Search Results (141)

Background: We evaluated the immediate and artificially aged micro-tensile bond strengths (μTBS) of Hi-Bond Universal, a universal adhesive containing mesoporous bioactive glass (MBG). Methods: Human dentin specimens were bonded using the following four application modes: Hi-Bond Universal in etch-and-rinse mode, Hi-Bond Universal in self-etch mode, Single Bond 2 in etch-and-rinse mode, and G-ænial Bond in self-etch mode. Specimens were tested either immediately or after artificial aging (thermocycling or water storage). μTBS values were analyzed statistically, and the resin–dentin interfaces were examined using FE-SEM (Field-emission scanning electron microscopy). Results: Results showed that both aging and adhesive mode significantly affected the μTBS (p < 0.0001). Immediately after bonding, etch-and-rinse modes produced significantly higher μTBS than the self-etch modes (p < 0.0001). Artificial aging reduced bond strength by approximately 30–50%; however, the μTBS of Hi-Bond Universal decreased less than that of Single Bond 2 after water storage. FE-SEM analysis also revealed detachment of the hybrid layer in most adhesives following aging; however, Hi-Bond Universal in the etch-and-rinse mode maintained a relatively intact adhesive layer after water storage. Conclusion: Etch-and-rinse application of MBG-containing adhesive may enhance the long-term durability of adhesive restorations. Full article

This study investigates the use of a salt template to synthesize mesoporous bioactive glass (MBG). Different salts were used as hard templates to create pores in the glass structure to investigate the possibility of using acid-soluble salt templates and to understand the properties of glass synthesized without thermal treatment. The MBGs were synthesized in a TRIS buffer solution at a pH of 9.5 to allow hydrolysis of the metal oxide precursors. The glass was then washed with mild acid to remove the template. After the samples were washed, some were subjected to thermal treatment, while others were not to investigate the impact of thermal treatment on the structure of the MBG. The successful synthesis of MBG was confirmed by X-ray diffraction, Fourier-transfer infrared spectroscopy, scanning emission scanning microscope, and nitrogen adsorption–desorption analysis. This synthesized MBG had a large surface area, pore volume, pore size, and high drug loading efficiency. MBG synthesized without thermal treatment had slower degradation over the test period, but higher loading efficiency and slower drug release, making it appropriate for applications requiring long-term drug delivery while maintaining its bioactivity. Full article

This study evaluated the influence of drying time, application mode, and agitation on the micro-tensile bond strength (μTBS) of a novel mesoporous bioactive glass-containing universal adhesive (Hi-Bond Universal). Twelve experimental groups were established according to drying time (blot-dry, 10 s dry, or 20 s dry), application mode (total-etch or self-etch), and agitation (with or without). The μTBS test and failure mode analysis were performed for each experimental group (n = 20), and an adhesive interface was observed using field-emission scanning electron microscopy. The μTBS of all experimental groups was analyzed using a three-way ANOVA and Tukey’s honestly significant difference (HSD) post hoc test (α = 0.05). The total-etch mode yielded higher μTBS than the self-etch mode in the blot-dry and 10 s dry groups (p < 0.05). Agitation also significantly increased the μTBS in the blot-dry and 10 s dry groups for both application modes (p < 0.05). However, application mode and agitation had no effect on the μTBS in the 20 s dry group (p > 0.05). FE-SEM revealed longer and more uniform resin tags after agitation in the blot-dry and 10 s dry groups for both application modes. In conclusion, total-etch mode and agitation effectively increased the bond strength of mesoporous bioactive glass-containing universal adhesives. Full article

Delayed or non-healing of bone defects in an aging, multi-morbid population is still a medical challenge. Current replacement materials, like autografts, are limited. Thus, artificial substitutes from biodegradable polymers and bioactive glasses (BGs) are promising alternatives. Here, novel cerium-doped mesoporous BG microparticles (Ce-MBGs) with different cerium content were included in photocrosslinkable, methacrylated gelatin (GelMA) for promoting cellular functions of human mesenchymal stem cells (hBMSCs). The composites were studied for intrinsic morphology and Ce-MBGs distribution by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). They were gravimetrically analyzed for swelling and stability, compressive modulus via Microsquisher^® and bioactivity by Fluitest^® calcium assay and inductively coupled plasma-optical emission spectrometry (ICP-OES), also determining silicon and cerium ion release. Finally, seeding, proliferation, and differentiation of hBMSCs was investigated. Ce-MBGs were evenly distributed within composites. The latter displayed a concentration-dependent but cerium-independent decrease in swelling, while mechanical properties were comparable. A MBG type-dependent bioactivity was shown, while an enhanced osteogenic differentiation of hBMSCs was achieved for Ce-MBG-composites and related to different ion release profiles. These findings show their strong potential in promoting bone regeneration. Still, future work is required, e.g., analyzing the expression of osteogenic genes, providing further evidence for the composites’ osteogenic effect. Full article

Strontium-added bioactive glass (SBG) has been widely used in bone tissue engineering. SBG can be prepared by conventional high-temperature melt-quenching or calcining sol-gelled powder at 700 °C or above. In the present study, the effects of calcination temperature (400–650 °C) and the amount of strontium addition (0–7 mol.%) were investigated simultaneously. The sol-gel process and post-calcination were used to prepare the Sr-added 58S bioactive glass (SBG) powders. The bioactivity of the SBG powder was assessed by immersing it in simulated body fluid, while biocompatibility and cytotoxicity were evaluated using L929 and MG63 cells, and a zebrafish animal model. The calcination temperatures were determined by thermogravimetric analysis based on the weight loss at various stages. X-ray diffraction was used to reveal the crystalline structure of calcined or SBF-immersed SBG powders. Meanwhile, the texture characteristics of SBG powders were examined by the BET method. Fourier-transformed infrared spectroscopy and scanning electron microscopy were used to investigate the absorption bands and powder morphology of SBG powders before and after SBF immersion. The experimental results showed that all SBG powders were mesoporous with a high specific surface area larger than 200 m²/g. SBG powder calcined at 650 °C with 5% Sr addition possessed a major Ca_14.92(PO₄)_2.35(SiO₄)_5.65 phase, the smallest pore size of 5.86 nm, and the largest specific surface area of 233 m²/g. It was noncytotoxic and exhibited good bioactivity and biocompatibility. Full article

Background/Objectives: Bone infection is one of the most prevalent complications in orthopedic surgery. This pathology is mostly due to bacterial pathogens, among which S. aureus stands out. The formation of a bacterial biofilm makes systemic treatment with antibiotics ineffective. Herein we propose a nanosystem composed of mesoporous bioactive glass nanoparticles (MBGN) loaded with levofloxacin and functionalized with N-acetylcysteine (NAC), aiming to offer an alternative to current treatments. These nanoparticles would present antibacterial activity able to disintegrate the biofilm and regenerate the peri-implantar osseous tissue. Methods: MBGN of composition 82.5 SiO₂—17.5 CaO have been synthesized, loaded with levofloxacin, and functionalized with NAC (MBGN-L-NAC). The antimicrobial activity against mature S. aureus biofilms and bioactivity of the nanosystem have been evaluated, as well as its biocompatibility and ability to promote murine pre-osteoblastic MC3T3-E1 differentiation. Results: MBGNs exhibited high surface areas and radial mesoporosity, allowing up to 23.1% (% w/w) of levofloxacin loading. NAC was covalently bound keeping the mucolytic thiol group, SH, available. NAC and levofloxacin combination enhances the activity against S. aureus by disrupting mature biofilm integrity. This nanosystem was biocompatible with pre-osteoblasts, enhanced their differentiation towards a mature osteoblast phenotype, and promoted bio-mimetic mineralization under in vitro conditions. MBGN-L-NAC nanoparticles induced greater osteogenic response of osteoprogenitor cells through increased alkaline phosphatase expression, increased mineralization, and stimulation of pre-osteoblast nodule formation. Conclusions: MBGN-L-NAC exhibits a more efficient antibacterial activity due to the biofilm disaggregation exerted by NAC, which also contributes to enhance the osteoinductive properties of MBGNs, providing a potential alternative to conventional strategies for the management of bone infections. Full article

Reconstruction of extensive bone defects due to age, trauma, or post-illness conditions remains challenging. Biomimetic scaffolds with osteogenic capabilities have been proposed as an alternative to the classical autograft and allograft implants. Three-dimensional scaffolds were obtained based on Ce-doped mesoporous bioactive glass (MBG) and Spongia agaricina (SA) as sacrificial templates functionalized with vitamin D₃. The study aimed to investigate the effect of vitamin D₃ functionalization on the optimal variant of a 3D scaffold doped with 3 mol% ceria, selected in our previous work based on its biological and physicochemical properties. Scanning electron microscopy (SEM) images of the non-functionalized/functionalized scaffolds revealed a porous structure with interconnected pores ranging from 100 to 350 μm. Fourier transform infrared spectroscopy (FTIR) and SEM analysis confirmed the surface functionalization. Cytotoxicity evaluation showed that all investigated scaffolds do not exhibit cytotoxicity and genotoxicity toward the Saos-2 osteosarcoma cell line. Moreover, the study demonstrated that functionalization with vitamin D₃ enhanced osteogenic activity in dental pulp stem cells (DPSCs) by increasing calcium deposition and osteocalcin secretion, as determined by Alizarin red stain and a colorimetric ELISA kit, as a result of its synergistic action with cerium ions. The results showed that the Ce-doped MBG scaffold functionalized with vitamin D₃ had the potential for applications in bone regeneration. Full article

(1) Background: The onset of inflammation and oxidative stress after biomaterial implantation can lead to complications and prolonged recovery times. To address this, bioactive mesoporous glasses doped with cerium (0, 3.6 and 5.3 mol%) were loaded with three different biomolecules—3-hydroxyflavone, quercetin and morin hydrate—to enhance antioxidant properties while preserving bioactivity. (2) Methods: Elemental analysis, specific surface area determination, spectroscopic techniques, evaluation of antioxidant activity and in vitro bioactivity assessment were performed to characterize mesoporous glass loaded with biomolecules. (3) Results: Biomolecule loading gives values in the range of 0.5–2.0% and 10.3–39.6% for loading content and loading efficiency, respectively. The loading order is quercetin > morine hydrate > 3-hydroxyflavone, and a cerium percentage of 3.6 seems to be a good compromise. The antioxidant properties evaluated on both solids and solutions in contact with simulated biological fluids improve markedly over loaded glasses, and the most promising results are obtained with quercetin. In the most efficient systems, the bioactivity results were delayed and more evident at longer times (168 h) but were still retained. (4) Conclusions: We obtained new materials still bioactive with improved antioxidant properties that can be proposed for the regeneration of both hard and soft tissues. Full article

Mesoporous bioactive glass (MBG) is an advanced biomaterial widely recognized for its application in bone regenerative engineering. This study synthesized an MBG powder (80 mol% SiO₂, 5 mol% P₂O₅, and 15 mol% CaO) using a facile sol-gel method with the non-ionic surfactant Pluronic^® P123, which acted as a pore-forming agent. MBGs form bioactive surfaces that facilitate HA formation, and the presence of Pluronic^® P123 increases the surface area and promotes HA nucleation. Various percentages of strontium (Sr) doping were examined to improve bioreactivity, biological response, and bone formation, with 3SMBG (3 mol% Sr) showing the highest specific surface area. In vitro biocompatibility tests revealed HA formation on all glass surfaces after immersion in simulated body fluid (SBF), indicated by sheet-like HA morphologies, the presence of PO₄³⁻ and CO₃²⁻ functional groups, and the amorphous structure along with SrCO₃ crystalline phases corresponding to HA and Sr-HA structures. Sr doping resulted in delayed initial degradation and sustained release of Sr²⁺, achieving over 95% cell viability. Surfactant-induced mesoporous structure and Sr incorporation synergistically enhance osteocyte induction and formation in vitro. These findings suggest that Sr-doped MBG, particularly with P123-assisted Sr/Ca substitution, optimizes the material’s properties for advanced bone regenerative applications. Full article

When dentin is directly exposed to the oral cavity for various reasons, such as a lack of enamel on the tooth surface, external stimuli to the dentin often cause transient discomfort known as dentin hypersensitivity. In order to block the incoming stimulus signal, an ideal treatment is to induce the production of minerals to block the dentinal tubules. In this work, a dentin-desensitizing plugging material was prepared by modifying mesoporous bioactive glass with gelatin, the mineralization and desensitization effects of which were compared with Gluma in in vitro experiments. These experiments confirmed that gelatin-modified bioactive glass (MBG@PDA@Gel) is more effective than traditional desensitizing agents at blocking dentin tubules. Following the successful synthesis of MBG@PDA@Gel, as confirmed by scanning electron microscopy, transmission electron microscopy, and other tests, the treatment of demineralized dentin with MBG@PDA@Gel demonstrated that the dentinal tubules were tightly blocked under scanning electron microscopy. MBG@PDA@Gel induces minerals in deeper layers of dentinal tubules, promoting remineralization and forming a unified structure with the tubule blockage. Animal studies showed that MBG@PDA@Gel can remineralize demineralized dentin, and it is stable in the oral cavity and does not fall out. MBG@PDA@Gel not only enhances the biocompatibility of the nanoparticle but also results in an overall uniform and rapid remineralization of the demineralized dentin. Full article

Mesoporous bioactive glass nanoparticles (MBGNs) doped with therapeutical ions present multifunctional systems that enable a synergistic outcome through the dual delivery of drugs and ions. The aim of this study was to evaluate influence of co-doping with strontium and magnesium ions (SrMg-MBGNs) on the properties of MBGNs. A modified microemulsion-assisted sol–gel synthesis was used to obtain particles, and their physicochemical properties, bioactivity, and drug-loading/release ability were evaluated. Indirect biological assays using 2D and 3D cell culture models on human bone marrow-derived mesenchymal stem cells (hBM-MSCs) and endothelial EA.hy926 cells, respectively, were used to determine biocompatibility of MBGNs, their influence on alkaline phosphatase (ALP) production, calcium deposition, and cytoskeletal organization. Results showed that Sr,Mg-doping increased pore volume and solubility, and changed the mesoporous structure from worm-like to radial–dendritic, which led to a slightly accelerated drug release compared to pristine MBGNs. Biological assays confirmed that particles are biocompatible, and have ability to slightly induce ALP production and calcium deposition of hBM-MSCs, as well as to significantly improve the proliferation of EA.hy926 compared to biochemical stimulation via vascular endothelial growth factor (VEGF) administration or regular media. Fluorescence staining revealed that SrMg-MBGNs had a similar effect on EA.hy926 cytoskeletal organization to the VEGF group. In conclusion, Sr,Mg-MBGNs might be considered promising biomaterial for biomedical applications. Full article

Bioactive glass nanoparticles (BGNs) are applied widely in tissue regeneration. Varied micro/nanostructures and components of BGNs have been designed for different applications. In the present study, nanorod-shaped mesoporous zinc-containing bioactive glass nanoparticles (ZnRBGNs) were designed and developed to form the bioactive content of composite materials for hard/soft tissue repair and regeneration. The nanostructure and components of the ZnRBGNs were characterized, as were their cytocompatibility and radical-scavenging activity in the presence/absence of cells and their ability to modulate macrophage polarization. The ZnRBGNs possessed a uniform rod shape (length ≈ 500 nm; width ≈ 150 nm) with a mesoporous structure (diameter ≈ 2.4 nm). The leaching liquid of the nanorods at a concentration below 0.5 mg/mL resulted in no cytotoxicity. More significant improvements in the antioxidant and M1-polarization-inhibiting effects and the promotion of M2 polarization were found when culturing the cells with the ZnRBGNs compared to when culturing them with the RBGNs. The doping of the Zn element in RBGNs may lead to improved antioxidant and anti-inflammatory effects, which may be beneficial in tissue regeneration/repair. Full article

Several therapeutic approaches have been developed to promote bone regeneration, including guided bone regeneration (GBR), where barrier membranes play a crucial role in segregating soft tissue and facilitating bone growth. This study emphasizes the importance of considering specific tissue requirements in the design of materials for tissue regeneration, with a focus on the development of a double-layered membrane to mimic both soft and hard tissues within the context of GBR. The hard tissue-facing layer comprises collagen and zinc-doped bioactive glass to support bone tissue regeneration, while the soft tissue-facing layer combines collagen and chitosan. The electrospinning technique was employed to achieve the production of nanofibers resembling extracellular matrix fibers. The production of nano-sized (~116 nm) bioactive glasses was achieved by microemulsion assisted sol-gel method. The bioactive glass-containing layers developed hydroxyapatite on their surfaces starting from the first week of simulated body fluid (SBF) immersion, demonstrating that the membranes possessed favorable bioactivity properties. Moreover, all membranes exhibited distinct degradation behaviors in various mediums. However, weight loss exceeding 50% was observed in all tested samples after four weeks in both SBF and phosphate-buffered saline (PBS). The double-layered membranes were also subjected to mechanical testing, revealing a tensile strength of approximately 4 MPa. The double-layered membranes containing zinc-doped bioactive glass demonstrated cell viability of over 70% across all tested concentrations (0.2, 0.1, and 0.02 g/mL), confirming the excellent biocompatibility of the membranes. The fabricated polymer bioactive glass composite double-layered membranes are strong candidates with the potential to be utilized in tissue engineering applications. Full article

Mesoporous bioactive glass nanoparticles (MBGNs) have attracted significant attention as multifunctional nanocarriers for various applications in both hard and soft tissue engineering. In this study, multifunctional strontium (Sr)- and zinc (Zn)-containing MBGNs were successfully synthesized via the microemulsion-assisted sol–gel method combined with a cationic surfactant (cetyltrimethylammonium bromide, CTAB). Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs exhibited spherical shapes in the nanoscale range of 100 ± 20 nm with a mesoporous structure. Sr and Zn were co-substituted in MBGNs (60SiO₂-40CaO) to induce osteogenic potential and antibacterial properties without altering their size, morphology, negative surface charge, amorphous nature, mesoporous structure, and pore size. The synthesized MBGNs facilitated bioactivity by promoting the formation of an apatite-like layer on the surface of the particles after immersion in Simulated Body Fluid (SBF). The effect of the particles on the metabolic activity of human mesenchymal stem cells was concentration-dependent. The hMSCs exposed to Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs at 200 μg/mL enhanced calcium deposition and osteogenic differentiation without osteogenic supplements. Moreover, the cellular uptake and internalization of Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs in hMSCs were observed. These novel particles, which exhibited multiple functionalities, including promoting bone regeneration, delivering therapeutic ions intracellularly, and inhibiting the growth of Staphylococcus aureus and Escherichia coli, are potential nanocarriers for bone regeneration applications. Full article

As the population ages, the number of patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) continues to increase. Infections after primary arthroplasty are rare but have high rates of morbidity and mortality, as well as enormous financial implications for healthcare systems. Numerous methods including the use of superhydrophobic coatings, the incorporation of antibacterial agents, and the application of topographical treatments have been developed to reduce bacterial attachment to medical devices. However, most of these methods require complex manufacturing processes. Thus, the main purpose of this study was to apply biocoatings to titanium (Ti) surfaces to increase their infection resistance and osteoconductivity via simple processes, without organic reagents. We modified titanium surfaces with a combination of aminomalononitrile (AMN) and an antibiotic-loaded mesoporous bioactive glass (MBG) and evaluated both the antibacterial effects of the coating layer and its effect on osteoblast proliferation and differentiation. The properties of the modified surface, such as the hydrophilicity, roughness, and surface morphology, were characterized via contact angle measurements, atomic force microscopy, and scanning electron microscopy. The cell proliferation reagent WST-1 assay and the alkaline phosphatase (ALP) assay were used to determine the degrees of adhesion and differentiation, respectively, of the MG-63 osteoblast-like cells on the surface. Antimicrobial activity was evaluated by examining the survival rate and inhibition zone of Escherichia coli (E. coli). The AMN coating layer reduced the water contact angle (WCA) of the titanium surface from 87° ± 2.5° to 53° ± 2.3° and this change was retained even after immersion in deionized water for five weeks, demonstrating the stability of the AMN coating. Compared with nontreated titanium and polydopamine (PDA) coating layers, the AMN surface coating increased MG-63 cell attachment, spreading, and early ALP expression; reduced E. coli adhesion; and increased the percentage of dead bacteria. In addition, the AMN coating served as an adhesion layer for the subsequent deposition of MBG-containing antibiotic nanoparticles. The synergistic effects of the AMN layer and antibiotics released from the MBG resulted in an obvious E. coli inhibition zone that was not observed in the nontreated titanium group. Full article