Preparation, Characterization and Antibacterial Effect of Chitosan Nanoparticles against Food Spoilage Bacteria

Understanding antimicrobial activity of biogenic selenium nanoparticles and selenium/chitosan nano-incorporates via studying their inhibition activity against key metabolic enzymes

Microbial metabolic enzymes play a crucial role in several biological processes that have a significant impact on growth and proliferation. Therefore, inhibiting specific key metabolic enzymes can be an applicable approach for developing antimicrobial agents that selectively target pathogens. In the current study, selenium nanoparticles (Se NPs) extracellularly biosynthesized by Nocardiopsis sp. MAR13 and Se NPs incorporated with nano-chitosan (NCh) (Se/Ch-nano-incorporate) were evaluated for their antimicrobial activity against various microbial pathogens such as Salmonella typhi, Proteus vulgaris, Staphylococcus aureus, Escherichia coli, Aspergillus flavus, Aspergillus niger, Rhizoctonia sp., Candida albicans ATCC10231. The synthesized Se NPs, and Se/Ch-nano-incorporate were characterized by UV-Vis., FTIR, HRTEM, SEM, EDX, DLS, Zeta potential, and XRD. Additionally, their inhibition activity against microbial metabolic key enzymes, including phosphoglucose isomerase (PGI), pyruvate dehydrogenase (PDH), glucose-6-phosphate dehydrogenase (G6PDH), and nitrate reductase (NR), was assessed. The impact on protein leakage from bacterial cell membranes was also evaluated as a potential mechanism of antimicrobial action. On the other hand, MCF-7 and A549 tumor cell lines, as well as WI-38 normal cell lines, were used to assess their cytotoxic activity. It was found that Se NPs were spherical with a diameter range of 60.2 to 120.2 nm. In contrast, Se/Ch-nano-incorporate had a roughly spherical shape with a diameter range of 21.4 to 32.7 nm and substantially higher stability. Both synthesized agents exhibited strong antimicrobial activity against the most tested microbial pathogens with substantial inhibitory effect on the tested enzymes and notable protein leakage. Furthermore, they showed potent anticancer activity against both tumor cell lines with low cytotoxicity against WI-38 normal cell line. Consequently, Se NPs and Se/Ch-nano-incorporate are highly recommended to be employed as antimicrobial and anticancer agents with promised biosafety, eco-friendliness, and efficacy.

Optimization of Achillea millefolium-Infused Chitosan Nanocarriers for Antibacterial and Dye Degradation Applications

The demand for plant-based nanocarriers and nanodrugs is increasing due to their versatile nature and compatibility. This research focuses on the optimization of Achillea millefolium-infused chitosan (CS) nanocarriers for antibacterial and dye degradation applications, emphasizing the novelty of this approach. Different dilutions of A. millefolium were loaded into low-molecular (LM)- and high-molecular-weight-CS nanocarriers using the ionotropic gelation method. The synthesized drug-loaded CS nanocarriers were characterized using ultraviolet (UV)-visible (Vis) spectroscopy, scanning electron microscopy, dynamic light scattering, Fourier-Transform Infrared, and high-performance liquid chromatography. The optimized nanocarriers were further analyzed for encapsulation efficiency (EE), antibacterial activity, and dye degradation capacity. The EE of the drug-loaded CS nanocarriers ranged from 15% to 100%. Notably, the LM-weight-CS-based nanocarriers demonstrated a significant dye degradation capacity, achieving an impressive 83% degradation rate for methylene orange (MO). Moreover, these nanoparticles (NPs) exhibited superior efficacy compared to un-immobilized counterparts. The A. millefolium-CS NPs also significantly enhanced the zone of inhibition against Escherichia coli and Staphylococcus aureus, demonstrating strong antibacterial potential. These results underscore the enhanced ability of the CS NP formulation to inhibit microbial growth and effectively degrade dyes. The combination of A. millefolium and CS NPs showcases potential for innovative therapeutic applications, particularly in wastewater treatment and antimicrobial therapies. This study provides novel insights into the development of effective plant-based nanocarriers, paving the way for future research in this field.

Chitosan Nanoparticles: A Promising Candidate in Wound Healing

The wound healing process is really interesting, dynamic, and complex, captivating researchers for a long time. With the growing worldwide concern regarding the prevalence of wounds and the associated healthcare challenges, efforts to expedite this natural process have intensified. Fortunately, with a particular focus on improving wound dressings, significant advancements have been made in wound care management including using of nanoparticle-based delivery systems. These nanoparticles, similar to molecular messengers, purchase vast promise for revolutionizing wound treatment. Among them, chitosan nanoparticles stand out as remarkable candidates. Their safety profile, biocompatibility, and bioactivity make them particularly appealing for wound care. In this article, we will delve into the intricacies of wound healing and then discuss the wound-healing properties of chitosan nanoparticles, supported by comprehensive study results. Current evidence highlights the wound-healing effects of chitosan nanoparticles, which can be considered independent agents for wound management. In conclusion, the utilization of chitosan nanoparticles for wound healing presents significant opportunities and potential.Graphical abstract [Formula: see text].

Chitosan and Its Nanoparticles: A Multifaceted Approach to Antibacterial Applications

Chitosan, a multifaceted amino polysaccharide biopolymer derived from chitin, has extensive antibacterial efficacy against diverse pathogenic microorganisms, including both Gram-negative and Gram-positive bacteria, in addition to fungi. Over the course of the last several decades, chitosan nanoparticles (NPs), which are polymeric and bio-based, have garnered a great deal of interest as efficient antibacterial agents. This is mostly due to the fact that they are used in a wide variety of applications, including medical treatments, food, chemicals, and agricultural products. Within the context of the antibacterial mechanism of chitosan and chitosan NPs, we present a review that provides an overview of the synthesis methods, including novel procedures, and compiles the applications that have been developed in the field of biomedicine. These applications include wound healing, drug delivery, dental treatment, water purification, agriculture, and food preservation. In addition to this, we focus on the mechanisms of action and the factors that determine the antibacterial activity of chitosan and its derivatives. In conjunction with this line of inquiry, researchers are strongly urged to concentrate their efforts on developing novel and ground-breaking applications of chitosan NPs.

Biogenic selenium nanoparticles and selenium/chitosan-Nanoconjugate biosynthesized by Streptomyces parvulus MAR4 with antimicrobial and anticancer potential

BACKGROUND

As antibiotics and chemotherapeutics are no longer as efficient as they once were, multidrug resistant (MDR) pathogens and cancer are presently considered as two of the most dangerous threats to human life. In this study, Selenium nanoparticles (SeNPs) biosynthesized by Streptomyces parvulus MAR4, nano-chitosan (NCh), and their nanoconjugate (Se/Ch-nanoconjugate) were suggested to be efficacious antimicrobial and anticancer agents.

RESULTS

SeNPs biosynthesized by Streptomyces parvulus MAR4 and NCh were successfully achieved and conjugated. The biosynthesized SeNPs were spherical with a mean diameter of 94.2 nm and high stability. Yet, Se/Ch-nanoconjugate was semispherical with a 74.9 nm mean diameter and much higher stability. The SeNPs, NCh, and Se/Ch-nanoconjugate showed significant antimicrobial activity against various microbial pathogens with strong inhibitory effect on their tested metabolic key enzymes [phosphoglucose isomerase (PGI), pyruvate dehydrogenase (PDH), glucose-6-phosphate dehydrogenase (G6PDH) and nitrate reductase (NR)]; Se/Ch-nanoconjugate was the most powerful agent. Furthermore, SeNPs revealed strong cytotoxicity against HepG2 (IC50 = 13.04 μg/ml) and moderate toxicity against Caki-1 (HTB-46) tumor cell lines (IC50 = 21.35 μg/ml) but low cytotoxicity against WI-38 normal cell line (IC50 = 85.69 μg/ml). Nevertheless, Se/Ch-nanoconjugate displayed substantial cytotoxicity against HepG2 and Caki-1 (HTB-46) with IC50 values of 11.82 and 7.83 μg/ml, respectively. Consequently, Se/Ch-nanoconjugate may be more easily absorbed by both tumor cell lines. However, it exhibited very low cytotoxicity on WI-38 with IC50 of 153.3 μg/ml. Therefore, Se/Ch-nanoconjugate presented the most anticancer activity.

CONCLUSION

The biosynthesized SeNPs and Se/Ch-nanoconjugate are convincingly recommended to be used in biomedical applications as versatile and potent antimicrobial and anticancer agents ensuring notable levels of biosafety, environmental compatibility, and efficacy.

Gelatin and Chitosan as Meat By-Products and Their Recent Applications

Meat by-products such as bones, skin, horns, hooves, feet, skull, etc., are produced from slaughtered mammals. Innovative solutions are very important to achieving sustainability and obtaining the added value of meat by-products with the least impact on the environment. Gelatin, which is obtained from products high in collagen, such as dried skin and bones, is used in food processing, and pharmaceuticals. Chitosan is derived from chitin and is well recognized as an edible polymer. It is a natural product that is non-toxic and environmentally friendly. Recently, chitosan has attracted researchers' interests due to its biological activities, including antimicrobial, antitumor, and antioxidant properties. In this review, article, we highlighted the recent available information on the application of gelatin and chitosan as antioxidants, antimicrobials, food edible coating, enzyme immobilization, biologically active compound encapsulation, water treatment, and cancer diagnosis.

Antifungal Carvacrol Loaded Chitosan Nanoparticles

The increased prevalence and incidence of fungal infections, of which Candida albicans represents one of the most life-threatening organisms, is prompting the scientific community to develop novel antifungal molecules. Many essential oils components are attracting attention for their interesting antifungal activities. Given the chemical and physical characteristics of these compounds, the use of appropriate nanodelivery systems is becoming increasingly widespread. In this study, chitosan nanoparticles were prepared using an ionic gelation procedure and loaded with the phenolic monoterpene carvacrol. After a bioassay guided optimization, the best nanoparticle formulation was structurally characterized by means of different spectroscopic (UV, FTIR and DLS) and microscopy techniques (SEM) and described for their functional features (encapsulation efficiency, loading capacity and release kinetics). The antifungal activity of this formulation was assayed with different Candida spp., both in planktonic and biofilm forms. From these studies, it emerged that the carvacrol loaded nanoparticles were particularly active against planktonic forms and that the antibiofilm activity was highly dependent on the species tested, with the C. tropicalis and C. krusei strains resulting as the most susceptible.

Antibacterial Activity of Chitosan Nanoparticles: A Review

In recent years, nanotechnology has attracted attention in many fields because it has several up-and-coming novel uses. Many researchers have suggested that chitosan nanoparticles (CS-NPs) and their derivatives are one of the best nanomaterials for delivering antibacterial activity. CS-NPs have a broad spectrum of antibacterial activity, but they manifest different inhibitory efficacy against gram-negative (G−) and gram-positive (G+) bacterial species. The mechanism of antibacterial action is an intricate process that varies between G− and G+ bacteria as a result of the differences in cell wall and cell membrane chemistry. In previous studies, greater antibacterial activity was more evident against G− bacteria than G+ bacteria, whereas in some studies G+ bacteria were more sensitive. Researchers predicted that the varied responses of bacteria are caused by the mixed hydrophilicity and negative charge distribution on the bacterial surface. Moreover, its activity depends on a number of variables including bacterial target (i.e., G− or G+ bacteria) and bacterial growth, as well as its concentration, pH, zeta-potential, molecular weight, and degree of acetylation. Therefore, this review examines current research on the mechanisms and factors affecting antibacterial activity, and application of CS-NPs specifically against animal and plant pathogenic bacteria.