TL;DR
This work presents a feasible strategy for developing multifunctional PLLA-based materials, demonstrating promising potential for use in active food packaging, wound dressings, and antimicrobial textiles.
Objective The world is accelerating to find alternative antimicrobial materials due to the rapid development of antibiotic-resistant bacteria. Electrospinning of polymeric nanofibers can provide an attractive platform of developing bioactive surfaces with improved antibacterial functionality. Purpose: The research aimed to determine how the molecular weight of chitosan as well as the incorporation of nanocrystalline cellulose (NCC) affected the morphology and antibacterial activity of polylactic acid (PLA)-based electrospun nanofibers. Methods: Nanofibers were prepared through needle electrospinning method. The morphological properties of the prepared nanofibers were determined by the use of the scanning electron microscopy (SEM). PLA was blended with two molecular weights of chitosan (7.5kDa and 15 kDa) in 8.5wt% concentration with or without NCC in the concentration of 8.5 wt% as well. The ASTM E2149-13a dynamic contact method was used to assess the anti-bacterial action against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Results: Results showed that the low molecular weight chitosan (7.5 kDa) formed smooth and uniform nanofibers (average diameter =169-180 nm), and chitosan of high molecular weight (15 kDa) formed beads with less homogeneous structures. Formulations with chitosan showed good antibacterial properties with growth inhibition of most strains tested being complete or almost complete in 1 hour. When NCC was added, there was an improvement in the fiber morphology and an increase inits antibacterial activity, especially with the 7.5 kDa chitosan formulation, which is indicating a synergist effect. In comparison, PLA or PLA/NCC fibers in the absence of chitosan exhibited low or ineffective antibacterial activity. Conclusion: The optimized Cs/NCC/PLA nanofibers, especially the one that contained low molecular weight chitosan, had a smoother and more uniform nanofibers and high spectrum antibacterial activity. The combination of chitosan and NCC boosts surface activity and membrane disruption of bacteria, which points to the possibility of using these composite nanofibers in biomedical applications as wound dressings and antimicrobial coating.
Electrospun poly-based fibers functionalized with silver and gold nanoparticles demonstrated an excellent balance of safety, cytocompatibility, and antibacterial performance, making them promising candidates for biomedical applications that require both inflammation control and antimicrobial protection.
Poly(lipoic acid) (PLA) often suffers from poor stability in physiological environments and limited adhesion, which restricts its practical use. To address these issues, a multicomponent adhesive hydrogel was constructed by integrating sodium lipoate (LANa) and tannic acid (TA) into the system. LANa helps adjust the hydrophilicity of the network, while TA, with abundant phenolic groups, establishes extensive hydrogen-bonding interactions with the polydisulfide chains. These combined effects effectively inhibit disulfide bond cleavage and enhance the overall stability of the material. At the same time, the disruption of crystalline domains leads to a more amorphous structure, giving the hydrogel improved transparency, self-healing behavior, and resistance to repeated deformation. With the introduction of catechol/pyrogallol groups from TA, the hydrogel shows strong adhesion under wet conditions (up to 289 kPa on porcine skin) and can bond to a wide range of substrates. It also demonstrates notable biofunctionality, including efficient ROS scavenging (∼92%), high antibacterial activity (>98%), and low hemolysis (0.77%). In addition, the stable ionic conductivity and mechanical flexibility enable its use as a strain sensor for monitoring human motion. Overall, this study provides a feasible strategy for enhancing the stability and functionality of PLA-based hydrogels, suggesting their applicability in biomedical adhesives and flexible electronic devices.
Polylactide (PLA) is a biodegradable polymer with satisfactory mechanical properties but lacks antimicrobial activity. In this work, PLA fibers were functionalized with a cationic derivative of poly(itaconic acid) (PTTIBuI) and treated using supercritical carbon dioxide (scCO2). Electrospun PLA and PLA + PTTIBuI fibers were subjected to scCO2 treatment at 200 bar and 60 °C for 3 and 6 h and subsequently characterized. Surface analysis revealed wrinkling, crystallization, increased crystallinity, and reduced hydrophobicity after treatment. Antimicrobial testing showed that PLA + PTTIBuI fibers significantly inhibited biofilm formation, with stronger effects against Acinetobacter baumannii (50–60%) than against methicillin-resistant Staphylococcus aureus (43–55%). Long-term scCO2 exposure increased antibacterial activity, likely due to increased surface accessibility of cationic groups. These results demonstrate that the combination of poly(itaconic acid)-based antimicrobial agents with supercritical fluid treatment is an effective strategy for tailoring PLA fibers with improved antimicrobial activity. The modified materials show strong potential for biomedical applications such as wound dressings and infection prevention agents.
Bacterial cellulose (BC), a renewable biopolymer, has emerged as a promising substrate for membrane fabrication due to its biocompatibility and sustainability. However, the intrinsic heterogeneity in BC fiber distribution results in polydisperse inter-fiber voids, impeding its widespread application in membrane technologies. To mitigate the inherent surface roughness and microporosity of BC substrates, a chitosan-tannic acid interlayer with tunable hydrophilicity was engineered. This interfacial modification facilitated the subsequent formation of an ultrathin, highly cross-linked polyamide selective layer, minimizing defect density in the forward osmosis (FO) membrane. The fabricated FO membrane exhibited a sustained permeate flux (9.07 L·m-2·h-1) and superior draw solute rejection (>94%), alongside strong anti-fouling durability against bovine serum albumin (BSA) and sodium alginate (SA). Moreover, it demonstrated enhanced chemical stability under acidic and alkaline cleaning regimens. Quantitative assessment via Nile red fluorescence revealed a 63% reduction in microplastic release compared to conventional membranes. Particularly in the application to apple juice concentration, the BC-CS/TA3-PA FO membrane increased the contents of total phenols, total flavonoids, and vitamin C by factors of 5.81, 4.14, and 2.46, respectively, compared with thermal concentration, while effectively retaining antioxidant activity in the concentrate. This work provides a foundational framework for fabricating BC-based FO membranes, introduces an innovative approach to eco-friendly, sustainable membrane development, and demonstrates the high feasibility and industrial potential of this novel membrane for apple juice concentration.