Alginate fibers are attractive for biomedical applications because of their biocompatibility and mild ionic crosslinking. This study investigated the effects of alginate concentration, calcium chloride (CaCl₂) concentration, and coagulation time on fiber morphology and mechanical properties. Alginate solutions (6–10 wt%) were wet-spun through a 0.58 mm spinneret into CaCl₂ baths (0.5–3 wt%). Rheological analysis showed dominant viscous behavior (G″ > G′), ensuring stable extrusion without premature gelation. Fiber morphology was examined by optical microscopy and scanning electron microscopy, while mechanical properties were evaluated by tensile testing. Among the conditions investigated, 8 wt% alginate, 1 wt% CaCl₂, and 5 min coagulation provided smooth and homogeneous fibers with favorable mechanical performance. Higher CaCl₂ concentrations or longer coagulation times were associated with more heterogeneous fibrillar structures and, under some conditions, reduced mechanical performance. These results provide insights into process–structure–property relationships in wet-spun alginate fibers and identify favorable processing conditions among those investigated for producing flexible filaments with characteristics of interest for biomedical textile materials, including knitted wound dressings. Biomedical performance and biocompatibility were not evaluated in the present study.

This study investigates the structure–property relationships of multi-functional urethane acrylate resins designed as photoreactive binders for UV-curable nail coatings. Four systems were examined: a commercial resin urethane dimethacrylate (UDMA), a bio-based acrylated epoxidized soybean oil (AESO), and two newly synthesized bio-based urethane acrylates derived from 1,3-propanediol (PDO–UA) and eugenol (EUG–UA). Photopolymerization kinetics were analyzed by realtime FTIR, while the properties of the cured coatings were also determined. The mechanical and thermal behavior of selfsupporting polymer films was evaluated by tensile testing and DSC analysis. The UDMA network exhibited the highest crosslink density, reflected in its high modulus (≈0.5 GPa), tensile strength (≈15 MPa), and Tg (≈60°C), making it suitable for use as a top coat. AESO showed moderate stiffness and flexibility, whereas PDO–UA and EUG–UA formed soft, low-Tg (–12 and –17°C) and highly deformable networks typical of elastomeric materials. The combined mechanical and thermal results confirmed that crosslink density strongly governs coating performance and applicability. This study demonstrates that blending UDMA with bio-based oligomers enables the design of sustainable, UV-curable nail lacquers with an optimal balance of hardness, flexibility, and adhesion to the natural nail plate.

We report a green route to Ag–TiO₂ nanocomposites using an Allium tuberosum extract, rich in organosulfur and polyphenolic constituents, as a dual-function biogenic reducer and stabilizer, enabling efficient Ag⁺→Ag⁰ conversion and capping of Ag–TiO₂ without the use of harsh reagents. The nanocomposites are formulated into chitosan-based inks for direct ink writing (DIW) of porous, mechanically robust, reusable membranes (optimal formulation T@5Ag–5ATE–CS) with a homogeneous Ag dispersion. Multiscale characterization (SEM/TEM, XRD, FTIR, UV–vis DRS, EDS mapping) confirms metallic Ag⁰ uniformly decorating TiO₂ and an extended visible-light response attributable to strong localized surface plasmon resonance. Under near-UV/visible irradiation, the membranes decolorize Remazol Midnight Black RGB dye with pseudo-first-order kinetics, yielding k_app up to 5.99·10^–3 min^–1 with R² ≈ 0.99 and outperforming pristine TiO₂. Response surface methodology identifies an optimum at pH 5.67, 28.87 mg·L^–1 dye, and 0.0257 g catalyst, delivering a predicted 96.41% versus experimental 95.07% removal (validation error 1.39%) with excellent model statistics (R² ≈ 0.995). The combined effects of Allium-tuberosum-assisted Ag plasmonics, TiO₂ photocatalysis, and chitosan-enhanced adsorption underpin the high photocatalytic activity and reusability, highlighting a scalable, eco-friendly pathway to printable photocatalytic/antimicrobial membranes for wastewater treatment.

In recent decades, numerous efforts have been dedicated to the investigation of eco-friendly non-isocyanate polyurethanes (NIPUs) as alternatives to conventional polyurethanes (PUs). Since isocyanates are classified by the EU as hazardous and toxic compounds, NIPUs offer a promising route to mitigate isocyanate-related health risks as well as other environmental concerns associated with traditional PU synthesis. In the present study, we report the synthesis as well as the detailed structural and thermal characterization of a new series of fully biobased non-isocyanate polyurethanes (NIPUs) based on aliphatic dicarboxylic acids of different chain lengths. The NIPUs were prepared via a two-step polyaddition reaction involving glycerol carbonate and diamine. Their synthesis enables a sustainable pathway to tailor NIPUs’ physicochemical properties via diacid structure control. Studies of their structure, thermal behavior and trends, morphological, and hydrolytic findings confirmed strong diacid chain length dependence on glass transition temperature (T_g ~13, 0, ‒5 and –23 °C), molecular weight, surface wettability, and enzymatic degradability. Short-chain diacids yielded NIPUs with rapid hydrolytic degradation, while their longer-chain analogs were hydrophobic and thermally stable. Contact angle measurements (~75–85°) also confirm these trends. The tunable properties position these materials among strong candidates for biomedical applications.

This research presents an eco-friendly approach for extracting chitosan from shrimp shell waste through ultrasound-assisted extraction (UAE) to prepare biocompatible aerogel scaffolds for biomedical applications. The study investigates the influence of various ultrasonic treatment times (10, 20, 30, 40 min) on the yield and structural and physicochemical properties of the extracted chitosan via characterization using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Among the tested conditions, the 30 min UAE-treated chitosan aerogels showed optimal porosity and structural integrity. Biocompatibility of the aerogels was evaluated, and the results confirmed their non-cytotoxic nature. The bioactivity of the chitosan aerogels was evaluated in terms of their in vitro wound closure ability and antibacterial properties. The aerogels demonstrated a wound closure rate of around 51% after 72 h, significantly higher than the untreated control (37%). In addition, they exhibited clear antibacterial activity against Escherichia coli and Staphylococcus aureus. This sustainable extraction and fabrication method not only adds value to marine waste but also produces functional biomaterials with potential applications in wound healing, tissue engineering, and regenerative medicine, supporting global efforts toward sustainability and circular bioeconomy.