Search Results (319)

In this study, multifunctional nanocomposite membranes were fabricated using biopolymeric polylactic acid (PLA) and cellulose acetate (CA) composites via electrospinning. The hydrophobic nanocomposite membranes were reinforced with varying concentrations of silicon dioxide (silica/SiO₂) nanoparticles. The developed PLA–CA–SiO₂ nanofibrous membranes are characterized using field emission scanning electron microscopy (FE- energy-dispersive SEM), energy-dispersive X-ray (EDX), elemental mapping, X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT–IR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. Various physical and mechanical properties of the bio-nanocomposite membrane, such as tensile testing, infrared thermal imaging, ultraviolet–visible spectroscopy (UV–Vis), water contact angle, hydrostatic pressure resistance, and breathability are also investigated. The analysis revealed that a small concentration of silica nanoparticles improves the morphological, mechanical, and thermal characteristics of nanocomposite membranes. The addition of silica nanoparticles improves the UV (A & B), visible and infrared blocking efficiency while also enhancing the waterproofness of protective textiles. The PLA–CA–SiO₂ biopolymer nanocomposite membrane has a fibrous microstructure and demonstrated the tensile strength of 11.2 MPa, a Young’s modulus of 329 MPa, an elongation at break of 98.5%, a hydrostatic pressure resistance of 27 kPa, and a water contact angle of 143.7°. The developed electrospun composite membranes with improved properties provide strong potential to replace petroleum-based membranes with biopolymer-based alternatives, promising improved and wider usage for bio-related applications. Full article

Biomaterials modified by antibacterial substances, including nanoparticles, open new opportunities for the effective treatment of infected wounds. Unfortunately, most publications focused only on experiments in vitro, with limited understanding of their potential for the clinic. This study evaluates the effectiveness in vivo of electrospun chitosan/polylactic acid (Ch/PLA) membranes enriched with silver nanoparticles (AgNPs) for purulent wound treatment. The composite biomaterial integrates chitosan’s biocompatibility and antimicrobial activity with PLA’s structural integrity, while AgNPs enhance antibacterial efficacy against major wound pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia aureus. A full-thickness purulent wound model was established in a rat model, and the animals were divided into three treatment groups: (i) Ch/PLA, (ii) Ch/PLA-AgNPs, and (iii) PLA-chlorhexidine (control). Wound healing was monitored over 21 days through macroscopic evaluation, histology, immunohistochemistry, and microbiological analysis. The Ch/PLA-AgNPs membranes significantly reduced bacterial colonization within 4–6 days, promoted granulation tissue formation, and accelerated epithelialization compared to the non-modified Ch/PLA scaffold. By day 15, complete wound closure was observed in the Ch/PLA-AgNPs group, comparable to PLA-chlorhexidine-treated wounds. Immunohistochemical analysis revealed a controlled inflammatory response with a balanced macrophage M1/M2 transition, supporting efficient tissue regeneration. Furthermore, systemic toxicity assessments indicated no significant adverse effects on internal organs. These findings demonstrate that electrospun Ch/PLA-AgNPs membranes effectively accelerate purulent wound healing by combining antimicrobial protection with biocompatible tissue support. This innovative approach presents a promising alternative to conventional wound dressings and paves the way for clinical applications in managing infected wounds. Full article

Electrospun nanofibrous membranes have gained considerable attention in bone tissue engineering due to their ability to mimic the extracellular matrix and provide a suitable environment for cell attachment and proliferation. This study investigates the fabrication, characterization, and biocompatibility of poly(L-lactic acid) (PLA)-based membranes enhanced with periclase (MgO) and gold nanoparticles (AuNPs). The membranes were fabricated using an optimized electrospinning process and subsequently characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), and contact angle measurements. Additionally, in vitro biodegradation studies in simulated body fluid (SBF) and cytocompatibility tests with osteoblast-like cells were conducted. The results demonstrated that the incorporation of MgO and AuNPs significantly influenced the structural and chemical properties of the membranes, improving their wettability and bioactivity. SEM imaging confirmed uniform fiber morphology with well-distributed nanoparticles. FT-IR spectroscopy indicated successful integration of bioactive components into the PLA matrix. Cytocompatibility assays showed that modified membranes promoted higher osteoblast adhesion and proliferation compared to pristine PLA membranes. Furthermore, biodegradation studies revealed a controlled degradation rate suitable for guided bone regeneration applications. These findings suggest that electrospun PLA membranes enriched with MgO and AuNPs present a promising biomaterial for GBR applications, offering improved bioactivity, mechanical stability, and biocompatibility. Full article

The growing demand for sustainable materials has led to increased interest in biodegradable polymer fibers and nonwoven mats due to their eco-friendly characteristics and potential to reduce plastic pollution. This review highlights how mechanical properties influence the performance and suitability of biodegradable polymer fibers across diverse applications. This covers synthetic polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), polycaprolactone (PCL), polyglycolic acid (PGA), and polyvinyl alcohol (PVA), as well as natural polymers including chitosan, collagen, cellulose, alginate, silk fibroin, and starch-based polymers. A range of fiber production methods is discussed, including electrospinning, centrifugal spinning, spunbonding, melt blowing, melt spinning, and wet spinning, with attention to how each technique influences tensile strength, elongation, and modulus. The review also addresses advances in composite fibers, nanoparticle incorporation, crosslinking methods, and post-processing strategies that improve mechanical behavior. In addition, mechanical testing techniques such as tensile test machine, atomic force microscopy, and dynamic mechanical analysis are examined to show how fabrication parameters influence fiber performance. This review examines the mechanical performance of biodegradable polymer fibers and fibrous mats, emphasizing their potential as sustainable alternatives to conventional materials in applications such as tissue engineering, drug delivery, medical implants, wound dressings, packaging, and filtration. Full article

The development of biodegradable nanocarriers has long been a priority for researchers and medical professionals in the realm of drug delivery. Because of their inherent benefits, which include superior biocompatibility, customizable degradability, easy surface functionalization, and stealth-like behavior, polylactic acid-hyperbranched polyglycerol (PLA-HPG) copolymers have demonstrated a promising future in the field of biomedical research. The synthesis of PLA-HPG copolymers and the creation of their nanoparticles for biomedical uses have been the focus of current efforts. In this review, we summarize the synthetic strategies of PLA-HPG copolymers and corresponding nanoparticles, and highlight their physicochemical properties, biocompatibility, and degradation properties. Furthermore, we introduce a number of PLA-HPG nanoparticles that are utilized for surface skin delivery, wound dressing, and in vivo drug delivery biological applications. Finally, we conclude by offering our thoughts on how this nanoplatform might advance in the future. Full article

Biosensors play a central role in the early detection of abnormal glucose levels in individuals with diabetes; therefore, the development of less invasive systems is essential. Herein, a 3D-printed colorimetric biosensor combining microneedles and chitosan nanoparticles was developed for glucose detection in sweat using machine learning. Briefly, hollow 3D-printed polylactic acid microneedles were constructed and loaded with chitosan nanoparticles encapsulating glucose oxidase, horseradish peroxidase, and the chromogenic substrate 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), resulting in the formation of the chitosan nanoparticle−microneedle patches. Glucose detection was performed colorimetrically by first incubating the chitosan nanoparticle−microneedle patches with glucose samples of varying concentrations and then by using photographs of the top side of each microneedle and a color recognition application on a smartphone. The Random Sample Consensus algorithm was used to train a simple linear regression model to predict glucose concentrations in unknown samples. The developed biosensor system exhibited a good linear response range toward glucose (0.025−0.375 mM), a low limit of detection (0.023 mM), a limit of quantification (0.078 mM), high specificity, and recovery rates ranging between 86–112%. Lastly, the biosensor was applied to glucose detection in spiked artificial sweat samples, confirming the potential of the proposed methodology for glucose detection in real samples. Full article

Background: Ophidism is a globally neglected health problem. In Argentina, Crotalus durissus terrificus (C.d.t., South American rattlesnake) is one of the species of greatest medical importance since its venom contains mainly crotoxin (CTX), a potent enzyme–toxin with PLA₂ activity, which is responsible for its high lethality. Objective: In this work, we aimed to generate nanovenoms (NVs), complexes formed by CTX adsorbed onto 150 nm silica nanoparticles (SiNPs), and to study their physicochemical, biological, and immunomodulatory activities for potential use as adjuvants (ADJs) in antivenom (AV) production. Methods: CTX was isolated and corroborated by SDS-PAGE. Then, CTX was adsorbed on the synthetized Stöber SiNPs’ surfaces, forming a monolayer and retaining its biological activity (as observed by the MTT cell proliferation assay using the THP-1 cell line). Results: Immunomodulatory activity revealed a high pro-inflammatory (IL-1β) response induced by SiNPs followed by NVs. In the case of the anti-inflammatory response, NVs presented significant differences for TGF-β only after cell activation with LPS. No significant differences were observed in IL-10 levels. Conclusions: Thus, these results suggest that NVs together with SiNPs could increase immunogenicity and enhance immune response, turning them into potential tools for the generation of new antivenoms. Full article

The effective healing of chronic wounds requires balancing antimicrobial activity with tissue regeneration. In this study, we developed a novel, eco-friendly synthesis method using Artemisia argyi extract to produce silver nanoparticles (AgNPs), addressing toxicity concerns associated with conventional chemical synthesis methods. Through optimization of multiple synthesis parameters, monodisperse spherical AgNPs with an average diameter of 6.76 ± 0.27 nm were successfully obtained. Plant-derived compounds from Artemisia argyi extract acted as efficient mediators for both reduction and stabilization, yielding nanoparticles with high crystallinity. The synthesized AgNPs exhibited potent antibacterial activity against both Gram-negative and Gram-positive bacteria, with minimum inhibitory concentrations of 8 μg/mL against Escherichia coli and 32 μg/mL against Staphylococcus aureus, while maintaining high biocompatibility with L929 fibroblasts at concentrations ≤ 8 μg/mL. When integrated into polylactic acid/collagen type I (PLA/Col1) nanofibrous matrices, the optimized 0.03% AgNPs/PLA/Col1 dressing significantly accelerated wound healing in a diabetic rat model, achieving 94.62 ± 2.64% wound closure by day 14 compared to 65.81 ± 1.80% observed in untreated controls. Histological analyses revealed a dual-functional mechanism wherein controlled silver ion release provided sustained antibacterial protection, while concurrently promoting tissue regeneration characterized by enhanced collagen deposition, reduced inflammation, and increased neovascularization. This innovative approach effectively addresses critical challenges in diabetic wound care by providing simultaneous antimicrobial and regenerative functions within a single biomaterial platform. Full article

Wound healing is a complex biological process that benefits from advanced biomaterials capable of modulating inflammation and promoting tissue regeneration. In this study, cerium oxide nanoparticles (CeO₂NPs) were green-synthesized using Hemerocallis citrina extract, which served as both a reducing and stabilizing agent. The CeO₂NPs exhibited a spherical morphology, a face-centered cubic crystalline structure, and an average size of 9.39 nm, as confirmed by UV-Vis spectroscopy, FTIR, XRD, and TEM analyses. These nanoparticles demonstrated no cytotoxicity and promoted fibroblast migration, while significantly suppressing the production of inflammatory mediators (TNF-α, IL-6, iNOS, NO, and ROS) in LPS-stimulated RAW264.7 macrophages. Gene expression analysis indicated M2 macrophage polarization, with upregulation of Arg-1, IL-10, IL-4, and TGF-β. Aligned polycaprolactone/polylactic acid (PCL/PLA) nanofibers embedded with CeO₂NPs were fabricated using electrospinning. The composite nanofibers exhibited desirable physicochemical properties, including porosity, mechanical strength, swelling behavior, and sustained cerium ions release. In a rat full-thickness wound model, the CeO₂ nanofiber-treated group showed a 22% enhancement in wound closure compared to the control on day 11. Histological evaluation revealed reduced inflammation, enhanced granulation tissue, neovascularization, and increased collagen deposition. These results highlight the therapeutic potential of CeO₂-incorporated nanofiber scaffolds for accelerated wound repair and inflammation modulation. Full article

This study aimed to design dual-responsive chitosan–polylactic acid nanosystems (PLA@CS NPs) for controlled and targeted ledipasvir (LED) delivery to HepG2 liver cancer cells, thereby reducing the systemic toxicity and improving the therapeutic selectivity. Two formulations were developed utilizing ionotropic gelation and w/o/w emulsion techniques: LED@CS NPs with a size of 143 nm, a zeta potential of +43.5 mV, and a loading capacity of 44.1%, and LED-PLA@CS NPs measuring 394 nm, with a zeta potential of +33.3 mV and a loading capacity of 89.3%, with the latter demonstrating significant drug payload capacity. Since most drugs work through interaction with DNA, the in vitro affinity of DNA to LED and its encapsulated forms was assessed using stopped-flow and other approaches. They bind through multi-modal electrostatic and intercalative modes via two reversible processes: a fast complexation followed by a slow isomerization. The overall binding activation parameters for LED (cordination affinity, K_a = 128.4 M⁻¹, K_d = 7.8 × 10⁻³ M, ΔG = −12.02 kJ mol⁻¹), LED@CS NPs (K_a = 2131 M⁻¹, K_d = 0.47 × 10⁻³ M, ΔG = −18.98 kJ mol⁻¹) and LED-PLA@CS NPs (K_a = 22026 M⁻¹, K_d = 0.045 × 10⁻³ M, ΔG = −24.79 kJ mol⁻¹) were obtained with a reactivity ratio of 1/16/170 (LED/LED@CS NPs/LED-PLA@CS NPs). This indicates that encapsulation enhanced the interaction between the DNA and the LED-loaded nanoparticle systems, without changing the mechanism, and formed thermodynamically stable complexes. The drug release kinetics were assessed under tumor-mimetic conditions (pH 5.5, 10 mM GSH) and physiological settings (pH 7.4, 2 μM GSH). The LED@CS NPs and LED-PLA@CS NPs exhibited drug release rates of 88.0% and 73%, respectively, under dual stimuli over 50 h, exceeding the release rates observed under physiological conditions, which were 58% and 54%, thereby indicating that the LED@CS NPs and LED-PLA@CS NPs systems specifically target malignant tissue. Release regulated by Fickian diffusion facilitates tumor-specific payload delivery. Although encapsulation did not enhance the immediate cytotoxicity compared to free LED, as demonstrated by an in vitro cytotoxicity in HepG2 cancer cell lines, it significantly enhanced the therapeutic index (2.1-fold for LED-PLA@CS NPs) by protecting non-cancerous cells. Additionally, the nanoparticles demonstrated broad-spectrum antibacterial effects, suggesting efficacy in the prevention of chemotherapy-related infections. The dual-responsive LED-PLA@CS NPs allowed controlled tumor-targeted LED delivery with better selectivity and lower off-target toxicity, making LED-PLA@CS NPs interesting candidates for repurposing HCV treatments into safer cancer nanomedicines. Furthermore, this thorough analysis offers useful reference information for comprehending the interaction between drugs and DNA. Full article

The surface modification of zinc oxide nanoparticles (ZnONPs) with organic compounds has been shown to improve their dispersibility. In this study, to develop a highly functional material, ZnONP modified with 6-amino-1-hexanol bearing both amino and hydroxyl functional groups was synthesized. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analyses confirmed that functionalized ZnONP was successfully obtained by a hydrothermal synthetic method. The mechanical properties of composite films of polylactic acid (PLA) reinforced with the functionalized ZnONP were then evaluated. The composite containing functionalized ZnONP exhibited a higher maximum stress than that containing unmodified ZnONP. These ZnONP/polymer composites therefore show promise as novel high-performance materials. Full article

This study focused on composites of magnetite magnetic nanoparticles (MNP) and poly(lactic acid) (PLA) prepared via sonochemical synthesis. The evaluation of MNP loadings (2, 5, 10, 15, and 20 wt.%) provided insights into the structural and reactivity properties of the materials. Methods used included XRD, FT-IR and Raman spectroscopy, SEM and TEM microscopy, textural and thermal analysis (TG and DTA), and magnetic property measurements. The agreement between theoretical and experimental MNP loadings was good. XRD patterns showed predominantly MNP and semicrystalline phases, with a minor maghemite phase detected by FT-Raman and magnetic measurements. FT-IR analysis revealed interactions between MNP and PLA, confirmed by thermal analysis showing higher transition temperatures for the composites (145 °C) compared to pure PLA (139 °C). FT-Raman spectra also indicated that PLA helps prevent iron oxide oxidation, enhancing nanoparticle stability. SEM and TEM micrographs showed well-dispersed, spherical nanoparticles with minimal agglomeration, dependent on MNP loading. The nanocomposites exhibited low N₂ adsorption, resulting in low surface area (~2.1 m²/g) and porosity (~0.03 cm³/g). Magnetic analysis indicated that in the 2MNP/PLA sample, MNP were in a superparamagnetic-like regime at 300 K, suggesting good dispersion of 2 wt.% MNP in the PLA matrix. Full article

Placing printed conductive patterns onto nonplanar substrates is a challenging task. In this work, we tested a simple method for depositing inkjet-printed conductive patterns onto 3D-printed pieces with cavities and sharp edges. First, a silver nanoparticle ink was used to print conductive patterns onto a flexible and porous substrate made of electrospun polycaprolactone (PCL). Then, the printed patterns were transferred to 3D-printed pieces made of polylactic acid (PLA) by temperature-promoted adhesion. Finally, the printed patterns were cured to render them conductive. The influence of the number of printed layers on their electrical and mechanical properties was evaluated. The printed patterns were also transferred to flexible substrates, such as thermoplastic polyurethane (TPU) and polyethylene terephthalate (PET) sheets, achieving conductivity after curing. Moreover, the printed patterns were effective for modular interconnection among successive transferred patterns, since it was possible to achieve electrical contact between them during the transfer process. Full article

In recent years, coffee waste by-products have been incorporated into polymer blends to reduce environmental pollution. In this study, coffee parchment (CP) was incorporated into biodegradable polylactic acid (PLA) and poly (butylene adipate-co-terephthalate) (PBAT) polymer blends to prepare ribbons through the extrusion process. Extracted green coffee bean oil (CO) was used as a plasticizer, and CP was used as a filler with and without functionalization. A solution of chitosan nanoparticles (ChNp) as a coating was applied to the ribbons. For the raw material, proximal analysis of the CP showed cellulose and lignin contents of 53.09 ± 3.42% and 23.60 ± 1.74%, respectively. The morphology of the blends was observed via scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) showed an increase in the ribbons’ thermal stability with the functionalization. The results of differential scanning calorimetry (DSC) revealed better miscibility for the functionalized samples. The mechanical properties showed that with CP incorporation into the blends and with the ChNp coating, the Young’s modulus and the tensile strength decreased with no significant changes in the elongation at break. This work highlights the potential of reusing different by-products from the coffee industry, such as coffee oil from green beans and coffee parchment as a filler, and incorporating them into PLA PBAT biodegradable polymer blend ribbons with a nanostructured antimicrobial coating based on chitosan for future applications in food packaging. Full article

A nanostructured sensing platform was developed by integrating gold-decorated lignin nanoparticles (AuLNPs) into electrospun polylactic acid (PLA) fibre mats. The composite material combines the high surface-to-volume ratio of PLA nanofibres with the chemical functionality of lignin—a polyphenolic biopolymer rich in hydroxyl and aromatic groups—enabling selective interactions with volatile amines through hydrogen bonding and Van der Waals forces. The embedded gold nanoparticles (AuNPs) further enhance the sensor’s electrical conductivity and provide catalytic sites for improved analyte interaction. The sensor exhibited selective adsorption of amine vapours, showing particularly strong affinity for dimethylamine (DMA), with a limit of detection (LOD) of approximately 440 ppb. Relative humidity (RH) was found to significantly influence sensor performance by facilitating amine protonation, thus promoting interaction with the sensing surface. The developed sensor demonstrated excellent selectivity, sensitivity and reproducibility, highlighting its potential for real-time detection of amines in environmental monitoring, industrial safety and healthcare diagnostics. Full article