Myogenesis and Analysis of Antimicrobial Potential of Silver Nanoparticles (AgNPs) against Pathogenic Bacteria

Antimicrobial nanoparticle-containing food packaging films for controlling Listeria spp.: An overview

Bacteria of the genus Listeria are ubiquitous in nature and are found in various food products and food processing facilities. The species Listeria monocytogenes is a food-borne pathogen that causes listeriosis with a high fatality rate. For the prevention and control of listeriosis, the identification of effective antilisterial compounds is desirable. The number of investigations on nanoparticles (NPs) with antimicrobial activity has increased in recent years. In this context, green nanotechnology is a field of science that focuses on the synthesis of NPs through biological pathways using a wide range of microorganisms and plant extracts, which has led to the biofabrication of novel antimicrobial agents that have demonstrated remarkable potential against pathogenic bacteria. In this review, in vitro studies of the inhibitory action of antimicrobial NPs obtained by green biosynthesis, including silver, gold, zinc, zinc oxide, copper, palladium, and selenium NPs, on the growth of Listeria spp. were comprehensively summarized. This review mainly highlights antimicrobial NPs in biopolymer films against L. monocytogenes. Furthermore, studies on NPs in biopolymer-based functional food packaging films against L. monocytogenes are listed. Finally, safety considerations are indicated. This review provides an overview of the antilisterial activity of bio-based antimicrobial NPs and the potential of nanotechnology as an innovative technology for the development of food packaging films containing antimicrobial NPs to control Listeria spp.

Synthesis and characterization of gelatin/chondroitin sulfate microgels with NaCl: Preliminary research toward wound healing applications

Gelatin and chondroitin sulfate are natural polymers with significant potential in the biomedical field, particularly for wound healing applications. They can form hydrogels that absorb exudates and exhibit anti-inflammatory and antioxidant properties. Silver nanoparticles (AgNPs) can be used as antibacterial agents in wound management. Moreover, the addition of NaCl may enhance the efficacy and mechanical properties of the microgels. This study focuses on the synthesis and characterization of gelatin/chondroitin sulfate powder hydrogels, both with and without AgNPs, obtained through fungal digestion and NaCl for potential acute wound healing application. As a result, AgNPs were successfully synthesized, they are spherical with an average size of 19 ± 6 nm. Microgels were obtained via electrostatic interactions and processed using spray drying equipment, the highest yield was 50.2 ± 7.1 %. Characterization results indicated that the composition significantly influenced the yield percentage, which was greater in samples containing NaCl. Moreover, particle areas varied significantly from 6.0 ± 1.3 μm2 to 85.6 ± 35.9 μm2 with the incorporation of salt. Swelling capacities were similar over time, with highest values at 15 min exceeding 500 % under physiological conditions. Notably, microgels exhibited enhanced disintegration resistance compared to gelatin alone, making them suitable for sustained wound coverage. The incorporation of AgNPs conferred notable antimicrobial activity; however, it adversely affected erythrocyte viability. Therefore, microgels without AgNPs, particularly those containing NaCl, may be suitable for acute wounds management, while alternative methods or lower concentrations of AgNPs may be required to retain antibacterial properties.

Evaluating the MDCK cell permeability of greenly synthesize bimetallic Ag/Zn Nanoparticles using leaf extract of Vallaris solanacea as a potential antipesticide-resistant agent

Bimetallic nanoparticles, particularly Ag/Zn bimetallic nanoparticles, have gained increasing attention due to their unique properties, making them suitable for a variety of applications such as catalysis, water treatment, and environmental remediation. This study aimed to elucidate the use of bimetallic nanoparticles of Ag/Zn as an alternative to resistant pesticides for pest control. Furthermore, this research demonstrates that BNPs can target specific pollutants and degrade them through various mechanisms. BNP docking with the Nilaparvata lugens cytochrome P450 (CYP6ER1) protein exhibited the lowest binding energy of -7.5 kcal/mol. The cell permeability analysis of BNP in plant cells reveals that the BNP has 0 % permeability towards any cell at -10 kcal/mol energy, which is the lowest free energy translocation pathway. The harmful leftover residues of the pesticides have a higher chance of degradability in case of interaction with BNP validated by chemical-chemical interaction analysis. Additionally, MDCK permeability coefficient of small molecules based on the regression model was calculated for BNP which authenticated the efficiency of BNP. Moreover, Swiss ADMET simulated absorption using a boiled egg model with no blood-brain barrier and gastrointestinal crossing for the expected BNP molecule has been observed. Significantly, the findings indicate that employing bimetallic nanoparticles like Ag/Zn is a crucial strategy for bioremediation because they proficiently decompose pesticides while posing no risk to humans. Our results will facilitate the design of novel BNPs materials for environmental remediation and pest control ensuring human health safety that are predicated on bimetallic nanoparticles.

Therapeutic Potential of Silver Nanoparticles (AgNPs) as an Antimycobacterial Agent: A Comprehensive Review

The uncontrolled emergence of multidrug-resistant mycobacterial strains presents as the primary determinant of the present crisis in antimycobacterial therapeutics and underscores tuberculosis (TB) as a daunting global health concern. There is an urgent requirement for drug development for the treatment of TB. Numerous novel molecules are presently undergoing clinical investigation as part of TB drug development. However, the complex cell wall and the lifecycle of M. tuberculosis within the host pose a significant challenge to the development of new drugs and, therefore, led to a shift in research focus towards alternative antibacterial compounds, notably nanotechnology. A novel approach to TB therapy utilizing silver nanoparticles (AgNPs) holds the potential to address the medical limitations imposed by drug resistance commonly associated with currently available antibiotics. Their broad-spectrum antimicrobial activity presents the utilization of AgNPs as a promising avenue for the development of therapeutics targeting mycobacterial-induced diseases, which can effectively target Mycobacterium tuberculosis, including drug-resistant strains. AgNPs can enhance the effectiveness of traditional antibiotics, potentially leading to better treatment outcomes and a shorter duration of therapy. However, the successful implementation of this complementary strategy is contingent upon addressing several pivotal therapeutic challenges, including suboptimal delivery, variability in intra-macrophagic antimycobacterial effect, and potential toxicity. Future perspectives may involve developing targeted delivery systems that maximize therapeutic effects and minimize side effects, as well as exploring combinations with existing TB medications to enhance treatment outcomes. We have attempted to provide a comprehensive overview of the antimycobacterial activity of AgNPs, and critically analyze the advantages and limitations of employing silver nanoparticles in the treatment of TB.

Metallic nanoparticles: a promising novel therapeutic tool against antimicrobial resistance and spread of superbugs

In recent years, antimicrobial resistance (AMR) has become an alarming threat to global health as notable increase in morbidity and mortality has been ascribed to the emergence of superbugs. The increase in microbial resistance because of harboured or inherited resistomes has been complicated by the lack of new and effective antimicrobial agents, as well as misuse and failure of existing ones. These problems have generated severe and growing public health concern, due to high burden of bacterial infections resulting from scarce financial resources and poor functioning health systems, among others. It is therefore, highly pressing to search for novel and more efficacious alternatives for combating the action of these super bacteria and their infection. The application of metallic nanoparticles (MNPs) with their distinctive physical and chemical attributes appears as promising tools in fighting off these deadly superbugs. The simple, inexpensive and eco-friendly model for enhanced biologically inspired MNPs with exceptional antimicrobial effect and diverse mechanisms of action againsts multiple cell components seems to offer the most promising option and said to have enticed many researchers who now show tremendous interest. This synopsis offers critical discussion on application of MNPs as the foremost intervening strategy to curb the menace posed by the spread of superbugs. As such, this review explores how antimicrobial properties of the metallic nanoparticles which demonstrated considerable efficacy against several multi-drugs resistant bacteria, could be adopted as promising approach in subduing the threat of AMR and harvoc resulting from the spread of superbugs.

Optimal Enzyme-Assisted Extraction of Phenolics from Leaves of Pongamia pinnata via Response Surface Methodology and Artificial Neural Networking

This research work seeks to evaluate the impact of selected enzyme complexes on the optimised release of phenolics from leaves of Pongamia pinnata. After preliminary solvent extraction, the P. pinnata leaf extract was subjected to enzymatic treatment, using enzyme cocktails such as kemzyme dry-plus, natuzyme, and zympex-014. It was noticed that zympex-014 had a greater extract yield (28.0%) than kemzyme dry-plus (17.0%) and natuzyme (18.0%). Based on the better outcomes, zympex-014-based extract values were subsequently applied to several RSM parameters. The selected model is suggested to be significant by the F value (12.50) and R2 value (0.9669). The applicability of the ANN model was shown by how closely the projected values from the ANN were to the experimental values. In terms of total phenolic contents (18.61 mg GAE/g), total flavonoid contents (12.56 mg CE/g), and DPPH test (IC50) (6.5 g/mL), antioxidant activities also shown significant findings. SEM analysis also revealed that the cell walls were damaged during enzymatic hydrolysis, as opposed to non-hydrolysed material. Using GC-MS, five potent phenolic compounds were identified in P. pinnata extract. According to the findings of this study, the recovery of phenolic bioactives and subsequent increase in the antioxidant capacity of P. pinnata leaf extract were both positively impacted by the optimisation approaches suggested, including the use of zympex-014.

Advancing biomedical applications: an in-depth analysis of silver nanoparticles in antimicrobial, anticancer, and wound healing roles

Introduction: Silver nanoparticles (AgNPs) have gained significant attention in biomedical applications due to their unique physicochemical properties. This review focuses on the roles of AgNPs in antimicrobial activity, anticancer therapy, and wound healing, highlighting their potential to address critical health challenges. Methods: A bibliometric analysis was conducted using publications from the Scopus database, covering research from 2002 to 2024. The study included keyword frequency, citation patterns, and authorship networks. Data was curated with Zotero and analyzed using Bibliometrix R and VOSviewer for network visualizations. Results: The study revealed an increasing trend in research on AgNPs, particularly in antimicrobial applications, leading to 8,668 publications. Anticancer and wound healing applications followed, with significant contributions from India and China. The analysis showed a growing focus on "green synthesis" methods, highlighting a shift towards sustainable production. Key findings indicated the effectiveness of AgNPs in combating multidrug-resistant bacteria, inducing apoptosis in cancer cells, and promoting tissue regeneration in wound healing. Discussion: The widespread research and applications of AgNPs underscore their versatility in medical interventions. The study emphasizes the need for sustainable synthesis methods and highlights the potential risks, such as long-term toxicity and environmental impacts. Future research should focus on optimizing AgNP formulations for clinical use and further understanding their mechanisms of action. Conclusion: AgNPs play a pivotal role in modern medicine, particularly in addressing antimicrobial resistance, cancer treatment, and wound management. Ongoing research and international collaboration are crucial for advancing the safe and effective use of AgNPs in healthcare.

Surface Charge-Modulated Toxicity of Cysteine-Stabilized Silver Nanoparticles

The toxicity of silver nanoparticles (AgNPs) depends on their physicochemical properties. The ongoing research aims to develop effective methods for modifying AgNPs using molecules that enable control over the processes induced by nanoparticles in both normal and cancerous cells. Application of amino acid-stabilized nanoparticles appears promising, exhibiting tunable electrokinetic properties. Therefore, this study focused on determining the influence of the surface charge of cysteine (CYS)-stabilized AgNPs on their toxicity towards human normal B (COLO-720L) and T (HUT-78) lymphocyte cell lines. CYS-AgNPs were synthesized via the chemical reduction. Transmission electron microcopy (TEM) imaging revealed that they exhibited a quasi-spherical shape with an average size of 18 ± 3 nm. CYS-AgNPs remained stable under mild acidic (pH 4.0) and alkaline (7.4 and 9.0) conditions, with an isoelectric point observed at pH 5.1. Following a 24 h treatment of lymphocytes with CYS-AgNPs, concentration-dependent alterations in cell morphology were observed. Positively charged CYS-AgNPs notably decreased lymphocyte viability. Furthermore, they exhibited grater genotoxicity and more pronounced disruption of biological membranes compared to negatively charged CYZ-AgNPs. Despite both types of AgNPs interacting similarly with fetal bovine serum (FBS) and showing comparable profiles of silver ion release, the biological assays consistently revealed that the positively charged CYS-AgNPs exerted stronger effects at all investigated cellular levels. Although both types of CYS-AgNPs have the same chemical structure in their stabilizing layers, the pH-induced alterations in their surface charge significantly affect their biological activity.

In vitro antimicrobial activity of silver nanoparticles against selected Gram-negative and Gram-positive pathogens

Background and aim

Infections caused by pathogenic bacteria increase patient morbidity and mortality and significantly raise treatment costs. The use of silver nanoparticles as an alternative treatment for S aureus, E coli, MRSA, E faecalis, K pneumoniae and P aeruginosa indicates their antibacterial effect and prompts medical research to consider the next generation of antibacterial drugs that could change antibiotic therapy. By combining silver nanoparticles with different classes of antibiotics, the antibacterial effect is evidenced by increased values of the inhibition zone compared to the values obtained for some antibiotics commonly used in the treatment of bacterial infections. This study focuses on comparing the antibacterial activity of antibiotics versus antibiotics combined with silver nanoparticles against various bacteria, by comparing inhibition zones obtained for both. We aim to prove that the size of the inhibition zone for antibiotics combined with silver nanoparticles is greater, thus confirming the improved antibacterial effect.

Metods

In this study we tested the antibacterial activity of solutions of silver nanoparticles alone or in combination with different antibiotics. We used standard bacterial strains, ATCC, both Gram positive bacteria Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, as well as Gram negative bacteria Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, but also on clinical isolates: a strain MRSA (Methicillin Resistant Staphylococcus aureus) and a PDR strain (pan drug resistant) of Klebsiella pneumoniae. Bacterial identification was performed using Vitek MS analyzer (bioMerieux). Antibiotic susceptibility determination was performed with VITEK2 COMPACT SYSTEM (bio Merieux, Inc Durham NC) with ready to use VITEK AST cards. The interpretation of the results was done in compliance with EUCAST 2023-2024 standards. Testing was performed for several classes of antibiotics, silver nanoparticle solutions in 2 concentrations (10 μg/mL and 100 μg/mL) and for combinations of antibiotics with silver nanoparticle solutions. The diameter of the inhibition zone (ZOI) for silver nanoparticles, antibiotics and silver nanoparticles combined with antibiotic against each bacterium was expressed in millimeters. The Kirby-Bauer disk-diffusion method, in accordance with current EUCAST standards, was used to analyze the antibacterial effect of antibiotics, silver nanoparticles, and antibiotics combined with silver nanoparticles at biocompatible doses of 10 and 100 μg/mL. The experiments were conducted in triplicate, and the results were almost identical.

Results

The results of this study show that the silver nanoparticles displayed antibacterial activity, proven by the appearance of the inhibition zone, in various sizes, for all bacteria studied. The antibiotic classes tested were beta-lactamins, first, second, third and fourth generation cephalosporins, macrolides, fluoroquinolones, lincosamides, aminoglycosides, glycopeptides, tetracyclines, oxazolidinones, sulfonamides, rifamycins, amphenicols. Testing S aureus ATCC 29213, the highest zone of inhibition was demonstrated for cephalosporins (32.6667 ± 0.701 mm), macrolides (31.6667 ± 0.701 mm, and lincosamides (29.6667 ± 0.701 mm). Testing MRSA (internal code GR0333), the highest zone of inhibition for combination of silver nanoparticles and antibiotics was demonstrated for fluoroquinolones (36.3333 ± 0.701 mm), lincosamides (32.3333 ± 0.701 mm), Fusid acid (32.3333 ± 0.701 mm) and aminoglicosides (31.3333 ± 0.701 mm). Testing E coli ATCC 25922 the highest zone of inhibition was for Fosfomycine, 39 mm and for E faecalis ATCC 29212 for aminoglicosides was 19 mm. For K pneumoniae (internal code GQ8575) the inhibition zone for silver nanoparticles 100 μg/mL was 12.3333 ± 0.701 mm and for P aeruginosa ATCC 27253 was 16 ± 1.214 mm.

Conclusions

The use of metallic nanoparticles, especially silver ones, as antimicrobial agents with definite bactericidal activity has led medical specialists to consider this new treatment which may change antibacterial therapy. Studies of in vitro combinations between silver nanoparticles and different classes of antibiotics represent a highly efficient and effective new antibacterial treatment against multidrug-resistant bacteria. To avoid the problem of antimicrobial resistance associated with conventional antibiotics, it is necessary to understand the adaptive mechanisms of bacteria under the action of metal nanoparticles, which could be exploited in future studies. Further in vitro and in vivo studies that would assess specify the biocompatibility and toxicity of silver nanoparticles will make these super nanomaterials the medicines of the future.

Characterization and antibacterial evaluation of Eco-friendly silver nanoparticles synthesized by halophilic Streptomyces rochei SSCM102 isolated from mangrove sediment

BACKGROUND

Antimicrobial resistance has surged due to widespread antimicrobial drug use, prompting interest in biosynthesizing nanoparticles from marine-derived actinomycetes extracellular metabolites, valued for their diverse bioactive compounds. This approach holds promise for addressing the urgent need for novel antimicrobial agents. The current study aimed to characterize novel bioactive compounds from unexplored biodiversity hotspots, halophilic Streptomyces sp. isolated from mangrove sediment in the Pichavaram region, India.

METHODS AND RESULTS

Streptomyces rochei SSCM102 was conclusively identified through morphological and molecular characterization. Synthesis of silver nanoparticles (AgNPs) from Streptomyces rochei SSCM102 was characterized using various techniques, including UV-Vis, XRD, SEM, EDX, and FT-IR. The UV-Vis spectrum of the reduced AgNPs exhibited a prominent peak at 380 nm, confirming the AgNPs. The UV-Vis spectrum confirmed the synthesis of AgNP, and SEM analysis revealed a cubic morphology with sizes ranging from 11 to 21 nm. The FTIR spectrum demonstrated a shift in frequency widths between 626 cm-1 and 3432 cm-1. The EDX analysis substantiated the presence of metallic silver, evident from a strong band at 1.44 keV. The synthesized AgNPs exhibited antibacterial efficacy against human pathogens Escherichia coli (64 ± 0.32 µg/ml), Klebsiella pneumoniae (32 ± 0.16 µg/ml), and Pseudomonas aeruginosa (16 ± 0.08 µg/ml) by MIC and MBC values of 128 ± 0.64 (µg/ml), 64 ± 0.32 (µg/ml) and 32 ± 0.16 (µg/ml), respectively. Additionally, at a concentration of 400 µg/ml, the AgNPs displayed a 72% inhibition of DPPH radicals, indicating notable antioxidant capacity. The LC50 value of 130 µg/mL indicates that the green-synthesized AgNPs have lower toxicity by Brine Shrimp Larvae assay.

CONCLUSION

The study's novel approach to synthesizing eco-friendly silver nanoparticles using Halophilic Streptomyces rochei SSCM102 contributes significantly to the field of biomedical research and drug development. By demonstrating potent antibacterial properties and aligning with sustainability goals, these nanoparticles offer promising avenues for novel antibacterial therapies.

Decoding antimicrobial resistance: unraveling molecular mechanisms and targeted strategies

Antimicrobial resistance poses a significant global health threat, necessitating innovative approaches for combatting it. This review explores various mechanisms of antimicrobial resistance observed in various strains of bacteria. We examine various strategies, including antimicrobial peptides (AMPs), novel antimicrobial materials, drug delivery systems, vaccines, antibody therapies, and non-traditional antibiotic treatments. Through a comprehensive literature review, the efficacy and challenges of these strategies are evaluated. Findings reveal the potential of AMPs in combating resistance due to their unique mechanisms and lower propensity for resistance development. Additionally, novel drug delivery systems, such as nanoparticles, show promise in enhancing antibiotic efficacy and overcoming resistance mechanisms. Vaccines and antibody therapies offer preventive measures, although challenges exist in their development. Non-traditional antibiotic treatments, including CRISPR-Cas systems, present alternative approaches to combat resistance. Overall, this review underscores the importance of multifaceted strategies and coordinated global efforts to address antimicrobial resistance effectively.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Phyto-synthesized silver nanoparticles from Sargassum subrepandum: anticancer, antimicrobial, and molluscicidal activities

In the realm of nanotechnology, the use of algae to produce nanoparticles is an environmentally friendly, sustainable, and economically viable strategy. In the present study, the brown macroalgae Sargassum subrepandum was utilized to effectively produce silver nanoparticles (AgNPs). Through various characterization techniques, the AgNPs' structural integrity was confirmed. AgNPs exhibited significant antimicrobial activity against Pseudomonas aeruginosa and Fusarium equiseti. AgNPs showed cytotoxic effects on the MCF-7 breast adenocarcinoma cell line with an IC50 of 12.5 µg/ml. Treatment with AgNPs resulted in a marked reduction in cell viability, alongside evident apoptotic and necrotic morphological changes in the cancer cells. Through molecular docking studies, a deeper understanding of the interaction between AgNPs and crucial proteins related to cancer has been achieved, AgNPs showed a promising molluscicidal action on Biomphalaria alexandrina snails, a Schistosoma mansoni intermediate host. The half-lethal dose (LC50) of AgNPs was determined to be 0.84 mg/L. The potential consequences of its administration include potential disruptions to the glycolysis profile, as well as potential impacts on the steroidal hormone's estrogen and testosterone and certain kidney function tests. This study highlights the diverse uses of algae-synthesized AgNPs, ranging from healthcare to environmental management, demonstrating their importance in advancing nano-biotechnological solutions.

Synthesis of Iron Oxide Nanoparticles from Madhuca indica Plant Extract and Assessment of Their Cytotoxic, Antioxidant, Anti-Inflammatory, and Anti-Diabetic Properties via Different Nanoinformatics Approaches

Recently, nanobiotechnology has attracted a lot of attention, as it is a rapidly emerging field that is still growing and developing efficient and advanced therapeutic protocols under the umbrella of nanomedicine. It can revolutionize solutions to biomedical problems by developing effective treatment protocols and therapeutics. However, focus and research are still required to make these therapeutics more effective and safer to use. In this study, iron oxide nanoparticles were synthesized from Madhuca indica extract using green synthesis protocols. The nanoparticles were further characterized based on their absorption spectrum, size, structural morphology, and other related parameters. Biological assays were also performed to evaluate biological applications for the synthesized nanoparticles. In silico analysis was performed to assess the druglike properties of synthesized nanoparticles. The results proved an optimized synthesis of the iron oxide nanoparticles with the size of 56 nm confirmed by SEM. The FTIR analysis predicted the presence of nitro and carbonyl groups in the synthesized nanoparticles. The 81% DPPH inhibition confirmed the antioxidant activity, and the 96.20% inhibition of egg albumin protein confirmed the anti-inflamatory activity. Additionally, the 73.26% inhibition of α-amylase, which was more than that of the control used, confirmed the antidiabetic activity. The ADMET analysis confirmed the synthesized nanoparticles as potential therapeutic candidates as well. However, further evaluation for safety concerns is still required to use these FeONPs as potential therapeutic agents. This study can be proved as a significant contribution to the scientific community and a gateway to the future scientists who are willing to work on nanomedicine and nanobiotechnology. ADMET analysis confirmed the synthesized nanoparticles as potential therapeutic candidates as well. However, further evaluation for safety concerns is still required to use these FeONPs and potential therapeutic agents.

Dandelion flower-fabricated Ag nanoparticles versus synthetic ones with characterization and determination of photocatalytic, antioxidant, antibacterial, and α-glucosidase inhibitory activities

In the present work, Silver nanoparticles (AgNPs) were fabricated through the dandelion flower hydroalcoholic extract, and their properties were characterized by FTIR, XRD, UV visible, SEM, and EDX. The results demonstrated that the average diameter of the green fabricated AgNPs is 45-55 nm (G-AgNPs). The antioxidant, antimicrobial, antidiabetic, and photocatalytic properties of G-AgNPs were compared with two commercially available different diameter sizes (20 and 80-100 nm) of AgNPs (C-AgNPs1- and C-AgNPs2, respectively). The sample's capacity for antioxidants was evaluated by DPPH free radical scavenging method. The consequences showed that G-AgNPs have higher radical scavenging activity (47.8%) than C-AgNPs2 (39.49%) and C-AgNPs1 (33.91%). To investigate the photocatalytic property, methylene blue dye was used. The results displayed that G-AgNPs is an effective photo-catalyst compared to C-AgNPs2 and C-AgNPs1, which respectively have an inhibition potential of 75.22, 51.94, and 56.65%. Also, the antimicrobial capacity of nanoparticles was assayed against, the gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria. The results indicated that G-AgNPs could effectively inhibit the growth of both bacteria, compared to C-AgNPs1 and C-AgNPs2. Finally, G-AgNPs exhibited a considerable α-glucosidase enzyme inhibitory effect (88.37%) in comparison with C-AgNPs1 (61.7%) and C-AgNPs2 (50.5%).

Planophila laetevirens-Mediated Synthesis of Silver Nanoparticles: Optimization, Characterization, and Anticancer and Antibacterial Potentials

Algal-mediated synthesis of nanoparticles (NPs) opens the horizon for green and sustainable synthesis of NPs that can be used in many fields, such as medicine and industry. We extracellularly synthesized silver NPs (Ag-NPs) using the novel microalgae Planophila laetevirens under optimized conditions. The isolate was collected from freshwater/soil, purified, morphologically identified, and genetically identified using light, inverted light, scanning electron microscopy, and 18S rRNA sequencing. The phytochemicals in the algal extract were detected by GC-MS. Aqueous biomass extracts and cell-free media were used to reduce silver nitrate to Ag-NPs. To get small, uniformly shaped, and stable Ag-NPs, various abiotic parameters, including precursor concentration, the ratio between the reductant and precursor, temperature, time of temperature exposure, pH, illumination, and incubation time, were controlled during the synthesis of Ag-NPs. B-P@Ag-NPs and S-P@Ag-NPs (Ag-NPs synthesized using biomass and cell-free medium, respectively) were characterized using UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis (EDX) and mapping, Fourier transform infrared (FTIR) spectroscopy, and a zeta sizer. S-P@Ag-NPs had a smaller size (10.8 ± 0.3 nm) than B-P@Ag-NPs (19.0 ± 0.6 nm), while their shapes were uniform quasispherical (S-P@Ag-NPs) and spherical to oval (B-P@Ag-NPs). EDX and mapping analyses demonstrated that Ag was the dominant element in the B-P@Ag-NP and S-P@Ag-NP samples, while FTIR revealed the presence of O-H, C-H, N-H, and C-O groups, indicating that polysaccharides and proteins acted as reductants, while polysaccharides/fatty acids acted as stabilizers during the synthesis of NPs. The hydrodynamic diameters of B-P@Ag-NPs and S-P@Ag-NPs were 37.7 and 28.3 nm, respectively, with negative charges on their surfaces, suggesting their colloidal stability. Anticancer activities against colon cancer (Sw620 and HT-29 cells), breast cancer (MDA-MB231 and MCF-7 cells), and normal human fibroblasts (HFs) were screened using the MTT assay. B-P@Ag-NPs and S-P@Ag-NPs had a greater antiproliferative effect against colon cancer than against breast cancer, with biocompatibility against HFs. The biocidal effects of the B-P@Ag-NPs and S-P@Ag-NPs were evaluated against Escherichia coli, Bacillus cereus, and Bacillus subtilis using agar well diffusion and resazurin dye assays. B-P@Ag-NPs and S-P@Ag-NPs caused higher growth inhibition of Gram-negative bacteria than of Gram-positive bacteria. B-P@Ag-NPs and S-P@Ag-NPs synthesized by P. laetevirens are promising antitumor and biocidal agents.

Enhancement of shelf-life of food items via immobilized enzyme nanoparticles on varied supports. A sustainable approach towards food safety and sustainability

This study was designed to extend the shelf life of fruits and vegetables through a novel technique based on utilization of microbially driven enzyme glucose oxidase and casting a fine layer of hydrogen peroxide on the food item that protected the fruit from decay. The produced nanoparticles (ZnO, Ag) were ligated with Glucose Oxidize (GOx) purified from Aspergillus niger. Post ligation studies revealed that ligated enzymes display relatively enhanced activity. Four types of sprays were prepared in order to compare their effectiveness. Glucose oxidase/silver nanoparticles (GOx/AgNPs), glucose oxidase/zinc oxide nanoparticles (GOx/ZnONPs), AgNPs and ZnONPs sprays were applied to guava fruit samples as post-harvest therapeutic agents for a period of 15 days. Fruit quality parameters such as total suspended solids (TSS), pH, weight loss, DPPH free radical capturing performance and firmness confirms that usage of the bioconjugates especially that of GOx/ZnONP was curiously active to maintain the physical appearance of fruit well along with no such deterioration in chemical composition of fruit. Consequently, enzymes ligated on the surface of nanoparticles (ZnONP) are exceptional for extension of post-harvest shelf life of fruits such as guava.

Entomopathogenic Fungi: An Eco-Friendly Synthesis of Sustainable Nanoparticles and Their Nanopesticide Properties

The agricultural industry could undergo significant changes due to the revolutionary potential of nanotechnology. Nanotechnology has a broad range of possible applications and advantages, including insect pest management using treatments based on nanoparticle insecticides. Conventional techniques, such as integrated pest management, are inadequate, and using chemical pesticides has negative consequences. As a result, nanotechnology would provide ecologically beneficial and effective alternatives for insect pest control. Considering the remarkable traits they exhibit, silver nanoparticles (AgNPs) are recognized as potential prospects in agriculture. Due to their efficiency and great biocompatibility, the utilization of biologically synthesized nanosilver in insect pest control has significantly increased nowadays. Silver nanoparticles have been produced using a wide range of microbes and plants, which is considered an environmentally friendly method. However, among all, entomopathogenic fungi (EPF) have the most potential to be used in the biosynthesis of silver nanoparticles with a variety of properties. Therefore, in this review, different ways to get rid of agricultural pests have been discussed, with a focus on the importance and growing popularity of biosynthesized nanosilver, especially silver nanoparticles made from fungi that kill insects. Finally, the review highlights the need for further studies so that the efficiency of bio-nanosilver could be tested for field application and the exact mode of action of silver nanoparticles against pests can be elucidated, which will eventually be a boon to the agricultural industry for putting a check on pest populations.

Molecular Characterization of spa, hld, fmhA, and lukD Genes and Computational Modeling the Multidrug Resistance of Staphylococcus Species through Callindra harrisii Silver Nanoparticles

The problem of multidrug resistance in bacterial pathogens is significant and is related to the high morbidity and death rates of living things due to increased levels of beta-lactamases. Plant-derived nanoparticles have gained a great significance in the field of science and technology to combat bacterial diseases, especially multidrug-resistant bacteria. This study examines the multidrug resistance and virulent genes of identified pathogenic Staphylococcus species obtained from Molecular Biotechnology and Bioinformatics Laboratory (MBBL), culture collection. The polymerase chain reaction-based characterization of Staphylococcus aureus and Staphylococcus argenteus having ON875315.1 and ON876003.1 accession IDs revealed the presence of the spa, LukD, fmhA, and hld genes. The green synthesis of silver nanoparticles (AgNPs) was carried out by utilizing the leaf extract of Calliandra harrisii, of which metabolites act as capping and reducing agents for the precursor of nano-synthesis, i.e., AgNO₃ of 0.25 M. The synthesized AgNPs were characterized via UV-vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis which inferred the bead-like shape of our nanoparticles with the size of 2.21 nm with the existence of aromatic and hydroxyl functional groups at surface plasmon resonance of 477 nm. The antimicrobial activity by AgNPs showed 20 mm inhibition of Staphylococcus species as compared to the vancomycin and cefoxitin antibiotics along with crude plant extract, which showed a minimum zone of inhibition. The synthesized AgNPs were also analyzed for various biological activities like anti-inflammatory with 99.15% inhibition in protein denaturation, antioxidant with 99.8% inhibition in free radical scavenging, antidiabetic with 90.56% inhibition of alpha amylase assay, and anti-haemolytic with 89.9% inhibition in cell lysis which shows good bioavailability and biocompatibility of the nanoparticles with the biological system of the living being. The amplified genes (spa, LukD, fmhA, and hld) were also analyzed for their interaction with AgNPs computationally at the molecular level. The 3-D structure of AgNP and amplified genes was retrieved from ChemSpider (ID: 22394) and Phyre2 online server, respectively. The binding affinities of AgNP with spa, LukD, fmhA, and hld were -7.16, -6.5, -6.45, and -3.3 kJ/mol, respectively, which infers a good docking score except of hld which is -3.3 kJ/mol due to its small size. The salient features of biosynthesized AgNPs proved to be an effective approach in combating the multidrug-resistant Staphylococcus species in the future.

Particle Nanoarchitectonics for Nanomedicine and Nanotherapeutic Drugs with Special Emphasis on Nasal Drugs and Aging

Aging is a multifunctional physiological manifestation. The nasal cavity is considered a major site for easy and cost-effective drug and vaccine administration, due to high permeability, low enzymatic activity, and the presence of a high number of immunocompetent cells. This review article primarily focuses on aging genetics, physical parameters, and the use of nanoparticles as delivery systems of drugs and vaccines via the nasal cavity. Studies have identified various genes involved in centenarian and average-aged people. VEGF is a key mediator involved in angiogenesis. Different therapeutic approaches induce vascular function and angiogenesis. FOLR1 gene codes for folate receptor alpha protein that helps in regulating the transport of vitamin B folate, 5-methyltetrahydrofolate and folate analogs inside the cell. This gene also aids in slowing the aging process down by cellular regeneration and promotes healthy aging by reducing aging symptoms. It has been found through the literature that GATA 6, Yamanaka factors, and FOLR1 work in synchronization to induce healthy and delayed aging. The role and applications of genes including CBS, CISD, SIRT 1, and SIRT 6 play a significant role in aging.