Macromolecular engineering of self-standing chitin/montmorillonite nanocomposite films with enhanced mechanical, thermal, antimicrobial, and antibiofilm performance

Barium Crosslinking in Bio‐Based Sodium Alginate Films: Improved Barrier and Thermal Performance Toward Biodegradable Packaging Applications

Growing environmental concerns associated with petroleum‐based plastics have intensified the demand for sustainable, biodegradable materials for packaging applications. Sodium alginate is a natural polysaccharide with excellent biodegradability, biocompatibility, and film‐forming ability; however, its high moisture sensitivity and moderate thermal stability limit its application. In this study, sodium alginate films were produced by solvent casting and ionically cross‐linked with BaCl 2 solutions at concentrations of 1%, 2%, and 5% (w/v) to evaluate the influence of Ba 2+ on their structural, barrier, and thermal properties. The films were characterized by SEM/EDS, FTIR‐ATR, TGA, and measurements of water vapor absorption, swelling, and mass loss. Cross‐linking promoted denser polymer networks, reducing water vapor absorption from 20% ± 0.55% to 10.5% ± 0.56% at 75% relative humidity, while swelling decreased from 40% ± 2.5% to 29% ± 0.9% after 400 min. TGA indicated improved thermal stability, and mass loss after 24 h in water ranged from 11% to 13%. SEM revealed a more compact morphology with crystalline deposits, while FTIR confirmed ionic interactions between alginate carboxylate groups and Ba 2+ ions. Overall, Ba 2+ cross‐linking significantly improved the physicochemical, barrier, and thermal properties of sodium alginate films, highlighting their potential as biodegradable packaging materials.

Waterborne Interfacial-Reinforcement Strategy for Sustainable Natural Rubber Latex Bioelastomers With Self-Healing, Crack Tolerance, and Multifunctional Durability.

Developing bio-based elastomers that combine mechanical robustness, crack tolerance, self-healing, and functional durability remains challenging. Here, we report a waterborne interfacial reinforcement and functionalization strategy to construct multifunctional natural rubber latex (NRL)-based bioelastomers. Ammonium persulfate (APS)-assisted treatment promotes interfacial coupling between NRL chains and cellulose nanofibers (CNFs), establishing nanofiber-mediated load-transfer and energy-dissipation pathways. ZnO nanoparticles introduce inorganic physical junctions that regulate interfacial stress transfer while providing UV shielding and antibacterial activity. The optimized NRL-g-CNF/ZnO composite exhibits a tensile strength of 9.68 MPa, toughness of 15.30 MJ·m-3, and efficient room-temperature self-healing, with tensile strength and toughness recovery of 96.9% and 92.8% after 48 h, respectively. The composite also shows pronounced crack tolerance, including a fracture energy of 32.5 kJ·m-2 and stable deformation of notched samples, together with improved short-term mechanical retention under the specified UV-aging conditions, antibacterial activity, a measurable soil-burial response, and preliminary cytocompatibility. This simple casting-based strategy provides a potentially scalable route to multifunctional bioelastomers with potential for selected packaging applications, protective coatings, antibacterial/UV-shielding films, and non-implantable flexible materials.

Zeolite-Reinforced PVA/Chitosan/Hyaluronic Acid Composite Films as Biocompatible Tissue Patches.

Tissue patches are biomaterial-based structures designed to support the repair of damaged or functionally impaired tissues and are required to exhibit biocompatibility, mechanical integrity, and suitable surface characteristics. In this study, poly(vinyl alcohol) (PVA), chitosan (Chi), and hyaluronic acid (HA)-based composite films reinforced with zeolite (0-0.5% w/v) were developed and evaluated as potential tissue patch materials. The incorporation of zeolite significantly influenced the physicochemical and mechanical properties of the films. The elastic modulus decreased from 293.78 ± 64.47 N/mm2 for the zeolite-free film to 106.21 ± 9.50 N/mm2 at the highest zeolite content, indicating tunable flexibility. Water contact angle values increased from 46.09° to 67.23°, while maintaining overall hydrophilicity. The films exhibited rapid swelling behavior, reaching equilibrium within 30 min, and demonstrated controlled biodegradation with mass losses exceeding 75% after 42 days. Biological evaluations showed that all formulations maintained cell viability above 70%, with values ranging from 87.26% to 78.63%, and supported cell adhesion, confirming their biocompatible nature. The novelty of this study lies in demonstrating that low-concentration zeolite incorporation enables controlled tuning of mechanical, surface, and biological properties within a single PVA-Chi-HA system, without compromising biocompatibility. These findings highlight the potential of zeolite-reinforced composite films as multifunctional and customizable tissue patch candidates for tissue engineering applications.

Mechanical and Antimicrobial Properties of Latex Films Modified with Silver and Hexagonal Boron Nitride Microheterogeneous Powders

Natural latex "Revultex LR" was successfully modified with two types of antimicrobial fillers: silver powder and hexagonal boron nitride powder. The resulting composite films exhibited enhanced mechanical properties, excellent dispersion stability, and pronounced antimicrobial activity. Hexagonal boron nitride demonstrated a high specific surface area (27,5 m2/g) and a mesoporous structure --- features that likely promote stronger interactions with the polymer matrix and potentially enhance functional performance. In contrast, silver powder exhibited a low specific surface area (2 m2/g) and was essentially non-porous. Zeta potential measurements of the filler dispersions ranged from --42,6 to --60,5 mV, indicating high electrostatic stability across all modified systems. Fourier-transform infrared (FTIR) spectroscopy revealed no new absorption peaks in the spectra of the composite films, suggesting that the incorporation of fillers did not induce chemical reactions between the powders and the primary components of the latex. The tensile strength of the composite films varied between 19,3 and 35 MPa. Antimicrobial testing showed selective activity: both fillers were most effective against Gram-positive bacteria ("Staphylococcus aureus"), while exhibiting reduced efficacy against Gram-negative bacteria ("Escherichia coli") and yeast-like fungi ("Candida albicans").

Hybrid kraft lignin-copper oxide nanoparticles as functional additives in natural rubber membranes for biomedical applications.

Lignin‑copper oxide hybrid nanoparticles (LNCuNPs) were synthesized via in situ reduction and incorporated into natural rubber latex (NR) membranes ate concentration from 1 to 4% wt% to develop bioactive biocomposites for wound dressing applications. Among the evaluated systems, LNCuNPs exhibited superior colloidal stability, lower polydispersity, and a narrower size distribution compared with the control CuONP systems. Structural analyses confirmed the successful physical incorporation of nanohybrids into the NR matrix, with no evidence of covalent interactions or significant alterations in thermal stability. The presence of LN-derived oxygen-containing groups increased surface polarity and modulated membrane wettability. Mechanically, LNCuNPs increased Young's modulus and reduced elongation at break, consistent with the typical reinforcement effect induced by particulate fillers and the reduced extensibility associated with particle-matrix interfacial constraints and/or the formation of rigid filler domains at higher loadings. The membranes demonstrated notable antimicrobial activity against Staphylococcus aureus. Biological evaluation using L929 fibroblasts demonstrated high cytocompatibility across all formulations. Scratch assays reveal enhanced cell migration and near-complete wound closure after 48 h for membranes containing 1% and 2 wt% LNCuNPs, whereas membranes containing 4 wt% LNCuNP exhibited reduced migratory performance. Overall, the controlled incorporation of LNCuNPs into NR resulted mechanically reinforced, cytocompatibility membranes with antimicrobial activity, and promising potential for sustainable wound dressings for tissue repair.

Smart Multifunctional Biocomposite Films from Tamarind Seed Starch/Cotton Waste Fibre, and Butterfly Pea (Clitoria ternatea) for Sustainable Food Packaging