Search Results (223)

The aim of this in vitro study was to evaluate the ability of the new strontium-containing composite, Stela (SDI, Victoria, Australia), to induce hydroxyapatite formation and promote remineralization of demineralized dentin, compared to SDR Flow+ (York, PA, USA). Twenty-four dentin slices (1 mm thick) were obtained from extracted wisdom teeth using a microtome and demineralized with 17% EDTA for 2 h. A layer of either Stela or SDR Flow+ was applied to each slice, allowed to set, and preserved in 0.1% thymol solution. Samples were analyzed at 1, 7, 14 and 28 days (n = 3 per group and time). Measurements were taken at baseline, after demineralization, and after application. Apatite formation was assessed using 'Fourier-transform infrared spectroscopy (FTIR), while changes in the Calcium/Phosphate (Ca/P) ratio were evaluated by Energy Dispersive Spectroscopy (EDX). Statistical comparisons were performed using the Wilcoxon test (p < 0.05). Both materials promoted carbonated hydroxyapatite formation and increases in calcium and phosphate. Stela exhibited an apatite peak (1420 cm⁻¹) as early as 24 h and significant increases in calcium and phosphate from day 7. SDR Flow+ reached its peak at 14 days and showed significant increases in the Ca/P ratio. By 28 days, both materials achieved comparable remineralization, confirming their effectiveness in treating demineralized dentine. Full article

In pancreatic cancer, cancer stem-like cells (CSCs) contribute to tumor initiation, reduced drug sensitivity, and recurrence. Limited strategies are currently available to target this cell population. Here we used a proteasome-low CSC enrichment system to identify microRNAs that negatively regulate CSC-like properties. From PANC-1 cells expressing a ZsGreen–ODC degron reporter, a proteasome-low population was isolated through sequential fluorescence-activated cell sorting of ZsGreen-positive cells. Molecular and functional analyses confirmed the CSC-like phenotype of this cell population. Integrated in silico analysis was used to select 31 microRNAs predicted to target CSC-related molecules, which were then evaluated by in vitro viability-based screening to identify candidates that selectively suppressed the viability of CSC-like cells, relative to non-CSCs. Moreover, comprehensive miRNA expression profiling revealed that miR-136-5p was downregulated in the CSC-like population and was therefore selected for further analysis. Mechanistically, miR-136-5p directly targets the 3′ untranslated region of DCLK1 and reduces its expression, with a greater reduction in the short isoform. Finally, in a CSC-derived xenograft mouse model, systemic delivery of miR-136-5p using super carbonate apatite nanoparticles significantly suppressed tumor growth. Taken together, these findings suggest that miR-136-5p restoration may provide a therapeutic approach for targeting CSC-driven tumor growth in pancreatic cancer. Full article

With increasing life expectancy and an aging global population, the demand for orthopedic and dental implants is increasing. Recently developed, citric-acid-based anodization processes facilitate the production of more bioactive oxide layers by incorporating important bone minerals such as Ca, P, and Mg and forming bone-like crystalline compounds such as carbonated apatite on titanium implant materials. The primary goal of the present study was to evaluate the applicability of these anodization processes to solid and 3D-printed titanium alloy substrates. The anodized oxides produced on each solid or 3D-printed lattice substrate revealed multi-scaled surface roughness profiles as evidenced by scanning electron microscopy, optical microscopy, and surface roughness analyses. Additionally, each oxide group was shown to incorporate substantial amounts of Ca, P, and Mg bone-mineral dopants and form AB-type carbonated apatite, as shown using a combination of energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and attenuated total reflectance–Fourier transform infrared spectroscopy analyses. Finally, each oxide group showed sustained Ca, P, and Mg ion release during an inductively coupled plasma spectroscopy dissolution assessment, and demonstrated early apatite-forming ability during simulated body fluid bioactivity testing. The findings of this study show much promise for the applicability of these novel oxide coatings to a wide variety of future titanium implant applications. Full article

Background/Aim: Pancreatic cancer remains one of the most lethal malignancies, with limited therapeutic options and an extremely poor prognosis. MicroRNAs (miRNAs), which regulate gene expression at the post-transcriptional level, have emerged as promising candidates for next-generation cancer therapeutics. The purpose of this study is to clarify the feasibility of miR-4711 as a potential therapeutic option against pancreatic cancer. Materials and Methods: The effects of miR-4711-5p were examined in pancreatic cancer cell lines with respect to cell proliferation, apoptosis, cancer stemness, cell cycle progression, and invasive capacity. RNA sequencing and in silico analyses were performed to identify potential target genes of miR-4711-5p. For in vivo safety evaluation, miR-4711-5p was formulated with super carbonate apatite, a delivery vehicle that is already amenable to large-scale production, and administered to cynomolgus monkeys. A nucleic acid dose equivalent to 10 times the effective dose observed in prior mouse efficacy studies was used. General clinical conditions, body weight, food consumption, ophthalmologic findings, electrocardiography, blood pressure, hematological and biochemical parameters, and histopathological changes were systematically assessed. Results: miR-4711-5p significantly suppressed cancer stemness, cell proliferation, and invasion, while inducing apoptosis and delaying cell cycle progression in pancreatic cancer cells. RNA sequencing and bioinformatic analyses identified MET, CTSA, and ANO1 as potential target genes of miR-4711-5p. In the cynomolgus monkey study, administration of miR-4711-5p formulated with super carbonate apatite resulted in no apparent differences compared with the control group in body weight, clinical observations, laboratory parameters, or histopathological findings, indicating the absence of treatment-related adverse effects even at a supra-therapeutic dose. Conclusions: These findings demonstrate that miR-4711-5p exerts potent antitumor effects against pancreatic cancer cells while exhibiting a favorable safety profile in a non-human primate model. Collectively, this study provides strong preclinical evidence supporting miR-4711-5p as a novel and safe therapeutic strategy for pancreatic cancer and represents an important step toward clinical application. Full article

The coal-based direct reduction followed by magnetic separation (CDRMS) is an efficient iron extraction and dephosphorization process, which requires adding additives to improve the phosphorus removal rate. Compared with other additives, sodium carbonate has the advantages of good iron index, high phosphorus removal rate and less environmental pollution. Its role in phosphorus-rich oolitic iron ore (PROIO) where phosphorus exists in the form of apatite has been proved. However, the influence on the phosphorus transformation process in the lattice of iron minerals is not clear. In this paper, the effect of sodium carbonate on phosphorus removal in iron minerals and iron recovery during CDRMS was studied. Compared with not adding chemicals, the addition of sodium carbonate significantly reduced the phosphorus content of direct reduced iron (DRI) from 0.69% to 0.09%. The iron grade increased from 93.28% to 95.08%, and the iron recovery rate rose from 90.61% to 96.48%. The mechanism of sodium carbonate was revealed by using a synchronous thermal analyzer (TG–DSC), X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), scanning electron microscope and energy dispersive spectrometer (SEM–EDS), and vibrating sample magnetometer (VSM). The results show that sodium carbonate reacted with silicon and aluminum components to form nepheline, and the lattice substitution of phosphorus in iron minerals and silicon in nepheline prevents the reduction of phosphorus. In addition, sodium carbonate promotes the reduction of iron minerals, resulting in an increase in the magnetic properties of the reduction products. Full article

Late Permian paleoenvironmental instability and recurrent biotic crises coincided with enhanced marine organic-carbon burial, yet ocean-circulation dynamics have remained underappreciated as a key driver. In particular, for the Wuchiaping Formation along the eastern margin of the Paleo-Tethys Ocean, the presence, variability, and mechanistic impact of upwelling—and its coupling with water-column redox structures—have not been systematically constrained, limiting a process-based understanding of organic-matter enrichment. Here, we integrate sedimentological, mineralogical, and multi-proxy geochemical data to investigate the dominant controls on organic matter enrichment in the Wuchiaping Formation shale succession from the northeastern Sichuan Basin. The Lower Wuchiaping Formation consists mainly of clay-rich shales deposited under oxic, shallow-water, and weakly stratified conditions, as indicated by low Ni/Co ratios (average 1.88), limited uranium enrichment (U_EF = 0.21), low Ba/Al ratios, and sparse biogenic debris. Biomarker indices (gammacerane index = 0.35; Pr/Ph = 1.91) suggest unfavorable preservation conditions, resulting in a low mean TOC of 0.78%. In contrast, the Upper Wuchiaping Formation is dominated by siliceous shales with elevated Ni/Co ratios (average 15.83), moderate uranium enrichment (U_EF = 2.48), abundant framboidal pyrite, radiolarian–planktic foraminiferal assemblages, and laminated apatite. High Ba/Al and Cd/Mo ratios, higher gammacerane values, and low Pr/Ph ratios (<1) indicate enhanced water-column stratification and bottom-water anoxia, leading to efficient organic matter preservation and a high mean TOC of 9.2%. Biomarker compositions reveal a shift from terrestrial-dominated organic matter in the Lower Wuchiaping Formation to algal- and plankton-derived inputs in the Upper Wuchiaping Formation. Collectively, these results indicate that intensified upwelling—rather than tectono-magmatic forcing alone—was the primary driver of enhanced productivity, strengthened redox stratification, and organic matter enrichment in the Upper Wuchiaping Formation. Our findings highlight the importance of upwelling–redox coupling as a key mechanism linking Late Permian ocean-system reorganization to spatially and stratigraphically heterogeneous organic-carbon accumulation along the Paleo-Tethyan margin. Full article

Phosphate is a crucial non-renewable mineral resource, mainly utilized in producing fertilizers that support global agriculture. As phosphorus is an indispensable nutrient for plant growth, phosphate holds a key position in ensuring food security. While deposits are distributed worldwide, the largest reserves are concentrated in Morocco. The Benguerir phosphate mining in Morocco generates heterogeneous waste (i.e., including overburden, tailings, and phosphogypsum) that complicates management and valorization, which is the beneficial reuse or value recovery from waste materials (e.g., use in cover systems, buffering, or other engineered applications). Therefore, it is essential to characterize their mineralogical properties to evaluate their environmental impact and possibilities for reuse or site revegetation. To do so, we integrate VNIR–SWIR reflectance spectroscopy with HandHeld X-ray fluorescence (HHXRF) to characterize phosphate waste rock and assess its reuse potential. For this purpose, field samples (n = 104) were collected, and their spectral reflectance was measured using an ASD FieldSpec 4 spectroradiometer (350–2500 nm) under standardized laboratory conditions. Spectra were processed (Savitzky–Golay smoothing, convex-hull continuum removal) and matched to ECOSTRESS library references; across the dataset, library matching achieved mean RMSE = 0.15 ± 0.053 (median 0.145; 0.085–0.350), median SAM = 0.134 rad, median SID = 0.029, and mean R² = 0.748 ± 0.170, with 84% of spectra yielding R² > 0.70. In parallel, HHXRF major and trace elements were measured on all samples to corroborate spectral interpretations. Together, these analyses resolve carbonate–clay–phosphate assemblages (dolomite commonly dominant, with illite/smectite–kaolinite, quartz, and residual carbonate-fluorapatite varying across samples). Elemental ratios (e.g., Mg/Ca distinguishing dolomite from calcite; K/Al indicating illite) reinforce spectral trends, and phosphate indicators delineate localized enrichment (P₂O₅ up to 23.86 wt % in apatite-rich samples). Overall, the combined workflow is rapid, low-impact, and reproducible, yielding coherent mineralogical patterns that align across spectroscopic and geochemical lines of evidence and providing actionable inputs for selective screening, targeted material reuse, and more sustainable mine reclamation planning. Full article

Apatite is a key indicator mineral whose chemical signature can reveal the genesis and evolution of ore-forming systems. However, correctly interpreting these signatures requires a robust discrimination between apatite types formed by different geological processes, such as metamorphism and hydrothermal activity. This study aims to chemically characterize and genetically classify apatite samples from the Slyudyanka deposit (Siberia, Russia) to establish discriminative geochemical fingerprints for metamorphic and hydrothermal apatite types. We analyzed 80 samples of apatite using total reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS). The geochemical data were processed using principal component analysis (PCA) and k-means cluster analysis to objectively discriminate the apatite types. Our analysis reveals three distinct geochemical groups. Metamorphic veinlet apatite is defined by high U and Pb, low REE, Sr, and Th, and suprachondritic Y/Ho ratios. Massive metamorphic apatite from silicate–carbonate rocks shows extreme REE enrichment and chondritic Y/Ho ratios. Hydrothermal–metasomatic apatite features high Sr, Th, and As, with intermediate REE concentrations and chondritic Y/Ho ratios. Furthermore, we validated the critical and anomalous Y concentrations in the metamorphic veinlet apatite by cross-referencing TXRF and ICP-MS data, confirming the reliability of our measurements for this monoisotopic element. We successfully established diagnostic geochemical fingerprints that distinguish apatite formed in different geological environments at Slyudyanka. The anomalous Y/Ho ratio in metamorphic veinlet apatite serves as a key discriminant and provides insight into specific fractionation processes that occurred during the formation of phosphorites in oceanic environments, which later transformed to apatites during high-grade metamorphism without a change in the Y/Ho ratio. This work underscores the importance of multi-method analytical validation for accurate geochemical classification. Full article

Bone is one of the most important organs of mammals, consisting of collagen and apatite. Various diseases, such as osteoporosis, can affect the components of bone tissue, their chemical composition and bone ultrastructure, which leads to changes in properties. In this paper, the effect of initial osteoporosis on the chemical composition of bone apatite and the ultrastructure of bone tissue from a mineralogical point of view is analyzed using rat femurs as an example. The chemical composition of bone apatite was studied using SEM, EDS and FTIR-ATR spectroscopy. The bone ultrastructure was examined using a transmission electron microscope. An increase in the content of carbonate ion in the position of the phosphorus group and a change in the orientation of apatite crystals inside mineral plates were revealed against the background of initial osteoporosis, which can affect not only the mechanical properties of bone, but also the stability of apatite under biological conditions. Full article

Bioactive glasses remain promising candidates for enhancing osseointegration on metallic implants. However, achieving a composition that combines controlled dissolution, cytocompatibility, and antimicrobial functionality remains an ongoing challenge. Building upon the prior structural and thermal characterization of boron-substituted 6P55 phosphosilicate glasses, this study investigates the biological consequences of incorporating 0, 5, 10, and 15 mol% B₂O₃ to determine their suitability as coatings for Ti6Al4V. Glass extracts were evaluated using L-929 fibroblast cultures (MTT assay and ImageJ-based cell counting), antimicrobial assays against Escherichia coli and Staphylococcus aureus using a semi-quantitative dilution-plating method, and SBF immersion studies to assess pH evolution, surface mineralization, and Ca/P ratio development. FTIR and SEM analyses revealed composition-dependent formation of phosphate-, carbonate-, and silicate-rich surface layers, with 5B exhibiting the most consistent early-stage hydroxyapatite-like signatures, supported by Ca/P ratios approaching the stoichiometric value. The pH measurements showed rapid alkalization for 5B and moderate buffering behavior at higher boron contents, consistent with boron-dependent modifications to network connectivity. Cytocompatibility studies demonstrated a dose- and time-dependent reduction in cell number at elevated B₂O₃ levels, whereas the 0B and 5B extracts maintained higher viability and preserved cell morphology. Antibacterial assays revealed strain-dependent and sub-lethal inhibitory effects, with E. coli exhibiting stronger sensitivity than S. aureus, likely due to differences in cell wall architecture and susceptibility to ionic osmotic microenvironment changes. When considered alongside previously published computational and physicochemical results, the biological data indicate that moderate boron incorporation (5 mol%) provides the most favorable balance between dissolution kinetics, apatite formation, cytocompatibility, and antimicrobial modulation. These findings identify the 5B composition as a strong candidate for further optimization toward bioactive glass coatings on Ti6Al4V implants. Full article

Guided bone regeneration (GBR) plays a key role in alveolar ridge augmentation and implant therapy, but the biological mechanisms governing its outcomes are not fully understood. Preclinical animal models provide critical insights that cannot be obtained in early human studies. Over the past 15 years, our group has developed and optimized a standardized rat calvarial GBR model using plastic caps, enabling reproducible and quantitative evaluation of bone regeneration through micro-computed tomography and histomorphometry. The present narrative review synthesizes the findings from our body of work. Our studies demonstrated that advanced substitutes such as hydroxyapatite/collagen composites and carbonate apatite provide favorable outcomes, indicating that local and systemic application of growth factors or parathyroid hormone can markedly enhance augmentation, and that barrier permeability critically modulates angiogenesis and osteogenesis. Moreover, systemic conditions such as nicotine exposure and estrogen deficiency profoundly compromise regenerative outcomes but can be partly mitigated by pharmacological interventions. Finally, regenerated bone within GBR spaces is biologically competent, although it remains less mature than native cortical bone. Together, these insights highlight the translational value of our GBR model and indicate the integration of spatial omics for the elucidation of the cellular mechanisms that will guide future regenerative strategies. Full article

To reduce the time of postoperative recovery and to prevent post-surgical complications, biocompatible synthetic materials with osteoconductive and osteoinductive properties are used as bone substitutes in large bone defect management. A simplified biomimetic approach to similar materials is based on the use of an inorganic filler, a polymer matrix, and a compatibilizer, mimicking the composition of the natural bone. Based on plate-like micro-sized carbonated hydroxyapatite (pCAp), we prepared compression-molded samples optionally containing an additional polyester component (poly(ε-caprolactone) PCL, poly(L-lactide) PLLA, or poly(L-methylglycolide) PLMG); syntheticblock copolymers comprising fragments of the corresponding polyester and poly(ethylene phosphoric acid) (PEPA) were also prepared and studied asa ‘two-in-one’ polymer matrix/compatibilizer. Bone regeneration experiments involving a three-month rat tibial defect model were conducted with 250–500 μm granules of the composites. Comparative studies of the introduction of the polyester-b-PEPA copolymer into composites revealed a positive effect, which manifests itself in accelerated bone regeneration, which further intensified for pCAp/PEPA-b-PLMG. The latter composite formulation was used to study the results of the introduction of cerium into the filler. One-month experiments with pCAp, CePO₄-doped pCAp, and composites of these inorganic fillers with PEPA-b-PLMG were conducted. For the first time, a positive synergistic effect of the presence of cerium and PEPA in the composite, which appeared in substitution of the implant material by two-thirds of newly formed partly matured bone, was observed four weeks after surgery. Full article

Titanium implants are widely used in medicine because of their favorable mechanical properties and biocompatibility; however, the rapidly forming titanium oxide coatings do not provide an ideal bioactive surface to stimulate osseointegration. This study aims to enhance titanium implant osseointegration through anodization processes designed to incorporate elements and compounds present within human bone into the surface oxides. Commercially pure titanium grade 4 (CPTi) discs were anodized in either oxalic, malic, or ascorbic acid-based electrolytes. Each resulting oxide exhibited complex surface topographies. EDS analyses revealed that Ca, P, and Mg bone chemistry dopant elements were incorporated into each of the oxide coatings. X-ray diffraction analyses revealed combinations of anatase and calcium titanate compounds present in each oxide. Additionally, two of the anodized oxides showed calcium oxide formation, and one oxide also revealed tricalcium phosphate (α-TCP) and hydroxyapatite (HA) formation. Subsequent FTIR spectroscopy analyses revealed carbonate substitution peaks to be present in two of the oxides. This finding indicated that the TCP and HA compounds shown in the XRD analyses of one oxide represented the formation of bone-like carbonated calcium phosphate compounds. A 21-day cell culture study showed favorable cell culture responses for each of the organic-acid-based anodized oxides. Moreover, two of the oxides showed good cytocompatibility and early osteogenic differentiation compared to non-anodized titanium controls. Thus, the organic acid anodization processes developed in this study show promise to enhance future titanium implant clinical outcomes. Full article

Conventional separation methods often prove ineffective for complex, refractory high-phosphorus iron ores. Recent advances propose a coal-based direct reduction dephosphorization-magnetic separation process, achieving significant dephosphorization efficiency. This review systematically analyzes phosphorus occurrence states in high-phosphorus oolitic iron ores across global deposits, particularly within iron minerals. We categorize contemporary research and elucidate dephosphorization mechanisms during coal-based direct reduction. Key factors influencing iron mineral phase transformation, iron enrichment, and phosphorus removal are comprehensively evaluated. Phosphorus primarily exists as apatite and collophane gangue m horization agents function by: (1) inhibiting phosphorus-bearing mineral reactions or binding phosphorus into soluble salts to prevent incorporation into metallic iron; (2) enhancing iron oxide reduction and coal gasification; (3) disrupting oolitic structures, promoting metallic iron particle growth, and improving the intergrowth relationship between metallic iron and gangue. Iron mineral phase transformations follow the sequence: Fe₂O₃ → Fe₃O₄ → FeO (FeAl₂O₄, Fe₂SiO₄) → Fe. Critical parameters for effective dephosphorization under non-reductive phosphorus conditions include reduction temperature, duration, reductant/dephosphorization agent types/dosages. Future research should focus on: (1) investigating phosphorus forms in iron minerals for targeted ore utilization; (2) reducing dephosphorization agent consumption and developing sustainable alternatives; (3) refining models for metallic iron growth and improving energy efficiency; (4) optimizing reduction atmosphere control; (5) implementing low-carbon emission strategies. Full article

Skarn-type iron ore is economically significant, and numerous skarn ore deposits have been identified in the North China Craton. The newly discovered orbicular diorite in this region is distinguished from other analogous rocks due to the accumulation of large magnetite particles, which may shed new light on the genesis of this ore type. The magnetite in different parts of the orbicular structure exhibits distinct compositional differences. For example, magnetite at the edge has a small particle size (200 μm) and is associated with the minerals plagioclase and hornblende, indicating that it crystallized from normal diorite magma. By contrast, magnetite in the core has a relatively large particle size (>1000 μm), is associated with apatite and actinolite, and contains apatite inclusions as well as numerous pores. The size of magnetite in the mantle falls between that of the edge and the core. The syngenetic minerals of magnetite in the mantle include epidote and plagioclase. The magnetites in the cores of orbicules have a higher content of Ti, Al, Ni, Cr, Sc, Zn, Co, Ga, and Nb than those in the rim. The δ⁵⁶Fe value of the core magnetite (0.46‰–0.78‰) is much higher than that of the mantle and rim magnetite in orbicules. Moreover, the δ⁵⁶Fe value of magnetite increases as the V content of magnetite gradually decreases. This large iron isotope fractionation is likely driven by liquid immiscibility that forms iron-rich melts under high oxygen fugacity. The reaction between magma and carbonate xenoliths (Ca, Mg)CO₃ during magma migration generates abundant CO₂, which significantly increases the oxygen fugacity of the magmatic system. Under the action of CO₂ and other volatile components, liquid immiscibility occurs in the magma chamber, and Fe-rich oxide melts are formed by the melting of carbonate xenoliths. Iron oxides (Fe₃O₄/Fe₂O₃₎ will crystallize close to the liquidus due to high oxygen fugacity. These characteristics of magnetite in the Tanling orbicular diorite (Wuan, China) indicate that diorite magma reacts with carbonate xenoliths to form “Fe-rich melts”, and skarn iron deposits are probably formed by the reaction of intermediate-basic magma with carbonate rocks that generate such “Fe-rich melts”. A possible reaction is as follows: diorite magma + carbonate → (magnetite-actinolite-apatite) + garnet + epidote + feldspar + hornblende + CO₂↑. Full article