In vivo bio-distribution and acute toxicity evaluation of greenly synthesized ultra-small gold nanoparticles with different biological activities

Ligand Shell Thickness of PEGylated Gold Nanoparticles Controls Cellular Uptake and Radiation Enhancement

The drive to improve the safety and efficacy of radiotherapies for cancers has prompted the development of nanomaterials that can locally amplify the radiation dose at a tumor without damaging the surrounding healthy tissue. Gold nanoparticles (Au NPs), in particular, exhibit promising radiosensitizing properties under kilovolt X-ray exposure, although the precise mechanism behind this enhancement is not fully understood. While most studies recognize the involvement of factors such as core composition, size, shape, and ligand chemistry in the effectiveness of Au NPs for radiation-induced cancer treatment, there is a scarcity of direct assessments that connect the photophysical properties of the nanomaterial with the observed cellular or biological outcomes. Despite previous evidence of low-energy electron (LEE) emission from Au NPs and their potential to initiate biological damage, to our knowledge, no studies directly correlate the secondary LEE emission with radiation-induced cell death. In this study we assessed Au NPs functionalized with polyethylene glycol (PEG) ligands of varying molecular weights and lengths (1, 5, and 20 kDa PEG) as potential radiosensitizers of A549 lung cancer cells using kilovolt X-ray source potentials (33-130 kVp). We assessed NP internalization using mass cytometry, radiation dose enhancement using clonogenic survival assays, and secondary LEE emission using a retarding field analyzer. Results reveal a statistically significant difference in cellular uptake and radiation dose enhancement for 5 kDa PEG-Au NPs compared to formulations using 1 and 20 kDa PEG, while analysis of secondary LEE emission spectra demonstrated that differences in the length of the PEG ligand did not cause statistically significant attenuation of secondary LEE flux. Consequently, we inferred increased cellular uptake of NPs to be the cause for the observed enhancement in radiosensitivity for 5 kDa PEGylated Au NPs. The approach used in this study establishes a more complete workflow for designing and characterizing the performance of nanomaterial radiosensitizers, allowing for quantification of secondary LEEs and cellular uptake, and ultimately correlation with localized dose enhancement that leads to cell death.

Green Innovation and Synthesis of Honeybee Products-Mediated Nanoparticles: Potential Approaches and Wide Applications

Bee products, abundant in bioactive ingredients, have been utilized in both traditional and contemporary medicine. Their antioxidant, antimicrobial, and anti-inflammatory properties make them valuable for food, preservation, and cosmetics applications. Honeybees are a vast reservoir of potentially beneficial products such as honey, bee pollen, bee bread, beeswax, bee venom, and royal jelly. These products are rich in metabolites vital to human health, including proteins, amino acids, peptides, enzymes, sugars, vitamins, polyphenols, flavonoids, and minerals. The advancement of nanotechnology has led to a continuous search for new natural sources that can facilitate the easy, low-cost, and eco-friendly synthesis of nanomaterials. Nanoparticles (NPs) are actively synthesized using honeybee products, which serve dual purposes in preventive and interceptive treatment strategies due to their richness in essential metabolites. This review aims to highlight the potential role of bee products in this line and their applications as catalysts and food preservatives and to point out their anticancer, antibacterial, antifungal, and antioxidant underlying impacts. The research used several online databases, namely Google Scholar, Science Direct, and Sci Finder. The overall findings suggest that these bee-derived substances exhibit remarkable properties, making them promising candidates for the economical and eco-friendly production of NPs.

Nanoencapsulation of extracts and isolated compounds of plant origin and their cytotoxic effects on breast and cervical cancer treatments: Advantages and new challenges

This review analyzes the current progress in loaded nanoparticles (NPs) of plant extracts or isolated antineoplastic compounds used in breast and cervical cancer treatments. Also, it provides a comprehensive overview of the contributions made by traditional medicine and nanomedicine to the research of two of the most prevalent types of cancer in women worldwide: breast and cervical cancer. Searches were conducted in electronic databases to gather relevant information related to the biological activity of the NPs, which were meticulously reviewed. Nanomedicine has advanced to incorporate plant compounds including their crude extracts, in the preparation of NPs. The most used method is green synthesis, whose most outstanding advantages, is the reduced preparation time, and the variety of results that can be obtained depending on the reaction times, pH, temperature, and concentration of both the bio-reducing agent and the compound or plant extract. Most of the studies focus on evaluating crude extracts with high polarity, such as aqueous, alcoholic, and hydroalcoholic extracts. In conclusion, exploring the use of organic compounds is considered an area of opportunity for further research and future perspectives. Most of the analyzed studies were conducted using in vitro assays, highlighting the relatively recent nature of this field. It is expected that future research will involve more in vivo assays, particularly focusing on isolated cell lines representing the most difficult-to-treat types of cancer, such as triple-negative breast cancer like MDA-MB-231. Notably the MCF-7 cell line is one of the most used, while limited studies were found concerning cervical cancer.

Green biologically synthesized metal nanoparticles: biological applications, optimizations and future prospects

In green biological synthesis, metal nanoparticles are produced by plants or microorganisms. Since it is ecologically friendly, economically viable and sustainable, this method is preferable to other traditional ones. For their continuous groundbreaking advancements and myriad physiochemical and biological benefits, nanotechnologies have influenced various aspects of scientific fields. Metal nanoparticles (MNPs) are the field anchor for their outstanding optical, electrical and chemical capabilities that outperform their regular-sized counterparts. This review discusses the most current biosynthesized metal nanoparticles synthesized by various organisms and their biological applications along with the key elements involved in MNP green synthesis. The review is displayed in a manner that will impart assertiveness, help the researchers to open questions, and highlight many points for conducting future research.

Biomolecular Corona of Gold Nanoparticles: The Urgent Need for Strong Roots to Grow Strong Branches

Gold nanoparticles (GNPs) are largely employed in diagnostics/biosensors and are among the most investigated nanomaterials in biology/medicine. However, few GNP-based nanoformulations have received FDA approval to date, and promising in vitro studies have failed to translate to in vivo efficacy. One key factor is that biological fluids contain high concentrations of proteins, lipids, sugars, and metabolites, which can adsorb/interact with the GNP's surface, forming a layer called biomolecular corona (BMC). The BMC can mask prepared functionalities and target moieties, creating new surface chemistry and determining GNPs' biological fate. Here, the current knowledge is summarized on GNP-BMCs, analyzing the factors driving these interactions and the biological consequences. A partial fingerprint of GNP-BMC analyzing common patterns of composition in the literature is extrapolated. However, a red flag is also risen concerning the current lack of data availability and regulated form of knowledge on BMC. Nanomedicine is still in its infancy, and relying on recently developed analytical and informatic tools offers an unprecedented opportunity to make a leap forward. However, a restart through robust shared protocols and data sharing is necessary to obtain "stronger roots". This will create a path to exploiting BMC for human benefit, promoting the clinical translation of biomedical nanotools.

Enhanced theranostic efficacy of epirubicin-loaded SPION@MSN through co-delivery of an anti-miR-21-expressing plasmid and ZIF-8 hybridization to target colon adenocarcinoma

Using targeted drug delivery systems has emerged as a promising approach to increase the efficacy of chemotherapy, particularly in combination with gene therapy. The overexpression of miR-21 plays a crucial role in colorectal cancer (CRC) progression, and targeted inhibition of miR-21 offers significant potential for enhancing CRC chemotherapy outcomes. In this study, a theranostic system based on mesoporous silica and superparamagnetic iron oxide nanoparticles (SPION@MSNs) was synthesized as a core-shell structure. After loading epirubicin (EPI) in the open pores of MSN, the plasmid expressing anti-miR-21 (pDNA) covered the outer surface with the help of a ZIF-8 (zeolitic imidazolate framework-8) film. Afterward, polyethylene glycol (PEG) and AS1411 aptamer were conjugated to the surface to improve the protective, biocompatibility, and targeting abilities of the nanocarrier. Moreover, the physicochemical characteristics as well as the loading capacity and release profile of EPI and pDNA were fully evaluated. The uptake of the nanoparticles by CRC and normal cell lines in addition to the anticancer effects related to targeted combinational therapy were investigated in vitro. Finally, in vivo tests were performed on BALB/c mice bearing colorectal tumors to evaluate the effectiveness of the targeted nanoparticles, their possible side effects, and also their application in fluorescence and magnetic imaging in vivo. The successful synthesis of SPION@MSN-EPI/pDNA-ZIF-8-PEG-Apt nanoparticles (∼68 nm) and good loading efficiency and controlled release of EPI and pDNA were confirmed. Moreover, hemolysis and gel retardation assays demonstrated the biocompatibility and plasmid protection. Cellular uptake and expression of copGFP illustrated selective entry and transient transfection of targeted nanoparticles, consistent with the cytotoxicity results that indicated the synergistic effects of chemo-gene therapy. The results of animal studies proved the high antitumor efficiency of targeted nanoparticles with minimal tissue damage, which was in line with fluorescence and magnetic imaging results. The novel synthesized nanoparticles containing SPION@MSN-ZIF-8 were suitable for CRC theranostics, and the combined approach of chemo-gene therapy suppressed the tumor more effectively.

Biological activity comparison between ciprofloxacin loaded to silica nanoparticles and silver nanoparticles for the inhibition of Brucella melitensis

Background and Aim

Brucella melitensis is responsible for brucellosis, a highly contagious, life-threatening disease that has a high impact in low- and middle-income countries. This study aimed to compare silica nanoparticles (SiO-NPs) loaded with ciprofloxacin with silver nanoparticles (AgNPs) loaded with ciprofloxacin to evaluate the possible replacement of silver by silica to enhance biological activity and reduce cytotoxicity.

Materials and Methods

SiO-NPs and AgNPs loaded with ciprofloxacin were characterized using ultraviolet spectroscopy, scanning electron microscopy, and dynamic light scattering microscopy for size demonstration and loading efficiency. Both nanoparticles were treated with B. melitensis Rev 1 to evaluate their biological activity. Nanoparticle toxicity was also evaluated using cytotoxicity and hemolysis assays.

Results

SiO-NP was found to have a smaller size (80 nm) and higher loading efficiency with polydispersity index and zeta potential of 0.43 and 30.7 mV, respectively, compared to Ag-NP (180 nm and 0.62 and 28.3 mV, respectively). SiO-NP was potent with a minimum inhibitory concentration of 0.043 μg/mL compared to Ag-NP (0.049 μg/mL), with a lower cytotoxicity and hemolysis activity.

Conclusion

SiO-NP, as a drug delivery system for ciprofloxacin, has better antimicrobial activity against B. melitensis with lower cytotoxicity and hemolysis activity. These results can be attributed to the enhanced physical characterization and better loading efficiency when compared to Ag-NP.

Effects of Spherical and Rod-like Gold Nanoparticles on the Reactivity of Human Peripheral Blood Leukocytes

Gold nanoparticles (GNPs) are widely used in the technological and biomedical industries, which is a major driver of research on these nanoparticles. The main goal of this study was to determine the influence of GNPs (at 20, 100, and 200 μg/mL concentrations) on the reactivity of human peripheral blood leukocytes. Flow cytometry was used to evaluate the respiratory burst activity and pyroptosis in monocytes and granulocytes following incubation with GNPs for 30 and 60 min. Furthermore, the concentration of interleukin-1β (IL-1β) in human blood samples was assessed using enzyme-linked immunosorbent assay (ELISA) after their incubation with GNPs for 24 h. Under the conditions tested in the study, the GNPs did not significantly affect the production of reactive oxygen species in the granulocytes and monocytes that were not stimulated using phorbol 12-myristate 13-acetate (PMA) in comparison to the samples exposed to PMA (p < 0.05). Compared to the control sample, the greatest significant increase in the mean fluorescence intensity of the granulocytes occurred in the samples incubated with CGNPs = 100 and 200 µg/mL for tinc = 30 and 60 min (p < 0.05). From our results, we conclude that the physicochemical properties of the nanoparticles, chemical composition, and the type of nanoparticles used in the unit, along with the unit and incubation time, influence the induced toxicity.

Investigating the fate and toxicity of green synthesized gold nanoparticles in albino mice

OBJECTIVE

This study aims to investigate the acute and chronic adverse effects of ∼50 nm (nanometer) gold nanoparticles (AuNPs) synthesized using Ziziphus zizyphus leaf extract in mice.

SIGNIFICANCE

AuNPs have shown promise for medical applications, but their safety and biocompatibility need to be addressed. Understanding the potential adverse effects of AuNPs is crucial to ensure their safe use in medical applications.

METHODS

The ∼50 nm AuNPs were synthesized using Ziziphus zizyphus leaf extract and characterized using scanning electron microscopy, dynamic light scattering, and zeta potential analysis. Mice were subjected to a single intraperitoneal injection of AuNPs at a dose of 1 g/mg (grams per milligram) or a daily dose of 1 mg/kg for 28 days. Various parameters, including gold bioaccumulation, survival, behavior, body weight, and blood glucose levels, were measured. Histopathological changes and organ indices were assessed.

RESULTS

Gold levels in the blood and heart did not significantly increase with daily administration of AuNPs. However, there were proportional increases in gold content observed in the liver, spleen, and kidney, indicating effective tissue uptake. Histopathological alterations were predominantly observed in the kidney, suggesting potential tissue injury.

CONCLUSIONS

The findings of this study indicate that ∼50 nm AuNPs synthesized using Z. zizyphus leaf extract can induce adverse effects, particularly in the kidney, in mice. These results highlight the importance of addressing safety concerns when using AuNPs in medical applications. Further investigations that encompass a comprehensive set of toxicological parameters are necessary to confirm the long-term adverse effects of AuNP exposure.

Enterobacter hormaechei-Driven Novel Biosynthesis of Tin Oxide Nanoparticles and Evaluation of Their Anti-aging, Cytotoxic, and Enzyme Inhibition Potential

Nanotechnology is a research hotspot that has gained considerable interest due to its potential inferences in the bioscience, medical, and engineering disciplines. The present study uses biomass from the Enterobacter hormaechei EAF63 strain to create bio-inspired metallic tin oxide nanoparticles (SnO2 NPs). The biosynthesized NPs were extensively analyzed using UV spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FTIR) techniques. The identification of the crystalline phase was confirmed by XRD. The SEM technique elucidated the morphological characteristics and size of SnO2 NPs. SEM investigation revealed that the SnO2 NPs have a size of 10 nm with spherical morphology. The capping of NPs was confirmed by FTIR analysis that revealed the presence of different compounds found in the biomass of the E. hormaechei EAF63 strain. Later, EDX confirmed the elemental composition of NPs. Moreover, the synthesized SnO2 NPs were employed for important applications including anti-aging, anti-Alzheimer's, anti-inflammatory, anti-larvicidal, and antibacterial action against sinusitis pathogens. The highest value was observed for Streptococcus pyogenes (19.75 ± 0.46), followed by Moraxella catarrhalis (17.49 ± 0.82) and Haemophilus influenzae (15.31 ± 0.73), respectively. Among the used concentrations, the highest inhibition of 76.8 ± 0.93 for 15-lipoxygenase (15-LOX) was observed at 400 μg/mL, followed by 67.4 ± 0.91 for cyclooxygenase-1 (COX-1). So, as an outcome, E. hormaechei-mediated SnO2 NPs might be considered as the safe and effective nanoplatforms for multifunctional biological applications in the field of nanomedicine.

Nano-Chitosan/Eucalyptus Oil/Cellulose Acetate Nanofibers: Manufacturing, Antibacterial and Wound Healing Activities

Accelerated wound healing in infected skin is still one of the areas where current therapeutic tactics fall short, which highlights the critical necessity for the exploration of new therapeutic approaches. The present study aimed to encapsulate Eucalyptus oil in a nano-drug carrier to enhance its antimicrobial activity. Furthermore, in vitro, and in vivo wound healing studies of the novel nano-chitosan/Eucalyptus oil/cellulose acetate electrospun nanofibers were investigated. Eucalyptus oil showed a potent antimicrobial activity against the tested pathogens and the highest inhibition zone diameter, MIC, and MBC (15.3 mm, 16.0 μg/mL, and 256 μg/mL, respectively) were recorded against Staphylococcus aureus. Data indicated a three-fold increase in the antimicrobial activity of Eucalyptus oil encapsulated chitosan nanoparticle (43 mm inhibition zone diameter against S. aureus). The biosynthesized nanoparticles had a 48.26 nm particle size, 19.0 mV zeta potential, and 0.45 PDI. Electrospinning of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers was conducted, and the physico-chemical and biological properties revealed that the synthesized nanofibers were homogenous, with a thin diameter (98.0 nm) and a significantly high antimicrobial activity. The in vitro cytotoxic effect in a human normal melanocyte cell line (HFB4) proved an 80% cell viability using 1.5 mg/mL of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers. In vitro and in vivo wound healing studies revealed that nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers were safe and efficiently enhanced the wound-healing process through enhancing TGF-β, type I and type III collagen production. As a conclusion, the manufactured nano-chitosan/Eucalyptus oil/cellulose acetate nanofiber showed effective potentiality for its use as a wound healing dressing.

Acute toxicity study of onion peel-derived gold nano-bioconjugate

The acute anti-inflammatory activity of onion peel-derived gold nano-bioconjugate was already established earlier. The current study was aimed to investigate the acute oral toxicity of onion peel-derived gold nano-bioconjugate (GNBC) for safe therapeutic utilization in vivo. The acute toxicity study was carried out in female mice for 15 days and showed no mortality and any abnormal complications. The lethal dose (LD50) was evaluated and found to be higher than 2000 mg/kg. After 15 days, animals were euthanized and hematological, and biochemical analyses were performed. In all hematological and biochemical assays, treated animals did not show significant toxicity when compared to the control group. The body weight, behavior, and histopathological studies showed that GNBC is nontoxic. Thereby, the results suggest that onion peel-derived gold nano-bioconjugate GNBC can be utilized for therapeutic applications in vivo.

Fungal Secondary Metabolites/Dicationic Pyridinium Iodide Combinations in Combat against Multi-Drug Resistant Microorganisms

The spread of antibiotic-resistant opportunistic microbes is a huge socioeconomic burden and a growing concern for global public health. In the current study, two endophytic fungal strains were isolated from Mangifera Indica roots and identified as Aspergillus niger MT597434.1 and Trichoderma lixii KU324798.1. Secondary metabolites produced by A. niger and T. lixii were extracted and tested for their antimicrobial activity. The highest activity was noticed against Staphylococcus aureus and E. coli treated with A. niger and T. lixii secondary metabolites, respectively. A. niger crude extract was mainly composed of Pentadecanoic acid, 14-methyl-, methyl ester and 9-Octadecenoic acid (Z)-, methyl ester (26.66 and 18.01%, respectively), while T. lixii crude extract's major components were 2,4-Decadienal, (E,E) and 9-Octadecenoic acid (Z)-, and methyl ester (10.69 and 10.32%, respectively). Moreover, a comparative study between the fungal extracts and dicationic pyridinium iodide showed that the combination of A. niger and T. lixii secondary metabolites with dicationic pyridinium iodide compound showed a synergistic effect against Klebsiella pneumoniae. The combined formulae inhibited the bacterial growth after 4 to 6 h through cell wall breakage and cells deformation, with intracellular components leakage and increased ROS production.

Nanostructured γ-Al2O3 Synthesis Using an Arc Discharge Method and its Application as an Antibacterial Agent against XDR Bacteria

In the last few years, many efforts have been devoted to investigating the antibacterial activity of metal nanoparticles, especially against multidrug-resistant bacteria. Recently extensively drug-resistant (XDR) bacteria have emerged and caused a global threat. The purpose of this manuscript was to synthesize nanostructured γ-Al2O3 as an antibacterial agent against some XDRs. The results showed that Al2O3 was a mix of rod and spherical shapes in the nano range with diameters of less than 30 nm. The zeta potential was determined to estimate the surface charge for the synthesized γ-Al2O3, which was recorded as −34 ± 1.8 mV, indicating good stability. The synthesized nanostructured γ-Al2O3 showed a potent antibacterial activity against extensively drug-resistant Acinetobacter baumanii, with an inhibition zone diameter that reached 19 mm and a minimum inhibitory concentration (MIC) value that reached 2 µg/mL. The observed antibacterial activity of the prepared Al2O3 nanoparticles confirmed that the main mechanistic actions include bacterial cells apoptosis, ROS increment, cellular membrane disruption, and DNA damage. The cytotoxic effect (CC50) of the prepared γ-Al2O3-NPs was 1250 µg/mL in a normal human lung fibroblast cell line (WI-38 cells). It can be concluded that the synthesized γ-Al2O3 had an acceptable toxicity, which may pave the way for its use as a potent agent in the fight against XDR bacteria.

Arc discharge rapid synthesis of engineered copper oxides nano shapes with potent antibacterial activity against multi-drug resistant bacteria

Nowadays Nano metals have received an eminent compromise of attention. Even though different nanostructure of same metal maybe gives different results in wide range applications. Copper oxide (CuO-NPs) and Copper Nano wires (CuO-NWs) were prepared in controlled size via the alternating current Arc discharge process. Deionized water and argon gas were the chosen dielectric medium during the process to obtain 2 different forms of copper oxides. By changing the dielectric material from deionized water to argon gas the shape of CuO nanoparticles changed from spherical (CuO-NPs) to wires (CuO-NWS). The yield prepared depicted the purity of the prepared CuO, and their diameters were about 10 ± 5 nm and 30 ± 3 nm for CuO-NWs and CuO-NPs respectively. In vitro cytotoxic effect of the prepared CuO-NWs & CuO-NPs using human normal lung fibroblast cell line (WI-38 cells) revealed that CuO-NWs & CuO-NPs CC₅₀ values were 458.8 and 155.6 µg/mL respectively. Both yields showed potent antibacterial activity against different multi-drug resistant Acinetobacter baumannii strains. A complete eradication of the bacterial growth was noticed after 4 Hrs incubation with CuO-NWs. Moreover, CuO-NWs showed superior antibacterial activity (with minimum inhibitory concentration reached 1.8 µg/mL) over CuO-NPs. The detailed antibacterial activity mechanism of CuO-NWs was further investigated; data proved the precipitation and adsorption of the nanoparticles on the bacterial cell surface leading to cell deformation with reactive oxygen species increment. The results explicated that the nanoparticles shape plays an essential role in the antibacterial activity. Rotational Arc discharge machine might be a promising tool to obtain various metal nanostructures with low cost and environmentally friendly with potent activity.

Novel Amoxicillin-Loaded Sericin Biopolymeric Nanoparticles: Synthesis, Optimization, Antibacterial and Wound Healing Activities

Infected wounds are a major threat among diabetic patients. Technological advancements are currently increasing the number of new adjunctive therapies that may be potent agents for speeding recovery, lowering the amputation rate and limiting infection recurrences. A novel formula with promising antibacterial activity, namely sericin/propolis/Amoxicillin nanoparticles, was assessed as a potent treatment of infected wounds in normal and diabetic rats. Skin wound healing efficiency was assessed through wound healing scorings, bacterial load assessment and histological examinations. It was revealed that upon using sericin/propolis/Amoxicillin nanoparticles, complete wound healing was successfully achieved after 10 and 15 days postinjury for nondiabetic and diabetic rats, respectively. However, the bacterial load in the induced infected wounds was extremely low (0-10 CFU/mL) after 15 days post-treatment. The histological studies revealed that the dermis was more organized with new matrix deposition, and mature collagen fibers were observed among the treated animal groups. The present study is the first preclinical study which reported the importance of silk sericin in the form of nano-sericin/propolis loaded with Amoxicillin as an effective treatment against bacterial wound infections.

Molasses-Silver Nanoparticles: Synthesis, Optimization, Characterization, and Antibiofilm Activity

Biofilms are matrix-enclosed communities of bacteria that are highly resistant to antibiotics. Adding nanomaterials with antibacterial activity to the implant surfaces may be a great solution against biofilm formation. Due to its potent and widespread antibacterial effect, silver nanoparticles were considered the most potent agent with different biological activities. In the present investigation, silver nanoparticles (AgNPs) were newly synthesized as antibiofilm agents using sugarcane process byproduct (molasses) and named Mo-capped AgNPs. The synthesized nanoparticles showed promising antimicrobial activity against S. aureus ATCC 6538 and C. albicans DAY185. Statistically designed optimization through response surface methodology was evaluated for maximum activity and better physical characteristics, namely the nanoparticles’ size and polydispersity index (PDI), and it was revealed that molasses concentration was the main effective factor. Minimal biofilm eradication concentration (MBEC) of Mo-capped AgNPs against S. aureus ATCC 6538 and C. albicans DAY185 was 16 and 32 µg/mL, respectively. Scanning electron microscope study of Mo-capped AgNP-treated biofilm revealed that AgNPs penetrated the preformed biofilm and eradicated the microbial cells. The optimally synthesized Mo-capped AgNPs were spherically shaped, and the average size diameter ranged between 29 and 88 nm with high proportions of Ag⁺ element (78.0%) recorded. Fourier-transform infrared spectroscopy (FTIR) analysis indicated the importance of molasses ingredients in capping and stabilizing the produced silver nanoparticles.

Micrococcus lylae MW407006 Pigment: Production, Optimization, Nano-Pigment Synthesis, and Biological Activities

Simple Summary

The global crisis of increased mortality rates due to the emergence of antimicrobial resistance and cancers has increased researchers’ efforts to find new, potent solutions through implementing natural products in the pharmaceutical industry. The present investigation produced echinenone (yellowish-orange pigment) from Micrococcus lylae MW407006 with potent pharmacological activities. A response surface methodology statistical design was used to optimize the biomass production, pigment concentration, and antimicrobial activity. The Spearman correlation coefficient was assessed, which indicated a strong linear relationship between biomass production, pigment concentration, and antimicrobial activity. Nano-echinenone was physically synthesized through the ball-milling technique. The synthesized nano-echinenone showed higher pharmacological activities (antimicrobial, antioxidant, and antitumor activities) in comparison with the crude pigment. The significantly high selectivity index of the synthesized nano-echinenone proved its safety and paved the way for its possible use in the pharmaceutical industry.

Abstract

Bacterial pigments (e.g., melanin and carotenoids) are considered to be among the most important secondary metabolites due to their various pharmacological activities against cancer and microbial resistance. Different pigmented bacterial strains were isolated from soil samples from El Mahmoudiyah governance and screened for their antimicrobial activity. The most promising pigment producer was identified as Micrococcus lylae MW407006; furthermore, the produced pigment was identified as echinenone (β-carotene pigment). The pigment production was optimized through a central composite statistical design to maximize the biomass production, pigment concentration, and the antimicrobial activity. It was revealed that the most significant fermentation parameters were the glucose (as a carbon source) and asparagine (as a nitrogen source) concentrations. Nano-echinenone was synthesized using the ball milling technique, characterized, and finally assessed for potential antimicrobial, antioxidant, and antitumor activities. The data revealed that the synthesized nano-echinenone had higher antimicrobial activity than the crude pigment. The cytotoxic potency of echinenone and nano-echinenone was investigated in different cell lines (normal and cancer cells). The inhibition of cell proliferation and induction of cell death was observed in Caco-2 and Hep-G2 cells. The data proved that nano-echinenone is a suitable candidate for use as a safe antimicrobial and anti-hepatocellular-carcinoma agent.

Silver/Snail Mucous PVA Nanofibers: Electrospun Synthesis and Antibacterial and Wound Healing Activities

Healthcare textiles are gaining great attention in the textile industry. Electrospun nanofibers are considered the golden soldiers due to their strength, flexibility, and eco-friendly properties. The present study aimed to evaluate the potency of polyvinyl alcohol (PVA) nanofibers loaded with newly biosynthesized silver nanoparticles (Ag-NPs) as a wound healing dressing. Chocolate-band snail (Eobania vermiculata) mucus (which is part of the Mollusca defense system) was used as a novel reducing and stabilizing agent. Data indicated the effectiveness of Eobania vermiculata's mucus in silver nanoparticle synthesis after a 24 h incubation time. The biosynthesized AgNPs-SM showed a 13.15 nm particle size, -22.5 mV ζ potential, and 0.37 PDI, which proved the stability of the synthesized nanoparticles. Eobania vermiculata mucus and AgNPs-SM showed potent antibacterial activity, especially against Pseudomonas aeruginosa. The electrospinning technique was applied in the fabrication of PVA/AgNPs-SM nanofibers, which were homogenous with a fine diameter of about 100-170 nm and showed a significantly high antimicrobial activity. In vitro and in vivo studies revealed that PVA/AgNPs-SM nanofibers were safe and efficiently enhanced the wound healing process (typical histological picture of the proliferative phase with compact and well aligned collagen fibers in the dermal tissue after 12 days) together with bacterial growth inhibition in the infected skin area.