In situ synthesis of silver nanoparticles into TEMPO-mediated oxidized bacterial cellulose and their antivibriocidal activity against shrimp pathogens

Dietary silver nanoparticle effects on Penaeus vannamei growth, histopathology, faecal microbiome, and acute hepatopancreatic necrosis disease survival

This study examines acute hepatopancreatic necrosis disease (AHPND) in shrimp farming, caused by specific strains of Vibrio (Vp AHPND+), and evaluates the potential of silver and silver chloride nanoparticles (Ag/AgCl NP) synthesised from marine resources as an antibacterial additive in shrimp feed. Penaeus vannamei juveniles were fed diets supplemented with 0, 10, 100, and 1000 mg Ag/AgCl per kg for 20 d. The highest weight gain (%WG) was observed in individuals consuming the 100 mg Ag kg-1 diet, with a 104.27 ± 4.11% increase. Histopathological analysis revealed that 10 and 100 mg Ag kg-1 improved hepatopancreas (HP) ultrastructure, whereas 1000 mg Ag kg-1 caused severe lesions, including cell necrosis. After infection with Vp AHPND+, survival rates increased from 27% in the control group to 78% in juveniles fed the 100 mg Ag kg-1 diet for 7 d. Microbiome analysis showed no significant changes in alpha diversity due to Ag/AgCl NP doses, although a notable shift was observed during the depuration phase. These findings highlight the potential of Ag/AgCl NP as a dietary supplement to improve growth, health, and disease resistance in shrimp farming, emphasising the importance of precise dosing to maximize benefits while minimising risks.

Regioselective functionalization of cellulose nanomaterial for advanced application

Cellulose nanomaterials (CNMs) with their remarkable properties and abundant natural sources have emerged as a versatile platform for material science. However, their widespread adoption to develop novel applications often hinges on precise control over their surface chemistry. Regioselective functionalization, i.e., the ability to modify specific hydroxy groups on the cellulose backbone or aldehyde reducing end group (REG), offers unparalleled control on their surface chemistry. This review highlights the exciting developments in regioselective functionalization of CNMs and their impacts on structure-property relationships. Key factors that influence regioselectivity are examined and exciting applications of regioselectively functionalized CNMs are reviewed. This review also highlights the need for efficient, large-scale regioselective functionalization techniques and identifies key areas for future research.

Metallic and non-metallic nanoparticles from plant, animal, and fisheries wastes: potential and valorization for application in agriculture

Global agriculture is facing tremendous challenges due to climate change. The most predominant amongst these challenges are abiotic and biotic stresses caused by increased incidences of temperature extremes, drought, unseasonal flooding, and pathogens. These threats, mostly due to anthropogenic activities, resulted in severe challenges to crop and livestock production leading to substantial economic losses. It is essential to develop environmentally viable and cost-effective green processes to alleviate these stresses in the crops, livestock, and fisheries. The application of nanomaterials in farming practice to minimize nutrient losses, pest management, and enhance stress resistance capacity is of supreme importance. This paper explores innovative methods for synthesizing metallic and non-metallic nanoparticles using plants, animals, and fisheries wastes and their valorization to mitigate abiotic and biotic stresses and input use efficiency in climate-smart and stress-resilient agriculture including crop plants, livestock, and fisheries.

Green Synthesized Silver Nanoparticles Using Lactobacillus Acidophilus as an Antioxidant, Antimicrobial, and Antibiofilm Agent Against Multi-drug Resistant Enteroaggregative Escherichia Coli

The present study was envisaged to employ the green synthesis and characterization of silver nanoparticles (AgNPs) using the potential probiotic strain Lactobacillus acidophilus, to assess its antibacterial as well as antibiofilm activity against multi-drug-resistant enteroaggregative Escherichia coli (MDR-EAEC) strains and to investigate their antioxidant activity. In this study, AgNPs were successfully synthesized through an eco-friendly protocol, which was then confirmed by its X-ray diffraction (XRD) pattern. A weight loss of 15% up to 182 °C with a narrow exothermic peak between 170 °C and 205 °C was observed in thermogravimetric analysis-differential thermal analysis (TGA-DTA), while aggregated nanoclusters were observed in scanning electron microscopy (SEM). Moreover, the transmission electron microscopy (TEM) imaging of AgNPs revealed a spherical morphology and crystalline nature with an optimum size ranging from 10 to 20 nm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of green synthesized AgNPs against the MDR-EAEC strains were found to be 7.80 mg/L and 15.60 mg/L, respectively. In vitro time-kill kinetic assay revealed a complete elimination of the MDR-EAEC strains after 180 min on co-incubation with the AgNPs. Moreover, the green synthesized AgNPs were found safe by in vitro haemolytic assay. Besides, the green synthesized AgNPs exhibited significant biofilm inhibition (P < 0.001) formed by MDR-EAEC strains. Additionally, a concentration-dependent antioxidant activity was observed in 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Hence, this study demonstrated potential antibacterial as well as antibiofilm activity of green synthesized AgNPs against MDR-EAEC strains with antioxidant properties and warrants further in-depth studies to explore it as an effective antimicrobial agent against MDR infections.

Facile route of synthesis of silver nanoparticles templated bacterial cellulose, characterization, and its antibacterial application

Bacterial cellulose (BC) produced from coconut water, commonly known as nata de coco, is a biopolymer with enormous properties. Compared to plant cellulose, BC has better mechanical strength and a greater degree of polymerization. BC’s high purity and high porosity make it a suitable candidate for the embedding and dispersion template for silver nanoparticles (AgNPs). This study investigated a facile and scalable method of making BC from coconut water and impregnated them with AgNO3 solution to produce AgNPs templated BC. The resulting materials were characterized by Fourier transform infra-Red (FTIR), scanning electron microscope (SEM), energy dispersive X-ray (EDX), and X-ray diffraction (XRD). The thermal stability was also investigated by thermogravimetric analysis (TGA). The antibacterial activity of AgNPs templated BC was challenged in cultures of gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli and showed an inhibition zone of growth in agar media. This study proves that the resulting AgNPs templated BC sheets are potential materials for antibacterial and industrial application that are low cost and easy to produce.

Synthesis approach-dependent antiviral properties of silver nanoparticles and nanocomposites

Numerous viral infections are common among humans, and some can lead to death. Even though conventional antiviral agents are beneficial in eliminating viral infections, they may lead to side effects or physiological toxicity. Silver nanoparticles and nanocomposites have been demonstrated to possess inhibitory properties against several pathogenic microbes, including archaea, bacteria, fungi, algae, and viruses. Its pronounced antimicrobial activity against various microbe-mediated diseases potentiates its use in combating viral infections. Notably, the appropriated selection of the synthesis method to fabricate silver nanoparticles is a major factor for consideration as it directly impacts antiviral efficacy, level of toxicity, scalability, and environmental sustainability. Thus, this article presents and discusses various synthesis approaches to produce silver nanoparticles and nanocomposites, providing technological insights into selecting approaches to generate antiviral silver-based nanoparticles. The antiviral mechanism of various formulations of silver nanoparticles and the evaluation of its propensity to combat specific viral infections as a potential antiviral agent are also discussed.

Cellulose-Based Materials for Water Remediation: Adsorption, Catalysis, and Antifouling

Cellulose-based materials have been advanced technologies that used in water remediation. They exhibit several advantages being the most abundant biopolymer in nature, high biocompatibility, and contain several functional groups. Cellulose can be prepared in several derivatives including nanomaterials such as cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidized cellulose nanofibrils (TOCNF). The presence of functional groups such as carboxylic and hydroxyls groups can be modified or grafted with organic moieties offering extra functional groups customizing for specific applications. These functional groups ensure the capability of cellulose biopolymers to be modified with nanoparticles such as metal-organic frameworks (MOFs), graphene oxide (GO), silver (Ag) nanoparticles, and zinc oxide (ZnO) nanoparticles. Thus, they can be applied for water remediation via removing water pollutants including heavy metal ions, organic dyes, drugs, and microbial species. Cellulose-based materials can be also used for removing microorganisms being active as membranes or antibacterial agents. They can proceed into various forms such as membranes, sheets, papers, foams, aerogels, and filters. This review summarized the applications of cellulose-based materials for water remediation via methods such as adsorption, catalysis, and antifouling. The high performance of cellulose-based materials as well as their simple processing methods ensure the high potential for water remediation.

Bacterial cellulose and its potential for biomedical applications

Bacterial cellulose (BC) is an important polysaccharide synthesized by some bacterial species under specific culture conditions, which presents several remarkable features such as microporosity, high water holding capacity, good mechanical properties and good biocompatibility, making it a potential biomaterial for medical applications. Since its discovery, BC has been used for wound dressing, drug delivery, artificial blood vessels, bone tissue engineering, and so forth. Additionally, BC can be simply manipulated to form its derivatives or composites with enhanced physicochemical and functional properties. Several polymers, carbon-based nanomaterials, and metal nanoparticles (NPs) have been introduced into BC by ex situ and in situ methods to design hybrid materials with enhanced functional properties. This review provides comprehensive knowledge and highlights recent advances in BC production strategies, its structural features, various in situ and ex situ modification techniques, and its potential for biomedical applications.

Enzymatic preparation of oxidized viscose fibers-based biosorbent modified with ε-polylysine for dyes removal and microbial inactivation

A novel fiber-based biosorbent for dyes removal and microbial inactivation was prepared by enzymatic oxidization of viscose fibers and further modification with ε-polylysine. Glucose oxidase (GOx) was first employed as the enzyme for oxidation of viscose fibers. The consequences illustrated that the hydroxyl group on C1 position of viscose fibers was successfully oxidized with oxidation ratio of 2.43 ± 0.31%. Subsequently, ε-polylysine with average molecular weight of 4.44 ± 1.13 KDa and antimicrobial activity to E. coli of 90.48 ± 1.64 was modified with oxidized viscose fibers by lipase. Experimental results showed that oxidized viscose fibers were successfully modified with ε-polylysine with optimum degree of modification (DM) of 13.56 ± 1.05%. This oxidized viscose fiber modified with ε-polylysine (OVF-PL) displayed good dyes adsorption (or dyes removal) capacity for both anionic and cationic dyes, especially for anion dyes. Furthermore, OVF-PL showed excellent antimicrobial activity against E. coli and B. subtilis, particularly for E. coli, with GIB of 92.65%. Such fiber-based may offer a new pathway for preparing economical and efficient biosorbent for environmental remedy purpose.

Current progress on the production, modification, and applications of bacterial cellulose

Adoption of biomass for the development of biobased products has become a routine agenda in evolutionary metabolic engineering. Cellulose produced by bacteria is a "rising star" for this sustainable development. Unlike plant cellulose, bacterial cellulose (BC) shows several unique properties like a high degree of crystallinity, high purity, high water retention, high mechanical strength, and enhanced biocompatibility. Favored with those extraordinary properties, BC could serve as ideal biomass for the development of various industrial products. However, a low yield and the requirement for large growth media have been a persistent challenge in mass production of BC. A significant number of techniques has been developed in achieving efficient BC production. This includes the modification of bioreactors, fermentation parameters, and growth media. In this article, we summarize progress in metabolic engineering in order to solve BC growth limitation. This article emphasizes current engineered BC production by using various bioreactors, as well as highlighting the structure of BC fermented by different types of engineered-bioreactors. The comprehensive overview of the future applications of BC, aims to provide readers with insight into new economic opportunities of BC and their modifiable properties for various industrial applications. Modifications in chemical composition, structure, and genetic regulation, which preceded the advancement of BC applications, were also emphasized.

Multifunctional nanocellulose/metal and metal oxide nanoparticle hybrid nanomaterials

Nanocellulose materials are derived from cellulose, the most abundant biopolymer on the earth. Nanocellulose have been extensively used in the field of food packaging materials, wastewater treatment, drug delivery, tissue engineering, hydrogels, aerogels, sensors, pharmaceuticals, and electronic sectors due to their unique chemical structure and excellent mechanical properties. On the other hand, metal and metal oxide nanoparticles (NP) such as Ag NP, ZnO NP, CuO NP, and Fe₃O₄ NP have a variety of functional properties such as UV-barrier, antimicrobial, and magnetic properties. Recently, nanocelluloses materials have been used as a green template for producing metal or metal oxide nanoparticles. As a result, multifunctional nanocellulose/metal or metal oxide hybrid nanomaterials with high antibacterial properties, ultraviolet barrier properties, and mechanical properties were prepared. This review emphasized recent information on the synthesis, properties, and potential applications of multifunctional nanocellulose-based hybrid nanomaterials with metal or metal oxides such as Ag NP, ZnO NP, CuO NP, and Fe₃O₄ NP. The nanocellulose-based hybrid nanomaterials have huge potential applications in the area of food packaging, biopharmaceuticals, biomedical, and cosmetics.

Biological synthesis of metallic nanoparticles (MNPs) by plants and microbes: their cellular uptake, biocompatibility, and biomedical applications

Metallic nanoparticles (MNPs) with their diverse physical and chemical properties have been applied in various biomedical domains. The increasing demand for MNPs has attracted researchers to develop straightforward, inexpensive, simple, and eco-friendly processes for the enhanced production of MNPs. To discover new biomedical applications first requires knowledge of the interactions of MNPs with target cells. This review focuses on plant and microbial synthesis of biological MNPs, their cellular uptake, biocompatibility, any biological consequences such as cytotoxicity, and biomedical applications. We highlighted the involvement of biomolecules in capping and stabilization of MNPs and the effect of physicochemical parameters particularly the pH on the synthesis of MNPs. Recently achieved milestones to understand the role of synthetic biology (SynBiol) in the synthesis of tailored MNPs are also discussed.

Applications of cellulose and chitin/chitosan derivatives and composites as antibacterial materials: current state and perspectives

The bacterial infections have always a serious problem to public health. Scientists are developing new antibacterial materials to overcome this problem. Polysaccharides are promising biopolymers due to their diverse biological functions, low toxicity, and high biodegradability. Chitin and chitosan have antibacterial properties due to their cationic nature, while cellulose/bacterial cellulose does not possess any antibacterial activity. Moreover, the insolubility of chitin in common solvents, the poor solubility of chitosan in water, and the low mechanical properties of chitosan have restricted their biomedical applications. In order to solve these problems, chemical modifications such as quaternization, carboxymethylation, cationization, or surface modification of these polymers with different antimicrobial agents, including metal and metal oxide nanoparticles, are carried out to obtain new materials with improved physiochemical and biological properties. This mini review describes the recent progress in such derivatives and composites with potential antibacterial applications.

Nanocellulose-Based Antibacterial Materials

In recent years, nanocellulose-based antimicrobial materials have attracted a great deal of attention due to their unique and potentially useful features. In this review, several representative types of nanocellulose and modification methods for antimicrobial applications are mainly focused on. Recent literature related with the preparation and applications of nanocellulose-based antimicrobial materials is reviewed. The fabrication of nanocellulose-based antimicrobial materials for wound dressings, drug carriers, and packaging materials is the focus of the research. The most important additives employed in the preparation of nanocellulose-based antimicrobial materials are presented, such as antibiotics, metal, and metal oxide nanoparticles, as well as chitosan. These nanocellulose-based antimicrobial materials can benefit many applications including wound dressings, drug carriers, and packaging materials. Finally, the challenges of industrial production and potentials for development of nanocellulose-based antimicrobial materials are discussed.