Search Results (419)

The main goal of this work was to develop nanoparticles of lysozyme (Lys) for biological and biomedical applications. The developed biosystems were based on Lys-loaded calcium alginate 2% and chitosan 1% beads and films with different concentrations of each polymer. Encapsulation efficiency was 100%. The ratio of adsorbed Lys on the films, Lys activity, and the release profile of Lys were measured using water and buffer solution at pH similar to the environment of cancer cells, at a controlled temperature of 37 °C and a constant speed, to assess the efficacy of the encapsulation process. Lys antimicrobial activity was assessed using Micrococcus lysodeikticus. Moreover, the anti-inflammatory and antioxidant properties of the developed biosystems were also evaluated. The anti-inflammatory activity of Lys released from calcium alginate 2%-chitosan 1% beads loaded with Lys was about 99%. These findings highlight the potential of the developed beads and films for biomedical applications, particularly in antimicrobial and anti-inflammatory therapies. Full article

In this work, sodium alginate/chitosan (SA/CS) blend films were prepared by thermo-compression for the first time. Glycerol and lactic acid were used as de-structuring agents for SA and CS, respectively. The chemical structures, thermal stability, phase morphology, mechanical properties, water resistance, film opacity, film color, and soil burial test of thermo-compressed SA/CS films were investigated. The results indicate that intermolecular interactions in polyelectrolyte complexes in SA/CS blends were detected. Blending with CS improved the thermal stability of SA-based films. The SA/CS films showed excellent phase compatibility between SA and CS. The addition of CS improved the tensile properties of the SA-based films. The incorporation of CS in SA films resulted in enhanced water resistance and opacity and a decrease in biodegradability under soil burial. Thermo-compressed SA/CS films show promise for development and increased production capacity. These films can be tailored by varying the SA/CS ratios to display different properties. This versatility makes them suitable for a range of sustainable and diverse applications, including wound dressing, drug delivery, biosorbents, and packaging. Full article

The growing demand for biodegradable and functional packaging has driven research toward polysaccharide-based materials with improved performance. In this study, sodium alginate films were modified using natural deep eutectic solvents (NADES) and acorn polyphenolic extract to enhance their antimicrobial, mechanical, and thermal properties. The films were acquired by solvent casting and characterized through mechanical, spectroscopic, thermal, and microbiological analyses. Both NADES and the polyphenolic extract enhanced tensile strength and flexibility through additional hydrogen bonding within the alginate network, while the extract also introduced antioxidant functionality. Among all tested formulations, the A4E2 film exhibited the most balanced performance. FTIR spectra revealed hydrogen bonding between the film components, and thermogravimetric analysis showed an approximately 15 °C (F-EXT) and 20 °C (F-DES) shift in the main DTG degradation peak, indicating enhanced thermal stability. Controlled-release experiments demonstrated the gradual diffusion of phenolic compounds in aqueous, acidic, and fatty simulants, with an initial release phase within the first 6 h followed by sustained release up to 48 h, confirming the films’ suitability for various food environments. The combined modification reduced the growth of Escherichia coli and Staphylococcus aureus by 30–35%, with inhibition zone diameters reaching 27.52 ± 2.87 mm and 25.68 ± 1.52 mm, respectively, evidencing synergistic antimicrobial activity. These results highlight the potential of NADES- and extract-modified alginate films as sustainable materials for active food packaging applications. Full article

The use of natural antimicrobials and advanced sensor technologies is increasingly explored to improve the safety and quality of dairy products like cheese. The current work evaluated the effect of sodium alginate edible films enriched with oregano essential oil (EO) on the microbial spoilage of Feta cheese and the fate of Escherichia coli O157:H7 and Listeria monocytogenes during storage. Samples were inoculated with approximately a 4 log CFU/g of pathogens and subsequently wrapped with edible films containing EO or left without, serving as controls. Samples were stored under aerobic and vacuum conditions at 4 and 12 °C. Microbiological analyses, pH, and sensory attributes were monitored during storage, while multispectral imaging (MSI) devices were used for rapid, non-invasive quality assessment. EO films moderately suppressed spoilage and pathogen survival, particularly under aerobic conditions. The MSI spectral data coupled with machine learning models provided reasonable results for the estimation of yeast and mould populations, with the best models coming from aerobic conditions, from benchtop-MSI data, with R² = 0.726 and RMSE = 0.426 from the Neural Networks model, and R² = 0.661 and RMSE = 0.696 from the LARS model. The results highlight the combined potential of natural antimicrobial films and MSI-based sensors for extending Feta cheese shelf life and enabling rapid, non-destructive monitoring, respectively. Full article

When an orthokeratology (ortho-k) lens contacts the ocular surface, tear film components such as lipids and proteins rapidly adsorb onto the lens, which may increase friction and contribute to discomfort if not properly removed. Polysaccharides have been reported to reduce protein deposition and improve lubrication, prompting the investigation of alginate acid and lambda-carrageenan in modulating the tribological properties of ortho-k lenses. An in vitro tribological property analysis of ortho-k lenses and protein adsorption and desorption analyses were carried out to investigate the lubricating ability of alginate acid and carrageenan. Zeta potential and turbidity analyses were further conducted to examine potential interactions between polysaccharides and tear film proteins. Tear film proteins significantly increased the friction coefficient of the ortho-k lens, whereas the addition of alginate acid and carrageenan markedly reduced friction. Electrostatic interaction and polysaccharide–protein complex formation were identified as possible mechanisms underlying these effects. These results demonstrate that alginate acid and carrageenan can modify the tribological and interfacial behavior of ortho-k lenses in protein-rich environments, suggesting their potential application in reducing friction-related complications in ortho-k lens wearers. Full article

It is well known that food waste, especially perishable fruits, is one of the pressing issues worldwide, and as much as 50% of harvested fruits are wasted in developing countries as a result of poor preservation methods. Other traditional options such as plastic films or chemical preservatives are harmful to the environment and to our health. In this work, the limitations are overcome through the fabrication of an innovative camellia saponin/sodium alginate (CS/SA) composite hydrogel film that not only recycles agricultural waste but also improves fruit protection. CS/SA films were prepared by ionic crosslinking with CaCl₂ with different CS content (0–10% w/v, corresponding to 0–3.1 wt% in air-dried films). Detailed SEM, FTIR, XRD and rheological studies indicated that CS addition led to a gradual microstructural densification, stronger intermolecular interactions (involving hydrogen bonding and electrostatic complexation) and superior viscoelasticity, with the best performance at 8% CS (2.5 wt% in dried film). Mechanical tests confirmed that the stable CS/SA film showed higher tensile strength (152 kPa) and compressive strength (353 kPa) than pure SA (10 kPa) with a relatively low Young’s modulus (0.82 MPa) and high elongation at break (116.33%), which could be easily peeled off from fruit surfaces—an essential benefit of this over stiff chitosan/alginate composites. Structure: The composite film exhibited lower porosity (103.2%), reduced moisture content (94.7%), a controlled swelling ratio (800%) and improved barrier property with a water vapor permeability of 1.3 $\times {10}^{-6}$ g·m⁻¹·s⁻¹·kPa⁻¹ and an oxygen permeability of 1.9 × cm³$·\mathsf{\mu }$m·m⁻²·d⁻¹·kPa⁻¹. The 8% CS film showed very strong antioxidant activity (86% DPPH scavenging). Results of application tests on bananas and strawberries indicated that the ripening process was delayed by the CS/SA coatings, the decay rate was decreased from 99.9% (uncoated control) to 55.6% after 9 days, the weight loss was reduced to 29.3%, and the fruit’s firmness and titratable acidity were maintained. This degradable, multifunctional hydrogel film has the potential to be a sustainable measure to simultaneously mitigate food waste, valorize agricultural byproducts, and protect the environment, which could offer substantial benefit for enhancing global food security as well as fruit shelf life. Full article

Background: Wound healing is a typical biological process that the human body accomplishes through well-defined stages. The complexity of the healing process continues to be a significant health challenge. Multifunctional polymeric bilayer wound dressings have emerged as a new treatment option, as they resemble the bilayer structure of skin. Methods: Here, we developed a bilayer film with two distinct features, i.e., a primary sodium alginate (Na-Alg)-based sustained release layer incorporated with bergamot essential oil (BEO) and a secondary immediate release layer of hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl cellulose (HEC) loaded with the antibacterial drug ofloxacin (OFX). Using the double solvent casting technique. Results: The resultant bilayer films exhibited good folding endurance and swelling capability. The antibacterial potential was appraised by assessing their capability to hinder the growth of S. aureus (40 mm zone of inhibition) and E. coli (46 mm zone of inhibition). A DPPH assay confirmed the anti-oxidant ability of the incorporated essential oil. The outcomes of the X-ray diffraction and FTIR analysis support the even and complete dispersion of the oil and drug into the polymeric matrix without any unwanted interaction. The SEM results revealed a slightly microstructured surface view, while microporous structures were discovered in the cross-section due to the presence of the oil and drug. In the in vivo wound model, the developed bilayer films demonstrated a quicker rate of wound closure (98.5% in 12 days) and avoided wound infection. Histological studies verified that the created dressing enhanced the deposition of mature collagen and promoted epithelialization. Conclusions: As a result, the unique blend of anti-inflammatory and antibacterial properties in bilayer films can significantly offer fresh perspectives for developing sophisticated, multipurpose wound dressings to hasten the healing of cutaneous wounds. Full article

Background/Objectives: Regardless of the underlying cause, wound infections are among the most common complications associated with wound formation. The increasing prevalence of antibiotic resistance poses significant challenges in wound management. Due to their favorable therapeutic properties, alginate films have recently emerged as promising biomaterials for wound treatment. Methods: The petroleum ether, chloroform, and methanol extracts of the endemic plant Stachys rupestris were prepared using the maceration technique. The antimicrobial activity of the extracts and the extract-loaded alginate film was evaluated by agar well diffusion and microdilution assays, while their antibiofilm activity was assessed by crystal violet staining in microplates. The anti-infective potential was investigated using the Caenorhabditis elegans infection model, the phytochemical composition was analyzed by HPLC-DAD, and cytotoxicity was determined by the MTT assay. The alginate film was prepared by the solvent casting method and characterized using FTIR spectroscopy and light microscopy. Results: All extracts demonstrated antimicrobial activity, with the methanol extract exhibiting the most potent antimicrobial and antibiofilm effects. Quinic acid was identified as the major constituent. Both the methanol extract and the film displayed no cytotoxic effects and showed significant antimicrobial and antibiofilm activities. Conclusions: The S. rupestris methanol extract-loaded film exhibited strong antimicrobial and antibiofilm properties, indicating its potential as a valuable therapeutic agent in supporting wound healing. Full article

Pediatric drug delivery presents unique challenges due to physiological and pharmacological differences across age groups, requiring specialized formulation approaches beyond simple dose adjustments of adult medications. This review synthesizes recent advances in polysaccharide-based pediatric drug delivery and highlights novel findings that may accelerate clinical translation. It summarizes how chitosan, alginate, hyaluronic acid, dextran, modified starches, and other polysaccharides are engineered into nanoparticles, hydrogels, films, and orodispersible/mini-tablet formulations to improve stability, bioavailability, taste masking, and controlled release across neonates to adolescents. These systems can accommodate developmental variations in absorption, distribution, metabolism, and excretion processes across pediatric subpopulations, with particular emphasis on oral and alternative administration routes. Evidence supporting unexpectedly high acceptability of mini-tablets, successful integration of modified polysaccharides in 3D-printed personalized low-dose therapies, and the emergence of blood–brain barrier-penetrating and RGD-functionalized polysaccharide nanocarriers for pediatric oncology are emphasized as novel, clinically relevant trends. This review also addresses regulatory considerations, safety profiles, and future perspectives. By integrating developmental insights with innovative formulation strategies, polysaccharide polymers offer promising solutions to improve medication adherence, safety, and efficacy across the pediatric age spectrum. Full article

This study investigates the formation, physicochemical properties, and interfacial behavior of interpolyelectrolyte complexes (IPECs) composed of chitosan (CS) and sodium alginate (ALG) in aqueous media at pH 4.5. Using a combination of turbidity, ζ-potential, conductivity, and interfacial tension measurements, we explore how mixing protocols and solution composition influence complex formation and stability. The results reveal that while ζ-potential remains largely unaffected by polymer concentration, turbidity and interfacial tension exhibit strong dependence, particularly near the stoichiometric charge equivalence point (Z ≈ 1). These findings suggest that neutral complexes formed at Z ≈ 1 display enhanced aggregation and surface activity, especially when ALG is in excess. Additionally, we extend the study to layer-by-layer (LbL) films assembled from CS and ALG, monitored via Quartz Crystal Microbalance with dissipation (QCM-D). The films exhibit quasi-linear growth and increasing elastic modulus with layer number, indicating uniform deposition and strong interlayer interactions. The viscoelastic properties of the multilayers further confirm the structural integrity and potential applicability of these systems in surface engineering and encapsulation technologies. Overall, this work provides a comprehensive understanding of CS–ALG complexation from bulk to interfacial assemblies. Full article

This review investigates the potential of sodium alginate, a biobased polysaccharide from brown algae, for food packaging applications. It analyzes the main challenges of cast films, including water vapor permeability, mechanical performance, and processability, and evaluates strategies to enhance these properties without chemical modification. Chemical modification is excluded because it would classify alginate as a plastic under EU regulations (PPWR, SUPD), conflicting with plastic-free packaging. The review synthesizes literature from 2004 to 2025 on pure sodium alginate films that are plasticized and ionically crosslinked without additional modifiers or nanofillers. While alginate provides excellent oxygen and fat barriers, its high water vapor permeability and brittleness limit broader use. Ionic crosslinking improves strength and water resistance, yet non-uniform networks remain a key challenge. Film performance is also influenced by drying temperature, mixing speed, molecular weight, and protein incorporation. This review differs from previous studies by highlighting the coupled effects of plasticization, ionic crosslinking, and processing limitations that together determine alginate’s industrial feasibility. Research gaps concern long-term stability and behavior under industrial packaging conditions. Given environmental and regulatory pressures to replace fossil-based plastics, sodium alginate shows strong potential as a scalable, renewable material for sustainable food packaging. Full article

Sodium alginate, a natural anionic polysaccharide, exhibits broad potential applications in food, biomedicine, and environmental engineering due to its favorable biocompatibility, degradability, and functional tunability. This review systematically summarizes its chemical structure, physicochemical characteristics, sources, and extraction methods. It also focused on modification strategies, including chemical approaches (e.g., esterification, oxidation, sulfation, graft copolymerization), physical methods (composite modification, irradiation cross-linking, ultrasound treatment), and biological (e.g., enzyme regulation), and elucidated their underlying mechanisms. In the context of food science, special emphasis is placed on food-compatible chemistries and mild modification routes (such as phenolic crosslinking, enzyme-assisted coupling, and other green reactions) that enable the development of edible films, coatings, and functional carriers, while distinguishing these from non-food-oriented chemical strategies. The review further highlights novel applications of modified sodium alginate in areas including food packaging, functional delivery systems, drug release, tissue engineering, and environmental remediation (heavy metal and dye removal). Overall, this work provides a comprehensive perspective linking modification pathways to food-relevant applications and clarifies how chemical tailoring of alginate contributes to the design of safe, sustainable, and high-performance bio-based materials. Full article

Food packaging serves a pivotal role in daily life, facilitating the efficient transportation of food and extending its shelf life. Petroleum-derived plastic packaging is extensively employed; however, its non-biodegradable nature poses significant environmental pollution and ecological degradation. Natural polymers (e.g., proteins such as gelatin and corn gluten protein; polysaccharides including pectin, chitosan, starch, cellulose, and alginate) and synthetic polymers (e.g., polyvinyl alcohol, polylactic acid, and polyhydroxyalkanoates) can be utilized to fabricate food packaging films, thereby achieving green and eco-friendly objectives. Nevertheless, the inferior mechanical strength and inadequate antibacterial activity of biopolymer-based packaging have restricted their practical applications. In recent years, nanomaterials (e.g., nanoparticles, nanotubes, nanofibers, and nanosheets) have been employed to enhance the performance of food packaging, emerging as a research hotspot. Notably, nanoparticles possess unique properties, including a high specific surface area, excellent dispersibility, and multifunctionality, which enables them to be easily incorporated into film matrices. Owing to their unique chemical structures, nanoparticles form strong interactions with film matrices, leading to a denser spatial structure. This not only markedly enhances the mechanical strength of the films, but also simultaneously improves their antibacterial and antioxidant capabilities. This review classifies and summarizes common nanomaterials based on their chemical compositions, providing a theoretical foundation and technical reference for the future development and application of nanomaterials in the field of bio-based active food packaging. Full article

Lung cancer remains one of the deadliest cancers worldwide, which highlights the urgent need for new diagnostic tools to detect reliable biomarkers. To enable scalable and cost-effective production, we developed reusable PDMS stamps patterned with electrodes to print flexible electrodes on PET substrates using a microcontact printing (µCP) approach. PET was chosen not only for its flexibility but also as a more sustainable alternative to conventional rigid materials. On these electrodes, three sensing platforms were tested for neuron-specific enolase (NSE) detection: APTES-based monolayers, electrospun PVA/alginate nanofibers, and electropolymerized polypyrrole (PPy) films. Voltammetric and fluorescence/AFM analyses confirmed that all three platforms could recognize the target analyte, with the PPy-CdTe configuration showing the strongest signal variation. Impedance spectroscopy further supported this finding, revealing a clear linear correlation between charge transfer resistance (RCT) and NSE concentration. The PPy-CdTe sensor demonstrated high sensitivity and consistent performance for NSE detection, achieving a detection limit (LOD) of 8.05 pg·µL⁻¹ and a quantification limit (LOQ) of 26.84 pg·µL⁻¹. Full article

Chronic wounds (CWs) represent a growing global health concern with profound clinical and socioeconomic implications. Studies indicate that approximately 15% of CWs remain unhealed one year after the initial treatment. At the same time, it is assumed that from 1% to 2% of the population of developed countries will suffer from chronic wounds during their lifetime. CWs severely impair patients’ quality of life. Current therapies (compression bandages, antibiotics, hyperbaric oxygen, and skin grafts) face limitations, including toxicity, contraindications, inefficacy in patients with comorbidities like diabetes, and high cost. Biological nanoparticles (BNPs), particularly extracellular vesicles (EVs), emerge as transformative solutions due to their innate biocompatibility, targeted biodistribution, and multifunctional regenerative properties. This review examines the mechanisms by which BNPs promote CW healing and drug delivery. Innovative BNP delivery platforms (chitosan hydrogels, alginate films) are evaluated, enabling sustained release and responsiveness to the wound microenvironment. Clinical advances, including exosome-laden hydrogels that accelerate healing in diabetic ulcers, underscore BNPs’ potential to overcome conventional therapy limitations. By addressing the challenges of both pathophysiological complexity and healthcare system burden, BNPs demonstrate the potential to improve patient outcomes in the management of chronic wounds. Full article