Ion Release Research Articles

Hydrogen induced phase transition and emergent properties in SrFeOx

Abstract Ionic modulation, in particular that by hydrogen intercalation, has become a powerful method to tune the material’s properties in recent years. Though the SrFeOx system is akin to SrCoOx that can be protonated to the HSrCoO2.5 phase, it remains a challenge for the hydrogenation of SrFeO2.5. In this work, starting from the perovskite SrFeO3-δ, we achieved the hydrogen intercalation and obtained a stable hydrogenated brownmillerite phase HSrFeO2.5 via Pt-catalyzed H-spillover at room temperature. The results indicate that the hydrogenation process is accompanied by the simultaneous oxygen ionic release, i.e., the perovskite SrFeO3-δ is the prerequisite of the hydrogen-induced phase transition. Then, by realization of the hydrogenation, the complete phase transition cycle among the perovskite SrFeO3-δ, brownmillerite SrFeO2.5 and the hydrogenated HSrFeO2.5 phase, are finished. Upon hydrogenation, SrFeO3-δ exhibits a remarkable 9.4% lattice expansion, and its electronic state undergoes a multi-step evolution, transforming from pristine helical antiferromagnetic insulator to a bad metal, and eventually returning to an antiferromagnetic insulator. Moreover, based on the obtained results we also successfully fabricated the microscale patterns with varied surface morphology and electric conductivity that can be used to construct electronic devices. This work provides a different pathway to modulate the properties of correlated and functional materials.

Oxygen Evolution Enhancement of Nickel (Hydr)Oxide via Iron Coordination Compound in Alkaline Conditions.

This study investigates the complex dynamics of the oxygen-evolution reaction (OER) in systems involving Ni(Fe) (hydr)oxides and the iron coordination compound Fe phthalocyanine-4,4',4″,4‴-tetrasulfonate. It offers a novel perspective on the interaction between nickel hydroxide and the Fe compound during the OER process. The Fe complex facilitates the controlled release of trace Fe ions into the Ni (hydr)oxides as it undergoes degradation or demetalation within the Ni(II)/(III) potential range. Once the electrode surface reaches saturation with Fe, additional contributions from Fe have minimal impact on OER activity, and the turnover frequency rapidly reaches its maximum value (approximately 1 s-1) under cyclic voltammetry. In situ Raman spectroscopy reveals that the interaction between the iron complex and the electrode surface, as well as the amount of complex deposited or adsorbed, depends on the applied potential of the electrode. Changes in the electrode's potential influence how the Fe complex binds to the surface, through mechanisms such as electrostatic attraction, chemical bonding, or other interactions. This underscores the critical role of potential control in optimizing electrode surface modifications and enhancing the efficiency of electrochemical processes involving the iron complex.

Trends in pH-triggered strategies for dental resins aiming to assist in preventing demineralization: A scoping review.

To identify and map the literature on the current state of pH-triggered strategies for resin-based materials used in direct restorative dentistry, focusing on innovative compounds, their incorporation and evaluation methods, and the main outcomes. Through a search across PubMed, Scopus, Embase, Web of Science, LILACS, Cochrane Library databases, and Google Scholar, this review identified studies pertinent to pH-responsive dental materials, excluding resin-modified glass ionomer cements. From the 981 records identified, 19 in vitro studies were included, concentrating on resin-based composite resins (50 %), dentin adhesives (25 %), and sealants (25 %). The review identified diverse pH-triggered strategies based on ion release, antibacterial release, antibacterial no release, association of contact-antibacterial compounds with acid neutralizer, and combined ion and antibacterial releasing systems for the development of pH-responsive dental materials. Despite the incorporation of innovative compounds such as nanoparticulated amorphous calcium phosphate (20 %), tetracalcium phosphate (40 %), chlorhexidine-loaded mesoporous silica nanoparticles (10 %), tertiary amine dodecylmethylaminoethyl methacrylate (5 %), and bioactive glass with 4 % nano-POSS (20 %), the mechanical integrity of the materials remained satisfactory, displaying flexural strength and elastic modulus that were similar to or better than control. Materials showcased pH-dependent release of calcium and phosphate ions, especially in acidic conditions, and potential for prevention of tooth demineralization, indicating decreased mineral loss and lesion depth. In general, ion releasing and antibacterial-based strategies alone or associated, comprising the incorporation of amorphous calcium phosphate, tetracalcium phosphate, chlorhexidine-loaded mesoporous silica nanoparticles, tertiary amine dodecylmethylaminoethyl methacrylate, and bioactive glass with 4 % nano-POSS were used to provide pH-responsiveness for composite resins, adhesive systems, or sealants, without compromise of the mechanical properties, and with promising potential for enhancing caries prevention. Advancements on smart pH-responsive dental resins based on ion-releasing and antibacterial associated strategies may contribute to prevent or reduce bacterial acid formation and demineralization of tooth structure at the interface between tooth tissues and restoration, possibly favoring the success of restorative treatment in the future.

Near-infrared light-enhanced polydopamine-based multifunctional nanoparticles for combination of chemodynamic and NO gas therapy in the treatment of osteosarcoma.

The emergence of treatment approaches that integrate conventional phototherapy with additional adjuvant treatments has garnered considerable interest. In this study, we proposed a complex utilizing Fe and polydopamine as a carrier, co-loaded with the nitric oxide initiator L-arginine (L-Arg) and the photosensitizer indocyanine green (ICG), as a potential strategy for the "photothermal/photodynamic/Chemodynamic/nitric oxide gas therapy" of osteosarcoma. Nanoparticles have the ability to undergo degradation within the mildly acidic conditions present in the tumor microenvironment. Consequently, the resulting release of Fe ions facilitates the consumption of hydrogen peroxide through Fenton/Fenton-like reactions, thereby generating hydroxyl radicals (•OH) that possess potent cytotoxic properties. L-Arg can also be catalyzed by reactive oxygen species (ROS) or NO synthase overexpressed in cancer cells to generate NO, which is not only used for gas therapy (GT), but also as a biological messenger to regulate vasodilation to relieve tumor hypoxia. More importantly, the addition of low-dose near-infrared laser can not only promote the efficiency of the above two reactions, but also achieve PTT/PDT and obtain good synergistic tumor treatment effects. The anti-tumor efficacy of nanoparticles was verified in the 143B mouse osteosarcoma model. This "PTT/PDT/CDT/GT" strategy expands bone tumor treatment options through nanoparticle-mediated enhanced therapy.

Nano Revolution: Harnessing Nanoparticles to Combat Antibiotic-resistant Bacterial Infections.

Nanoparticles, defined as particles ranging from 1 to 100 nanometers in size, are revolutionizing the approach to combating bacterial infections amid a backdrop of escalating antibiotic resistance. Bacterial infections remain a formidable global health challenge, causing millions of deaths annually and encompassing a spectrum from common illnesses like Strep throat to severe diseases such as tuberculosis and pneumonia. The misuse of antibiotics has precipitated the rise of resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Mycobacterium tuberculosis (MDR-TB), and carbapenem-resistant Enterobacteriaceae (CRE), underscoring the critical need for innovative therapeutic strategies. Nanotechnology offers a promising avenue in this crisis. Nanoparticles possess unique physical and chemical properties that distinguish them from traditional antibiotics. Their high surface area to volume ratio, ability to be functionalized with various molecules, and distinctive optical, electronic, and magnetic characteristics enable them to exert potent antibacterial effects. Mechanisms include physical disruption of bacterial membranes, generation of Reactive Oxygen Species (ROS), and release of metal ions that disrupt bacterial metabolism. Moreover, nanoparticles penetrate biofilms and bacterial cell walls more effectively than conventional antibiotics and can be precisely targeted to minimize off-target effects. Crucially, nanoparticles mitigate the development of bacterial resistance by leveraging multiple simultaneous mechanisms of action, which make it challenging for bacteria to adapt through single genetic mutations. As research advances, nanotechnology holds immense promise in transforming antibacterial treatments, offering effective solutions that address current infections and combat antibiotic resistance globally. This review provides a comprehensive overview of nanoparticle applications in antibacterial therapies, highlighting their mechanisms, advantages over antibiotics, and future directions in healthcare innovation.

Metal-organic framework (MOF)-bioactive glass (BG) systems for biomedical applications - A review.

In recent years, metal-organic frameworks (MOFs) have emerged as promising materials for biomedical applications, owing to their superior chemical versatility, unique textural properties and enhanced mechanical properties. However, their fast and uncontrolled degradation, together with the reduced bioactivity have restricted their clinical potential. To overcome these limitations, MOFs can be synergistically combined with other materials, such as bioactive glasses (BGs), known for their bioactivity and therapeutic ion releasing capabilities. Besides comparing MOFs and BGs, this review aims to present the latest achievements of different MOFs/BGs materials, with a particular focus on their complementary and synergistic properties. Key findings show that combining MOFs and BGs enables the development of composite materials with superior physicochemical and biological properties. Moreover, by choosing appropriate processing techniques, BGs and MOFs can be fabricated as scaffolds or coatings with fast mineralization ability and high corrosion resistance. In addition, incorporation of MOFs/BGs in hydrogels improves mechanical stability, bioactivity and antibacterial properties, while maintaining biocompatibility. The mechanisms behind the antibacterial properties, likely coming from the release of metal ions and organic ligands, are also discussed. Overall, this review highlights the current research directions and emerging trends in the synergistic use of MOFs and BGs for biomedical applications, which represents a novel strategy for developing a new family of advanced therapeutic materials.

Technological dental sealants: in vitro evaluation of material properties and antibiofilm potential

BackgroundDue to the launch of new self-etching and self-adhesive sealing materials combined with the release of bioactive ions in the dental market, this in vitro study aimed to compare physical values of surface roughness (RS), vickers microhardness (VM), compositional energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), microbiological tests (inhibition halo-HI and surface microbial adhesion-MAS) and mechanical microshear bond strength (MBS).MethodsThe following groups were analyzed: Beautisealant® self-etching sealant (Shofu)(G1), FluroShield® conventional sealant (Dentsply)(G2- Control Group), Flow Constic® self-adhesive/self-etching resin (DMG)(G3) and Beautifil Flow Plus F03® conventional resin (Shofu)(G4). For the physical and compositional tests, specimens were molded and submitted to finishing/polishing in a metallographic polisher. RS and VM were measured through 5 readings. For the HI test, specimens were exposed to S. mutans for 24 h in brain–heart infusion (BHI) agar under microaerophilic conditions, with the diameter of the HI (mm) measured by digital caliper. For the MAS test, a bacterial biofilm of S. mutans was induced for five days in BHI broth + 5% sucrose and measurement of CFU/ml (log10 from serial dilutions). For the MBS test, specimens were made in bovine enamel with the addition of the experimental group FluroShield® (Dentsply) + Single Bond Universal® adhesive (3 M)(G5) and measured in a universal testing machine. Data were submitted to ANOVA and Tukey's post hoc tests (p < 0.05) using the SPSS software.ResultsDifferent compositions proven in the EDS test were not determinants of the promotion of different RS: G1 = 0,19 (± 0,07), G2 = 0,15 (± 0,053), G3 = 0,13 (± 0,046), G4 = 0,14 (± 0,056); HI: G1 = 17,7 (± 1,36), G2 = 18,7 (± 3,47), G3 = 18,9 (± 4,87), G4 = 17,9 (± 3,61) and MAS: G1 = 5,22 (± 0,12), G2 = 5,15 (± 0,15), G3 = 5,12 (± 0,20), G4 = 5,06 (± 0,24). However, statistically influenced the values of VM: G1 = 16,71 (± 1,93), G2 = 16,28 (± 4,91), G3 = 26,11 (± 3,46), G4 = 37.9 (± 4.87), promoted lesser bacterial adhesion (G4 = 5.06 ± 0.24), and demonstrated fluoride ion only in the G4. Higher MBS was found in the conventional materials G5 = 8.38 (± 2.05) and G2 = 6.28 (± 1.35).ConclusionsBioactive materials and self-adhesive/self-etching for sealing pits and fissures did not demonstrate superior mechanical and antimicrobial properties performance compared to conventional techniques.

Development of a multi-functional naringin-loaded bioglass/carboxymethyl chitosan/silk fibroin porous scaffold for hemostasis and critical size bone regeneration.

Persistent bleeding and limited repair capacity greatly threaten patients with bone destruction. Designing inorganic-organic biomimetic scaffolds with quick hemostasis and osteogenesis functions will solve this problem. A novel degradable and naringin (NG) loaded porous scaffold (SCB-N) based on APTES-modified bioactive glass (ABG), carboxymethyl chitosan and silk fibroin is developed. ABG and NG enhance the strength of the scaffolds. The scaffolds can release NG and bioactive ions (Ca2+ and Si4+), promoting the expression of osteogenesis (OCN, BMP-2), angiogenesis (VEGF), and neurogenesis (TB3, GFAP) genes in bone mesenchymal stem cells (BMSCs) and the related proteins (OCN, BMP-2, VEGF, GFAP). When implanting the scaffolds in rat cranial critical size defects, all scaffolds exhibit good compatibility, and SCB-N2 (with ABG and 1mg/mL NG) group significantly promotes new bone regeneration and the formation of M2-type macrophages. Transcriptome sequencing results confirmed the osteogenic differentiation of BMSCs stimulated by SCB-N2 scaffolds is mainly regulated through MAPK and Wnt signaling pathways. Moreover, SCB-N2 group demonstrates quick hemostasis in vitro and in vivo due to the high adsorption ability and Ca ions release. The novel bionic scaffolds loaded with ion/traditional Chinese medicine monomer, possess the capabilities of hemostasis, neurovascularization, osteogenesis and immunomodulation, therefore exhibiting potential in bone repair.

Calcination-Induced Tight Nano-Heterointerface for Highly Effective Eradication of Rib Fracture-Related Infection by Near-Infrared Irradiation.

Rib fracture-related infection is a challenging complication of thoracic trauma due to the difficulty of treating it with antibiotics alone and the need for a second operation to remove the infected fixator and sterilize the surrounding infected tissue. In this study, inspired by the photocatalytic performance of and ion release from silver-based materials, including Ag3PO4 and Ag2S, a hybrid Ag3PO4-Ag2S heterojunction was prepared based on in situ anion exchange and a one-step calcination process to design a nonantibiotic coating aimed at preventing and treating rib fracture-related infection with short-term 808 nm near-infrared irradiation. Calcination at 250 °C enhanced the inductive effect of the phosphate radical and led to the formation of a tight nanoheterogeneous interface between Ag3PO4 and Ag2S, thereby promoting interfacial electron transfer and reducing the recombination of photogenerated carriers. The result was improved photodynamic performance of the Ag3PO4-Ag2S coating. Moreover, metal-Ag3PO4-Ag2S had a significant photothermal effect and released only a small amount of Ag+. The synergy of Ag3PO4-Ag2S endowed the coating with high antibacterial efficacy, eliminating 99.90 ± 0.05 and 99.95 ± 0.03% of Staphylococcus aureus and Escherichia coli, respectively, after 15 min of NIR irradiation in vitro, and 99.66 ± 0.13% of Staphylococcus aureus in vivo. This biocompatible Ag3PO4-Ag2S coating exhibited superb efficacy in eliminating rib fracture-related infection and reducing the associated inflammation.

Magnesium-ion-doped silica nanosheets as degradable drug carriers with enhanced antibacterial activity and cellular uptake.

Mesoporous silica nanoparticles (MSNs) have attracted significant interest in drug delivery applications due to their good biocompatibility and high specific surface area. However, conventional MSNs typically have small pore sizes and low degradation rates, resulting in limited drug loading capacity and potential in vivo nanoparticle accumulation. This study focuses on the synthesis of novel magnesium (Mg) ion-doped silica nanoparticles (MgMSNs) using a chemical precipitation method followed by calcination. In contrast to the nanorod-shaped MSNs, the Mg ion-doped silica nanoparticles exhibited a nanosheet-shaped morphology. When the added Mg2+ concentration was 5 mM, the prepared nanosheets (5MgMSNs) showed superior antibacterial activity and increased curcumin-loading capacity compared to pure silica nanoparticles. Additionally, the natural green fluorescence of curcumin allowed for the visualization of cellular uptake, confirming the efficient internalization of 5MgMSNs by L929 cells. Notably, under acidic conditions, the release of Mg ions and the degradability of the nanoparticles were enhanced, indicating pH-responsive release behavior. Overall, these results highlight the favorable degradability and improved cellular uptake capacity of nanosheet Mg-incorporated silica nanoparticles, suggesting their potential for loading polyphenol drugs such as curcumin and achieving efficient drug release within cells.

3D‐Printed Biomimetic Ceramic Scaffolds with Photothermal/Chemodynamic Effects and Ionic Microenvironment for Preventing Tumor Recurrence and Promoting Vascularized Bone Reconstruction

AbstractOsteosarcoma is an aggressive malignant bone tumor predominantly affecting adolescents and young adults, characterized by a high mortality rate. A significant challenge in treatment is the presence of residual tumor cells and associated bone defects. Here, a novel functionalized biomimetic ceramic scaffold is presented, which combines photothermal and chemodynamic therapies to effectively target bone tumors while promoting vascularized bone regeneration through an optimized ionic microenvironment. The scaffold consists of a 3D‐printed zinc‐doped β‐tricalcium phosphate ceramic matrix and a biomimetic dopamine‐modified hyaluronic acid hydrogel membrane loaded with Ti3C2 MXene and iron ions. In the tumor microenvironment, the hydrogel membrane degrades rapidly, releasing iron ions that lead to glutathione depletion and downregulation of glutathione peroxidase 4. When exposed to near‐infrared light, Ti3C2 enhances local temperature and catalyzes the redox cycling of iron ions, leading to the generation of hydroxyl radicals through Fenton reactions. This process results in lipid peroxidation and induces ferroptosis of tumor cells. Following the clearance of residual tumor cells, the gradual release of iron and zinc ions encourages osteogenic differentiation and vascularization, facilitating vascularized bone regeneration. Therefore, the biomimetic ceramic scaffold exhibits effective anti‐osteosarcoma properties while supports bone repair, presenting a promising treatment option for osteosarcoma‐associated bone defects.

CuO/Cu2O Coatings via Plasma Electrolytic Oxidation on Ti–4.5Cu Alloy: A Synergistic Approach to Antibacterial Properties and Cytocompatibility

In this article, plasma electrolytic oxidation (PEO) is applied to Ti–4.5Cu alloy to prepare a Cu2O/CuO containing coating to improve the antimicrobial properties and cytocompatibility. Scanning electron microscopy and X‐ray photoelectron spectroscopy are used to characterize the surface microstructure as well as the elemental valence states, and electrochemical tests and inductively coupled plasma spectroscopy are used to determine the corrosive properties and Cu‐ion release behavior, and the antimicrobial properties are evaluated by plate counting method and the cytotoxicity is evaluated by methylthiazolyldiphenyl‐tetrazolium bromide (MTT) method. In the results, it is shown that PEO treatment significantly improves the hardness, hydrophilicity, roughness, corrosion resistance, and accelerated Cu‐ion release. In the plate counting method results, it is shown that the antimicrobial capacity of Ti–4.5Cu alloys is significantly increased to &gt;99.9% after the PEO treatment due to multiple effects of the release of Cu ions and the formation of Cu2O and CuO. Furthermore, PEO treatment promotes the proliferation of L929 cells while the surface morphology after sandblasting has a further value‐added effect on cell adhesion. It is concluded that Cu ion and the surface morphology play a decisive role in the adhesion and proliferation of the cells.

Advancements in Surface Modification of NiTi Alloys for Orthopedic Implants: Focus on Low-Temperature Glow Discharge Plasma Oxidation Techniques

Nickel–titanium (NiTi) shape memory alloys are promising materials for orthopedic implants due to their unique mechanical properties, including superelasticity and shape memory effect. However, the high nickel content in NiTi alloys raises concerns about biocompatibility and potential cytotoxic effects. This review focuses on the recent advancements in surface modification techniques aimed at enhancing the properties of NiTi alloys for biomedical applications, with particular emphasis on low-temperature glow discharge plasma oxidation methods. The review explores various surface engineering strategies, including oxidation, nitriding, ion implantation, laser treatments, and the deposition of protective coatings. Among these, low-temperature plasma oxidation stands out for its ability to produce uniform, nanocrystalline layers of titanium dioxide (TiO2), titanium nitride (TiN), and nitrogen-doped TiO2 layers, significantly enhancing corrosion resistance, reducing nickel ion release, and promoting osseointegration. Plasma-assisted oxynitriding processes enable the creation of multifunctional coatings with improved mechanical and biological properties. The applications of modified NiTi alloys in orthopedic implants, including spinal fixation devices, joint prostheses, and fracture fixation systems, are also discussed. Despite these promising advancements, challenges remain in achieving large-scale reproducibility, controlling process parameters, and reducing production costs. Future research directions include integrating bioactive and antibacterial coatings, enhancing surface structuring for controlled biological responses, and expanding clinical validation. Addressing these challenges can unlock the full potential of surface-modified NiTi alloys in advanced orthopedic applications for safer, longer-lasting, and more effective medical implants.

Silver Nanoparticles as Antimicrobial Agents in Veterinary Medicine: Current Applications and Future Perspectives

Silver nanoparticles (AgNPs) have gained significant attention in veterinary medicine due to their antimicrobial properties and potential therapeutic applications. Silver has long been recognized for its ability to combat a wide range of pathogens, and when engineered at the nanoscale, silver’s surface area and reactivity are greatly enhanced, making it highly effective against bacteria, viruses, and fungi. This narrative review aimed to summarize the evidence on the antimicrobial properties of AgNPs and their current and potential clinical applications in veterinary medicine. The antimicrobial action of AgNPs involves several mechanisms, including, among others, the release of silver ions, disruption of cell membranes and envelopes, induction of oxidative stress, inhibition of pathogens’ replication, and DNA damage. Their size, shape, surface charge, and concentration influence their efficacy against bacteria, viruses, and fungi. As a result, the use of AgNPs has been explored in animals for infection prevention and treatment in some areas, such as wound care, coating of surgical implants, animal reproduction, and airway infections. They have also shown promise in preventing biofilm formation, a major challenge in treating chronic bacterial infections. Additionally, AgNPs have been studied for their potential use in animal feed as a supplement to enhance animal health and growth. Research suggested that AgNPs could stimulate immune responses and improve the gut microbiota of livestock, potentially reducing the need for antibiotics in animal husbandry. Despite their promising applications, further research is necessary to fully understand the safety, efficacy, and long-term effects of AgNPs on animals, humans, and the environment.

Development of a Chitosan-Silver Nanocomposite/β-1,3-Glucan/Hyaluronic Acid Composite as an Antimicrobial System for Wound Healing

An ideal wound dressing should be biocompatible, exhibit high antibacterial activity, and promote blood coagulation in the wound. In this study, we used chitosan as a multifunctional template to synthesize silver nanoparticles embedded in chitosan (Ag NP@CHI), which were then combined with β-1,3-glucan/hyaluronic acid (HA) to form an Ag NP@CHI/β-1,3-glucan/HA composite material with biocompatibility, wound healing-promoting properties, and antibacterial activity. A high concentration of chitosan led to the formation of smaller crystalline structures of Ag NPs and improved their dispersion within the chitosan matrix, but decreased their antibacterial potency. The Ag NP@CHI prepared with 1.0 mg/mL chitosan had the smallest particle size and good antibacterial activity. Compared to Ag NP@CHI, the prepared Ag NP@CHI/β-1,3-glucan/HA composite significantly enhanced biocompatibility, cell migration, hemocompatibility, and blood coagulation, with a minor reduction in antibacterial efficiency due to restricted ionic silver release and diffusion. With its high biocompatibility, hemocompatibility, promotion of blood coagulation and wound healing, and antibacterial efficiency, Ag NP@CHI@β-1,3-glucan/HA demonstrates potential as a wound healing composite in the future.

Physical, chemical and biological properties of MTA Angelus and novel AGM MTA: an in vitro analysis

IntroductionMineral trioxide aggregate (MTA) is a calcium silicate-based cement that has changed conventional dental therapeutic approaches. This study aimed to evaluate physical, chemical and biological properties of novel AGM MTA, in comparison with MTA Angelus.MethodsThe samples were prepared according to the manufacturer’s instructions. The initial and final setting times were measured via a Gillmore needle following the ISO 6876:2012 standard. The radiopacity of the materials was evaluated against an aluminium step wedge on the basis of the ISO 6876 and 13,116 standards. The pH changes were measured at intervals of 3, 6, 24, 72, 96 and 144 h postimmersion in Hank’s solution and calcium ion release was analysed after 168 h of immersion via inductively coupled plasma optical emission spectroscopy (ICP‒OES). Moreover, the cytotoxicity was assessed through the MTT assay on human dental pulp stem cells (hDPSCs) after 24 and 72 h of exposure to the set/fresh status of various dilutions of MTA extracts, following the ISO 10993-12 standard.ResultsNo significant difference was found between the initial setting times of the two materials (Angelus: 11.0 ± 1.0 min, AGM: 10.3 ± 1.5 min); however, MTA Angelus demonstrated a significantly shorter final setting time. Both materials met the minimum radiopacity requirements according to the ISO 6876 standard, with MTA Angelus exhibiting greater radiopacity than AGM MTA. Both materials created an alkaline environment without presenting any differences in each time point and AGM MTA released significantly greater amounts of calcium ions. In the cytotoxicity assessment, while the diluted extracts of both materials did not elicit any cytotoxic effects, the nondiluted samples, after 72 h of exposure, as well as the 30-min set AGM MTA after 24 h of exposure, were shown to be cytotoxic.ConclusionsIn conclusion, MTA Angelus presented a faster setting time and lower cytotoxicity, while AGM MTA demonstrated greater calcium ion release. However, both materials presented clinically acceptable properties and AGM MTA could be a potential alternative to MTA Angelus. However, further clinical studies are required to confirm its application.

Evaluation of mechanical properties and ion-releasing of 3D printing resins containing S-PRG filler: A preliminary study

This study aimed to evaluate ionic release, flexural strength and water absorption of UDMA resins containing 0-30 wt% surface pre-reacted glass-ionomer (S-PRG) filler fabricated by a DLP 3D printer. Release of Al, B, Na, Sr and F ions were measured by inductively coupled plasma (ICP) and an ion meter. Flexural strength test and water absorption measurements were performed according to the International Organization for Standardization (ISO) 4049 standard and ISO 1567 standard, respectively. Sr ions were released the most, followed by F, B, Na and Al ions. The highest flexural strength was recorded with the S-PRG filler amount 0 wt%, followed by the S-PRG filler amounts 30, 20 and 10 wt%. Water absorption after one week was below the 32 µg/mm3 mark specified by ISO 1567. The release of ions was confirmed using UDMA-based photopolymerized resin containing S-PRG filler. Furthermore, the results suggest that this resin could be used for provisional restoration.

Cu-Mn nanocomposite for enhanced tumor cuproptosis achieved by remodeling the tumor microenvironment and activating the antitumor immunogenic responses.

Cuproptosis is a newly discovered mode of cell death, which is caused by excess copper and results in cell death via the mitochondrial pathway. However, the complex tumor microenvironment (TME) is characterized by many factors, including high levels of glutathione and lack O2, limit the application of traditional cuproptosis agents in antitumor therapy. Herein, we report a hyaluronic acid modified copper-manganese composite nanomedicine (CMCNs@HA) to remodel the TME and facilitate efficient cuproptosis in tumor. The integration of CuO2 and MnO2 into CMCNs@HA endows this nanoplatform to generate O2 and deplete GSH in tumor site, ensuring the environment is beneficial to the cuproptosis of tumor. The glutathione (GSH) depletion process is accompanied by the release of Mn2+ ions. The released Mn2+ ions improve the cuproptosis through efficient chemodynamic therapy and initiate immune response via activating the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which significantly suppresses tumor growth and inhibits tumor metastases. In addition, the Mn2+ ions release process enables this nanoplatform to work as activable T1 contrast agent to achieve accurate tumor diagnosis. This functionally complementary composite metal nanomaterial may provide effective ideas regarding the application of cuproptosis in designing tumor therapeutic regimens. STATEMENT OF SIGNIFICANCE: Cuproptosis in combination with cGAS-STING offers significant potential for tumor treatment. Here, we constructed TME responsive copper-manganese composite nanomaterials (CMCNs@HA) to augment tumor cuproptosis. GSH depletion, hypoxia relief, and effective chemodynamic therapy caused by CMCNs@HA facilitate the progression of cuproptosis. Besides, CMCNs@HA successfully initiate immune response via activating the cyclic GMP-AMP synthase-stimulator of interferon genes pathway and significantly inhibits tumor metastases. Simultaneously, released Mn2+ ions provide real-time magnetic resonance imaging (MRI) signal changes, enabling accurate tumor diagnosis and monitoring of the therapeutic process.

Dose-dependent enhancement of in vitro osteogenic activity on strontium-decorated polyetheretherketone

Polyetheretherketone (PEEK) is widely used in orthopedic and dental implants due to its excellent mechanical properties, chemical stability, and biocompatibility. However, its inherently bioinert nature makes it present weak osteogenic activity, which greatly restricts its clinical adoption. Herein, strontium (Sr) is incorporated onto the surface of PEEK using mussel-inspired polydopamine coating to improve its osteogenic activity. X-ray photoelectron spectroscopy and ion release assay results confirm that different concentrations of Sr are incorporated onto the PEEK substrate surfaces. The strontium-modified PEEK samples show a stable Sr ion release in 35 days of detection. Better results of MC3T3-E1 pre-osteoblasts adhesion, spreading, and proliferation can be observed in strontium-modified PEEK groups, which demonstrates strontium-modified PEEK samples with the improved MC3T3-E1 pre-osteoblasts compatibility. The boosted osteogenic activity of strontium-modified PEEK samples has been demonstrated by the better performed of ALP activity, extracellular matrix mineralization, collagen secretion, and the remarkable up-regulation of ALP, OCN, OPN, Runx2, Col-I, BSP, and OSX of the MC3T3-E1 pre-osteoblasts. Additionally, the strontium-modified PEEK samples exhibit a dose-dependent enhancement of osteoblasts compatibility and osteogenic activity, and the PEEK-Sr10 group shows the best. These findings indicate that strontium-decorated PEEK implants show promising application in orthopedic and dental implants.

Macroporous coating of silver-doped hydroxyapatite/silica nanocomposite on dental implants by EDTA intermediate to improve osteogenesis, antibacterial, and corrosion behavior

Coating a titanium (Ti) implant with hydroxyapatite (HA) increases its bioactivity and biocompatibility. However, implant-related infections and biological corrosion have restricted the success of implant. To address these issues, a modified HA nanocomposite (HA/silica-EDTA-AgNPs nanocomposite) was proposed to take advantage of the sustained release of silver nanoparticles (AgNPs) and silicate ions through the silica-EDTA chelating network. As a result, a uniform layer of nanocomposite, compared to HA as the gold standard, was formed on Ti implants without fracture and with a high level of adhesion, using plasma electrolytic oxidation (PEO). Bioactivity assessment evidenced a shift in the surface phase of the Ti implant to generation of beta-tricalcium phosphate, a more bioresorbable material than HA. Metabolic activity assessments using human dental pulp stem cells revealed that Ti surfaces modified by the new nanocomposite are superior to bare and HA-modified Ti surfaces for cell attachment and proliferationin vitro. In addition, it successfully inhibited bacterial growth and induced osteogenesis on the implant surface. Finally, potentiodynamic polarization behavior of Ti implants before and after coating confirmed that a thick oxide interface layer on the modified Ti surface acts as an electrical barrier and protects the substrate layer from corrosion. Therefore, the HA/silica-EDTA/Ag nanocomposite presented here, compared to HA, can better coat Ti dental implants due to its good biocompatibility and osteoinductive activity, along with improved biological stability.