Journal of Materials Science: Materials in Medicine最新文献

Hydroxyapatite (HA) coatings on carbon fiber-reinforced carbon (C_f/C) composites hold promise for orthopedic implants. However, the interface between HA and C_f/C is prone to delamination, limiting its application. To address this, a polydopamine (PDA)-polyvinyl alcohol (PVA)-graphene oxide (GO) transition layer was introduced to reinforce and toughen HA coatings on C_f/C composites (PDA-PVA-GO/C_f/C) via hydrothermal electro-deposition/post-hydrothermal treatment. For comparison, the PDA and PDA/PVA transition layers were also prepared on C_f/C, designated as PDA/C_f/C and PDA-PVA/C_f/C, respectively. The precursor and transformed coatings obtained were monetite and HA. XRD analyses revealed that PDA and PVA infiltrated the monetite lattice without affecting the HA lattice parameters. Remarkably, scratch tests demonstrated that the HA/PVD-PVA-GO coating on C_f/C exhibited a dense configuration and compact interfacial structure, achieving a maximum critical load of 51.5 N, surpassing other reported electrochemically prepared HA coatings. Moreover, scratch tests indicated a more homogeneous scratch pattern with no sudden delamination of the coating from the matrix. In vitro assessments revealed that all HA coatings with the transition layer exhibited enhanced bioactivity and cell compatibility compared with HA alone. In particular, PDA/PVA/GO-C_f/C exhibited the best superior efficacy in promoting the proliferation of mouse embryonic osteoblast precursor (MC3T3-E1) cells and significantly increased Alkaline phosphatase (ALP) production in rat bone marrow mesenchymal stem cells (BMSCs). These findings underscore the potential of PDA-PVA-GO/C_f/C as a promising biomaterial for bone regeneration.

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Magnesium, an essential element in human physiology, is predominantly located in bone tissue. Since the early 20th century, magnesium-based biomaterials have demonstrated osteoinductive and angiogenic potential, positioning them as promising candidates for bone regeneration strategies. Hydrogels, composed of crosslinked hydrophilic polymers, provide a three-dimensional microenvironment mimicking the extracellular matrix (ECM), thereby supporting cell adhesion, nutrient diffusion, and controlled release of bioactive ions such as Mg²⁺. Recent advances in material science have enabled the design of multifunctional magnesium-loaded hydrogels that synergistically combine mechanical stability, immunomodulation, and spatiotemporal Mg²⁺ release to address critical-sized bone defects. This review systematically examines hydrogel classifications and elucidates magnesium-mediated biological signaling pathways that drive bone repair. A meta-analysis of 10 studies retrieved from PubMed, Web of Science, Scopus, and Embase was performed to assess the efficacy of magnesium-containing hydrogels in bone repair. The findings demonstrate that magnesium significantly enhances bone repair processes, underscoring its potential as a therapeutic agent for bone defect treatment.

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A thermosensitive hydrogel dressing was developed for the healing of diabetic foot ulcers (DFUs) using Epigallocatechin gallate (EGCG) and recombinant human epidermal growth factor (rhEGF). Hyaluronic acid (HA), poloxamer 407 (P407), and pectin (PE) were used to form the sol-gel transition matrix, which exhibited a sol-to-gel transition around 30 °C. The hydrogel was physiologically stable. Structural and morphological characterization using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the efficient incorporation of EGCG and rhEGF in a porous nanoarchitecture. Rheological analysis showed the storage modulus is quite constant over the frequency range (0.01–10 Hz), and compression analysis showed a compressive strength of 40.85 kPa, ensuring mechanical appropriateness for various wound conditions. This hydrogel had a water content of 76.64% and a water vapor transmission rate of 6011.44 g/m²/day, favorable to maintain a moist wound surface. Antibacterial tests showed inhibition rates of 73.53% against Escherichia coli and 75.37% against Staphylococcus aureus. In vitro with RAW 264.7 macrophages and L929 fibroblasts showed >90% cell survival, increased migration with 92.53% wound closure by 48 h, strong antioxidant activity, and considerable decrease in TNF-α and IL-6 (pro-inflammatory cytokines). Combining a natural antioxidant and bioactive protein within a responsive hydrogel matrix presented a synergistic solution, holding significant promise for enhancing diabetic wound healing by antimicrobial, anti-inflammatory, and regenerative processes.

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The fabrication of the EGCG-rhEGF@HA-P407-PE hydrogel, an advanced wound dressing designed for diabetic foot ulcers

In order to develop inorganic antibacterial and antiviral materials that function in the dark, we synthesized La₂Sn₂O₇, Mg₂SnO₄, and MgSn(OH)₆, which are compounds of La₂O₃ and MgO, which have solid basicity, and SnO₂, which has the Mars-van Krevelen (MvK) mechanism. After obtaining each sample as a single-phase white powder through hydrothermal or coprecipitation method, their antibacterial and antiviral activities were evaluated with reference to ISO procedures in the dark for bacteria and viruses with different characteristics. The dependence of activity on the evaluation method suggested that, except for Mg₂SnO₄, the proximity or contact of the viruses or bacteria to the sample surface played an important role in activity. Comparison of the activity of each sample with those of the simple oxides of constituent elements, La₂O₃, MgO, and SnO₂, clarified that pH, solid basicity, phosphate affinity, and the MvK mechanism contribute to antibacterial and antiviral activity. The extent of these contributions varied depending on the sample. The study results revealed that La₂Sn₂O₇ not only exhibits high antibacterial and antiviral activity against bacteria and viruses in the dark; it also has the ability to decompose organic dyes under UV irradiation. This material might be used as a newly developed environmental purification material providing continuous antibacterial and antiviral effects day and night, able to clean surfaces during UV light exposure.

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In this study, an innovative hydroxyapatite–titanium–magnesium oxide composite coating was successfully fabricated on Ti₆Al₄V alloy using plasma spraying to enhance its mechanical and corrosion performance for biomedical applications. Granulation of nano-sized HA powder (~100 ± 20 nm) produced spherical agglomerates in the range of 5–20 µm, ensuring suitable flowability for uniform coating deposition. SEM analyses confirmed dense and crack-minimized layers for both pure HA (~105 µm thick) and composite (~98 µm thick) coatings. XRD revealed the formation of additional CaTiO₃ and MgO phases in the composite, strengthening interfacial bonding. The composite coating exhibited a significant improvement in adhesion strength, reaching 29.2 ± 3.4 MPa, compared to 6.9 ± 0.6 MPa for pure HA. Vickers hardness also increased from 431.3 ± 5.8 HV (HA) to 537.9 ± 1.9 HV (composite coating), outperforming the uncoated Ti₆Al₄V substrate (360.8 ± 1.7 HV). Electrochemical tests showed that the composite coating achieved a lower corrosion current density (9.72 × 10⁻⁸ A/cm²) and higher polarization resistance (41.2 kΩ·cm²) than the HA-only coating (1.19 × 10⁻⁶ A/cm², 28.9 kΩ·cm²), indicating enhanced corrosion resistance.

Venous thromboembolism ranks as the third most prevalent cardiovascular disease. Nanotechnology-based drug carriers show significant potential for thrombolytic therapy. However, existing systems face challenges, including environmental impact and limited accessibility. To address these, we developed a novel delivery system using human black hair-derived nanoparticles (HNPs). These HNPs were loaded with the thrombolytic agent urokinase plasminogen activator (uPA) and a minimal concentration of gold nanoparticles (AuNPs). These components were encapsulated within a polyvinyl alcohol (PVA) membrane to create the nanocapsule drug delivery system, uPA-Au@HNP@PVA. Upon intravenous injection into a rat model with venous thrombosis, the system leveraged targeted blood flow to reach thrombus sites. Under 1064 nm NIR irradiation, the PVA membrane dissolved, exposing and releasing the drugs for intelligent thrombolysis. This system demonstrated excellent thrombolytic efficacy both in vivo and in vitro, coupled with robust biocompatibility in various biological tests, suggesting a wide range of potential applications.

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Representation: a. Depiction of the uPA-Au@HNP@PVA synthesis process. b. Diagrammatic explanation of intelligent thrombolytic therapy for specific drug delivery in a rat venous thrombosis model: I. Intravenous administration of uPA-Au@HNP@PVA; II. Targeted delivery to thrombus sites, navigation of uPA-Au@HNP@PVA to the thrombus location through targeted blood circulation, whereupon exposure to 1064 nm NIR irradiation causes a temperature rise, resulting in PVA dissolution, and drug release; III. NIR-triggered drug release and thrombolysis. Intelligent thrombolysis facilitated by 1064 nm NIR irradiation.

The critical bone defect is a common clinical challenge worldwide, characterized by long recovery times, a substantial risk of infection, and high disability rates. There remains a significant demand for synthetic bone-repairing materials to address this issue. In this study, porous monetite was synthesized through the reaction between monocalcium phosphate monohydrate and β-tricalcium phosphate, using paraffin microspheres as pore-forming agents. An injectable biphasic cement was then developed by blending the monetite granules with hemihydrate calcium sulfate, designed for minimally invasive surgical applications. The cement demonstrated excellent biocompatibility and osteogenic properties in vitro. Furthermore, in vivo studies confirmed the cement’s superior bone repair capabilities, indicating its promising potential for the treatment of critical bone defects.

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A highly porous composite with gradient degradation was developed by mixing porous monetite granules and hemihydrate calcium sulfate, and the composite has the effect of promoting the formation of new bone.

The development of Iron oxide nanoparticles (IONPs) from the green sources has significant attraction due to their eco-compatibility, safety, and nontoxic nature. This work demonstrated the synthesis of IONPs using the aqueous root extract of Cyperus rotundus, a traditional antibacterial plant source (Cr-IONPs). The synthesized Cr-IONPs were characterized by various analytical instruments DLS, Zeta, XRD, SEM, VSM, etc. to evaluate its physicochemical and magnetic nature. The results confirmed the uniform shape of Cr-IONPs within a size range of 30–70 nm. Additionally, they exhibited excellent colloidal stability with a Zeta potential value of −30.50 ± 1.79 mV. The VSM analysis revealed a superparamagnetic nature with zero remanence value. The antibacterial study showed that Cr-IONPs exhibited strong antibacterial potential in a concentration-dependent manner. Both Pseudomonas aeruginosa (P. aeruginosa) and Staphyllococcus aureus (S. aureus) strains demonstrated that Cr-IONPs exhibit potent antibacterial activity in a concentration-dependent manner. Furthermore, the diameter of the zone of inhibition increased with higher concentrations of the Cr-IONPs. These results demonstrate that the Cr-IONPs synthesized via a greener approach using C. rotundus extract exhibit strong antibacterial activity and biocompatibility, making them a promising candidate as a future antibacterial agent against multi-drug-resistant bacteria. Additionally, their superparamagnetic nature also broadens their potential for biomedical applications, including targeted drug delivery and diagnostics.

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Hyaluronic acid was crosslinked using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to form hydrogels with low elastic modulus. These hydrogels were swollen in water and the elastic modulus was obtained with a contact mechanics approach in ambient conditions using a low-load mechanical tester under compression. The modulus was measured during both the approach and retraction of the cylindrical probe into the gel and was found to be of the order of 30 kPa. The modulus was also measured from a stress-strain curve (47 kPa), in reasonable agreement with the contact mechanics approach. However, nanoindentation and rheology measurements reveal much smaller moduli, indicating that the technique used interrogates different length scales within the gel. This has profound implications for the applications of hydrogels used, for example, in tissue engineering. The values reported here are likely to be appropriate for applications where contact with the spinal cord is necessary. It is argued that a contact mechanics approach is appropriate for the characterization of hydrogels for applications designed for contact with tissue.

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The favorable antibacterial properties of the orthopedic implants can effectively reduce the risk of postoperative bacterial infection. Herein, CuS/PEEK biocomposites with an excellent antibacterial activity were successfully prepared by the method of cold pressing in combining with sintering molding technology. The investigation on the antibacterial properties revealed that the CuS/PEEK biocomposites exhibited superior antibacterial ability against both S. aureus and E. coli, whose antibacterial rates were 99.87% and 99.89%, respectively, while the CuS content in the bicomposites was up to 5%. Moreover, The antibacterial rates of CuS/PEEK composites against S. aureus and E. coli were as high as 99.98% after bacterial strain and CuS/PEEK co-cultivation for 15 min under light irradiation, indicating that the light irradiation and CuS/PEEK composites have the synergistic effect on the antibacterial activity. The antibacterial mechanisms verified that the photo-thermal effect of CuS and the continuous release of Cu²⁺ and S^2- ions in the composites played an important role for the improving antibacterial activity of CuS/PEEK composites.

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