Journal of Materials Science: Materials in Medicine最新文献

This study explores the microstructural evolution, mechanical properties, and corrosion behavior of AZ91 composites reinforced with hydroxyapatite (HA) particles, processed at varying rotational speeds (600, 1000, and 1400 rpm) using a deformation-driven metallurgy process. Microstructural analysis revealed that plastic deformation and heat generation during processing resulted in complete bonding between AZ91 powder particles and reinforcements, forming a fine equiaxed microstructure through dynamic recrystallization. The average grain size increased with rotational speed, measuring 54.2 ± 1.3 µm, 67.1 ± 1.5 µm, and 74.5 ± 1.9 µm for samples processed at 600, 1000, and 1400 rpm, respectively, highlighting the dominant role of temperature in grain growth. Mechanical testing demonstrated a decreasing trend in hardness and tensile strength with increasing rotational speed. The hardness dropped from 85.2 ± 2.9 HV0.1 at 600 rpm to 71.2 ± 6.8 HV0.1 at 1400 rpm, while ultimate tensile strength declined from 334.2 ± 6.3 MPa to 265.3 ± 4.9 MPa. Corrosion resistance was significantly influenced by processing parameters. The lowest corrosion current density (40.901 µA/cm²) and highest polarization resistance (Rp = 239.996 Ω·cm²) were observed in samples processed at 600 rpm, demonstrating enhanced corrosion resistance due to finer grains and uniform HA dispersion. In contrast, at 1400 rpm, increased grain size and uneven HA distribution contributed to a higher corrosion rate and reduced Rp (186.194 Ω·cm²).

Chemotherapy and photothermal therapy have demonstrated significant promise in the treatment of gastric cancer. A stable, effective, and safe photothermal agent is needed in this synergic system. Here, carbon quantum dots (CDs), an efficient photothermal agent, were first developed. By encapsulating CDs and the gastric cancer drug camptothecin (CT) in liposomes (Lip), a folic acid (FA)-targeted multifunctional photothermal nanosystem was rationally developed. To augment the photothermal performance and accelerate liposome cleavage for drug release, a NIR photothermal agent, indocyanine green (IG), was incorporated into the bilayer membranes. This built photothermal multifunctional nanosystem was triggered by an NIR laser and demonstrated payload-controlled release, in addition to exceptional performance with a photothermal conversion efficacy of up to 46.97%. The multifunctional photothermal nanosystem demonstrated superior cytocompatibility, stimuli-responsive drug release, improved tumor-specific targeting, and efficient cell death of NCI-N87 gastric cancer cells through multimodal synergic treatment. The effective development of this NIR-triggered, cell-targeted, photothermal, multifunctional nanosystem would enhance the therapeutic efficiency of gastric cancer therapy and offer a potential approach for designing and developing synergistic chemo-photothermal combination therapies.

This study evaluates a new self-gripping, slowly resorbable mesh (SRM) for ventral hernia repair, focusing on its in vitro degradation and in vivo biocompatibility in a rabbit model. Traditional ventral hernia repair methods often use permanent synthetic meshes, which can have limitations. Slowly resorbable synthetic meshes, such as the SRM, offer a promising alternative by providing temporary support and gradually degrading to be replaced by the body’s own tissue. The SRM, made from a poly(L-lactide) and trimethylene carbonate copolymer, was tested for its mechanical properties and degradation behavior. In vitro degradation was assessed according to ISO 13781:2017, while in vivo biocompatibility was evaluated following ISO 10993-6 guidelines. The study included native and pre-degraded samples implanted in New Zealand White rabbits, with assessments at 4, 10-, 26-, 52-, and 78-week post-implantation. Results showed that the SRM provided mechanical support for at least 20 weeks, with favorable integration and biocompatibility. The in vitro degradation profile indicated a steady decline in molecular weight, while in vivo studies revealed controlled degradation and minimal inflammatory response. Comparative analysis with the commercially available TIGr® Matrix Surgical Mesh demonstrated that the SRM had similar or better performance in terms of tissue response and degradation. The preclinical results of SRM, combined with the findings from this ISO 10993 Part 6 standard study, provide important data for market approval filings and the initiation of clinical evaluations.

Allergic rhinitis (AR) is a common inflammatory condition requiring innovative therapeutic approaches. This study introduces a nanocomposite hydrogel system combining Arnica montana extract and propolis-loaded chitosan nanoparticles (AMEPROCNPs) with menstrual blood-derived mesenchymal stem cells (MenSCs), designed for sustained delivery and enhanced mucosal healing. The system demonstrated biocompatibility, effective drug release, and strong mucoadhesion. In vitro studies showed marked reductions in pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α, alongside significant cytoprotection against oxidative stress. In vivo, the optimized formulation (HYDROMenSC-CNP-8) substantially alleviated AR symptoms and significantly downregulated key Th2-associated cytokines (IL-4, IL-5, IL-13) and TNF-α, while upregulating IFN-γ levels, comparable to Fluticasone Propionate. These results suggest that the AMEPROCNPs-loaded MenSC-collagen hydrogel represents a promising, safe, and effective alternative to current AR therapies. Furthermore, this system holds potential for broader application in treating other inflammatory and allergic diseases.

Cardiac patches represent a groundbreaking approach in the treatment of heart disease, offering a new hope for patients with damaged heart tissue following a myocardial infarction (MI). These engineered patches not only provide essential structural support to weakened heart tissue but also actively promote regeneration by recreating a functional, contractile environment. However, achieving long-term success with cardiac patches requires innovative strategies to address the complexities of the cardiac environment. This review addresses the significant challenge of maintaining cell viability and functionality in the large-scale production of cardiac patches. It aims to advance the effectiveness of cardiac patches for clinical applications in treating heart diseases through various methods, including the incorporation of conductive materials and the use of biocompatible scaffold materials to mimic native cardiac tissue. Strategies to promote vascularization, optimize cell sources, and refine cell culture conditions are also discussed. Additionally, controlled release systems for growth factors, surface modification techniques, and mechanical conditioning during in vitro culture are highlighted as crucial aspects of patch fabrication.

Graphical Abstract

Objectives

This study evaluated the mechanical and surface characteristics of the transition zone of multilayered translucent zirconia (TZ) after aging and analyzed the correlation between the 4-point bending flexural strength (4PBFS) and biaxial flexural strength (BFS) in each zone.

Methods

Traditional (3Y-TZP of LT; L, 4Y-TZP of MT; M) and multilayered TZ (5Y-TZP of MT Multi; T, 3Y/5Y-TZP of Prime; P, 4Y/5Y-TZP of Prime esthetic; E) IPS E.max ZirCAD blocks were used to fabricate 525 disk-shaped and 300 bar-shaped specimens. Specimens were separated into three groups, aged in an autoclave at 134 °C under 0.2 MPa for 0 h, 5 h, and 10 h. The mechanical and surface characteristics of the transition zone in multilayered TZ were analyzed, following statistical analyses (α = 0.05).

Results

L showed the highest 4PBFS and BFS, irrespective of aging. Consistent correlations between the 4PBFS and BFS were found in all groups. L showed the highest Weibull characteristic strength under all conditions. T showed the highest nanoindentation hardness and Young’s modulus, and the Vickers hardness of L and P were lower than other groups. Aging led to surface uplifts and microcracks caused by phase transformation, particularly in L and P.

Conclusions

The flexural strength of 3Y/5Y-TZP and 4Y/5Y-TZP was comparable to that of 3Y-TZP and 4Y, 5Y-TZP respectively, regardless of aging. Surface roughness showed a marked increase after aging in 3Y-TZP and 3Y/5Y-TZP. Furthermore, the interaction between yttria content and aging was evident across all mechanical and surface characteristics, except for flexural strength.

Graphical Abstract

Opacification of intraocular lenses (IOLs) due to the formation of calcium phosphate occurs because of their contact with the aqueous humor (AH), which is supersaturated with respect to calcium phosphate. Calcification of IOLs was simulated in vitro using a batch reactor in which the IOLs were exposed to solutions simulating AH. Based on the precise and reproducible measurement of the rates of formation of mineral deposits on the IOLs, it is possible to develop reliable screening tests of different types of IOL materials. Depending on their material composition, IOLs are expected to present different active sites for the growth of deposits. Measurements of the kinetics of formation of hydroxyapatite (Ca₅(PO₄)₃OH; HAP) were used to compare the relative tendency of IOL towards calcification. The trend the IOLs tested showed towards calcification was found to correlate with contact angle values. In the case of hydrophobic IOLs, the surface charge calculated from the corresponding zeta potential measurements was low in comparison with the respective high (absolute) values of the mineralizing hydrophilic IOLs, suggesting strong correlation between surface charge and tendency to calcify. The in vitro results align with the in vivo tests, suggesting that in vivo tests can be safely substituted or at least significantly reduced by the in vitro model.

Graphical Abstract

Intrauterine adhesions pose a significant challenge to female fertility, with current treatments showing limited efficacy and safety concerns, including poor biocompatibility and secondary trauma risks. In this work, we present a novel biodegradable bacterial nanocellulose (BC)-based physical barrier that integrates controlled drug release capabilities for preventing intrauterine adhesions. Through TEMPO-mediated oxidation and N-vinyl pyrrolidone grafting, we developed BC membranes exhibiting superior biocompatibility (cell death rate <5%) and selective fibroblast inhibition. The system achieves controlled biodegradation over 14 days while maintaining mechanical integrity (tensile strength >2.0 MPa) and providing sustained β-estradiol release. This approach represents a significant advancement in intrauterine adhesion prevention strategies.

When measured in vitro, the release of metal ions from orthodontic alloys is typically carried out in artificial saliva (AS), a medium with many advantages but lacking the biological complexity of natural human saliva. In this study, we measured ion release profiles from the complete orthodontic fixed appliance, comprising stainless steel and NiTi parts, in a proteinaceous media (yeast extract peptone dextrose, YPD) and compared it to AS. Two immersion models were used, differing in medium replenishment dynamics. To elucidate the metal release results, surface chemistry and topography were analysed using atomic force microscopy (AFM) followed by roughness analysis, and elemental analysis of the top micrometric and nanometric layer (SEM/EDX and XPS analyses).The results showed that proteinaceous media promoted the leaching of Fe, Cu, and Al while suppressing Ni and Cr. Ni²⁺ and Cr³⁺ ions were detected in the top layer on NiTi in AS, but not in YPD. A rough “wavy” surface layer was formed in AS, as opposed to smaller sharper entities formed in YPD. Cu(I) compounds on orthodontic bands were detected in both media. The replenishment of the media during immersion influenced the development of surface chemistry and ion leaching for both types of media, AS and YPD. The results obtained in this study are expected to provide a significant advancement over previous studies using artificial saliva (only).

Graphical Abstract

This study evaluates how next-generation silicone impression materials intended for dental use behave during polymerization, as well as their dimensional stability, mechanical properties, degradation patterns, and in silico toxicity levels. Silicone materials are preferred for dental applications because of their outstanding mechanical properties and compatibility with biological tissues. The performance of these materials is susceptible to environmental conditions including temperature changes, humidity levels, and exposure to oral fluids. Patient safety requires evaluation of degradation product toxicity concerns. It is crucial to examine these properties at the molecular level to enhance material durability and safety during clinical use. The structural, mechanical, and stability properties of silicone materials were modeled through molecular dynamics (MD) simulations using BIOVIA Materials Studio 2020. Material characterization and evaluation of mechanical properties were performed with the Forcite module using the COMPASSIII force field. The study simulated polymerization dynamics to understand the reaction mechanisms while employing the Kinetix and DMol3 modules to analyze dimensional stability under various environmental stresses. The CASTEP and DMol3 modules, along with the OSIRIS DataWarrior, were employed to forecast degradation pathways and potential toxicity. The combination of an elastic modulus of 2.533 GPa and tensile strength of 5.387 MPa allows Polydimethylsiloxane (PDMS) to show superior flexibility and rigidity, which qualifies it as the best choice for dental impression materials. Methacryloxypropyltrimethoxysilane (3.248 GPa) and hexaphenylcyclotrisiloxane (3.017 GPa) exhibited enhanced stiffness, suggesting their usefulness in load-bearing scenarios. In silico toxicity predictions indicated that most silicone derivatives demonstrated acceptable biocompatibility, although some silane compounds showed potential risks requiring further experimental validation. Under simulated conditions, the materials maintained stable configurations and exhibited positive polymerization dynamics, indicating that they could provide high durability along with dimensional stability for dental usage. This study highlights the superior balance of flexibility, rigidity, and safety exhibited by PDMS, while also identifying Methacryloxypropyltrimethoxysilane and hexaphenylcyclotrisiloxane as candidates for specialized load-bearing dental applications. Promising in silico findings require experimental validation and clinical testing to establish their practical applications.