This study investigated the biodegradation of natural rubber (NR), nitrile butadiene rubber (NBR), and NR/NBR blend rubber gloves over 60 days using the consortium CK. NR gloves showed the highest weight loss (62%), followed by NR/NBR blend gloves (22%) and NBR gloves (5.2%). SEM showed cracks and holes with bacterial colonization on NR and NR/NBR blend, whereas the NBR surface remained largely unchanged with negligible attachment. Viable cell counts increased in NR from 1.5×108 to 3.5×108 CFU/mL, but decreased in the NR/NBR blend and NBR from 8.2×108 to 1.2×106 and 1.2×108 to 3.2×103 CFU/mL, respectively. ATR-FTIR analysis of NR indicated degradation products, including polyisoprene oligomers and aldehydic products, suggesting oxidative cleavage of the polyisoprene backbone. NR degraded so extensively that the rubber pieces disintegrated into tiny fragments and mechanical properties were not measurable, consistent with the contact angle decrease from 65.8° to 51.2°. In contrast, the NR/NBR blend preserved part of its mechanical performance, although tensile strength, elongation at break, and force at break decreased from 18.89 to 2.5 MPa, 645 to 605 %, and 5.78 to 2.5 N, respectively. NBR also showed decreases from 36.47 to 16 MPa, 565 to 71 %, and 6.98 to 0.50 N. High-throughput 16S rRNA gene sequencing of the NR-degrading consortium CK identified Pseudoxanthomonas, Olivibacter, Nocardia, and other taxa presented during the rubber degradation process. These findings indicate that incorporation of NBR into NR helped preserve part of glove mechanical performance during degradation, while the presence of NR enhanced biodegradability compared with NBR.
Polymer networks in rubber vulcanisates are commonly characterised by crosslink density and crosslink structure. These crosslink characteristics greatly influence the properties of vulcanised rubber compounds. Therefore, their reliable characterisations are essential. However, well-established methods such as equilibrium swelling, thiol-amine method, proton nuclear magnetic resonance, and Mooney-Rivlin have some shortcomings, including being time-consuming, expensive and toxic due to the use of harmful chemicals. This study investigated whether Temperature Scanning Stress Relaxation (TSSR), a safe, cost-effective and time-saving method, can be used to determine polymer network density and to distinguish different types of sulphidic crosslinks in vulcanisates by analysing their non-isothermal stress relaxation behaviour. Carbon black- and silica-filled styrene-butadiene rubber compounds were prepared with different types and amounts of fillers, as well as different types of accelerators and silane coupling agents. The crosslink characteristics of these compounds were analysed using TSSR and equilibrium swelling in combination with thiol-amine treatment. Based on the correlation analyses between the data from TSSR-measurements and the conventional crosslink characterisations, results reveal that the total crosslink density can be determined using the peak area of the relaxation spectrum in the temperature range of . This implies that the breakage of sulphur crosslinks is the main mechanism contributing to stress relaxation in this temperature range. By analysing the spectrum peak area at different temperature regions, it is possible to distinguish between crosslink structures. The results illustrate that polysulphidic, disulphidic and monosulphidic crosslink densities correspond to the peak areas at temperature ranges of , and , respectively.
The incorporation of industrial by-products and recycled composite waste in concrete provides an effective approach to improving sustainability while reducing cement consumption. This study examines the mechanical and durability performance of M30-grade concrete incorporating high-volume fly ash, silica fume, and mechanically recycled automotive glass fiber–reinforced polymer (GFRP) fibers. Silica fume was maintained at a constant replacement level of 10%, while fly ash content was varied from 0% to 40% by weight of cement. Recycled GFRP fibers obtained from end-of-life car bumper waste were incorporated at amounts of 0.5, 1.0, and 1.5% by weight of binder. The workability of fresh concrete was assessed using slump tests, and the compressive strength (CS), split tensile strength (STS), and flexural strength (FS) were determined at curing ages of 3, 7, 28, and 56 days. Durability performance was evaluated through chloride resistance, sulphate resistance, water absorption, and alkalinity tests. The results indicate that fly ash replacement up to 35%, when combined with silica fume and recycled GFRP fibers, enhances later-age mechanical performance while maintaining acceptable workability and durability characteristics. The optimum mixture, containing 35% fly ash, 10% silica fume, and 1.0% recycled GFRP fibers, achieved increases of approximately 25.5, 63, and 55% in CS, STS, and FS, respectively, at 28 days compared with conventional concrete. Response surface methodology (RSM) was used to optimize fly ash and GFRP fiber contents, achieving a high overall desirability with balanced mechanical performance. An artificial neural network (ANN) model developed for performance prediction showed good agreement with experimental results.
An optimized vacuum-based technology for synthesizing Ga–Li alloys with controlled lithium content ranging from 10 to 50 at.% was developed and experimentally validated. The process combines two-stage lithium purification (chemical treatment and vacuum distillation) with high-temperature homogenization under residual pressure ≤10−5 Pa, ensuring low contamination levels and precise stoichiometry control. Comprehensive characterization using SEM, XRD (ICDD PDF-4+), DSC (25–500 °C), and ICP-MS demonstrates the formation of thermodynamically stable intermetallic phases Ga7Li2 and Ga9Li5 in the near-stoichiometric composition region. The observed phase assemblage is governed by equilibrium thermodynamics rather than kinetic limitations, as confirmed by the absence of metastable phases and the consistency between XRD and DSC results. Distinct endothermic transitions at ∼320 °C and ∼388 °C are attributed to transformations associated with Ga7Li2 and Ga9Li5 phases, respectively, in agreement with the equilibrium Ga–Li phase diagram. The synthesized alloys exhibit high compositional accuracy (deviation ≤0.6 at.%) and microstructural homogeneity, confirming the effectiveness of the developed synthesis route. A key finding is the experimentally confirmed reduction in lithium thermodynamic activity, leading to a decrease in saturated vapor pressure by 3–4 orders of magnitude compared to pure lithium in the temperature range 400–500 °C. This effect is highly important for fusion applications, as it suppresses lithium evaporation and improves compatibility with structural materials. The developed synthesis methodology and the obtained structure–property relationships demonstrate that Ga–Li intermetallic alloys are promising candidates for liquid metal plasma-facing components and tritium-related systems in next-generation fusion reactors.
This study investigates the effect of topology optimization (0-50% weight reduction) on the mechanical performance of fused deposition modelling (FDM) fabricated polylactic acid (PLA), polyethylene terephthalate glycol (PETG), and acrylonitrile butadiene styrene (ABS) for lightweight biomedical structural applications. Standardized specimens were manufactured and evaluated through tensile, compressive and flexural testing, supported by finite element analysis and scanning electron microscopy (SEM) to examine structural behavior and microstructural characteristics. The results indicate that PLA exhibited the highest tensile (60 MPa) and flexural strength (90 MPa), while ABS showed relatively stable compressive performance. At full material density (100%), PLA showed the highest tensile strength (60 MPa), followed by PETG (55 MPa) and ABS (45 MPa). With a 50% weight reduction, tensile strength decreased to 36 MPa for PLA and PETG and 32 MPa for ABS. In compression, ABS retained a compressive strength of 49 MPa even after 50% material removal through topology optimization, while PLA decreased from 70 MPa to 49 MPa and PETG from 68 MPa to 50 MPa. A similar decreasing trend was observed in flexural strength, where PLA reduced from 90 MPa to 58 MPa, PETG from 85 MPa to 58 MPa and ABS from 80 MPa to 58 MPa. An optimal topology optimization range of 30–40% was identified, achieving substantial weight reduction while maintaining mechanical performance. This study provides a systematic multi-material comparison and identifies an optimal topology optimization range for lightweight polymer structures intended for future biomedical applications.
Pine wood as natural composite has been extensively used in building construction, manufacturing furniture, and making musical instruments. California foothill pine or gray pine (Pinus sabiniana) is used as basic building materials for box crates and railway ties. It is also used for musical instruments (drums) making. Red pine (Pinus resinosa) is strong and durable for making furniture and flooring. It is suitable for outdoor applications such as fencing and framing, railroad ties, and cabin logs. Red pine wood also finds applications in musical instruments, especially for guitar bodies, offering warm and resonant tones. Mechanical testing is indispensable for design and performance enhancement of pine wood structures and components. Since the bonding strength and wear resistance of wood are related to shear deformation behavior, torsion test is considered as an effective method for evaluating the performance of pine wood. In this work, the strength and rigidity of both California foothill pine (gray pine) and red pine were evaluated under pure shear through torsion test. It has been found that the average shear strength of the gray pine is 7.12 MPa. The red pine showed higher average shear strength of 14.67 MPa. The modulus of rigidity of the gray pine is about 2.59 ± 0.46 GPa; while the red pine has the modulus of rigidity as high as 3.47 ± 0.62 GPa. Statistical analysis of the shear strength data reveals the Weibull moduli (m) of gray pine and red pine are 2.44 and 3.74, respectively. The characteristic shear strength (with a failure probability of 63.2%) of the gray pine is 8.04 MPa. The value of characteristic shear strength for red pine is 16.15 MPa. The statistical analysis on both pines indicates that the red pine is over one time stronger than the foothill (gray) pine under torsional loading.
Natural-fiber-reinforced polypropylene (PP) biocomposites are promising lightweight materials, but direct comparison among fiber types remains difficult because previous studies often used different materials and processing conditions. This study evaluated the effects of fiber type and loading on the tensile strength, Izod impact strength, and fracture morphology of injection-molded PP biocomposites reinforced with pineapple leaf fiber (PALF), banana fiber (BF), and coir fiber (CF). The fibers were treated with 5 wt% NaOH, ground, sieved through a 125 μm mesh, and compounded with PP and 5 wt% MAPP based on the PP/fiber blend mass. All formulations were processed under identical extrusion and injection-molding conditions at nominal fiber loadings of 10, 20, and 30 wt%. The ground particles had similar mean aspect ratios of 5.53–5.68. Processed neat PP showed tensile and impact strengths of 33.49 MPa and 1.24 kJ/m2, respectively. PP–PALF showed the highest tensile strength of 34.91 MPa at 10 wt% and impact strength of 2.75 kJ/m2 at 30 wt%, corresponding to numerical increases of 4.2% and 121.8% relative to processed neat PP. Two-way ANOVA showed significant effects of fiber type and loading on both properties, with a significant interaction only for tensile strength. Tensile strength decreased at higher loadings in PP–BF and PP–CF but remained relatively stable in PP–PALF, whereas impact strength generally increased. SEM revealed loading-dependent differences in matrix deformation, cavities, clustered or fiber-rich regions, exposed fibrous particles, and localized openings. Overall, PP–PALF provided the highest mean mechanical properties among the investigated systems.
Nanoparticles (NPs) have gained attention in bone regeneration for their ability to enhance osteogenesis, improve mechanical properties, and modulate immune responses. This review focuses on the use of various NPs, including iron oxide (IONPs), hydroxyapatite (HAP), carbon nanotubes (CNTs), and gold nanoparticles (Au-NPs), Silver nanoparticles, in bone repair applications. These NPs show potential in mimicking the natural bone microenvironment, promoting cell proliferation, and facilitating targeted drug delivery. The paper presents a comparative analysis of NP synthesis methods, including top-down and bottom-up approaches, alongside their clinical relevance. While NPs have demonstrated success in preclinical studies, challenges such as biocompatibility, particle toxicity, and regulatory hurdles remain. This review emphasizes the need for standardized in vivo models to evaluate long-term effects and ensure clinical success. Novel contributions include highlighting advancements in smart nanomaterials and scaffold engineering, which can significantly accelerate bone regeneration processes. However, gaps remain in achieving scalable, safe, and effective nanoparticle-based therapies for widespread clinical use. The review concludes with future directions, calling for further research on optimizing NP characteristics and addressing current limitations in bone tissue engineering.
The focus of this study is on how the composition of Cu/Ag nanofilms affects the surface interactions. The adatom binding energies of Cu atoms on the (111) surface of Cu/Ag nanofilms are also examined. Molecular dynamics (MD) simulations reveal that the binding energy of Cu adatoms varies significantly with alloy concentration. This research uncovers a non-linear relationship between binding energy and alloy composition, with optimal surface binding occurring at a 28% Ag content. Cu/Ag nanofilms with less than 64% Ag content exhibited enhanced adatom binding energies compared to that of pure Cu. The binding energy at specific alloy concentrations depends on the nearest neighbor configurations of Cu and Ag atoms beneath the adatom. The hypergeometric probability distribution and clustering techniques are used to successfully distinguish between various nearest neighbor configurations. Deviations between the computational results and probability theory demonstrate that Cu adatoms tend to bond more closely with Cu surface atoms than with Ag surface atoms, skewing adatoms away from the expected FCC and HCP bonding sites.
In the submersible, HSC (half split casing), and end suction centrifugal pump sets, sand cast LTB (leaded tin bronze) alloys are well-liked bearing alloys. The comparative tribological characteristics of LTB and LTBGr (leaded tin bronze graphite) are shown by this experimental investigation. The presence of α and δ phases in the copper matrix is determined by the quantity of Sn element in the composition, according to morphological analysis of sand-cast mixed LTB alloys using an optical emission microscope (OEM). Up to 9% of Sn by weight, solid solution α-phase formation was observed; nucleation for ẞ and δ phase formation occurred after this, which is converted into δ phase at room temperature. The addition of Sn% increases the hardness of LTB alloys, while the increase in Pb% acts as a softening agent between 7.0 and 14.0% of Sn; however, after 12% of Sn addition, third-body abrasion due to brittleness and pullout character increases in the wear of LTB alloys. The lowest mass wear rate among the tested samples of LTB alloys was found to be 2.869 × 10‾4 mg/Nm and COF of 0.560 at 1500 rpm and 50 N normal load, 10 min of rotation for Cu 9Sn10Pb2Ni1Zn alloy, while the optimum mass wear rate and COF were 2.763 × 10‾3 mg/Nm and 0.34 for Cu 10 Sn11Pb 2Ni 1Zn. Similarly, the optimum mass wear rate and COF values were found to be 3.007 × 10‾3 mg/Nm and 0.207 under the same testing parameters for Cu 10Sn 8 Pb 2Ni 1Zn 2Gr.
This study investigated the shape memory effect of a four-dimensional (4D) printed acrylonitrile-butadiene-styrene/thermoplastic polyurethane (ABS/TPU) blend for use in fused deposition modeling (FDM) three-dimensional (3D) printing. The composite polymer filament was formed by blending ABS and TPU using a single-screw filament extruder at ABS/TPU mass ratios of 40/60, 50/50, 60/40, 70/30, 80/20, and 90/10. These filaments were used in FDM 3D printing to produce shape memory polymers (SMPs). The thermal and mechanical properties of the printed SMPs with various mass ratios were analyzed. An ABS/TPU blend with a mass ratio of 50/50 was selected as a preliminary example for testing shape memory effects. Therefore, it is also straightforward to manufacture. Thermogravimetric analysis and differential scanning calorimetry revealed that it exhibited improvement in thermal properties, where Td was 1% of 277.5 °C, Tg was 103.8 °C, Tc was 135.3 °C, and Tm2 was 235.0 °C. A dynamic mechanical analysis showed that the storage modulus, loss modulus, and dynamic damping factor of the ABS/TPU composite all improved. The tensile test results showed that the energy absorption rate, storage modulus, and shape fixity of the composites were enhanced by the tensile strength of ABS, whereas the elongation at break and shape recovery ability of the composites were increased by the elastic recovery behavior of TPU.
The inherent structural weaknesses found in traditional cast aluminum parts are primarily caused by their dendritic formations. To counteract this, the Gas-Induced Semi-Solid (GISS) technique is utilized to facilitate a semi-solid state that yields nearly spherical, non-dendritic grains of consistent size, thereby enhancing the material's overall mechanical performance. As the automotive industry shifts toward electric vehicles, semi-solid cast aluminum is becoming a critical material for structural assemblies, often joined using Friction Stir Spot Welding (FSSW). Therefore, this work investigates the FSSW characteristics of semi-solid metal 5083 aluminum alloy (SSM5083), focusing on the mechanical properties and fatigue behavior of the joints. The experimental results showed that the best welding settings at 1600 rpm for the tool's rotation speed, 5 s for the dwell time, and 10 mm/min for the plunging feed rate produced a maximum lap shear strength of 4062 N. The hardness profiles showed values of 96.2 HV on the Advancing Side (AS) and 91.6 HV on the Retreating Side (RS), with an upward trend in hardness toward the stir zone boundary. Furthermore, the fatigue life equation was established for up to 2x106 cycles, determining an endurance limit of 757 N. Fractographic analysis via scanning electron microscopy (SEM) indicated that fatigue crack initiation predominantly occurred on the Advancing Side (AS), characterized by prominent beach marks and crack propagation features.
This study presents a computational estimation of the compressibility factor for pure cadmium in both vapor and liquid phases at 1 bar and phase-specific temperatures. For the vapor phase at the boiling point (1040 K), the second virial coefficient is computed from the Mayer function using a Lennard-Jones potential, yielding B = 12.89 cm3/mol and Zvap = 1.000151, indicative of near-ideal gas behavior. A sensitivity analysis confirms that Zvap remains within 5E-3% of unity under ±10% variations in the potential parameters ε and σ, and the temperature dependence of B(T) over 600–1500 K shows that Zvap approaches the ideal-gas limit from above throughout the process-relevant range.For the liquid phase at the melting point (594.22 K), the Embedded Atom Method is applied under a delta-function approximation of the radial distribution function, yielding Zliq = 0.005232. This result is validated against an NVT Monte Carlo simulation using the same EAM parameters, which reproduces the expected liquid-metal structure with a first-peak position at 2.83 Å and a coordination number Nc = 12.1, consistent with literature values. Finite-size convergence is demonstrated for N = 256–864 atoms. Comparison with an experimental estimate Zexp = 2.87E-4, derived from thermophysical density data, confirms that both values satisfy Z ≪ 1. A sensitivity analysis shows that while Zliq is numerically sensitive to the pair-potential parameters, the conclusion of near-incompressibility remains robust across ±30% parameter variations. The molar-volume contrast (Vliq = 14.02 cm3/mol vs Vvap = 85 334.9 cm3/mol) highlights the transition from a cohesive liquid metal to a disordered, near-ideal vapor.
This investigation presents a novel approach to improving water bottle preforms by balancing sustainability, production efficiency, and quality. This research integrates statistical techniques, numerical simulations, and machine learning to enhance product design, reduce manufacturing costs, and improve functional performance. Key injection molding parameters were optimized using the Taguchi method and Analysis of Variance (ANOVA) to mitigate warpage, wastage, and material processing defects. Optimal process parameters identified include a 280 °C melt temperature, 100 °C mold temperature, 40 °C ambient temperature, 2.8 s of holding pressure time, and 3.0 s of cooling time. These settings achieved superior dimensional stability, limiting the total peak warpage displacement to 0.0806 mm, comprising 0.0381 mm from residual stress, 0.0467 mm from quenching, and 0.0379 mm from orientation effects. The transition to the packing stage reduced the peak volumetric shrinkage to 13.69%, significantly enhancing the integrity of the components. ANN was established for warpage prediction, achieving a root mean square error up to 0.519. This confirms a strong association between simulated outcomes and experimental data, with an average correlation from 81.03% to 99.46%. The proposed model outperformed alternative machine learning approaches, specifically exceeding the 28.02% of Random Forest and the 16.61% of XGBoost models. This study demonstrates the efficacy of integrating advanced analytical techniques for rapid prototype development, design optimization, and high-quality plastic component manufacturing.
The development of heat-gain mitigating construction materials from agro-industrial residues is relevant for improving building-envelope performance while promoting circular material use. This study evaluated a rice husk-derived biosilica aerogel as a lightweight additive for scaled cementitious blocks. Rice husk was converted into amorphous biosilica through acid leaching, washing, drying, and calcination at 550 °C. The obtained precursor was transformed into a biosilica aerogel by alkaline dissolution, acid neutralization, aging, washing, ethanol exchange, freezing, and freeze-drying. The biosilica precursor showed characteristic Si-O-Si and Si-OH bands, an amorphous XRD halo between 22° and 26° 2θ, Si- and O-rich surface composition, a BET surface area of 256 m2 g-1, a mean pore width of 3.79 nm, and a total pore volume of 0.32 cm3 g-1. Among the tested formulations, the additive-free AG-SiO2 aerogel showed the lowest apparent density, approximately 0.26-0.33 g cm-3, and was selected for block-scale evaluation. Under outdoor exposure, aerogel-modified blocks showed lower internal temperatures than the reference block. The AG-1.00 formulation achieved the highest thermal-response improvement, with a maximum temperature reduction of 7 °C and an average ΔT of 2.71 °C during the 14 h test. These results support the potential of the proposed rice husk-derived biosilica aerogel as a lightweight additive for heat-gain mitigation. However, direct thermal conductivity, compressive strength, moisture resistance, and durability tests are still required before construction-scale application.
Concrete structures subjected to various types of cracks, which accelerate the ingress of aggressive agents and reduce the structure's service life. Therefore, crack repair is essential for restoring structural integrity and prolonging the lifespan of structural members. The use of green and bio-based materials in concrete construction, including concrete crack repair, offers a route to a lower-impact, locally sourced alternative. Date molasses is an abundant and inexpensive agro-product with high viscosity and water-reducing properties. In this study, date molasses was used as a novel bio-based technique for repairing concrete cracks. Date molasses was mixed with cement to produce a cement-date molasses mixture (CMM). Concrete specimens with controlled artificial cracks were prepared and treated with epoxy, CMM, and a blend of CMM and epoxy to evaluate the effectiveness of those treatments in crack repair. Post-repair performance of these materials was assessed using hardened density and ultrasonic pulse velocity (UPV), alongside compressive, tensile, and flexural strengths measured before and after the repair process. Fracture toughness parameters, including stress intensity factor and fracture toughness, were also introduced. A Permeability test was also conducted. The results showed that the increase in the UPV of the CMM-epoxy specimens was about 10.6% higher than that of the untreated specimens. For compressive strength evaluation, the CMM-treated specimens exhibited the highest strength gain between 28 and 56 days, exceeding 25%. Toughness parameters showed excellent results for the date molasses with an increase of more than 150% compared to epoxy-treated specimens. On the other hand, the CMM-epoxy composite demonstrated a notable improvement in restoring splitting resistance, reaching 3.080 MPa for the bonded samples. Overall, the findings indicate that the date molasses-based repair composite is promising in applications for as an eco-friendly alternative to conventional epoxy repair for non-critical and moderately loaded concrete elements.
This study investigates the influence of carbon and glass fiber reinforcements on the microstructure, physical characteristics, and mechanical performance of chemically foamed bisphenol-A epoxy composites. Epoxy composite foams were fabricated using azodicarbonamide as the chemical blowing agent, with foaming and curing carried out simultaneously. A full factorial design of experiments (DOE) was employed to systematically evaluate the effects of fiber type, fiber weight percentage (3 and 6 wt%), and fiber length (3 and 6 mm) on foam density, cell morphology, compressive properties, and energy absorption. Scanning electron microscopy (SEM) was used to characterize the cellular structure, while compression testing was performed to assess the mechanical performance. The results demonstrated that fiber reinforcement significantly enhanced the structural and mechanical properties of the epoxy foams by increasing density, reducing cell size, increasing cell density, and improving compressive strength and energy absorption. Among the investigated formulations, the G6W6L specimen containing 6 wt% carbon fiber with a fiber length of 6 mm exhibited the best overall performance, achieving improvements of 57% in compressive strength and 63% in energy absorption compared with the unreinforced foam. Statistical analysis confirmed that fiber weight percentage, fiber type, and fiber length significantly influenced the measured responses, while multi-response optimization identified the G6W6L formulation as the optimum combination for simultaneously maximizing mechanical performance. These findings demonstrate that carbon fiber is a more effective reinforcement than glass fiber for chemically foamed epoxy composites and highlight the potential of these lightweight materials for energy-absorbing and structural applications in the automotive, transportation, and protective engineering sectors.
This study presents an atomic-scale investigation into the dissolution behavior and structural evolution of Zinc/Strontium (Zn/Sr) co-doped 45S5 bioglass using Molecular Dynamics (MD) simulations. The primary objective was to elucidate how the substitution of Calcium (Ca) with Strontium (Sr), in the presence of Zinc (Zn), influences the network connectivity (NC), structural homogeneity, and degradability of bioactive glasses (BGs). Results indicate that the dominant structural unit remains Q2, consistent with the characteristic structure of 45S5 bioglass. As SrO content increases, a slight rise in the fraction of Q2 species was observed, suggesting a more pronounced chain-like structure. Interestingly, while the calculated NC exhibited an increasing trend with Sr substitution, other key metrics told a different story. The total bond density (Fnet) decreased significantly with higher SrO content, indicating a reduction in overall structural strength. Furthermore, the study evaluated structural homogeneity using the R-factor, revealing that increasing SrO content enhances the structural uniformity of the glass, bringing it closer to the homogeneity of the Sr-free control sample. The structural insights were experimentally validated through the evaluation of the 45-ZS5 sample, which demonstrated significant bioactivity despite the co-doping of Zn and Sr. This confirms that the structural modifications induced by Zn/Sr substitution do not compromise the material's biological function. Collectively, these findings suggest that in the 45-ZS5 sample, the reduction in bond strength and density, coupled with improved structural homogeneity, optimizes the degradability of the BGs. This enhanced degradability promotes more uniform ion release, thereby improving the therapeutic efficiency and bioactivity of Zn/Sr-co-doped 45S5 bioglass.
Titanium modifications have demonstrated to provide more suitable strategies for implant osseointegration. This investigation evaluated the effect of alkalinization and functionalization of titanium discs with collagen type I (polished or alkali-treated) on the response of osteoblasts. Materials and methods Titanium discs were manually polished and subjected to alkalinization with NaOH at 5 mol/L for 24 h at 60 °C, followed by determination of surface topography and roughness. Then, they were submitted to functionalization wth collagen type I (1 mg/mL) for 4 h at 37 °C, followed by osteoblasts seeding (SaOs-2). After 7 days, cell adhesion onto each substrate was evaluated (n = 3) as also cell viability (n = 6), alkaline phosphatase (ALP) activity (n = 6) and gene expression of osteogenic markers (n = 6). Titanium surfaces were analyzed by Fourier transform infrared spectroscopy/FTIR (n = 3). Data of surface roughness, viability, ALP activity and gene expression were also analyzed by ANOVA two-way and Tukey tests (alpha = 0.05), while data on cell adhesion and FTIR were qualitatively evaluated. Results All parameters were increased for the titanium surface subjected to alkalinization and the combination of the two protocols (alkalinization and functionalization with collagen type I) promoted the better results, with higher cell adhesion, viability, ALP activity and gene expression. FTIR demonstrated the main chemical groups of collagen and hydroxyl. The alkalinization of titanium surfaces with NaOH and the functionalization of these surfaces with collagen were effective strategies on stimulating osteoblasts response. The combination of both demonstrated to be the best conditions to cells response.
