Strontium Ions Research Articles

Strontium-based quaternary ammonium salt chitosan particles for ultrafast hemostasis of open fracture.

The management of open bone defects poses a formidable challenge in clinical practice, primarily due to issues such as profuse bleeding, inflammation, bacterial infections, and compromised bone fracture healing. To tackle these complexities, we have devised a novel hemostatic powder, namely the compound strontium-based chitosan quaternary ammonium salt hemostatic powder (QCS@SrT-TA). This innovative powder leverages the self-assembly of tripolyphosphate and strontium ions, facilitated by a positively charged core cross-linker. Furthermore, its surface has been strategically modified with polyphenol and positively charged macromolecules, imparting unique properties. The mesoporous architecture of QCS@SrT-TA facilitates rapid moisture absorption, enhancing its efficacy. In preclinical studies using rat tail artery amputation and liver bleeding models, QCS@SrT-TA exhibited remarkable performance, significantly reducing both bleeding time and volume (62.39 ± 2.89 mg, 35.33 ± 4.16 s in tail amputation, 63.7 ± 5.19 mg, 62.33 ± 9.61 s in liver bleeding). Notably, the positively charged strontium ions and quaternary ammonium salts within the powder were effective in removing bacteria, minimizing the risk of infection. Beyond hemostasis, QCS@SrT-TA demonstrates additional therapeutic benefits. It polarizes M2 macrophage phenotypes and promotes angiogenesis within bone defect sites, accelerating bone healing processes. Ultimately, a substantially enhanced and notable functional recovery is achieved. In summary, the rapid hemostatic, potent antibacterial, anti-inflammatory, and angiogenesis-promoting characteristics of QCS@SrT-TA hold immense promise as a groundbreaking clinical treatment strategy for open bone defects.

Regulation of Bone Remodeling by Metal-Phenolic Networks for the Treatment of Systemic Osteoporosis.

Osteoporosis is a systemic metabolic disease that impairs bone remodeling by favoring osteoclastic resorption over osteoblastic formation. Nanotechnology-based therapeutic strategies focus on the delivery of drug molecules to either decrease bone resorption or increase bone formation rather than regulating the entire bone remodeling process, and osteoporosis interventions suffer from this limitation. Here, we present a multifunctional nanoparticle based on metal-phenolic networks (MPNs) for the treatment of systemic osteoporosis by regulating both osteoclasts and osteoblasts. In the osteoporotic microenvironment, the MPN nanoparticles degrade and trigger the release of bioactive metals (strontium ions, SrII) to promote osteogenesis and functionalized phenols (epigallocatechin gallate, EGCG) to suppress osteoclastogenesis. Injecting these nanoparticles into the tail vein of an ovariectomized mouse model, trabecular bone loss has been significantly prevented in the femoral head and vertebrae, along with increased trabecular bone volume and decreased trabecular bone separation. Overall, this work represents a versatile approach to explore MPN nanomaterials for the treatment of systemic osteoporosis and related orthopedic diseases.

A novel biowaste-derived magnetic adsorbent for efficient removal of cadmium, cobalt and strontium ions from industrial wastewater

A novel biowaste-derived magnetic adsorbent for efficient removal of cadmium, cobalt and strontium ions from industrial wastewater

Chloroquine inhibits artificial oocyte activation induced by ethanol or Sr²⁺ but not by sperm in mice

Calcium release from the endoplasmic reticulum via sperm-derived phospholipase C zeta is crucial for oocyte activation during fertilization. Chloroquine (CQ) inhibits the increase in cytoplasmic calcium. This study investigated the effects of CQ on fertilization and oocyte activation. Oocytes were collected from ICR mice, and in vitro fertilization and artificial oocyte activation with strontium ions (Sr2+) and ethanol were performed in the presence of 50 µM CQ. Pronuclear formation was assessed via Hoechst33242 nuclear staining, cortical granule release was evaluated using lens culinaris agglutinin-fluorescein isothiocyanate (LCA-FITC) staining, and cytosolic calcium levels were measured using fluorescence microscopy with Cal-520 AM. In the presence of CQ, no pronuclei were formed even 8 h after Sr²⁺-induced oocyte activation. Furthermore, cortical granule release in CQ-treated oocytes was significantly suppressed, although not completely inhibited, and no increase in cytosolic calcium was detected. CQ also inhibited pronuclei formation during ethanol-induced oocyte activation. In in vitro fertilization, although the fertilization rate was decreased in the CQ-treated group, in which CQ treatment was continuously applied during insemination, pronuclear formation and cortical granule release were observed. The decrease in the fertilization rate was likely attributable to reduced sperm motility and decreased penetration of the zona pellucida. The findings indicate that the oocyte activation pathways triggered by ethanol/Sr²⁺ and sperm are distinguishable by CQ, and that CQ can be used as a selective inhibitor of oocyte activation induced by Sr2+ or ethanol treatment.

Study on the Mechanism of Black Phosphorus Nanosheets Loading Sr2+ Used in Photothermal Antibacterial Treatment.

Bacterial infections seriously affect the health of patients and their incidence is very high. Photothermal therapy has shown promising prospects in the treatment of bacterial infections as it can effectively kill bacteria and reduce inflammation. Black phosphorus (BP) is an emerging nanoparticle that can generate heat under the action of near-infrared light, it can safely and effectively kill bacteria through photothermal therapy. In this experiment, black phosphorus was used as a photothermal agent to kill bacteria and strontium ions were loaded onto BP to enhance its stability and antibacterial performance. BP was obtained by liquid phase exfoliation and Sr2+ was loaded onto the surface of BP by electrostatic interaction. BP-Sr was synthesized via electrostatic interactions and characterized using various techniques. The cytocompatibility of BP-Sr was evaluated by CCK8 assay and live/dead staining which showed no significant cytotoxicity with a concentration not exceed 50μg/mL. Meanwhile, the antibacterial effects showed 99% of bacteria died after 10 min under the action of a 2 W/cm2 laser and the structure of bacteria was destroyed. Finally, the transcriptomic results suggest that bacteria death may be related to membrane destruction, metabolic disorders, and transport damage. HE staining and Gram staining also showed that inflammation was significantly alleviated after laser treatment. These findings propose a great solution for bacterial infection and also enrich the theoretical framework supporting the application of BP-Sr in the field of antibiosis.

Construction of strontium-loaded injectable lubricating hydrogel and its role in promoting repair of cartilage defects.

Injuries such as articular cartilage defects are prevalent factors in the development and progression of joint diseases. The discontinuity of the articular surface due to cartilage defects significantly accelerates the onset of arthritis. Cartilage tissue-engineered scaffolds are essential for restoring the continuity of the articular surface. This study presents a dual-network hydrogel, GelMA-FT/Sr2+, which demonstrates excellent lubrication properties and accelerates the healing of cartilage defects. The hydrogel is composed of a methacrylated gelatin (GelMA) network, an N-fluorenylmethoxycarbonyl-L-tryptophan (FT) network, and strontium ions (Sr2+). The results indicate that the hydrogel exhibits lubricating properties, and the incorporation of Sr2+ extends the degradation time of the hydrogel. Additionally, the hydrogel shows biocompatibility and enhances chondrogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) into cartilage. In vivo studies further confirm the hydrogel's efficacy in promoting the repair of cartilage defects in a rat model of cartilage injury. In conclusion, the GelMA-FT/Sr2+ hydrogel is a promising scaffold for cartilage tissue engineering, notable for its excellent lubrication properties, ability to recruit stem cells, and effectiveness in facilitating cartilage defect repair.

Multisite synergistic interaction induced selective adsorption of CB5-Ti3C2T2 complex for strontium ion: A combined theoretical and experimental study.

In this work, we use a well-defined water-soluble macrocyclic molecule cucurbit[5]uril (CB5) to modify 2D Ti3C2T2 MXene and assemble a novel high-performance adsorbent CB5-Ti3C2T2 for Sr ion by density functional theory and experimental methods. The structural stabilities of two distinct types of CB5-Ti3C2T2 (T = F, O and OH) complexes, i.e., CB5-Ti3C2T2(V) and CB5-Ti3C2T2(P) configurations are proved by binding energy and ab initio molecular dynamics (AIMD) simulations. Calculations of adsorption properties reveal that all the considered CB5-Ti3C2T2 complexes can act as efficient adsorbents for Sr ion, among which CB5-Ti3C2O2 complex possesses the best performance. The high affinity (the calculated adsorption energies < -7.6 eV) and selectivity of CB5-Ti3C2T2 complex for Sr ion are attributed to the synergistic effect between CB5 molecule and Ti3C2T2 MXene in the adsorption process, which arises from the multisite interactions of portal carbonyl groups of CB5 and surface functional groups of Ti3C2T2 towards Sr. Finally, CB5-Ti3C2T2 complex was successfully synthesized, and experimental results confirm its synergistic effect, good selectivity and high removal efficiency for Sr ions. In the treatment of strontium-containing wastewater with low concentrations, the distribution coefficient and decontamination factor of CB5-Ti3C2T2 for Sr were determined to be as high as 2.88 × 105 mL/g and 144.9, respectively, and the separation factor (SFSr/Ca) achieved a notable value of 67. 5. This work is expected to present a new strategy for the construction of high-performance MXene-based adsorbent for radionuclide elimination.

Gingival Soft Tissue Integrative Zirconia Abutments with High Fracture Toughness and Low-Temperature Degradation Resistance.

Low fracture toughness, low-temperature degradation (LTD) susceptibility, and inadequate soft tissue integration greatly limit the application of zirconia ceramic abutment. Integrating the "surface" of hard all-ceramic materials into the gingival soft tissue and simultaneously promoting the "inner" LTD resistance and fracture toughness is challenging. Composite ceramics are effective in improving the comprehensive properties of materials. In this study, we aim to develop a zirconia composite abutment with high "inner" structure stability and "surface" bioactivities simultaneously and to explore the mechanism of performance improvement. Therefore, elongated SrAl12O19 and equiaxed Al2O3 were introduced into the zirconia matrix by using the Pechini method. Reinforcements of different shapes can promote the density, reduce the grain size, and increase the phase stability of composite ceramics, which improves the fracture toughness and LTD susceptibility. In addition, the released strontium ions (Sr2+), without sacrificing the mechanical properties of the material, could activate the biological capacity of the zirconia surface by activating the M2 polarization of macrophages through the Sr2+/calcium-sensing receptor/SH3 domain-binding protein 5 axis, thereby promoting the collagen matrix synthesis of fibroblasts and the angiogenesis of vascular endothelial cells. This successful case proposes a novel strategy for the development of advanced high-strength and bioactive all-ceramic materials by introducing reinforcements containing biofunctional elements into the ceramic matrix. The approach paves the way for the widespread application of such all-ceramic materials in soft-tissue-related areas.

Strontium Ions Release from Novel Bioactive Glass-Containing Glass Ionomer Cements: A Preliminary Study

This study was conducted to measure the release of strontium ions that leached-out from novel bioactive glass-containing glass ionomer cements and also to evaluate effect of adding bioactive glass particles in various percentages on the strontium rate at different intervals. A series of ionomer glasses were synthesised based on 4.5SiO2-3Al2O3-0.75P2O5-3(CaO/SrO)-2(CaF2/SrF2) systems with varying strontium substitution from 0%Sr to 100%Sr. The cement discs were prepared with incorporation of sodium-free bioactive glass via substitutional basis and then were immersed in 10 ml of artificial saliva. After certain periods ranged from 7 days up to 28 days, the discs were collected and solution was analysed using inductively coupled plasma optical emission spectroscopy in order to obtain the cumulative release of strontium ions. Strontium ions release increased with increasing in strontium for calcium substitution, particularly during the first week of immersion. The highest strontium release was obvious from the fully strontium-substituted compositions. However, the strontium rate decreased with increasing in addition of bioactive glass at all time points. A substantial variation in strontium concentrations in the surrounding media was clearly observed with increasing both strontium and bioactive glass amounts in the parent glasses/cements. An extended work should be done to identify the optimal concentrations of strontium and bioactive glass that could combine together to manufacture an ideal bioactive material for dental applications.

Remediation of Ni2+ and Sr2+ ions from aqueous solutions by acacia gum/polyacrylic acid hydrogel reinforced with TiO2 nanoparticles

Abstract Globally, the environment and public health are progressively threatened due to water resource contaminants. For this purpose, a unique polyfunctional nanocomposite is created to remediate heavy metals from aqueous media. The basis of it is TiO2 composite nanoparticles (NPs) manufactured via embedding titanium oxide (TiO2) into acacia gum/acrylic acid (AG/AAc). Nanocomposite hydrogels, bearing different functional groups, are constructed employing a gamma irradiation approach that would operate as adsorbents to remove strontium (Sr2+) and nickel (Ni2+) ions from their wastes. The structure of the prepared hydrogel and its nanocomposites were confirmed by FTIR, whereas the morphology was characterized by SEM. XRD and EDX analysis confirms that the TiO2 NPs are successfully encapsulated into the prepared hydrogel. The presence of TiO2 enhances the thermal stability of the prepared hydrogel. Adsorption extent is evaluated comprehensively concerning temperature, contact time, adsorbent dosage, metal ion concentration, and pH. The physical connection between the adsorbent surface and metal ions is strengthened once TiO2 NPs are included in a copolymeric matrix, which enhances adsorption. Pseudo-second-order kinetics accurately depict the adsorption process, and the Freundlich isotherm provides the most relevant explanation of the equilibrium data. There is a demonstration that sorption is a spontaneous, feasible, and endothermic chemisorption process by examining a variety of thermodynamic parameters, including ΔH, ΔG, and ΔS.

Incorporation of metal-doped silicate microparticles into collagen scaffolds combines chemical and architectural cues for endochondral bone healing.

Regeneration of large bone defects remains a clinical challenge until today. While existing biomaterials are predominantly addressing bone healing via direct, intramembranous ossification (IO), bone tissue formation via a cartilage phase, so-called endochondral ossification (EO) has been shown to be a promising alternative strategy. However, pure biomaterial approaches for EO induction are sparse and the knowledge how material components can have bioactive contribution to the required cartilage formation is limited. Here, we combined a previously developed purely architecture-driven biomaterial approach with the release of therapeutic metal ions from tailored silicate microparticles. The delivery platform was free of calcium phosphates (CaP) that are known to support IO but not EO and was employed for the release of lithium (Li), magnesium (Mg), strontium (Sr) or zinc (Zn) ions. We identified an ion-specific cellular response in which certain metal ions strongly enhanced cell recruitment into the material and showed superior chondrogenesis and deposition collagen II by human mesenchymal stromal cells (MSCs). At the same time, in some cases microparticle incorporation altered the mechanical properties of the biomaterial with consequences for cell-induced biomaterial contraction and scaffold wall deformation. Collectively, the results suggest that the incorporation of metal-doped silicate microparticles has the potential to further improve the bioactivity of architectured biomaterials for bone defect healing via EO. STATEMENT OF SIGNIFICANCE: Endochondral bone healing, a process that resembles embryonic skeletal development, has gained prominence in regenerative medicine. However, most therapeutic biomaterial strategies are not optimized for endochondral bone healing but instead target direct bone formation through IO. Here, we report on a novel approach to accelerate biomaterial-guided endochondral bone healing by combining cell-guiding collagen scaffolds with therapeutic metal-doped silicate microparticles. While other strategies, such as hypoxia-mimic drugs and iron-chelating biomaterials, have been documented in the literature before to enhance EO, our approach uniquely implements enhanced bioactivity into a previously developed biomaterial strategy for bone defect regeneration. Enhanced cell recruitment into the material and more pronounced chondrogenesis were observed for specific hybrid scaffold formulations, suggesting a high relevance of this new biomaterial for improved endochondral bone healing.

Optimization of Structural, Dielectric, and Electrical Properties in Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 through site engineering for Biocompatible Energy Harvesting

Piezoelectric energy harvesting has recently gained attention due to its high power density and potential for self-powered sensor networks. This study investigates the effects of dopants on Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramics, examining Strontium (Sr2+), Zinc (Zn2+), and praseodymium (Pr3+/4+) ions at different sites and their impact on structural, dielectric, and electrical properties. X-ray diffraction and Rietveld analysis reveal a coexistence of tetragonal and rhombohedral/orthorhombic phases, with a predominant tetragonal phase, confirmed by Raman analysis. Energy-dispersive X-ray spectroscopy ensures chemical homogeneity. The density measurements indicate a dense microstructure with a relative density of 90-95%. Dielectric analysis shows a relaxor-like behavior in AB-site doped BCZT ceramics, validated by polarization-electric field hysteresis loops. B-site doped BCZT ceramics exhibit ultra-low leakage currents, approximately 103 times lower than undoped BCZT. An optimized biocompatible flexible film-based energy harvester, incorporating A-site doped BCZT ceramic particles, demonstrated impressive energy harvesting capabilities. A simple finger tapping generated ~80.2V and ~18.2nA, with an average peak-to-peak power density of 7.6 µW-cm-3. These results highlight the significant potential of dopant inclusion in BCZT ceramics, marking a major advancement in doping strategies for piezoelectric energy harvesting in miniature electronics.

Selective and sensitive portable colorimetric detection of strontium and iodide ions based on G4 DNAzyme/hemin

The radioactive component strontium-90 (90Sr) has attracted considerable attention, but detection remains challenging because there are no specific energy beams to indicate its presence. Due to the short half-life of 131I (8.04 d), the difficulty of detection without nuclear contamination, and the different analysis methods compared to other artificial radionuclides, research on the rapid detection method of 131I in seawater is minimal. In this work, we propose the design of a novel aptamer-based colorimetric sensing system for the visual detection of strontium and iodide ions. This method is based on the ability of hemin to self-assemble with G4 and form a G4/hemin complex with strong peroxidase-like nanozyme activity. At the same time, in the presence of G4/hemin, I− can synergistically catalyze the oxidation of TMB by H2O2, transforming it from colorless to dark blue oxTMB. Under optimal experimental conditions, absorbance was linearly with Sr2+ concentration from 0.8 nM to 7 μM, with a detection limit of 0.11 nM, and absorbance from 0.05 μM to 100 μM with I− concentration. In addition, an integrated portable colorimetric test platform has been developed to realize the on-site portable detection of I−, providing a technical solution for radioactivity detection and analysis, and helping to monitor the migration of radioactive I− and Sr2+ in the environment.

Carboxymethyl chitosan/alendronate sodium/Sr2+ modified TiO2 nanotube arrays enhancing osteogenic activity and antibacterial property

Titanium and its alloys are widely used as orthopedic implants owing to their good mechanical properties and excellent corrosion resistance. However, the insufficient osteogenic activity and antibacterial properties hinder their clinical applications. To address these issues, TiO2 nanotube arrays (TNT) were first fabricated on the TA2 alloy surface via an anodizing technique, and strontium ions (Sr2+) were then loaded by hydrothermal reaction (TNT + Sr) and annealing treatment (TNT + A). Subsequently, the polydopamine layer (TNT + PDA) was constructed to immobilize the carboxymethyl chitosan and alendronate sodium (TNT + CA) mixture. The prepared coatings were thoroughly characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectrometer (XPS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffractometer (XRD), and water contact angle measurement. The results confirmed that Sr2+ ions, polydopamine, and carboxymethyl chitosan/alendronate sodium were successfully immobilized on the nanotubes. The coating of TNT + CA significantly enhanced the hydrophilicity, and effectively delayed the release of Sr2+ and alendronate. The TNT + CA coating significantly promoted osteoblast adhesion and proliferation, and up-regulated the expressions of alkaline phosphatase (ALP), osteocalcin (OCN), and osteoblast-specific transcription factor (RUNX2). TNT + CA was able to rapidly induce in situ hydroxyapatite deposition from the simulated body fluid (SBF). Moreover, TNT + CA coating showed inhibition against Escherichia coli and Staphylococcus aureus (especially against Escherichia coli). The prepared TNT + CA coating provides a novel strategy for enhancing bone affinity, improving osteoblast behaviors, and antibacterial properties of titanium-based biomaterials.

Synergistic catecholamine and coordination chemistry for enhanced bioactivity and secondary grafting activity of zirconia dental implants

The inherent bioinertness of zirconia (ZrO2) hinders its early bone integration, presenting a significant obstacle to its widespread use in dental implant technologies. Addressing this, we developed a surface coating leveraging the synergistic effects of catecholamine and coordination chemistry inspired by the mussel byssus cuticle. This coating, named PDPA@Sr, is enriched with strontium ions and amine groups, resulting from a simple immersion of polydopamine (PD)-coated ZrO2 in an alkaline strontium chloride and poly(allylamine) (PA) solution. Compared to conventional mussel-inspired PD coatings, PDPA@Sr demonstrates enhanced aesthetic properties and mechanical stability. The continuous release of strontium ions from the coating significantly enhances osteogenesis, while the abundant surface amine groups offer notable antibacterial effects. More importantly, these amine groups also enable a variety of chemical modifications, including electrostatic adsorption, carbodiimide chemistry, Michael addition, Schiff base formation, and click chemistry, thus providing a multifaceted platform for the advanced surface modification of ZrO2 implants.

Quasi-1D Oxides as Electrocatalysts for Water-Splitting: Case Study of Sr9M2Mn5O21 (M = Co, Ni, Cu, Zn).

We have demonstrated that multimetal oxides with a quasi-1D structure can be effective electrocatalysts for water electrolysis. Four materials have been systematically investigated, namely, Sr9Co2Mn5O21, Sr9Ni2Mn5O21, Sr9Cu2Mn5O21, and Sr9Zn2Mn5O21, comprising 1D chains of face-sharing MnO6 octahedra and MO6 trigonal prisms (M = Co, Ni, Cu or Zn), which are held together by strontium ions located between the chains. These materials show a consistent trend in electrocatalytic properties for both half-reactions of water-splitting, i.e., oxygen evolution and hydrogen evolution reactions (OER and HER). In particular, Sr9Ni2Mn5O21 has an outstanding performance for OER, with an overpotential of 0.37 V, which is lower than those of many 3D and 2D oxides, and rivals the activity of noble metal catalysts, such as RuO2. This is important given that the OER is considered the bottleneck of the water-slitting process. Chronopotentiometry studies, combined with X-ray photoelectron spectroscopy (XPS) and X-ray diffraction experiments pre- and post-reaction, indicate that Sr9Ni2Mn5O21 is highly stable and retains its structural integrity upon electrocatalytic reactions. This study highlights the potential of quasi-1D oxides as active electrocatalysts for water-splitting.

An investigation on the structural, morphological, optical, and antibacterial activity of Sr:CuS nanostructures

The aim of the present study is to synthesize Cu1−xSrxS (x = 0.00, 0.025, 0.05, 0.075, and 0.1) nanoparticles (NPs) using an easy chemical co-precipitation method in an efficient, inexpensive, and simple technique. The structural, morphological, and optical properties of the prepared samples were investigated using XRD, TEM, XRF, UV–Vis DRS, and PL characterization techniques. XRD spectra confirmed the Sr-doped copper sulfide nanoparticles have a hexagonal structure with crystallite sizes ranging from 15.15 to 16.04 nm, and, by XRF, the presence of the dopant was detected. TEM analysis confirmed that strontium ions had an effect on the shape of the CuS nanostructure, and the particle size increased from 16.27 to 17.32 nm after doping. A study using UV-Vis showed the presence of Sr doping increased the optical energy band gap (1.38 eV to 1.59 eV). At room temperature, one photoluminescence (PL) band was found at 826 nm. The antibacterial activity of CuS nanostructures against E. coli, P. aeruginosa, Klebsiella pneumonia, and S. aureus was evaluated by zone of inhibition. Sr doped CuS NPs exhibited the highest antibacterial activity against S. aureus (17 to 29 mm). Also, the results demonstrated that samples doped with 5, 7.5, and 10% Sr exhibited inhibitory effects against all the tested microbial strains higher than the antibiotic.

High extraction efficiency of N,N,N′,N′-tetracyclohexyldiglycolamide for Sr(II): An experimental and crystal structure study

To improve the ability of diglycolamide extractants for the extraction of Sr(II) from high-level waste liquid, N,N,N′,N′-tetracyclohexyl-diglycolamide (TCHDGA) was proposed and studied to extract Sr(II) from nitrate media. TCHDGA was prepared and characterized by 1H Nuclear Magnetic Resonance Spectroscopy (NMR), 13C NMR, and Fourier Transform Infrared Spectroscopy (FT-IR). Various factors affecting extraction were studied systematically. In just 20 s, the extraction rate can reach approximately 98.2 %. The extraction capacity of cyclohexyl-substituted extractant TCHDGA is tens of times higher than that with linear or branched chain alkyl. The chemical structure of the complex has been demonstrated to be [Sr 3TCHDGA]·(NO3)2, based on FT-IR, X-ray Photoelectron Spectroscopy (XPS), and crystal structure analysis. The crystal belongs to the monoclinic system, space group P21, and a strontium ion coordinates with nine oxygen atoms, all of which contribute from TCHDGA. The stripping rate can reach over 99 % when using distilled water or 0.50 mol·L−1 oxalic acid as stripping agents.

Dandelion-shaped strontium-gallium microparticles for the hierarchical stimulation and comprehensive regulation of wound healing.

The management of full-thickness skin injuries continues to pose significant challenges. Currently, there is a dearth of comprehensive dressings capable of integrating all stages of wound healing to spatiotemporally regulate biological processes following full-thickness skin injuries. In this study, we report the synthesis of a dandelion-shaped mesoporous strontium-gallium microparticle (GE@SrTPP) achieved through dopamine-mediated strontium ion biomineralization and self-assembly, followed by functionalization with gallium metal polyphenol networks. As a multifunctional wound dressing, GE@SrTPP can release bioactive ions in a spatiotemporal manner akin to dandelion seeds. During the early stages of wound healing, GE@SrTPP demonstrates rapid and effective hemostatic performance while also exhibiting antibacterial properties. In the inflammatory phase, GE@SrTPP promotes M2 polarization of macrophages, suppresses the expression of pro-inflammatory factors, and decreases oxidative stress in wounds. Subsequently, during the stages of proliferation and tissue remodeling, GE@SrTPP facilitates angiogenesis through the activation of the Hypoxia-inducible factor-1α/vascular endothelial growth factor (HIF-1α/VEGF) pathway. Analogous to the dispersion and rooting of dandelion seeds, the root-like new blood vessels supply essential nutrients for wound healing. Ultimately, in a rat chronic wound model, GE@SrTPP achieved successful full-thickness wound repair. In summary, these dandelion-shaped GE@SrTPP microparticles demonstrate comprehensive regulatory effects in managing full-thickness wounds, making them highly promising materials for clinical applications.

Effect of mineralized solution on protective properties of clays in radioactive waste isolation

In this paper there were studied the mineral composition and sorption properties as well as filtration properties of natural clay samples from “Gorodnoe” deposit of Brest region and “Markovskoe” deposit of Gomel region. It was determined that clay mineral montmorillonite of the samples contains illite phase in the structure, which is 4,8 wt.% in “Gorodnoe” sample and 3,6 wt.% in “Markovskoe” sample. The illite phase was shown to contain highly selective sorption sites for 137Cs. 85Sr sorption mostly takes place on montmorillonite. It was determined that model mineralized solution (the solution imitating chemical composition of water solution if water penetrates a radioactive waste disposal and consequently passes through concrete, Na-bentonite and again concrete layers) doesn’t affect 137Cs sorption, but significantly affects 85Sr sorption. Distribution coefficients (Kd ) of 137Cs sorption on studied clay samples are higher than 103 dm3 /kg, indicating high sorption properties of the clays towards 137Cs. Kd 85Sr for sorption on the clay samples in the model mineralized solution is 30 times lower than Kd 137Cs mostly because of competition between strontium and calcium ions. It was determined that filtration coefficient values of clays from “Gorodnoe” and “Markovskoe” deposits are 2,4 and 1,3 times higher after being treated with the model mineralized solution than the filtration coefficient values for raw clay samples. Hence, the clay from “Markovskoe” deposit is more resistant to the influence of the model mineralized solution than the clay from “Gorodnoe” deposit. The overall results of the research state that the clay from “Markovskoe” deposit can be used in the underlying layer of low- and medium-level radioactive waste disposal facility at NPP.