Search Results (117)

Background/Objectives: Gamma irradiation is a promising terminal sterilization method for nanoparticle-based biomedical systems. However, its potential effects on the physicochemical properties and biological performance of multifunctional nanomaterials must be carefully evaluated. This study aimed to assess the structural integrity, sterility, and cytocompatibility of magnetic nanoparticles (MNPs) and bioactive-glass-coated magnetic nanoparticles (MNPBGs), both based on magnetite (Fe₃O₄), after gamma irradiation. Methods: MNPs and MNPBGs were synthesized and subjected to gamma irradiation at 25 kGy, with additional doses explored in preliminary evaluations. Physicochemical characterizations were performed using XRD, TEM, SAED, and Raman spectroscopy. FTIR analyses were conducted on bioactive glass (BG) controls without magnetite. Sterility was evaluated via microbiological assays. Cytocompatibility and nitric oxide (NO) production were assessed using RAW 264.7 macrophages and Saos-2 osteosarcoma cells. Prussian blue staining was used to evaluate cellular uptake. Results: Gamma irradiation preserved the crystal structure, morphology, and size distribution of the nanoparticles. FTIR revealed only minor changes in the silicate network of BG, such as reduced intensity and slight shifting of Si-O-Si and Si-O-NBO bands, indicating limited radiation-induced structural rearrangement without affecting the material’s stability or cytocompatibility. Microbiological assays confirmed complete inhibition of microbial growth. All irradiated samples exhibited high cytocompatibility, with MNPBGs demonstrating enhanced biological responses. Notably, MNPBGs induced a more pronounced NO production in macrophages. Cellular uptake of nanoparticles by Saos-2 cells remained unaffected after irradiation. Conclusions: Gamma irradiation at 25 kGy is an effective sterilization strategy that maintains the structural and functional integrity of MNPs and MNPBGs. These findings support their safe use in sterile biomedical applications, particularly for bone-related therapies involving immunomodulation and drug delivery, with potential relevance for cancer treatment strategies such as osteosarcoma. Full article

The growing demands for highly functional biomedical implants necessitate introducing innovative and easy-to-apply surface functionalization techniques, especially when it comes to stainless steel substrates. This study investigated the co-deposition of chitosan and Cu-doped bioactive glass on AISI 316L steel surfaces, with the latter providing a matrix in which fine bioactive glass powders are distributed. Cu-doping into the matrix of bioactive glass was conducted to assess its influence on the bioactivity, antibacterial properties, and structural integrity of the coating. The microstructure, mechanical properties, phase composition, and surface roughness of coated specimens were investigated through a scanning electron microscope (SEM), X-ray diffraction analysis (XRD), energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma (ICP), contact angles, adhesion tensile tests, and laser profilometry analyses. Results of adhesion tests indicated that Cu addition did not have a major implication for the mechanical properties of the coating layers. Results also revealed that the Cu-doped bioactive glass featured a hydrophilic and a rather uneven surface, both being upsides for biomedical properties. The cytotoxicity and antibacterial assessments showed promising cell viability and antibacterial properties of the deposited coatings. Full article

The development of bioactive coatings for metallic implants is essential to enhance osseointegration and improve implant longevity. In this study, composite thin films based on bioactive glass and melittin were synthesized using the matrix-assisted pulsed laser evaporation technique and deposited onto titanium substrates. The coatings were characterized using physicochemical analysis methods, including scanning electron microscopy, atomic force microscopy, contact angle measurements, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. Simulated body fluid immersion tests were also conducted to assess bioactivity over time. Scanning electron microscopy and atomic force microscopy revealed dense, irregular surface textures with nanoscale features and an average roughness of ~120 nm, favorable for cell adhesion. Contact angle measurements showed a significant shift from hydrophobic (~95° for bare titanium) to moderately hydrophilic (~62° for the bioglass and melittin coating) surfaces, indicating improved biocompatibility. Electrochemical impedance spectroscopy demonstrated enhanced corrosion resistance in simulated body fluid, with the coating exhibiting a ~45% decrease in impedance magnitude after 12 h of immersion, compared to only 4% for bare titanium. Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy analyses confirmed the progressive formation of a carbonated apatite layer after 7 days of simulated body fluid exposure, suggesting high bioactivity and osteoconductive potential. The combined effects of bioactive glass and melittin in the thin film structure offer promising applications in orthopedic and dental implants, enhancing both biological performance and structural integrity. Full article

Polyetheretherketone (PEEK) is a widely used material in bone tissue engineering due to its favorable mechanical properties and radiolucency. However, its bioinert nature and lack of osteogenic activity restrict its ability to support effective bone regeneration. In this study, a novel APS-coated plasma-treated sulfonated bioactive PEEK scaffold (APS/PSBPK) was developed to overcome these limitations. The scaffold integrates strontium-doped bioactive glass (SrBG) to enhance biocompatibility and osteogenic potential, while astragalus polysaccharide (APS) was incorporated via plasma cleaning to modulate immune responses and promote vascularization. In vitro studies demonstrated that the APS/PSBPK scaffold facilitates M2 macrophage polarization, reduces pro-inflammatory cytokines, and enhances the secretion of anti-inflammatory factors. It also promotes endothelial cell migration and angiogenesis while supporting the adhesion, proliferation, and osteogenic differentiation of rBMSCs. In vivo experiments revealed that the scaffold effectively regulates the immune microenvironment, promotes vascularization, and accelerates bone regeneration. Thus, the APS/PSBPK composite scaffold serves as a multifunctional biomaterial with significant potential for applications in bone repair and regeneration by combining immunomodulation, angiogenesis, and osteogenesis. Full article

Bone grafting is one of the most used surgical techniques to favor bone regeneration and repair in orthopedic procedures. Despite autografting continuing to be considered the gold standard, allogeneic bone tissues remain a viable alternative albeit in the last decades, only a few studies have been carried out to translate enhanced allogeneic bone grafts into clinical solutions. In this in vitro study, cortical allogeneic bone samples were coated with copper-doped bioactive glass 45S5 (Cu-BG) by means of the pulsed-laser deposition technique to combine the mechanical support and osteoconductive properties of human bone with the osteogenic and pro-angiogenic features of the bioactive material. Contact angle (CA), scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements were carried out to quantitatively compare the impact on the bone surface properties of the morphological changes induced by the presence of the coating. Specifically, the obtained results have shown a total absorption of the drop on the coated samples. The coating on the bone tissue surface consisted of a homogeneous Cu-BG background layer with micrometric grain-like aggregates on it—a morphological feature that can facilitate osteoblast adhesion and proliferation. Cytotoxicity and cell viability were carried out on Saos-2 osteoblast-like cells, demonstrating the biocompatibility of the novel composite bone tissue and the absence of cytotoxic residuals. Moreover, human bone marrow-derived mesenchymal stem cells (hBMSCs) were seeded on Cu-BG and not-coated (NC) samples to evaluate the bioactivity and their differentiation toward the osteogenic phenotype. Our findings showed the pro-osteogenic and pro-angiogenic potential of Cu-BG coatings, although dynamic changes were observed over time. At seven days, the Cu-BG samples exhibited significantly higher expressions of SP7, SPP1, and BGLAP genes, indicating an enhanced early osteogenic commitment. Moreover, VEGF expression was significantly increased in Cu-BG compared to the control. These results pave the way for the development of an innovative class of bone-based products distributed by tissue banks. Full article

The long-term corrosion and antibacterial evaluation of bioactive coating obtained by matrix-assisted pulsed laser evaporation (MAPLE) on TiZrTaAg is crucial for assessing its potential in biomedical applications. The MAPLE deposition technique involves the formation of a dense and adherent layer on the surface of the alloy which can include a multitude of components such as bioactive glass, ZnO and graphene oxide. Long-term corrosion studies in simulated body fluids evaluate the stability and integrity of the coating over extended periods, ensuring its durability in the physiological environment. The results showed that the coatings, especially the one incorporating graphene oxide (GO), significantly reduced the corrosion rate of TiZrTaAg compared to the uncoated alloy. Antibacterial evaluation assesses the coating’s ability to inhibit bacterial colonization and biofilm formation, which are major concerns in implant-associated infections. The coatings demonstrated high antibacterial activity, with the one with the GO-containing film exhibiting the highest bacterial inhibition, achieving 83% against Staphylococcus aureus and 71% against Escherichia coli. The study concluded that the MAPLE-modified TiZrTaAg alloy with bioactive coatings, particularly the one with GO, shows promising potential for biomedical applications due to enhanced corrosion resistance and strong antibacterial properties. Full article

To design bioactive glass compositions with optimal thermal, mechanical, and bioactive properties as coatings on Ti6Al4V metallic implants, we investigated phosphosilicate bioactive glasses based on the 6P55 composition. SiO₂ was substituted with B₂O₃ to improve adhesion to the metallic implants and physical properties. This substitution significantly altered the glass structure and is hypothesized to improve adhesion. Computational and experimental methods revealed that boron substitution introduced BO₃ and BO₄ units, disrupted the Si-O network, and formed non-bridging oxygens (NBOs), resulting in a decrease in density and glass transition temperature (T_g). These changes were attributed to boron’s dual role as a network former and modifier, influencing coordination environments and connectivity. Thermal and structural analyses showed that optimal boron levels improved thermal expansion and network flexibility, which are critical for coating applications. By integrating molecular dynamics simulations and experimental techniques, this study provides valuable insights into tailoring glass compositions for enhanced performance on metallic substrates. Full article

Many tissues exhibit structural anisotropy, which imparts orientation-specific properties and functions. However, recapitulating the cellular patterns found in anisotropic tissues presents a remarkable challenge, particularly when using soft and wet hydrogels. Herein, we develop self-assembled anisotropic magnetic Fe₃O₄ micropatterns on polyethylene glycol hydrogels utilizing dipole–dipole interactions. Under the influence of a static magnetic field, Fe₃O₄ nanoparticles align into highly ordered structures with a height of 400–600 nm and a width of 8–10 μm. Furthermore, our layer-by-layer assembly technique enables the creation of oriented micropatterns with varying densities and heights, which can be further manipulated to form three-dimensional structures by adjusting the angle of the magnetic field. These anisotropic magnetic Fe₃O₄ micropatterns can be applied to various substrates, including treated glass slides, standard glass slides, silicon wafers, and polydimethylsiloxane. The patterned Fe₃O₄ scaffolds, modified with gold coating, effectively enhance cellular adhesion, orientation, and osteogenic differentiation of bone marrow-derived stem cells, which is crucial for effective tissue repair. Overall, this study presents an efficient strategy for constructing anisotropic Fe₃O₄ micropattern hydrogels, providing a bioactive platform that significantly enhances cellular functions. Full article

Magnesium alloys, despite having a number of attractive properties, encounter difficulties in clinical applications due to their rapid degradation rate in the physiological environment. In this work, a Bioglass (BG)-incorporated plasma electrolytic oxidation (PEO) coating was applied on the AZ31 Mg alloy to overcome this major limitation. PEO treatment was carried out in constant current mode with and without the addition of BG particles. The effects of BG particles on the coating’s morphology, composition, adhesion, electrochemical corrosion resistance and bioactivity were analyzed. SEM micrographs revealed that BG submicron particles were well adhered to the surface and the majority of them were entrapped in the micropores. Furthermore, the adhesion strength of the coated layer was adequate—a maximum value of 22.5 N was obtained via a micrometer scratch test. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results revealed that the degradation rate of the Mg alloy was slowed down by up to 100 times, approximately. Moreover, the PEO–BG layer considerably enhanced the in vitro bioactivity of the Mg alloy in a simulated body fluid (SBF) environment; a prominent apatite layer was witnessed through SEM imaging. Consequently, the BG-incorporated PEO layer on Mg AZ31 alloy exhibited some promising outcomes and, therefore, can be considered for biomedical applications. Full article

This article reviews the research and development focus of metallic glasses in the field of biomedical applications. Metallic glasses exhibit a short-range ordered and long-range disordered glassy structure at the microscopic level, devoid of structural defects such as dislocations and grain boundaries. Therefore, they possess advantages such as high strength, toughness, and corrosion resistance, combining characteristics of both metals and glasses. This novel alloy system has found applications in the field of biomedical materials due to its excellent comprehensive performance. This review discusses the applications of Ti-based bulk metallic glasses in load-bearing implants such as bone plates and screws for long-term implantation. On the other hand, Mg-based metallic glasses, owing to their degradability, are primarily used in degradable bone nails, plates, and vascular stents. However, metallic glasses as biomaterials still face certain challenges. The Young’s modulus value of Ti-based metallic glasses is higher than that of human bones, leading to stress-shielding effects. Meanwhile, Mg-based metallic glasses degrade too quickly, resulting in the premature loss of mechanical properties and the formation of numerous bubbles, which hinder tissue healing. To address these issues, we propose the following development directions: (1) Introducing porous structures into titanium-based metallic glasses is an important research direction for reducing Young’s modulus; (2) To enhance the bioactivity of implant material surfaces, the surface modification of titanium-based metallic glasses is essential. (3) Developing antibacterial coatings and incorporating antibacterial metal elements into the alloys is essential to maintain the long-term effective antibacterial properties of metallic biomaterials. (4) Corrosion resistance must be further improved through the preparation of composite materials, while ensuring biocompatibility and safety, to achieve controllable degradation rates and degradation modes. Full article

Bioactive glasses (BGs) have attracted significant attention in the biomaterials field due to their ability to promote soft and hard tissue regeneration and their potential for various clinical applications. BGs offer enriched features through the integration of different therapeutic inorganic ions within their composition. These ions can trigger specific responses in the body conducive to a battery of applications. For example, zinc, a vital trace element, plays a role in numerous physiological processes within the human body. By incorporating zinc, BGs can inhibit bacterial growth, exert anti-inflammatory effects, and modify bioactivity, promoting better integration with surrounding tissues when used in scaffolds for tissue regeneration. This article reviews recent developments in zinc-containing BGs (ZBGs), focusing on their synthesis, physicochemical, and biological properties. ZBGs represent a significant advancement in applications extending beyond bone regeneration. Overall, their biological roles hold promise for various applications, such as bone tissue engineering, wound healing, and biomedical coatings. Ongoing research continues to explore the potential benefits of ZBGs and to optimize their properties for diverse clinical applications. Full article

This literature review deals with the electrophoretic deposition of bioactive glass coatings on metallic substrates to produce bone implants. Biocompatible metallic materials, such as titanium alloys or stainless steels, are commonly used to replace hard tissue functions because their mechanical properties are appropriate for load-bearing applications. However, metallic materials barely react in the body. They need a bioactive surface coating to trigger beneficial biological and chemical reactions in the physiological environment. Bioactive coatings aim to improve bone bonding, shorten the healing process after implantation, and extend the lifespan of the implant. Bioactive glasses, such as 45S5, 58S, S53P4, 13-93, or 70S30C, are amorphous materials made of a mixture of oxides that are accepted by the human body. They are used as coatings to improve the surface reactivity of metallic bone implants. Their high bioactivity in the physiological environment induces the formation of strong chemical bonding at the interface between the metallic implant and the surrounding bone tissue. Electrophoretic deposition is one of the most effective solutions to deposit uniform bioactive glass coatings at low temperatures. This article begins with a review of the different compositions of bioactive glasses described in the scientific literature for their ability to support hard tissue repair. The second part details the different stages of the bioactivity process occurring at the surface of bioactive glasses immersed in a physiological environment. Then, the mechanisms involved in the electrophoretic deposition of bioactive glass coatings on metallic bone implants are described. The last part of the article details the current developments in the process of improving the properties of bioactive glass coatings by adding biocompatible elements to the glassy structure. Full article

Carbonated apatite (CAp), known as the main mineral that makes up human bone, can be utilized in conjunction with scaffolds to increase their bioactivity. Various methods (e.g., co-precipitation, hydrothermal, and biomimetic coatings) have been used to provide bioactivity by forming CAp on surfaces similar to bone minerals. Among them, the use of simulated body fluids (SBF) is the most popular biomimetic method for generating CAp, as it can provide a mimetic environment. However, coating methods using SBF require at least a week for CAp formation. The long time it takes to coat biomimetic scaffolds is a point of improvement in a field that requires rapid regeneration. Here, we report a step-wise biomimetic coating method to form CAp using calcium carbonate vaterite (CCV) as a precursor. We can manufacture CCV-transformed CAp (V-CAp) on the surface in 4 h at least by immersing CCV in a phosphate solution. The V-CAp deposited surface was analyzed using scanning electron microscopy (SEM) images according to the type of phosphate solutions to optimize the reaction conditions. X-ray diffraction (XRD) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) analysis validated the conversion of CCV to V-CAp on surfaces. In addition, the bioactivity of V-CAp coating was analyzed by the proliferation and differentiation of osteoblasts in vitro. V-CAp showed 2.3-folded higher cell proliferation and 1.4-fold higher ALP activity than the glass surface. The step-wise method of CCV-transformed CAp is a biocompatible method that allows the environment of bone regeneration and has the potential to confer bioactivity to biomaterial surfaces, such as imparting bioactivity to non-bioactive metal or scaffold surfaces within one day. It can rapidly form carbonated apatite, which can greatly improve time efficiency in research and industrial applications. Full article

The ability of bone biomaterials to promote osteogenic differentiation is crucial for the repair and regeneration of osseous tissue. The development of a temporary bone substitute is of major importance in enhancing the growth and differentiation of human-derived stem cells into an osteogenic lineage. In this study, nanocomposite hydrogels composed of gelatin methacryloyl (GelMA), bioactive glass (BG), and multiwall carbon nanotubes (MWCNT) were developed to create a bone biomaterial that mimics the structural and electrically conductive nature of bone that can promote the differentiation of human-derived stem cells. GelMA-BG-MWCNT nanocomposite hydrogels supported mesenchymal stem cells derived from human induced pluripotent stem cells, hereinafter named iMSCs. Cell adhesion was improved upon coating nanocomposite hydrogels with fibronectin and was further enhanced when seeding pre-differentiated iMSCs. Osteogenic differentiation and mature mineralization were promoted in GelMA-BG-MWCNT nanocomposite hydrogels and were most evidently observed in the 70-30-2 hydrogels, which could be due to the stiff topography characteristic from the addition of MWCNT. Overall, the results of this study showed that GelMA-BG-MWCNT nanocomposite hydrogels coated with fibronectin possessed a favorable environment in which pre-differentiated iMSCs could better attach, proliferate, and further mature into an osteogenic lineage, which was crucial for the repair and regeneration of bone. Full article

The aging population and increasing incidence of trauma among younger age groups have heightened the increasing demand for reliable implant materials. Effective implant materials must demonstrate rapid osseointegration and strong antibacterial properties to ensure optimal patient outcomes and decrease the chance of implant rejection. This study aims to enhance the bone–implant interface by utilizing 45S5 bioglass modified with various concentrations of Fe₃O₄ as a coating material. The effect of the insertion of Fe₃O₄ into the bioglass structure was studied using Raman spectroscopy which shows that with the increase in Fe₃O₄ concentration, new vibration bands associated with Fe-related structural units appeared within the sample. The bioactivity of the prepared glasses was evaluated using immersion tests in simulated body fluid, revealing the formation of a calcium phosphate-rich layer within 24 h on the samples, indicating their potential for enhanced tissue integration. However, the sample modified with 8 mol% of Fe₃O₄ showed low reactivity, developing a calcium phosphate-rich layer within 96 h. All the bioglasses showed antibacterial activity against the Gram-positive and Gram-negative bacteria. The modified bioglass did not present significant antibacterial properties compared to the bioglass base. Full article