Search Results (564)

Background: The aim of this review is to summarize and evaluate the properties of antibacterial polysaccharides for application in dental implantology to identify knowledge gaps and provide new research ideas. Methods: The electronic databases PubMed, Medline, ProQuest, and Google Scholar were used to search for peer-reviewed scientific publications published between 2018 and 2025 that provide insights to answer research questions on the role of antibacterial polysaccharides in combating pathogens in dental implantology without triggering immune reactions and inflammation. Further research questions relate to the efficacy against various dental pathogens and the understanding of the antibacterial mechanism, which may enable the development of functionalized polysaccharides with long-term antibacterial activity. Results: Biomedical implants have revolutionized medicine but also increased the risk of infections. Implant infections are a major problem in implantology and lead to implant failure and replacement. An antibacterial coating could be an excellent strategy to extend the lifespan of implants and improve the quality of the patient’s life. Bacterial resistance to antibiotics poses significant challenges for researchers, forcing them to search for new ways to prevent bacterial infections in implantology. Antibacterial natural polymers have recently received considerable research attention due to their long-term antibacterial activity. Polysaccharides from marine sources, such as chitosan and alginate, or pectin, xanthan, etc., from various plants, appear to be promising biopolymers for such applications in implantology due to their antibacterial activity, biocompatibility, and osteogenic properties. The antibacterial activity of these natural biopolymers depends on their chemical and physical properties. Nanopolysaccharides exhibit higher antibacterial activity than conventional polysaccharides, but their toxicity to human cells must be considered. Their antibacterial activity is based on the disruption of bacterial DNA or RNA synthesis, increased cell wall permeability, membrane disruption, and cytoplasmic leakage. Conclusions: Polysaccharides are a class of natural polymers with a broad spectrum of biological activities. They exhibit antioxidant, immunomodulatory, anticoagulant, anticancer, anti-inflammatory, antibacterial, and antiviral activity. Furthermore, polysaccharides are non-cytotoxic and exhibit good biocompatibility with osteogenic cells. Bactericidal polysaccharides are attractive new antibacterial materials against implant infections and open up new perspectives in implantology. Full article

Methicillin-resistant Staphylococcus aureus (MRSA), a multidrug-resistant pathogen, poses a significant threat to global healthcare. This review evaluates the potential of marine algal metabolites as novel antibacterial agents against MRSA. We explore the clinical importance of S. aureus, the emergence of MRSA as a “superbug”, and its resistance mechanisms, including target modification, drug inactivation, efflux pumps, biofilm formation, and quorum sensing. The limitations of conventional antibiotics (e.g., β-lactams, vancomycin, macrolides) are discussed, alongside the promise of algal-derived compounds such as fatty acids, pigments, polysaccharides, terpenoids, and phenolic compounds. These metabolites exhibit potent anti-MRSA activity by disrupting cell division (via FtsZ inhibition), destabilizing membranes, and inhibiting protein synthesis and metabolic pathways, effectively countering multiple resistance mechanisms. Leveraging advances in algal biotechnology, this review highlights the untapped potential of marine algae to drive innovative, sustainable therapeutic strategies against antibiotic resistance. Full article

The marine seaweed Undaria pinnatifida belongs to the large group of brown macroalgae (Ochrophyta) and is valued both as a nutritious food and a source of pharmaceutical compounds. It has been widely consumed in East Asia as part of the traditional diet and is generally regarded as a “healthy longevity food.” Consequently, it represents one of the most promising natural sources of biomedicinal and bioactive products. This review aims to synthesize current scientific evidence on the pharmacologically active compounds of U. pinnatifida, emphasizing their mechanisms of action and therapeutic potential in neurodegenerative and chronic diseases. This narrative review is based on a comprehensive literature search of peer-reviewed articles from scientific databases, focusing on studies addressing the pharmacological properties of U. pinnatifida and its major bioactive constituents. Recent research highlights that compounds such as fucoxanthin (a carotenoid), fucosterol (a sterol), fucoidan (a polysaccharide), alginate, and dietary fiber found in U. pinnatifida possess significant potential for developing treatments for conditions including goitre, urinary diseases, scrofula, dropsy, stomach ailments, and hemorrhoids. Moreover, these compounds exhibit remarkable pharmacological properties, including immunomodulation, antitumor, antiviral, antioxidant, antidiabetic, anti-inflammatory, anticoagulant, antithrombotic, and antibacterial activities, all with low toxicity and minimal side effects. Additionally, U. pinnatifida shows promise in the treatment or prevention of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, as well as neuropsychiatric conditions like depression, supported by its antioxidant effects against oxidative stress and neuroprotective activities. Numerous in vitro and in vivo studies have confirmed that U. pinnatifida polysaccharides (UPPs), particularly fucoidans, exhibit significant biological activities. Thus, accumulating evidence positions UPPs as promising therapeutic agents for a variety of diseases. Full article

Marine biomass represents a valuable yet underexploited resource for the development of high-value biomaterials. Recent advances have highlighted the significant potential of marine-derived polysaccharides, proteins, and peptides in biomedical applications, most notably in drug delivery and wound healing. This review provides a comprehensive synthesis of current research on the extraction, processing and pharmaceutical valorization of these biopolymers, with a focus on their structural and functional properties that allow these materials to be engineered into nanocarriers, hydrogels, scaffolds, and smart composites. Key fabrication strategies such as ionic gelation, desolvation, and 3D bioprinting are critically examined for their role in drug encapsulation, release modulation, and scaffold design for regenerative therapies. The review also covers preclinical validation, scale-up challenges, and relevant regulatory frameworks, offering a practical roadmap from sustainable sourcing to clinical application. Special attention is given to emerging technologies, including stimuli-responsive biomaterials and biosensor-integrated wound dressings, as well as to the ethical and environmental implications of marine biopolymer sourcing. By integrating materials science, pharmaceutical technology and regulatory insight, this review aims to provide a multidisciplinary perspective for researchers and industrial stakeholders seeking sustainable and multifunctional pharmaceutical platforms for precision medicine and regenerative therapeutics. Full article

The growing demand for sustainable, functional ingredients in the food industry has driven interest in marine-derived biopolymers. Among marine sources, microalgae represent a promising yet underexplored reservoir of bioactive gel-forming compounds, particularly extracellular polysaccharides (EPSs), both sulfated and non-sulfated, as well as proteins that exhibit unique gelling, emulsifying, and stabilizing properties. This study focuses on microalgal species with demonstrated potential to produce viscoelastic, shear-thinning gels, making them suitable for applications in food stabilization, texture modification, and nutraceutical delivery. Recent advances in biotechnology and cultivation methods have improved access to high-value strains, which exhibit promising physicochemical properties for the development of novel food textures, structured formulations, and sustainable food packaging materials. Furthermore, these microalgae-derived gels offer additional health benefits, such as antioxidant and prebiotic activities, aligning with current trends toward functional foods containing prebiotic materials. Key challenges in large-scale production, including low EPS productivity, high processing costs, and lack of regulatory frameworks, are critically discussed. Despite these barriers, advances in cultivation technologies and biorefinery approaches offer new avenues for commercial application. Overall, microalgal gels hold significant promise as sustainable, multifunctional ingredients for clean-label food formulations. Full article

Oceans are increasingly viewed as a new frontier for economic development, contributing to the bridge between food industry, sea bioeconomy, and health. Nowadays, oceans are under attention as a strategy for creating opportunities and driving innovation, and their vital importance will become even more evident in the years to come. Therefore, it is crucial to study oceans under a holistic approach, taking the maximum value of their abundant resources in a sustainable way. As such, blue bioeconomy is the path forward, since it is a development strategy that meets the economic potential without compromising the environmental health. A special look needs to be taken at the underutilized resources and by-products, which hold unexploited value. For instance, green macroalgae are widespread marine macroalgae that lack industry applications, despite being rich in biopolymers (polysaccharides) and antioxidants. Moreover, fish by-products are also rich sources of biopolymers, mostly proteins. Thus, among other potential uses, raw materials could be explored to produce functional edible coatings under a blue bioeconomy approach. A detailed characterization of raw materials is the first step for the development of value-added products. These topics will be addressed in this review. Full article

Marine algae offer environmentally friendly platforms for green nanoparticle synthesis. This study reports the biosynthesis of silver nanoparticles using polysaccharides isolated from the brown alga Chnoospora minima (PAgNPs) and evaluates their therapeutic potential. Fourier Transform Infrared Spectroscopy (FTIR) confirmed algal polysaccharide functional groups. Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) analysis characterized the nanoparticles as spherical (~84 nm average size), stable (zeta potential −18.5 mV), and containing elemental silver without nitrogen. The PAgNPs exhibited potent antioxidant activity (~100% DPPH scavenging) and significant antimicrobial efficacy, particularly against Staphylococcus aureus and Candida species. Crucially, PAgNPs displayed potent antiproliferative activity against human lung cancer cells (A549, IC₅₀: 13.59 µg/mL). In contrast, toxicity to normal Vero cells was significantly lower (IC₅₀: 300.2 µg/mL), demonstrating notable cancer cell selectivity (SI 22.1). Moderate activity was observed against MCF-7 breast cancer cells (IC₅₀: 100.7 µg/mL). These results demonstrate that C. minima polysaccharide facilitates the synthesis of biocompatible AgNPs with promising antimicrobial and selective anticancer capabilities, highlighting their potential for further development as nanotherapeutics. Full article

The fast-disintegrating capsules rapidly disintegrate in various physiological environments, ensuring therapeutic efficacy. The formulation of plant-based capsules with balanced mechanical and fast disintegration characteristics continues to present technical challenges in pharmaceutical development. In this study, natural marine polysaccharides were utilized to achieve both rapid disintegration and excellent mechanical properties by combining κ-Carrageenan (κ-C) and ι-Carrageenan (ι-C). Additionally, the selection of KCl + NaCl mixed coagulants, along with the evaluation of their types, mass fractions, and ratios, enhanced the mechanical properties and transmittance of the capsules. FTIR analysis revealed that the membrane with a 5:5 κ-C/ι-C ratio formed hydrogen bonds, which were beneficial to its fast disintegration. SEM analysis revealed a dense microstructure in this formulation, contributing to its improved mechanical properties. Finally, this study hypothesizes that the disintegration behaviors of the capsules exhibited significant pH dependence, with ion exudation predominating in pH 1.2 and pH 7.0 media, while swelling dominated under pH 4.5 and pH 6.8 media. The prepared carrageenan blend-based capsules exhibited fast disintegration properties while maintaining excellent mechanical and barrier properties, thereby broadening the application of plant-based capsules in the field of medicine. Full article

Chronic pain affects approximately 20% of the global adult population, posing significant healthcare and economic challenges. Effective management requires addressing both biological and psychosocial factors, with emerging therapies such as antioxidants and marine algae offering promising new treatment avenues. Marine algae synthesize bioactive compounds, including polyphenols, carotenoids, and sulfated polysaccharides, which modulate oxidative stress, inflammation, and neuroimmune signaling pathways implicated in pain. Both preclinical and clinical studies support their potential application in treating inflammatory, neuropathic, muscular, and chronic pain conditions. Notable constituents include polyphenols, carotenoids (such as fucoxanthin), vitamins, minerals, and sulfated polysaccharides. These compounds modulate oxidative stress and inflammatory pathways, particularly by reducing reactive oxygen species (ROS) and downregulating cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Brown and red algae produce phlorotannins and fucoidans that alleviate pain and inflammation in preclinical models. Carotenoids like fucoxanthin demonstrate neuroprotective effects by influencing autophagy and inflammatory gene expression. Algal-derived vitamins (C and E) and minerals (magnesium, selenium, and zinc) contribute to immune regulation and pain modulation. Additionally, sulfated polysaccharides suppress microglial activation in the central nervous system (CNS). Marine algae represent a promising natural source of bioactive compounds with potential applications in pain management. Although current evidence, primarily derived from preclinical studies, indicates beneficial effects in various pain models, further research is necessary to confirm their efficacy, safety, and mechanisms in human populations. These findings advocate for the continued exploration of marine algae as complementary agents in future therapeutic strategies. Full article

As emerging contaminants increasingly detected in aquatic and terrestrial ecosystems, environmental estrogens (EEs) pose significant ecological risks to marine ecosystems, particularly affecting photosynthetic microorganisms occupying fundamental roles in marine food webs. This review summarizes the current knowledge on the toxicological effects of EEs in marine microalgae through a systematic analysis of dose-dependent physiological, biochemical, and molecular responses. Experimental evidence reveals a biphasic response pattern characterized by growth promotion and photosynthetic enhancement in microalgae under low-concentration EE exposure (0.1–10 μg/L), while marked inhibition of both growth and photosynthetic activity was observed at elevated EE concentrations (>50 μg/L). Notably, sustained EE exposure induces metabolic reprogramming, manifested through reduced protein and polysaccharide biosynthesis concurrent with accelerated lipid accumulation. Cellular stress responses include significant ultrastructural alterations such as chloroplast membrane disruption, cell wall thickening, and the formation of multicellular aggregates. The study further elucidates the concentration-dependent modulation of toxin metabolism, with sublethal doses stimulating intracellular microcystin synthesis (1.5–2.3-fold increase), while acute exposure triggers toxin release through membrane permeabilization. At molecular levels, transcriptomic analyses identify the up-regulation of heat shock proteins (HSP70/90) and the differential expression of genes governing cell cycle progression (cyclin-D), apoptotic pathways (caspase-3), photosynthetic electron transport (psbA), and oxidative stress responses (SOD, CAT). These findings demonstrate that EEs exert multilevel impacts on microalgal physiology through interference with fundamental metabolic processes, potentially disrupting marine primary productivity and biogeochemical cycles. The identified response mechanisms provide critical insights for environmental risk assessment and establish a conceptual framework for investigating estrogenic pollutant effects in aquatic ecosystems. Full article

Heparin, a widely used polysaccharidic anticoagulant of animal origin, is associated with risks of contamination and adverse effects, notably bleeding and thrombocytopenia. These limitations have prompted interest in alternative sulfated polysaccharides with anticoagulant properties and improved safety profiles. This study explored the anticoagulant potential of two marine bacterial exopolysaccharides (EPS), infernan and diabolican. It assessed whether chemical modifications (depolymerization, oversulfation) could enhance their anticoagulant properties compared to unfractionated and low molecular weight heparins. Native EPS were depolymerized to generate different molecular weights and then chemically oversulfated to increase negative charge density. Anticoagulant activities were evaluated using clotting and thrombin generation assays (TGA). Molecular docking was performed to model interactions with antithrombin and heparin cofactor II. Only highly sulfated derivatives significantly prolonged activated partial thromboplastin time while showing negligible effect on thrombin time and anti-factor Xa activity. They present different structures, and their binding to antithrombin is not achieved via the classic pentasaccharide motif. In TGA, these derivatives inhibited thrombin formation at higher doses than heparin but induced a marked delay in clot generation. Docking analyses supported their ability to bind serpins, albeit with lower specificity than heparin. Their limited anti-Xa activity and non-animal origin position them as promising anticoagulant candidates. Full article

This study systematically investigates for the first time the effects of dual-site co-cultivation on spectral characteristics and trace element enrichment in marine-cultured Akoya pearls from Beihai, China. Akoya pearls were cultured over a one-year period, with the final 40-day stage designated as the terminal phase. During this period, two experimental groups of pearl oysters were established: Group Y remained in Beihai for continued local cultivation and harvest, while Group B was transferred to Weihai, Shandong Province, for terminal-stage farming under different thermal conditions. A series of comparative analyses were performed using Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Raman spectroscopy, X-ray fluorescence (XRF), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The FTIR results revealed distinct differences between the two groups in the distribution of amide and polysaccharide functional groups, particularly around 1643 cm⁻¹ and 1100 cm⁻¹. The UV-Vis spectra of Group B displayed characteristic absorption bands at 430 nm and 460 nm, associated with the organic matrix of the nacre. Raman spectroscopy further indicated a higher abundance of organic-related vibrational features in Group B. Additionally, both XRF and LA-ICP-MS analyses consistently showed significant differences in the concentrations and distributions of trace elements, particularly copper (Cu), cobalt (Co), and zinc (Zn). The findings demonstrate that the dual-site co-cultivation mode significantly impacts both the organic composition and trace element enrichment patterns in seawater Akoya pearls. This research provides valuable references for optimizing environmental parameters in pearl cultivation processes. Full article

Alginate lyases are critical enzymes in hydrolyzing alginate into alginate oligosaccharides (AOS), which are bioactive compounds known for their antioxidant properties and ability to lower serum glucose and lipid concentrations. However, elucidating catalytic mechanisms and discovering enzymes with enhanced catalytic efficiency remain long-term challenges. Here, we report AlgL2491, a novel bifunctional and cold-adapted alginate lyase from Pseudoalteromonas carrageenovora ASY5, belonging to the polysaccharide lyase family 18. This enzyme uniquely cleaves both polyguluronic (polyG) and polymannuronic (polyM), predominantly releasing disaccharides, trisaccharides, and tetrasaccharides after 12 h of hydrolysis. The enzyme achieves peak catalytic efficiency at 35 °C and pH 7.5, with activity increasing 5.5-fold in 0.5 M of NaCl. Molecular dynamics simulations demonstrate that salt ions enhance structural stability by minimizing conformational fluctuations and strengthening interdomain interactions, providing mechanistic insights into its salt-activated behavior. The alginate oligosaccharides (AOS) exhibit excellent free radical-scavenging activities of 86.79 ± 0.31%, 83.42 ± 0.18%, and 71.28 ± 2.27% toward hydroxyl, ABTS, and DPPH radicals, with IC50 values of 8.8, 6.74, and 9.71 mg/mL, respectively. These findings not only reveal the salt-activation mechanism of AlgL2491 and highlight the potential value of its hydrolysate in antioxidant activity but also provide a sustainable industrial solution in industrial-scale AOS production directly from marine biomass, eliminating the need for energy-intensive desalination of alginate, which may inform future biocatalyst design for marine polysaccharide valorization. Full article

Skin health must be ensured at all times in the case of wounds when the skin is subjected to traumatic actions that require multiple wound-healing measures. Wound healing is a complex, multi-phase biological process critical for restoring skin integrity after trauma. This study investigates the development and evaluation of a novel composite hydrogel formulated from collagen peptides extracted from the jellyfish Rhizostoma pulmo and hydroethanolic extracts from the brown alga Cystoseira barbata, both sourced from the Romanian Black Sea coast. Throughout the work, the characteristics due to the biochemical compositions of the extracts from the brown alga C. barbata and from the jellyfish R. pulmo are highlighted as important, emphasizing the content of polysaccharides, proteins, and lipids. Total phenol content was analyzed for three extracts from natural products. The biochemical composition, antioxidant, antimicrobial, and in vitro wound-healing properties of the components and their composite (JPC-ALG) were assessed. The rheological behavior and optical microscopy studies of collagen hydrogels were prepared. The general mechanisms of wound healing with the involvement of polysaccharides and collagen peptides existing in all categories of extracts were highlighted. The study of the effects of JPC-ALG composites and individual extracts on fibroblast and keratocyte cell lines is also presented. Results demonstrated that the composite exhibited synergistic effects, enhancing fibroblast and keratinocyte migration and proliferation, key factors in wound closure. The findings support the potential application of this marine-derived bioactive composite as a promising biomaterial for wound-healing therapies. Full article

Algal polysaccharides are a kind of bioactive compound with diverse pharmacological applications, yet their structure–activity relationships and therapeutic potential in chronic disease management remain systematically underexplored. This review comprehensively analyzes the structural characteristics of brown, red, and green algal polysaccharides, revealing how specific structural features—such as glycosidic linkage patterns and sulfate group positioning—dictate their biological activities. We also demonstrated their multifaceted roles in diabetes, cancer, and cardiovascular diseases through distinct mechanisms, including gut microbiota modulation via short-chain fatty acid production, antioxidant enzyme activation, and targeted inhibition of pathological signaling pathways like mTOR and JAK-STAT3. The work further evaluates extraction methodologies, highlighting the advantages of emerging techniques such as enzyme-assisted and ultrasonic extraction for preserving bioactive integrity. By integrating fundamental research with practical applications in functional foods, this synthesis provides critical insights for harnessing algal polysaccharides in precision nutrition and sustainable biomedicine, while identifying key challenges in standardization and environmental safety that warrant future investigation. Full article