskite phase, the basicity of the surface and the oxygen diffusion rate increased. This contributed to the CO dissociative adsorption, formation of active carbon, and its further interaction with atomic hydrogen.

Alginate templated synthesis, characterization and in vitro osteogenic evaluation of strontium-substituted hydroxyapatite

The objective of this study is to explore the potential role of alginate (Alg) in the crystallization of metal-substituted hydroxyapatite, with application in orthopaedic reconstruction. The alginate at different concentrations (0.5 and 1.0 wt%) facilitated in situ mineralization of hydroxyapatite (HA) and strontium-substituted HA (SHA, 10 and 30 mol%). The incorporation of the biopolymer and dopant induced notable changes in HA, including reduced crystal size from 31.0 to 16.4 nm and increased lattice volume from 577.3 to 598.0 Å3. The superior affinity of alginate for Sr2+ than for Ca2+ resulted in higher residual alginate in Alg/SHA (13.0 to 19.0 %) compared to Alg/HA (7.1 to 8.2 %). This residual alginate influenced composite properties: surface charge decreased from −26.5 to −45.7 mV, microhardness increased from 0.33 to 0.54 GPa, and dissolution increased from 0.17 to 0.39 %. The in vitro studies revealed that strontium substitution as well as the organization and crystallographic aspects of apatite regulated osteoblastic cell survival, proliferation, differentiation, and biomineralization. The findings suggest that an alginate concentration of 0.5 wt% is optimal for the crystallization of SHA with 10 mol% substitution, and its resulting composite possesses the ideal biomechanical properties to imitate native bone.

Identification of strontium substitution mechanism in hematite via calcium solution

Nonradioactive strontium (Sr) are produced as a result of radioactive decay of heavier elements such as uranium and thorium. Nonradioactive Sr shares physicochemical similarities with Ca and can replace it during bone formation, which may cause bone cancer in humans. Hence, concerning the potential hazards associated with strontium, it is imperative to eliminate it. The present study aimed to investigate the removal mechanisms of hematite-adsorbed strontium by calcium solution. Strontium was adsorbed to hematite at pH 8 and 10 and washed with calcium solution. X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS), scanning electron microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (after Ca washing) were performed on the samples before and after washing. Analyses and fitting by XANES and EXAFS confirmed the formation of an inner-sphere complex of strontium at pH 10. The XRD spectra showed that SrCO3 and SrFe2O4 formed at pH 8 and 10, respectively. After washing with the calcium solution, strontium was directly substituted to form CaCO3 and CaFe2O4. The X-ray photoelectron spectroscopy results provided a systematic analysis of the proportions of hematite and strontium, confirming the substitution of strontium with calcium. This substitution could be attributed to the physicochemical similarities between calcium and strontium. This study confirms the substitution of Sr with Ca, highlighting the physicochemical similarity of the Sr and Ca that facilitates substitution reactions.

Long-Term Fate and Efficacy of a Biomimetic (Sr)-Apatite-Coated Carbon Patch Used for Bone Reconstruction.

Critical bone defect repair remains a major medical challenge. Developing biocompatible materials with bone-healing ability is a key field of research, and calcium-deficient apatites (CDA) are appealing bioactive candidates. We previously described a method to cover activated carbon cloths (ACC) with CDA or strontium-doped CDA coatings to generate bone patches. Our previous study in rats revealed that apposition of ACC or ACC/CDA patches on cortical bone defects accelerated bone repair in the short term. This study aimed to analyze in the medium term the reconstruction of cortical bone in the presence of ACC/CDA or ACC/10Sr-CDA patches corresponding to 6 at.% of strontium substitution. It also aimed to examine the behavior of these cloths in the medium and long term, in situ and at distance. Our results at day 26 confirm the particular efficacy of strontium-doped patches on bone reconstruction, leading to new thick bone with high bone quality as quantified by Raman microspectroscopy. At 6 months the biocompatibility and complete osteointegration of these carbon cloths and the absence of micrometric carbon debris, either out of the implantation site or within peripheral organs, was confirmed. These results demonstrate that these composite carbon patches are promising biomaterials to accelerate bone reconstruction.

Effect of Strontium Substitution on the Tribocatalytic Performance of Barium Titanate.

This study investigates the impact of Sr doping on the tribocatalytic performance of BaTiO3 in degrading organic pollutants. Ba1-xSrxTiO3 (x = 0-0.3) nanopowders are synthesized and their tribocatalytic performance evaluated. By doping Sr into BaTiO3, the tribocatalytic performance was enhanced, resulting in an approximately 35% improvement in the degradation efficiency of Rhodamine B using Ba0.8Sr0.2TiO3. Factors such as the friction contact area, stirring speed, and materials of the friction pairs also influenced the dye degradation. Electrochemical impedance spectroscopy revealed that Sr doping improved BaTiO3's charge transfer efficiency, thereby boosting its tribocatalytic performance. These findings indicate potential applications for Ba1-xSrxTiO3 in dye degradation processes.

Effect of pectin on the crystallization of strontium substituted HA for bone reconstruction application

The biomacropolymers of bone extracellular matrix (ECM) guide the growth of hydroxyapatite (HA) with various ionic substitutions. Pectin, a plant polysaccharide with chemical similarities to ECM, was investigated for its potential to promote the crystallization of strontium-substituted HA (SH). The influence of pectin (0.5 and 1.0 wt%) on the in situ mineralization of SH (10 and 30 mol% calcium substitution with strontium) was studied. The preferential affinity of pectin to strontium over calcium favoured the incorporation of strontium in apatite, decreased crystal size (18.85–26.22 nm) and retained more pectin residues (8–16%). The residual pectin strongly interacted with small SH particles, resulting in high microhardness (0.43–0.85 GPa) and high surface charge (−32.1 to −30.3 mV), while weak interaction with large HA particles resulted in low microhardness (0.15–0.25 GPa) and low surface charge (−35.4 to −34.6 mV). The in vitro cellular study using human osteoblast-like MG-63 cells demonstrated that inorganic size and material crystallinity play a vital role in regulating osteogenesis. The study suggests that the synchronization of low pectin concentration (0.5 wt%) and high strontium substitution in HA (30 mol%) offers the desired microhardness and in vitro osteogenic properties to emulate natural bone.

Crystal structure and magnetic property correlations in Ba1−x Sr x Fe12O19 (0 ≤ x ≤ 1) hexaferrites

This paper reports a comprehensive study on the structure-property correlations in strontium-substituted barium hexaferrite and their suitability for possible applications at room temperature. A series of samples, Ba1−x Sr x Fe12O19 (0 ≤ x ≤ 1) synthesized by citrate-based sol-gel auto-combustion technique, were characterized by various physicochemical characterization techniques. The x-ray diffraction data of these samples ensure the single-phase formation and the variation of crystallographic parameters as a function of strontium substitution was discussed. The decrease in lattice parameters with increasing strontium (x) substitution ensures the applicability of Vegard’s law for the present system. The scanning electron micrographs reveal some of the grains in hexagonal shape in these samples. Raman data revealed the interconnection between magnetic ion site occupancies and the corresponding magnetization contributions, thereby ensuring the structure-property correlations in these samples. As these hexaferrites consist of layers of (ferro- and antiferro-) magnetic domains, the sub-lattice magnetic contributions were estimated by fitting the magnetic hysteresis loops (M − H) data using theoretical models. The magnetization versus temperature (M − T) graphs confirmed the above room-temperature ferromagnetic behavior. This study clearly reveals that proper tuning of their structural properties can result in optimal magnetic properties, making them suitable for permanent magnet and room-temperature magnetic device applications.

Effect of strontium substitution on functional activity of phosphate-based glass.

Phosphate-based glass (PBG) is a bioactive agent, composed of a glass network with phosphate as the primary component and can be substituted with various therapeutic ions for functional enhancement. Strontium (Sr) has been shown to stimulate osteogenic activity and inhibit pro-inflammatory responses. Despite this potential, there are limited studies that focus on the proportion of Sr substituted and its impact on the functional activity of resulting Sr-substituted PBG (PSr). In this study, focusing on the cellular biological response we synthesized and investigated the functional activity of PSr by characterizing its properties and comparing the effect of Sr substitution on cellular bioactivity. Moreover, we benchmarked the optimal composition against 45S5 bioactive glass (BG). Our results showed that PSr groups exhibited a glass structure and phosphate network like that of PBG. The release of Sr and P was most stable for PSr6, which showed favorable cell viability. Furthermore, PSr6 elicited excellent early osteogenic marker expression and inhibition of pro-inflammatory cytokine expression, which was significant compared to BG. In addition, compared to BG, PSr6 had markedly higher expression of osteopontin in immunocytochemistry, higher ALP expression in osteogenic media, and denser alizarin red staining in vitro. We also observed a comparable in vivo regenerative response in a 4-week rabbit calvaria defect model. Therefore, based on the results of this study, PSr6 could be identified as the functionally optimized composition with the potential to be applied as a valuable bioactive component of existing biomaterials used for bone regeneration.

GEOCHEMICAL MARKERS OF THE JOINT STRUCTURAL AND COMPOSITIONAL EVOLUTION OF THE BASEMENT AND COVER (NORTHERN LADOGA SWECOFENNIDES, RUSSIA)

Detailed studies of the deeply metamorphosed Early Precambrian rocks of the Northern Ladoga region allowed us to distinguish three deformation stages of the Svecofennian tectogenesis during which there occurred significant structural and compositional transformations of the "cover (Paleoproterozoic) – basement (Archean)" system. In addition to the structural-paragenetic analysis, which allowed to allocate transversal structural paragenesis in both floors, there are some other opportunities in the recognition of their-hosted granitoid veined bodies with a positive Eu anomaly. The rock varieties with this anomaly are always high in barium and do not show a direct correlation between the Eu anomaly and (La/Yb)n, Ca and Sr. This is contrary to the ideas about the occurrence of a positive Eu anomaly due to the substitution of divalent strontium by Eu++ and suggests that the formation of such rocks took place under the influence of deep reduced fluids. It was found that granitoids with a positive Eu anomaly were formed during the first and last stages of the structure evolution, with a predominance of brittle deformations and a deep-reduced fluid breakthrough. At the second stage, with the dominant manifestation of plastic deformations, when such fluids could be "blocked" within the system, there was a formation of granitoids with low barium concentrations and a negative Eu anomaly.

Mechanochemical synthesis of strontium- and magnesium-substituted and cosubstituted hydroxyapatite powders for a variety of biomedical applications

Hydroxyapatite (HA) is a biocompatible material widely used in various biomedical applications. Stoichiometric HA has low bioactivity and does not possess antibacterial properties. One way to modify HA properties is to substitute some ions in stoichiometric HA, i.e., to dope HA, for attaining desired properties, e.g., improved bioactivity or an antibacterial effect. This work shows that a soft mechanochemical method of HA synthesis allows to obtain bioactive HA containing strontium ions, magnesium ions, or both. Substituted HAs with substitution degree x(Mg) = 0.5 mol or x(Sr) = 1.5 mol were synthesized, as was cosubstituted HAs contained both magnesium and strontium ions with x(Mg) = 0.5 mol or x(Sr) = 1.5 mol. The resulting materials were investigated by simultaneous thermal analysis, scanning electron microscopy, granulometry, powder X-ray diffraction, Fourier transform infrared, Raman spectroscopy, and X-ray photoelectron spectroscopy. Thermal stability of the obtained materials was studied too. The partial calcium substitution with strontium and/or magnesium changed both HA crystal lattice parameters and positions of absorption bands of phosphate groups in Fourier transform infrared and Raman spectra. X-ray photoelectron spectra of the synthesized materials contain peaks of all elements with binding energies corresponding to substituted HA. The strontium substitution, unlike the magnesium substitution, did not reduce HA thermal stability. The crystal lattice of Sr-substituted HA is stable up to 1300 °C, just as stoichiometric HA. Magnesium cations left HA at 800 °C, forming Mg-substituted β-Ca3(PO4)2. At the cosubstitution, thermal stability of HA became slightly lower. Partial decomposition of the material began already at 700 °C. Accordingly, during manufacturing of medical devices from the proposed materials, their low thermal stability should be taken into account. To preserve the structure of Mg-Sr-cosubstituted HA, heat treatment conditions should not exceed 700 °C.

Strontium Substituted Tricalcium Phosphate Bone Cement: Short and Long‐Term Time‐Resolved Studies and In Vitro Properties

AbstractDue to a significant influence of strontium (Sr) on bone regeneration, Sr substituted β‐tricalcium phosphate (Sr‐TCP) cement is prepared and investigated by short‐ and long‐term time‐resolved techniques. For short‐term investigations, energy‐dispersive X‐ray diffraction, infrared spectroscopy, and, for the first time, terahertz time‐domain spectroscopy techniques are applied. For long‐term time‐resolved studies, angular dispersive X‐ray diffraction, scanning electron microscopy, mechanical tests, and behavior in Ringer solution are carried out. After 45 min of the cement setting, the Sr‐TCP phase is no longer detectable. During this time period, an appearance and constant increase of the final brushite phase are registered. The compressive strength of the Sr‐TCP cement increases from 4.5 MPa after 2 h of setting and reaches maximum at 13.3 MPa after 21 d. After cement soaking for 21 d in Ringer solution, apatite final product, with an admixture of brushite and TCP phases is detected. The cytotoxicity aspects of the prepared cement are investigated using NCTC 3T3 fibroblast cell line, and the cytocompatibility—by human dental pulp mesenchymal stem cells. The obtained results allow to conclude that the developed Sr‐TCP cement is promising for biomedical applications for bone tissue.