Marine organisms: Pioneer natural sources of polysaccharides/proteins for green synthesis of nanoparticles and their potential applications

Sustainability in the green engineering of nanocomposites based on marine-derived polysaccharides and collagens: A review

Nanocomposites are sophisticated materials that incorporate nanostructures into matrix materials, such as polymers, ceramics and metals. Generally, the marine ecosystem exhibits severe variability in terms of light, temperature, pressure, and nutrient status, forcing the marine organisms to develop variable, complex and unique chemical structures to boost their competitiveness and chances of survival. Polymers sourced from marine creatures, such as chitin, chitosan, alginate, sugars, proteins, and collagen play a crucial role in the bioengineering field, contributing significantly to the development of nanostructures like nanoparticles, nanocomposites, nanotubes, quantum dots, etc. These nanostructures offer a wide array of features involving mechanical strength, thermal stability, electrical conductivity, barrier and optical characteristics compared to traditional composites. Notably, marine nanocomposites have distinctive roles in a wide spectrum of applications, among them anti-cancer, anti-microbial, antioxidant, cytotoxic, food packing, tissue engineering and catalytic actions. Sol-gel, hot pressing, chemical vapor deposition, catalytic decomposition, dispersion, melt intercalation, in situ intercalative polymerization, high-energy ball milling and template synthesis are common processes utilized in engineering nanocomposites. According to our literature survey and the Web of Science, chitosan, followed by cellulose, chitin and MAPs emerge as the most significant marine polymers utilized in the construction of nanocomposites. Taken together, the current manuscript underscores the biogenesis of nanocomposites, employing marine polymers using eco-friendly processes. Furthermore, significant emphasis in this area is needed to fully explore their capabilities and potential benefits. To the best of our knowledge, this manuscript stands as the first comprehensive review that discusses the role of marine-derived polymers in engineering nanocomposites for various applications.

Comparative Study of Physicochemical Properties and Antibacterial Potential of Cyanobacteria Spirulina platensis-Derived and Chemically Synthesized Silver Nanoparticles

The "green synthesis" of nanoparticles (NPs) offers cost-effective and environmentally friendly advantages over chemical synthesis by utilizing biological sources such as bacteria, algae, fungi, or plants. In this context, cyanobacteria and their components are valuable sources to produce various NPs. The present study describes the comparative analysis of physicochemical and antibacterial properties of chemically synthesized (Chem-AgNPs) and cyanobacteria Spirulina platensis-derived silver NPs (Splat-AgNPs). The physicochemical characterization applying complementary dynamic light scattering and transmission electron microscopy revealed that Splat-AgNPs have an average hydrodynamic radius of ∼ 28.70 nm and spherical morphology, whereas Chem-AgNPs are irregular-shaped with an average radius size of ∼ 53.88 nm. The X-ray diffraction pattern of Splat-AgNPs confirms the formation of face-centered cubic crystalline AgNPs by "green synthesis". Energy-dispersive spectroscopy analysis demonstrated the purity of the Splat-AgNPs. Fourier transform infrared spectroscopy analysis of Splat-AgNPs demonstrated the involvement of some functional groups in the formation of NPs. Additionally, Splat-AgNPs demonstrated high colloidal stability with a zeta-potential value of (-50.0 ± 8.30) mV and a pronounced bactericidal activity against selected Gram-positive (Enterococcus hirae and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Salmonella typhimurium) bacteria compared with Chem-AgNPs. Furthermore, our studies toward understanding the action mechanism of NPs showed that Splat-AgNPs alter the permeability of bacterial membranes and the energy-dependent H+-fluxes via FoF1-ATPase, thus playing a crucial role in bacterial energetics. The insights gained from this study show that Spirulina-derived synthesis is a low-cost, simple approach to producing stable AgNPs for their energy-metabolism-targeted antibacterial applications in biotechnology and biomedicine.

Unlocking the potential of Opuntia species mucilage in chemistry

Herein, we describe a detailed protocol to extract the mucilage from different species of the genus Opuntia spp. (i.e., Opuntia Ficus (OFi), Opuntia Dillenii (ODi) and Opuntia Robusta (ORo)). The extracted mucilage was characterized by NMR, FTIR-ATR, HPLC, and TGA. OFi was found to have the highest phenolic content, 7.84 ± 1.93 mg catechol/g mucilage. The mucilage from the three species were characterized by having a high content of monosaccharides, being mannose and glucose the most abundant components (ca. 48-73 % and 23-35 %, respectively). In the context of biomass revalorization, the mucilage was proven to serve as a reducing and stabilizing agent in the synthesis of gold nanoparticles (AuNP/mucilage). The synthesis was optimized with a mucilage concentration of 2 mg/mL using 12.5 μL of KAuCl4 and was carried out at 80 °C for 90 min. This protocol afforded spherical nanoparticles with an average size of 9.7 ± 4.0 nm that were stable for at least 14 days, as demonstrated by TEM. Synthesized AuNP/mucilage was evaluated as a plasmonic catalyst for the reduction of 4-nitrophenol as model reaction, showing a considerable enhancement in its kapp of 97 % under white light and a decrease of 24.8 % in its activation energy.

Nrf2-mediated ferroptosis of spermatogenic cells involved in male reproductive toxicity induced by polystyrene nanoplastics in mice

Microplastics (MPs) and nanoplastics (NPs) have become hazardous materials due to the massive amount of plastic waste and disposable masks, but their specific health effects remain uncertain. In this study, fluorescence-labeled polystyrene NPs (PS-NPs) were injected into the circulatory systems of mice to determine the distribution and potential toxic effects of NPs in vivo. Interestingly, whole-body imaging found that PS-NPs accumulated in the testes of mice. Therefore, the toxic effects of PS-NPs on the reproduction systems and the spermatocytes cell line of male mice, and their mechanisms, were investigated. After oral exposure to PS-NPs, their spermatogenesis was affected and the spermatogenic cells were damaged. The spermatocyte cell line GC-2 was exposed to PS-NPs and analyzed using RNA sequencing (RNA-seq) to determine the toxic mechanisms; a ferroptosis pathway was found after PS-NP exposure. The phenomena and indicators of ferroptosis were then determined and verified by ferroptosis inhibitor ferrostatin-1 (Fer-1), and it was also found that nuclear factor erythroid 2-related factor 2 (Nrf2) played an important role in spermatogenic cell ferroptosis induced by PS-NPs. Finally, it was confirmed in vivo that this mechanism of Nrf2 played a protective role in PS-NPs-induced male reproductive toxicity. This study demonstrated that PS-NPs induce male reproductive dysfunction in mice by causing spermatogenic cell ferroptosis dependent on Nrf2.

Nanoparticles-mediated entomotoxicology: lessons from biologica

Nanotechnology has grown in importance in medicine, manufacturing, and consumer products. Nanoparticles (NPs) are also widely used in the field of insect pest management, where they show a variety of toxicological effects on insects. As a result, the primary goal of this review is to compile and evaluate available information on effects of NPs on insects, by use of a timely, bibliometric analysis. We also discussed the manufacturing capacity of NPs from insect tissues and the toxic effects of NPs on insects. To do so, we searched the Web of Science database for literature from 1995 to 2023 and ran bibliometric analyses with CiteSpace© and Bibliometrix©. The analyses covered 614 journals and identified 1763 relevant documents. We found that accumulation of NPs was one of the top trending topics. China, India, and USA had the most published papers. The most overall reported models of insects were those of Aedes aegypti (yellow fever mosquito), Culex quinquefasciatus (southern house mosquito), Bombyx mori (silk moth), and Anopheles stephensi (Asian malaria mosquito). The application and methods of fabrication of NPs using insect tissues, as well as the mechanism of toxicity of NPs on insects, were also reported. A uniform legal framework is required to allow nanotechnology to fully realize its potential while minimizing harm to living organisms and reducing the release of toxic metalloid nanoparticles into the environment.

A review on green approaches utilizing phytochemicals in the synthesis of vanadium nano particles and their applications

In the modern era, inorganic nanoparticles have received profound attention as they possess boundless applications in various fields. Among these, vanadium-based nanoparticles (VNPs) are highly remarkable due to their inherent physiological and biological properties with many therapeutic and other applications, such as drug delivery systems for diseases like cancer, environmental remediation, energy storage, energy conversion, and photocatalysis. Moreover, physically, and chemically synthesized VNPs are very versatile, however, these synthesis routes cause concern to health and the environment due to the highly savage reaction conditions, using highly toxic and harsh chemicals, which compel the researchers to develop an eco-friendly, greener, and sustainable route for synthesis. In this outlook, to avoid the innumerable limitations, a bio approach is used over chemical and physical methods. This present review emphasis on the role of various biological components in the synthesis, especially Phyto-molecules that acts as capping and reducing agent, and solvent system for the nanoparticles synthesis. Furthermore, the influence of various factors on the biogenic synthesized nanoparticles has also been discussed. Finally, potential applications of as-synthesized VNPs, principally as an antimicrobial agent and their role as a nanomedicine, energy applications as a supercapacitor, and photocatalytic agents, have been discussed.

Review of Marine Cyanobacteria and the Aspects Related to Their Roles: Chemical, Biological Properties, Nitrogen Fixation and Climate Change

Marine cyanobacteria are an ancient group of photosynthetic microbes dating back to 3.5 million years ago. They are prolific producers of bioactive secondary metabolites. Over millions of years, natural selection has optimized their metabolites to possess activities impacting various biological targets. This paper discusses the historical and existential records of cyanobacteria, and their role in understanding the evolution of marine cyanobacteria through the ages. Recent advancements have focused on isolating and screening bioactive compounds and their respective medicinal properties, and we also discuss chemical property space and clinical trials, where compounds with potential pharmacological effects, such as cytotoxicity, anticancer, and antiparasitic properties, are highlighted. The data have shown that about 43% of the compounds investigated have cytotoxic effects, and around 8% have anti-trypanosome activity. We discussed the role of different marine cyanobacteria groups in fixing nitrogen percentages on Earth and their outcomes in fish productivity by entering food webs and enhancing productivity in different agricultural and ecological fields. The role of marine cyanobacteria in the carbon cycle and their outcomes in improving the efficiency of photosynthetic CO2 fixation in the chloroplasts of crop plants, thus enhancing the crop plant's yield, was highlighted. Ultimately, climate changes have a significant impact on marine cyanobacteria where the temperature rises, and CO2 improves the cyanobacterial nitrogen fixation.

Carbon Quantum Dots Based on Marine Polysaccharides: Types, Synthesis, and Applications

The marine environment offers a vast array of resources, including plants, animals, and microorganisms, that can be utilized to extract polysaccharides such as alginate, carrageenan, chitin, chitosan, agarose, ulvan, porphyra, and many more. These polysaccharides found in marine environments can serve as carbon-rich precursors for synthesizing carbon quantum dots (CQDs). Marine polysaccharides have a distinct advantage over other CQD precursors because they contain multiple heteroatoms, including nitrogen (N), sulfur (S), and oxygen (O). The surface of CQDs can be naturally doped, reducing the need for excessive use of chemical reagents and promoting green methods. The present review highlights the processing methods used to synthesize CQDs from marine polysaccharide precursors. These can be classified according to their biological origin as being derived from algae, crustaceans, or fish. CQDs can be synthesized to exhibit exceptional optical properties, including high fluorescence emission, absorbance, quenching, and quantum yield. CQDs' structural, morphological, and optical properties can be adjusted by utilizing multi-heteroatom precursors. Moreover, owing to their biocompatibility and low toxicity, CQDs obtained from marine polysaccharides have potential applications in various fields, including biomedicine (e.g., drug delivery, bioimaging, and biosensing), photocatalysis, water quality monitoring, and the food industry. Using marine polysaccharides to produce carbon quantum dots (CQDs) enables the transformation of renewable sources into a cutting-edge technological product. This review can provide fundamental insights for the development of novel nanomaterials derived from natural marine sources.

Teleost Piscidins-In Silico Perspective of Natural Peptide Antibiotics from Marine Sources

Fish, like all other animals, are exposed to constant contact with microbes, both on their skin and on the surfaces of their respiratory and digestive systems. Fish have a system of non-specific immune responses that provides them with initial protection against infection and allows them to survive under normal conditions despite the presence of these potential invaders. However, fish are less protected against invading diseases than other marine vertebrates because their epidermal surface, composed primarily of living cells, lacks the keratinized skin that serves as an efficient natural barrier in other marine vertebrates. Antimicrobial peptides (AMPs) are one type of innate immune protection present in all life forms. AMPs have been shown to have a broader range of biological effects than conventional antibiotics, including antibacterial, antiviral, antiprotozoal, and antifungal effects. Although other AMPs, such as defensins and hepcidins, are found in all vertebrates and are relatively well conserved, piscidins are found exclusively in Teleost fish and are not found in any other animal. Therefore, there is less information on the expression and bioactivity of piscidins than on other AMPs. Piscidins are highly effective against Gram-positive and Gram-negative bacteria that cause disease in fish and humans and have the potential to be used as pharmacological anti-infectives in biomedicine and aquaculture. To better understand the potential benefits and limitations of using these peptides as therapeutic agents, we are conducting a comprehensive study of the Teleost piscidins included in the "reviewed" category of the UniProt database using bioinformatics tools. They all have amphipathic alpha-helical structures. The amphipathic architecture of piscidin peptides and positively charged residues influence their antibacterial activity. These alpha-helices are intriguing antimicrobial drugs due to their stability in high-salt and metal environments. New treatments for multidrug-resistant bacteria, cancer, and inflammation may be inspired by piscidin peptides.

Nanotechnology future in food using carbohydrate macromolecules: A state-of-the-art review

It is commonly known that agricultural pest and disease management is achieved through the use of agricultural chemicals and other synthetic compounds, which can contaminate water, soil, and food. Using agrochemicals indiscriminately has negative effects on the environment and poor food quality. In contrast, the world's population is increasing rapidly, and arable land is diminishing daily. Traditional agricultural methods must be replaced by nanotechnology-based treatments that efficiently address both the demands of the present and the needs of the future. As a promising contributor to sustainable agriculture and food production worldwide, nanotechnology has been applied through innovative and resourceful tools. Recent advances in nanomaterial engineering have increased agricultural and food sector production and protected crops using nanoparticles (1000 nm). Agrochemicals, nutrients, and genes can now be distributed to plants in a precise and tailored manner through nanoencapsulation (nanofertilizers, nanopesticides, and genes). Despite the advancement of technology in agriculture, some areas remain unexplored. The various agricultural domains must therefore be updated in priority order. The development of long-lasting and efficient nanoparticle materials will be key to the development of future eco-friendly and nanoparticle-based technologies. We thoroughly covered the many types of nanoscale agro-materials and gave an overview of biological techniques in nano-enabled tactics that can effectively reduce plant biotic and abiotic challenges while potentially boosting plant nutritional values.

Extraction of bioactive polysaccharide from Ulva prolifera biomass waste toward potential biomedical application

Ulva prolifera macroalgae blooming caused by water eutrophication seriously affects the marine ecological environment. Exploring an efficient approach to turning algae biomass waste into high-value-added products is significant. The present work aimed to demonstrate the feasibility of the bioactive polysaccharide extraction from Ulva prolifera and to evaluate its potential biomedical application. A short autoclave process was proposed and optimized using the response surface methodology to extract Ulva polysaccharides (UP) with high molar mass. Our results indicated that UP with high molar mass (9.17 × 10⁵ g/mol) and competitive radical scavenging activity (up to 53.4 %) could be effectively extracted with the assistance of Na₂CO₃ (1.3 %, wt.) at a solid-liquid ratio of 1/10 in 26 min. The obtained UP mainly composes of galactose (9.4 %), glucose (73.1 %), xylose (9.6 %), and mannose (4.7 %). The biocompatibility of the UP and its potential application as a bioactive ingredient in 3D cell culture has been evaluated and confirmed by confocal laser scanning microscopy and fluorescence microscope imaging inspection. This work demonstrated the feasibility of extracting bioactive sulfated polysaccharides with potential applications in biomedicine from biomass waste. Meanwhile, this work also provided an alternative solution to deal with the environmental challenges incurred by algae blooming worldwide.

Arctium lappa (Burdock): Insights from ethnopharmacology potential, chemical constituents, clinical studies, pharmacological utility and nanomedicine

Arctium lappa L. is a medicinal edible homologous plant, commonly known as burdock or bardana, which belongs to the Asteraceae family. It is widely distributed throughout Northern Asia, Europe, and North America and has been utilized for hundreds of years. The roots, fruits, seeds, and leaves of A. lappa have been extensively used in traditional Chinese Medicine (TCM). A. lappa has attracted a great deal of attention due to its possession of highly recognized bioactive metabolites with significant therapeutic potential. Numerous pharmacological effects have been demonstrated in vitro and in vivo by A. lappa and its bioactive metabolites, including antimicrobial, anti-obesity, antioxidant, anticancer, anti-inflammatory, anti-diabetic, anti-allergic, antiviral, gastroprotective, hepatoprotective, and neuroprotective activities. Additionally, A. lappa has demonstrated considerable clinical efficacies and valuable applications in nanomedicine. Collectively, this review covers the properties of A. lappa and its bioactive metabolites, ethnopharmacology aspects, pharmacological effects, clinical trials, and applications in the field of nanomedicine. Hence, a significant attention should be paid to clinical trials and industrial applications of this plant with particular emphasis, on drug discovery and nanotechnology.

Design, Synthesis, Fungicidal and Insecticidal Activities of Novel Diamide Compounds Combining Pyrazolyl and Polyfluoro-Substituted Phenyl into Alanine or 2-Aminobutyric Acid Skeletons

Thirty novel diamide compounds combining pyrazolyl and polyfluoro-substituted phenyl groups into alanine or 2-aminobutyric acid skeletons were designed and synthesized with pyflubumide as the lead compound to develop potent and environmentally friendly pesticides. The preliminary bioassay results indicated that the new compounds containing the para-hexa/heptafluoroisopropylphenyl moiety exhibit fungicidal, insecticidal, and acaricidal activities. This is the first time that the para-hexa/heptafluoroisopropylphenyl group is a key fragment of the fungicidal activity of new N-phenyl amide compounds. Most of the target compounds exhibited moderate to good insecticidal activity against Aphis craccivora at a concentration of 400 μg/mL, and some showed moderate activity at a concentration of 200 μg/mL; in particular, compounds I-4, II-a-10, and III-26 displayed higher than 78% lethal rates at 200 μg/mL. Compound II-a-14 exhibited a 61.1% inhibition at 200 μg/mL for Tetranychus cinnabarinus. In addition, some of the target compounds exhibited good insecticidal activities against Plutella xylostella at a concentration of 200 μg/mL; the mortalities of compounds I-1, and II-a-15 were 76.7% and 70.0%, respectively. Preliminary analysis of the structure-activity relationship (SAR) indicated that the insecticidal and acaricidal activities varied significantly depending on the type of substituent and substitution pattern. The fungicidal activity results showed that compounds I-1, II-a-10, II-a-17, and III-26 exhibited good antifungal effects. Enzymatic activity experiments and in vivo efficacy of compound II-a-10 were conducted and discussed.

Polycladia myrica-based delivery of selenium nanoparticles in combination with radiotherapy induces potent in vitro antiviral and in vivo anticancer activities against Ehrlich ascites tumor

Background: Over the last few decades, nanotechnology has entered daily life through various applications, therefore, there has been a trend toward developing new approaches to green-mediated nanotechnology that encourage nanomaterial formation through biological methods such as plants or microorganisms. Algae have gained increasing attention from nanotechnology scientists and have paved the way for the emergence of "algae nanotechnology" as a promising field. Methods: Via using the aqueous extract of the brown alga Polycladia myrica, selenium nanoparticles were synthesized and characterized by using seven instruments: SEM, TEM, UV spectra, Zeta potential, EDX, X-ray diffraction, and FTIR. P. myrica selenium nanoparticles (PoSeNPs) were then examined for their antiviral activity against HSV-1 (Herpes simplex I) and anticancer against human colon cancer cell line (HCT-116) in vitro and in vivo alone and in combination with laser therapy of power 2 mW against Ehrlich carcinoma (EAC). Results: PoSeNPs ranging between 17.48 nm and 23.01 nm in size, and EDX revealed the selenium mass and its atoms as 0.46% ± 0.07% and 0.08% ± 0.01% respectively. Their anticancer potentiality in vitro was with maximum inhibitions of 80.57% and 73% and IC₅₀ = 14.86 μg/mL and 50 mg/mL against HCT-116 and EAC cell lines respectively, while their in vivo alone and in combination with laser therapy of power 2 mW showed a potent therapy effect against Ehrlich ascites carcinoma (EAC). Conclusion: This study concluded that PoSeNPs do not have a toxic effect; they exhibit high effectiveness as a photothermal agent for cancer therapy, with promising applications in future biomedical fields. The combined therapy showed a significant decrease in tumor volume, massive tumor cell necrosis, shrinking, and disappearance. It also showed improvement in liver TEM, histology, kidney function: urea and creatinine, and liver enzymes: ALT, and AST.

Macroalgae as biofactories of metal nanoparticles; biosynthesis and food applications

Nanotechnology has opened a new frontier in recent years, capable of providing new ways of controlling and structuring products with greater market value and offering significant opportunities for the development of innovative applications in food processing, preservation, and packaging. Macroalgae (MAG) are the major photoautotrophic group of living beings known as a potential source of secondary metabolites, namely phenolic compounds, pigments, and polysaccharides. Biosynthesis based on the abilities of MAG as "nanobiofactories" targets the use of algal secondary metabolites as reducing agents to stabilize nanoparticles (NPs). Nowadays, most of the studies are focused on the use of metal (Ag, Au) and metal-oxide (CuO, ZnO) NPs derived from algae. The eco-friendly biosynthesis of metal NPs reduces the cost and production time and increases their biocompatibility, due to the presence of bioactive compounds in MAG, making them suitable for a wide variety of applications. These compounds have been attributed to the antimicrobial and antioxidant properties responsible for their application through innovative technologies such as nanoencapsulation, nanocomposites, or biosensors in the food industry. Nevertheless, toxicity is a key factor that should be considered, so the applicable regulation needs to guarantee the safe use of metal NPs. Consequently, the aim of this review will be to compile the available information on MAG-mediated metal NPs, their biosynthesis, and potential food applications.

Chemical modifications in the structure of marine polysaccharide as serviceable food processing and preservation assistant: A review

Marine polysaccharides are a kind of natural polysaccharides which isolated and extracted from marine organisms. Now some marine polysaccharides, such as chitosan, sodium alginate and agar, have been proven to exhibit antibacterial, antioxidant functions and biocompatibility, which are often used to preserve food or improve the physicochemical properties of food. However, they still have the defects of unsatisfactory preservation effect and biological activity, which can be remedied by its modification. Chemical modification is the most effective of all modification methods. The advances in common chemical modification methods of chitosan, sodium alginate, agar and other marine polysaccharides and research progress of modified products in food processing and preservation were summarized, and the influence of additional reaction conditions on the existence of chemical modification sites of polysaccharides was discussed. The modification of functional groups in natural marine polysaccharides leads to the change of molecular structure, which can improve the physical, chemical and biological properties of marine polysaccharides. Chemically modified products have been used in various fields of food applications, such as food preservatives, food additives, food packaging, and food processing aids. In general, chemical modification has excellent potential for food processing and preservation, which can improve the function of marine polysaccharides.

Marine macroalgae polysaccharides-based nanomaterials: an overview with respect to nanoscience applications

Background

Exploration of marine macroalgae poly-saccharide-based nanomaterials is emerging in the nanotechnology field, such as wound dressing, water treatment, environmental engineering, biosensor, and food technology.

Main body

In this article, the current innovation and encroachments of marine macroalgae polysaccharide-based nanoparticles (NPs), and their promising opportunities, for future prospect in different industries are briefly reviewed. The extraction and advancement of various natural sources from marine polysaccharides, including carrageenan, agarose, fucoidan, and ulvan, are highlighted in order to provide a wide range of impacts on the nanofood technology. Further, seaweed or marine macroalgae is an unexploited natural source of polysaccharides, which involves numerous different phytonutrients in the outermost layer of the cell and is rich in sulphated polysaccharides (SP), SP-based nanomaterial which has an enhanced potential value in the nanotechnology field.

Conclusion

At the end of this article, the promising prospect of SP-based NPs and their applications in the food sector is briefly addressed.

Multifunctional Medical Grade Resin with Enhanced Mechanical and Antibacterial Properties: The Effect of Copper Nano-Inclusions in Vat Polymerization (VPP) Additive Manufacturing

Vat photopolymerization (VPP) is an additive manufacturing process commonly used in medical applications. This work aims, for the first time in the literature, to extend and enhance the performance of a commercial medical-grade resin for the VPP process, with the development of nanocomposites, using Copper (Cu) nanoparticles as the additive at two different concentrations. The addition of the Cu nanoparticles was expected to enhance the mechanical properties of the resin and to enable biocidal properties on the nanocomposites since Cu is known for its antibacterial performance. The effect of the Cu concentration was investigated. The nanocomposites were prepared with high-shear stirring. Specimens were 3D printed following international standards for mechanical testing. Their thermal and spectroscopic response was also investigated. The morphological characteristics were examined. The antibacterial performance was evaluated with an agar well diffusion screening process. The experimental results were analyzed with statistical modeling tools with two control parameters (three levels each) and eleven response parameters. Cu enhanced the mechanical properties in all cases studied. 0.5 wt.% Cu nanocomposite showed the highest improvement (approximately 11% in tensile and 10% in flexural strength). The antibacterial performance was sufficient against S. aureus and marginal against E. coli.

Structural Diversity, LC-MS-MS Analysis and Potential Biological Activities of Brevibacillus laterosporus Extract

Lake Mariout is Egypt's degraded coastal marine habitat that encompasses a variety of wastes. The biodiversity and hard environmental conditions allow the co-existence of organisms with high resistance and rich metabolism, making them potential candidates for screening and isolating novel microbial strains. A bacterial isolate (BF202) cultured from the marine sediments of Alexandria's Mariout Lake (Egypt) was tested for its antimicrobial and anticancer potential. The phylogenetic analysis of the isolated strain's 16S rDNA and gyrB revealed that BF202 belongs to Brevibacillus laterosporus (B. laterosporus). Antibiosis of B. laterosporus was confirmed against microbial pathogens including Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, and Staphylococcus aureus. The highest antibacterial activity was detected on glucose peptone medium after 18 h of incubation at 35 °C, and at pH of 7.0 in the presence of mannose and ammonium carbonate as carbon and nitrogen sources, respectively. The cytotoxicity of the methanolic extract against breast cancer (MCF-7) and normal Vero cell lines, using the MTT test, revealed IC50 values of 7.93 and 23.79 µg/mL, respectively. To identify apoptotic and necrotic cells, a flow cytometric analysis using annexin V-FITC/PI dual-labeling was utilized and recorded a higher number of necrotic cells compared to apoptotic ones. Similarly, the cell cycle S-phase arrest was reported. The LC-MS-MS investigation of B. laterosporus extract and the molecular networking database analysis demonstrated five strategic diketopiperazine compounds with antimicrobial and anticancer activities. Taken together, this research shows that the crude extract of B. laterosporus might be an effective agent against drug-resistant bacteria and malignant disorders due to its richness in diketopiperazines.

Exopolysaccharides from marine microbes with prowess for environment cleanup

A variety of both small and large biologically intriguing compounds can be found abundantly in the marine environment. Researchers are particularly interested in marine bacteria because they can produce classes of bioactive secondary metabolites that are structurally diverse. The main secondary metabolites produced by marine bacteria are regarded as steroids, alkaloids, peptides, terpenoids, biopolymers, and polyketides. The global urbanization leads to the increased use of organic pollutants that are both persistent and toxic for humans, other life forms and tend to biomagnified in environment. The issue can be addressed, by using marine microbial biopolymers with ability for increased bioremediation. Amongst biopolymers, the exopolysaccharides (EPS) are the most prominent under adverse environmental stress conditions. The present review emphasizes the use of EPS as a bio-flocculent for wastewater treatment, as an adsorbent for the removal of textile dye and heavy metals from industrial effluents. The biofilm-forming ability of EPS helps with soil reclamation and reduces soil erosion. EPS are an obvious choice being environmentally friendly and cost-effective in processes for developing sustainable technology. However, a better understanding of EPS biosynthetic pathways and further developing novel sustainable technologies is desirable and certainly will pave the way for efficient usage of EPS for environment cleanup.

Marine Algae Extract (Grateloupia Sparsa) for the Green Synthesis of Co3O4NPs: Antioxidant, Antibacterial, Anticancer, and Hemolytic Activities

The aqueous extract of red algae was used for bio-inspired manufacturing of cobalt oxide nanoparticles (Co3O4NPs) and for antioxidant, antibacterial, hemolytic potency, and anticancer activity. Typical, characterization techniques include UV-Vis, SEM, EDAX, TEM, FTIR, XRD, and TGA. Using an X-ray diffraction assay, the size of the Co3O4NPs crystal was determined to range from 23.2 to 11.8 nm. Based on TEM and SEM pictures, biosynthesized Co3O4NPs' had a homogeneous spherical morphology with a 28.8 to 7.6 nm average diameter. Furthermore, Co3O4NPs biological properties were investigated, including determining the antibacterial potency using the zone of inhibition (ZOI) method and determining the minimal inhibitory concentration (MIC). The antibacterial activity of Co3O4NPs was higher than that of the ciprofloxacin standard. Alternatively, scavenging of DPPH free radical investigation was carried out to test the antioxidant capacitance of Co3O4NPs, revealing significant antioxidant ability. The biosynthesized Co3O4NPs have a dose-dependent effect on erythrocyte viability, indicating that this technique is harmless. Furthermore, bioinspired Co3O4NPs effectively against HepG2 cancer cells (IC50: 201.3 μg/ml). Co3O4NPs would be a therapeutic aid due to their antioxidant, antibacterial, and anticancer properties.

An ocean of possibilities: a review of marine organisms as sources of nanoparticles for cancer care

Seas and oceans have been explored for the last 70 years in search of new compounds that can support the battle against cancer. Marine polysaccharides can act as nanomaterials for medical applications and marine-derived bioactive compounds can be applied for the biosynthesis of metallic and nonmetallic nanoparticles. Nanooncology can be used in numerous fields including diagnostics, serving as drug carriers or acting as drugs. This review focuses on marine-derived nanoparticles with potential oncological applications. It classifies organisms used for nanoparticle production, explains the production process, presents different types of nanoparticles with prospective applications in oncology, describes the molecular pathways responsible for numerous nanomedicine applications, tags areas of nanoparticle implementation in oncology and speculates about future directions.

Marine-Bioinspired Nanoparticles as Potential Drugs for Multiple Biological Roles

The increased interest in nanomedicine and its applicability for a wide range of biological functions demands the search for raw materials to create nanomaterials. Recent trends have focused on the use of green chemistry to synthesize metal and metal-oxide nanoparticles. Bioactive chemicals have been found in a variety of marine organisms, including invertebrates, marine mammals, fish, algae, plankton, fungi, and bacteria. These marine-derived active chemicals have been widely used for various biological properties. Marine-derived materials, either whole extracts or pure components, are employed in the synthesis of nanoparticles due to their ease of availability, low cost of production, biocompatibility, and low cytotoxicity toward eukaryotic cells. These marine-derived nanomaterials have been employed to treat infectious diseases caused by bacteria, fungi, and viruses as well as treat non-infectious diseases, such as tumors, cancer, inflammatory responses, and diabetes, and support wound healing. Furthermore, several polymeric materials derived from the marine, such as chitosan and alginate, are exploited as nanocarriers in drug delivery. Moreover, a variety of pure bioactive compounds have been loaded onto polymeric nanocarriers and employed to treat infectious and non-infectious diseases. The current review is focused on a thorough overview of nanoparticle synthesis and its biological applications made from their entire extracts or pure chemicals derived from marine sources.

Biogenic Synthesis of ZnO Nanoparticles and Their Application as Bioactive Agents: A Critical Overview

Zinc oxide is a safe material for humans, with high biocompatibility and negligible cytotoxicity. Interestingly, it shows exceptional antimicrobial activity against bacteria, viruses, fungi, etc., especially when reduced to the nanometer size. As it is easily understandable, thanks to its properties, it is at the forefront of safe antimicrobials in this pandemic era. Besides, in the view of the 2022 European Green Deal announced by the European Commission, even science and nanotechnology are moving towards “greener” approaches to the synthesis of nanoparticles. Among them, biogenic ZnO nanoparticles have been extensively studied for their biological applications and environmental remediation. Plants, algae, fungi, yeast, etc., (which are composed of naturally occurring biomolecules) play, in biogenic processes, an active role in the formation of nanoparticles with distinct shapes and sizes. The present review targets the biogenic synthesis of ZnO nanoparticles, with a specific focus on their bioactive properties and antimicrobial application.

Cryoprotective Roles of Carboxymethyl Chitosan during the Frozen Storage of Surimi: Protein Structures, Gel Behaviors and Edible Qualities

Carboxymethyl chitosan (CMCh) is an ampholytic chitosan derivative that manifests versatile applications in food industry, such as antibacterial ingredients and nutritional additives. However, its use as a cryoprotectant remains under-researched. In this study, the cryoprotective effect of CMCh oligosaccharide (CMCO) on frozen surimi (silver carp) was systematically investigated in terms of protein structures, gelling behaviors, and sensory qualities. CMCO (0.6%) was incorporated in the surimi before frozen storage (-18 °C for 60 days) while the commercial cryoprotectant (4% sucrose, 4% sorbitol) was used as a positive control. Results indicated that CMCO could inhibit the freezing-induced denaturation of myofibrillar protein, whose values of solubility, Ca2+-ATPase and sulfhydryl content were 24.8%, 64.7%, and 17.1% higher than the nonprotected sample, respectively, while the surface hydrophobicity was 21.6% lower. Accordingly, CMCO stabilized microstructure of the surimi gels associated with improved gel strength, viscoelasticity, water-holding capacities, and whiteness. Moreover, the cryoprotective effect of CMCO with higher degree of carboxymethyl substitution (DS: 1.2) was more pronounced than that of low-DS-CMCO (DS: 0.8). Frozen surimi treated with high-DS-CMCO achieved competitive gelling properties and sensory acceptability to those with the commercial counterpart. This study provided scientific insights into the development of ampholytic oligosaccharides as food cryoprotectants.