Search Results (177)

Recently, plastic and agricultural waste have gained attention as sustainable alternatives. Despite efforts to recycle these materials, much still ends up in landfills, raising environmental concerns. To optimize their potential, these wastes ought to be transformed into value-added products for diverse industrial applications. This work focused on producing thin composite material films using olive oil solid waste called JEFT and recycled plastic bottles. JEFT was cleaned, dried, and processed mechanically via ball milling to produce nano- and micron-sized particles. Composite films were produced via melt compounding and compression molding with a rapid cooling process for controlled crystallinity and enhanced flexibility. Their density, water absorption, tensile strength, thermal stability, water permeability, functional groups, and biodegradation were comprehensively analyzed. Results indicated that 50% JEFT in recycled plastic accelerated thermal deterioration (42.7%) and biodegradation (13.4% over 60 days), highlighting JEFT’s role in decomposition. Peak tensile strength (≈32 MPa) occurred at 5% JEFT, decreasing at higher concentrations due to agglomeration. Water absorption and permeability slightly increased with JEFT content, with only a 1% rise in water permeability for 50% JEFT composites after 60 days. JEFT maintained the recycled plastic’s surface chemistry, ensuring stability. The findings of this study suggest that JEFT/r-HDPE films show potential as greenhouse coverings, enhancing crop production and water efficiency while improving plastic biodegradation, offering a sustainable waste management solution. Full article

The overuse of nonrenewable resources has motivated intensive research and the development of new types of green bio-based and degradable feedstocks derived from natural sources, such as cellulose derivates, also in nanoforms. The inclusion of such nanoparticles in bio-based polymers with the aim of providing reinforcement is a trend, which, when associated with the incorporation active compounds, creates active packaging suitable for the packaging of highly perishable food, thus contributing to the product’s shelf-life extension. Chitosan (Ch)/sage essential oil (SEO) bionanocomposite reinforced with nanocrystalline cellulose (CNC) was cast as active packaging for the preservation of fresh poultry meat. Meat samples were wrapped in different bioplastics (pristine chitosan, chitosan with commercial CNC, chitosan with CNC obtained from three different lignocellulosic crops, giant reed (G), kenaf (K), and miscanthus (M), chitosan with SEO, and chitosan with SEO and CNC), while unwrapped samples were tested as the control. Periodically, samples were evaluated in terms of their physicochemical properties and microbial growth. Additionally, bionanocomposites were also evaluated in terms of their in situ antimicrobial properties, as well as migration toward food simulants. Meat samples protected with bionanocomposites showed lower levels of microbiological growth (2–3 logs lower than control) and lipid oxidation (20–30% lower than in control), over time. This was attributed to the intrinsic antimicrobial capacity of chitosan and the high oxygen barrier properties of the films resulting from the CNC inclusion. The SEO incorporation did not significantly improve the material’s antimicrobial and antioxidant activity yet interfered directly with the meat’s color as it migrated to its surface. In the in vitro assays, all bionanocomposites demonstrated good antimicrobial activity against B. cereus (reduction of ~8.2 log) and Salmonella Choleraesuis (reduction of ~5–6 log). Through the in vitro migration assay, it was verified that the SEO release rate of phenolic compounds to ethanol 50% (dairy products simulate) was higher than to ethanol 95% (fatty food simulate). Furthermore, these migration tests proved that nanocellulose was capable of delaying SEO migration, thus reducing the negative effect on the meat’s color and the pro-oxidant activity recorded in TBARS. It was concluded that the tested chitosan/nanocellulose bionanocomposites increased the shelf life of fresh poultry meat. Full article

Regenerative endodontics seeks to restore the vascularized pulp–dentin complex following conventional root canal therapy, yet reliable neovascularization within the constrained root canal remains a key challenge. This study investigates the development of an injectable, dual-curing hydrogel based on methacrylated decellularized amniotic membrane (dAM-MA) and compares its performance to a conventional gelatin methacryloyl (GelMA). The dAM-MA platform was designed for biphasic release, incorporating both free vascular endothelial growth factor (VEGF) for an initial burst and matrix-metalloproteinase-cleavable VEGF conjugates for sustained delivery. The dAM-MA hydrogel achieved shape-fidelity via thermal gelation at 37 °C and possessed tunable stiffness (0.5–7.8 kPa) after visible-light irradiation. While showing high cytocompatibility comparable to GelMA (>125% hDPSC viability), the dAM-MA platform markedly outperformed the control in promoting endothelial tube formation (up to 800 µm total length; 42 branch points at 96 h). The biphasic VEGF release from dAM-MA matched physiological injury kinetics, driving both early chemotaxis and late vessel maturation. These results demonstrate that dAM-MA hydrogels combine native extracellular matrix complexity with practical, dual-curing injectability and programmable VEGF kinetics, offering a promising scaffold for minimally invasive pulp–dentin regeneration. Full article

The growing interest in probiotic bacteria within the food industry is driven by their recognized health benefits for consumers. However, preserving their therapeutic viability and stability during gastrointestinal transit remains a formidable challenge. Hence, this research aimed to enhance the viability of Lactobacillus reuteri through microencapsulation using a binary polysaccharide mixture composed of low acyl gellan gum (LAG), high acyl gellan gum (HAG), and calcium for the microencapsulation of L. reuteri. To achieve this, the Box–Behnken design was applied, targeting the optimization of L. reuteri microencapsulated to withstand simulated gastrointestinal conditions. The microcapsules were crafted using the internal ionic gelation method, and optimization was performed using response surface methodology (RSM) based on the Box–Behnken design. The model demonstrated robust predictive power, with R² values exceeding 95% and a lack of fit greater than p > 0.05. Under optimized conditions—0.88% (w/v) LAG, 0.43% (w/v) HAG, and 24.44 mM Ca—L. reuteri reached a viability of 97.43% following the encapsulation process. After 4 h of exposure to simulated gastric fluid (SGF) and intestinal fluid (SIF), the encapsulated cells maintained a viable count of 8.02 log CFU/mL. These promising results underscore the potential of biopolymer-based microcapsules, such as those containing LAG and HAG, as an innovative approach for safeguarding probiotics during gastrointestinal passage, paving the way for new probiotic-enriched food products. Full article

There is insufficient evidence regarding the cytotoxicity of restorative 3D-printing resins, used as part of the digital workflow in dentistry. This study presents a novel comparative evaluation of cell viability and adhesion using human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs), a less commonly used but clinically relevant cell line in dental biomaterials research. The aim of this study was to evaluate the cell viability of WJ-MSCs seeded on 3D-printed resins intended for temporary restorations. Resin discs of three commercial 3D-printing resins (NextDent C&B, Leaf Dental C&B, and UNIZ Temp) and a conventional self-curing acrylic resin (NicTone) were used. WJ-MSCs were cultured on the specimens for 1, 4, and 10 days. Cell viability was assessed using the PrestoBlue assay, Live/Dead immunofluorescence staining, and 7AAD/Annexin V staining. Cell adhesion was evaluated using scanning electron microscopy. Direct exposure to the 3D-printed resins and the self-curing acrylic caused slight reductions in cell viability compared to the control group in both microscopic analyses. 7AAD/Annexin V showed the highest percentage of viable WBCs for the conventional acrylic (34%), followed by UNIZ (35%), NextDent (42%), and Leaf Dental (36%) (ANOVA p < 0.05 Tukey’s post-hoc test p < 0.05). These findings suggest that 3D-printed resins could be considered safe for use in temporary restorations. Full article

This research focuses on designing polymer membranes as biocompatible materials using home-built electrospinning equipment, offering alternative solutions for tissue regeneration applications. This technological development supports cell growth on biomaterial substrates, including hepatocellular carcinoma (Hep-G2) cells. This work researches the compatibility of polymer membranes (fiber mats) made of polyvinylidene difluoride (PVDF) for possible use in cellular engineering. A standard culture medium was employed to support the proliferation of Hep-G2 cells under controlled conditions (37 °C, 4.8% CO₂, and 100% relative humidity). Subsequently, after the incubation period, electrochemical impedance spectroscopy (EIS) assays were conducted in a physiological environment to characterize the electrical cellular response, providing insights into the biocompatibility of the material. Scanning electron microscopy (SEM) was employed to evaluate cell adhesion, morphology, and growth on the PVDF polymer membranes. The results suggest that PVDF polymer membranes can be successfully produced through electrospinning technology, resulting in the formation of a dipole structure, including the possible presence of a polar β-phase, contributing to piezoelectric activity. EIS measurements, based on R_ct and C_dl values, are indicators of ion charge transfer and strong electrical interactions at the membrane interface. These findings suggest a favorable environment for cell proliferation, thereby enhancing cellular interactions at the fiber interface within the electrolyte. SEM observations displayed a consistent distribution of fibers with a distinctive spherical agglomeration on the entire PVDF surface. Finally, integrating piezoelectric properties into cell culture systems provides new opportunities for investigating the influence of electrical interactions on cellular behavior through electrochemical techniques. Based on the experimental results, this electrospun polymer demonstrates great potential as a promising candidate for next-generation biomaterials, with a probable application in tissue regeneration. Full article

Tissue-engineered scaffolds, particularly composite scaffolds composed of polymers combined with ceramics, bioactive glasses, or nanomaterials, play a vital role in regenerative medicine by providing structural and biological support for tissue repair. As scaffold designs grow increasingly complex, the need for non-invasive imaging modalities capable of monitoring scaffold integration, degradation, and tissue regeneration in real-time has become critical. This review summarizes current non-invasive imaging techniques used to evaluate tissue-engineered constructs, including optical methods such as near-infrared fluorescence imaging (NIR), optical coherence tomography (OCT), and photoacoustic imaging (PAI); magnetic resonance imaging (MRI); X-ray-based approaches like computed tomography (CT); and ultrasound-based modalities. It discusses the unique advantages and limitations of each modality. Finally, the review identifies major challenges—including limited imaging depth, resolution trade-offs, and regulatory hurdles—and proposes future directions to enhance translational readiness and clinical adoption of imaging-guided tissue engineering (TE). Emerging prospects such as multimodal platforms and artificial intelligence (AI) assisted image analysis hold promise for improving precision, scalability, and clinical relevance in scaffold monitoring. Full article

This study presents a multi-modal investigation into the wear behavior of bio-based epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs) at 0–0.75 wt%. A Taguchi L16 orthogonal array was employed to systematically assess the influence of MWCNT content, load (20–50 N), and sliding speed (1–2.5 m/s) on wear rate (WR), coefficient of friction (COF), and surface roughness (Ra). Statistical analysis revealed that MWCNT content contributed up to 85.35% to wear reduction, with 0.5 wt% identified as the optimal reinforcement level, achieving the lowest WR (3.1 mm³/N·m) and Ra (0.7 µm). Complementary morphological characterization via SEM and AFM confirmed microstructural improvements at optimal loading and identified degradation features (ploughing, agglomeration) at 0 wt% and 0.75 wt%. Regression models (R² > 0.95) effectively captured the nonlinear wear response, while a Random Forest model trained on GLCM-derived image features (e.g., correlation, entropy) yielded WR prediction accuracy of R² ≈ 0.93. Key image-based predictors were found to correlate strongly with measured tribological metrics, validating the integration of surface texture analysis into predictive modeling. This integrated framework combining experimental design, mathematical modeling, and image-based machine learning offers a robust pathway for designing high-performance, sustainable nanocomposites with data-driven diagnostics for wear prediction. Full article

This research work focused on the development of an adsorbent biocomposite material based on polyhydroxybutyrate (PHB) and cellulose acetate derived from sugarcane (Saccharum officinarum) fibre, through cellulose acetylation. The resulting material represents both an accessible and effective alternative for the treatment and remediation of water contaminated with heavy metals, such as Ni (II). The biocomposite was prepared by blending cellulose acetate (CA) with the biopolymer PHB using the solvent-casting method. The resulting biocomposite exhibited a point of zero charge (pHpzc) of 5.6. The material was characterised by FTIR, TGA-DSC, and SEM analyses. The results revealed that the interaction between Ni (II) ions and the biocomposite is favoured by the presence of functional groups, such as –OH, C=O, and N–H, which act as active adsorption sites on the material’s surface, enabling efficient interaction with the metal ions. Adsorption kinetics studies revealed that the biocomposite achieved an optimal adsorption capacity of 5.042 mg/g at pH 6 and an initial Ni (II) concentration of 35 mg/L, corresponding to a removal efficiency of 86.44%. Finally, an analysis of the kinetic and isotherm models indicated that the experimental data best fit the pseudo-second-order kinetic model and the Freundlich isotherm. Full article

Medical phantoms are essential to imaging calibration, clinician training, and the validation of therapeutic procedures. However, most ultrasound phantoms prioritize acoustic realism while neglecting the viscoelastic and anisotropic properties of fibrous soft tissues. This gap limits their effectiveness in modeling realistic biomechanical behavior, especially in wave-based diagnostics and therapeutic ultrasound. Current materials like gelatine and agarose fall short in reproducing the complex interplay between the solid and fluid components found in biological tissues. To address this, we developed a soft, anisotropic composite whose dynamic mechanical properties resemble fibrous biological tissues such as skin and skeletal muscle. This material enables wave propagation and vibration studies in controllably anisotropic media, which are rare and highly valuable. We demonstrate the tunability of damping and stiffness aligned with fiber orientation, providing a versatile platform for modeling soft-tissue dynamics and validating biomechanical simulations. The phantoms achieved Young’s moduli of 7.16–11.04 MPa for skin and 0.494–1.743 MPa for muscles, shear wave speeds of 1.51–5.93 m/s, longitudinal wave speeds of 1086–1127 m/s, and sound absorption coefficients of 0.13–0.76 dB/cm/MHz, with storage, loss, and complex moduli reaching 1.035–6.652 kPa, 0.1831–0.8546 kPa, and 2.138–10.82 kPa. These values reveal anisotropic response patterns analogous to native tissues. This novel natural fibrous composite system affords sustainable, low-cost ultrasound phantoms that support both mechanical fidelity and acoustic realism. Our approach offers a route to next-gen tissue-mimicking phantoms for elastography, wave propagation studies, and dynamic calibration across diverse clinical and research applications. Full article

The persistent contamination of aquatic environments by heavy metals, particularly Pb²⁺, Cd²⁺, and Cu^2+, poses a serious global threat due to their toxicity, persistence, and bioaccumulative behavior. In response, low-cost and eco-friendly adsorbents are being explored, among which CaCO₃-based biocomposites derived from mollusk shells have shown exceptional performance. In this study, a hybrid biocomposite composed of poly(vinyl alcohol) (PVA) and oyster shell-derived CaCO₃ was computationally investigated using Density Functional Theory (DFT) to elucidate the electronic and structural basis for its high metal-removal efficiency. Calculations were performed at the B3LYP/6-311++G(d,p), M05-2X/6-311+G(d,p), and M06-2X/6-311++G(d,p) levels using GAUSSIAN 16. Among them, B3LYP was identified as the most balanced in terms of accuracy and computational cost. The hybridization with CaCO₃ reduced the HOMO-LUMO gap by 20% and doubled the dipole moment (7.65 Debye), increasing the composite’s polarity and reactivity. Upon chelation with metal ions, the gap further dropped to as low as 0.029 eV (Cd²⁺), while the dipole moment rose to 17.06 Debye (Pb²⁺), signaling enhanced charge separation and stronger electrostatic interactions. Electrostatic potential maps revealed high nucleophilicity at carbonate oxygens and reinforced electrophilic fields around the hydrated metal centers, correlating with the affinity trend Cu²⁺ > Cd²⁺ > Pb²⁺. Fukui function analysis indicated a redistribution of reactive sites, with carbonate oxygens acting as ambiphilic centers suitable for multidentate coordination. Natural Bond Orbital (NBO) analysis confirmed the presence of highly nucleophilic lone pairs and weakened bonding orbitals, enabling flexible adsorption dynamics. Furthermore, NCI/RDG analysis highlighted attractive noncovalent interactions with Cu²⁺ and Pb²⁺, while FT-IR simulations demonstrated the formation of hydrogen bonding (O–H···O=C) and Ca²⁺···O coordination bridges between phases. Full article

Both biochemical cues and the electrophysiological microenvironment play a pivotal role in influencing cell behaviors. In this study, collagen/polypyrrole biomimetic electroactive composite coatings with a fiber network structure were constructed on the surface of titanium substrates by hot alkali treatment and stepwise electrochemical deposition. Materialistic characterization and electrochemical performance tests demonstrated that the titanium electrodes modified with collagen/polypyrrole composite coatings exhibited the surface morphology of a collagen film layer, and their electroactivity was significantly enhanced. Cellular experiments demonstrated that the collagen in the composite coatings could provide good biomimetic biochemical cues as a main extracellular matrix component, which have a substantial effect in promoting cell adhesion, proliferation, and osteogenic differentiation. Furthermore, under exogenous electrical signals, the polypyrrole coating has the capacity to facilitate an appropriate electrophysiological microenvironment, thereby promoting osteogenic differentiation. The collagen/polypyrrole composite coating exhibited a better effect in promoting osteogenic differentiation among all samples by simultaneously providing the appropriate biochemical cues and electrophysiological microenvironments. This work demonstrates the feasibility of synergistic pro-osteogenesis by biochemical cues and an electrophysiological microenvironment, which is instructive for the field of bone tissue engineering. Full article

If a method for developing organic polymer/apatite core–shell microspheres encapsulating organic polymer microspheres with apatite shells can be constructed, it is possible to establish a fundamental methodology to fabricate apatite capsules for drug delivery carriers. In this study, polystyrene (PS) microspheres were used as model substances in organic polymer microspheres, and the effects of the surface functional groups on the PS microspheres on the amount of Ca²⁺ ions introduced onto the PS microspheres were investigated. The PS/apatite core–shell microspheres were prepared by immersing Ca²⁺-incorporated PS microspheres in a reaction solution containing Ca²⁺, HPO₄²⁻, and Mg²⁺ to coat the surface of PS microspheres with apatite. Particle characterization of the prepared PS/apatite core–shell microspheres was performed, and the relationships among the surface functional groups, surface potential, Ca²⁺ adsorption, and apatite shell formation in the aqueous solution on the PS microspheres were investigated. Full article

Objective: To evaluate the color stability and microhardness of resin-based bioactive composites after brushing with over-the-counter whitening toothpastes. Methods: A conventional resin (Luna 2) and two bioactive resins (Stela Mix and Activa Presto) were tested. Four toothpastes were used: Colgate Fresh Gel (control), Colgate Max White, Yotuel, and Crest 3D White. Forty disks of each material were prepared and divided into four subgroups. The disks were brushed to simulate three months of daily brushing. Microhardness and color changes were measured before and after brushing. Color variation was calculated using the ΔE_ab, ΔE₀₀, and ΔWI_D indexes. Wilcoxon and two-way ANOVA tests were performed (p < 0.05). Results: In the Luna 2 and Stela groups, the b* parameter decreased significantly with all toothpastes (p < 0.05), while lightness and a* remained stable with no significant differences (p > 0.05). Stela Mix and Activa Presto exhibited color changes within the “moderately unacceptable” range according to ΔE₀₀ (>1.8 and ≤3.6). Based on the ΔWI_D index, Luna 2 showed the highest variation when treated with Colgate Max (2.14 ± 1.33) and the lowest in the control group (1.08 ± 0.56A), remaining within acceptable margins with all treatments. The microhardness values before/after treatment remained for Luna 2 between 77.44 and 76.97; for Stela Mix between 76.24 and 74.13; and for Activa presto between 74.5 and 71.33. Differences were not significant for any of the pastes within each composite (p > 0.05). Conclusions: The evaluated bioactive resins exhibited color changes within the moderately unacceptable range. Colgate Max White induced the most significant color changes. Microhardness was not affected by treatment with whitening toothpastes. Full article

One of the most interesting and poorly studied carriers of medicinal substances is the polymer clay composite material (PCCM). Bentonite clays are used in pharmacy for the manufacturing of various dosage forms, as well as in the adsorption of drugs to slow their release. Polymer–clay nanocomposites have demonstrated significantly improved properties compared to pure polymers. A review of recent scientific advances has shown promising results regarding the application of polymer–clay materials in medicine and bioengineering, particularly in the development of carrier sorbents with prolonged action for controlled drug release. As a result, interest in polymer–clay systems is steadily growing and gaining momentum. This paper focuses on the structure and properties of bentonite clays, including their sorption, ion exchange, binding, and rheological properties. The methods for preparing intercalated and exfoliated nanocomposites, such as radical intercalative polymerization in situ on clay surfaces, are reviewed. Furthermore, the improved efficacy and exposure times of PCCMs, combined with their enhanced bactericidal properties, are analyzed for the creation of universal and multifunctional preparations for medical use. Full article