Response Surface Methodology Optimization of Melanin Production by Streptomyces cyaneus and Synthesis of Copper Oxide Nanoparticles Using Gamma Radiation

Bioactive Streptomycetes: A Powerful Tool to Synthesize Diverse Nanoparticles With Multifarious Properties

Nanobiotechnology has gained significant attention due to its capacity to generate substantial benefits through the integration of microbial biotechnology and nanotechnology. Among microbial organisms, Actinomycetes, particularly the prominent genus Streptomycetes, have garnered attention for their prolific production of antibiotics. Streptomycetes have emerged as pivotal contributors to the discovery of a substantial number of antibiotics and play a dominant role in combating infectious diseases on a global scale. Despite the noteworthy progress achieved through the development and utilization of antibiotics to combat infectious pathogens, the prevalence of infectious diseases remains a prominent cause of mortality worldwide, particularly among the elderly and children. The emergence of antibiotic resistance among pathogens has diminished the efficacy of antibiotics in recent decades. Nevertheless, Streptomycetes continue to demonstrate their potential by producing bioactive metabolites for the synthesis of nanoparticles. Streptomycetes are instrumental in producing nanoparticles with diverse bioactive characteristics, including antiviral, antibacterial, antifungal, antioxidant, and antitumor properties. Biologically synthesized nanoparticles have exhibited a meaningful reduction in the impact of antibiotic resistance, providing resources for the development of new and effective drugs. This review succinctly outlines the significant applications of Streptomycetes as a crucial element in nanoparticle synthesis, showcasing their potential for diverse and enhanced beneficial applications.

Interpretation of adsorption isotherm and kinetics behind fluorene degradation

The gradual release of slow-degrading polycyclic aromatic hydrocarbons into the environment creates a high level of threat to aquatic and terrestrial life worldwide. Remediation of these PAHs should be designed in such a way that it poses as few or no environmental hazards as possible. In our study, we examined the degradation ability of the synthesized MnO2 nanoparticles against fluorene. The MnO2 nanoparticle prepared was found to be spherical from the SEM analysis. XRD analysis confirms the average crystallite size as 31.8652 nm. Further, the characterization of nanoparticles was confirmed by UV-DRS, FT-IR, DLS, and HPLC techniques. The extent of adsorption potential of the synthesized nanoparticles was established from the batch adsorption studies and the kinetic and isotherm model was interpreted. The antimicrobial properties of the synthesized MnO2 nanoparticles were analyzed.

Streptomycetes as Microbial Cell Factories for the Biotechnological Production of Melanin

Melanins are complex, polymeric pigments with interesting properties like UV-light absorbance ability, metal ion chelation capacity, antimicrobial action, redox behaviors, and scavenging properties. Based on these characteristics, melanins might be applied in different industrial fields like food packaging, environmental bioremediation, and bioelectronic fields. The actual melanin manufacturing process is not environmentally friendly as it is based on extraction and purification from cuttlefish. Synthetic melanin is available on the market, but it is more expensive than animal-sourced pigment and it requires long chemical procedures. The biotechnological production of microbial melanin, instead, might be a valid alternative. Streptomycetes synthesize melanins as pigments and as extracellular products. In this review, the melanin biotechnological production processes by different Streptomyces strains have been revised according to papers in the literature. The different fermentation strategies to increase melanin production such as the optimization of growth conditions and medium composition or the use of raw sources as growth substrates are here described. Diverse downstream purification processes are also reported as well as all the different analytical methods used to characterize the melanin produced by Streptomyces strains before its application in different fields.

Green and cost-effective biofabrication of copper oxide nanoparticles: Exploring antimicrobial and anticancer applications

Nanotechnology has made remarkable advancements in recent years, revolutionizing various scientific fields, industries, and research institutions through the utilization of metal and metal oxide nanoparticles. Among these nanoparticles, copper oxide nanoparticles (CuO NPs) have garnered significant attention due to their versatile properties and wide-range applications, particularly, as effective antimicrobial and anticancer agents. CuO NPs can be synthesized using different methods, including physical, chemical, and biological approaches. However, conventional chemical and physical approaches are expensive, resource-intensive, and involve the use of hazardous chemicals, which can pose risks to human health and the environment. In contrast, biological synthesis provides a sustainable and cost-effective alternative by eliminating chemical pollutants and allowing for the production of CuO NPs of tailored sizes and shapes. This comprehensive review focused on the green synthesis of CuO NPs using various biological resources, such as plants, microorganisms, and other biological derivatives. Current knowledge and recent trends in green synthesis methods for CuO NPs are discussed, with a specific emphasis on their biomedical applications, particularly in combating cancer and microbial infections. This review highlights the significant potential of CuO NPs in addressing these diseases. By capitalizing on the advantages of biological synthesis, such as environmental safety and the ability to customize nanoparticle characteristics, CuO NPs have emerged as promising therapeutic agents for a wide range of conditions. This review presents compelling findings, demonstrating the remarkable achievements of biologically synthesized CuO NPs as novel therapeutic agents. Their unique properties and mechanisms enable effective combating against cancer cells and various harmful microbial infections. CuO NPs exhibit potent anticancer activity through diverse mechanisms, including induction of apoptosis, inhibition of angiogenesis, and modulation of signaling pathways. Additionally, their antimicrobial activity manifests through various mechanisms, such as disrupting microbial membranes, generating reactive oxygen species, and interfering with microbial enzymes. This review offers valuable insights into the substantial potential of biologically synthesized CuO NPs as an innovative approach for future therapeutic interventions against cancer and microbial infections.

Production and characterization of melanin pigment from black fungus Curvularia soli AS21 ON076460 assisted gamma rays for promising medical uses

Owing to the growing need for natural materials in different fields, studying melanin production from biological sources is imperative. In the current study, the extracellular melanin pigment was produced by the fungus Curvularia soli AS21 ON076460. The factors that affect the production of melanin were optimized by the Plackett-Burman design (P-BD). The effect of gamma irradiation on melanin productivity was investigated. The maximum melanin yield (3.376 mg/L) was elicited by a stimulus of gamma irradiation at 1.0 kGy. The results evoked that, Curvularia soli AS21 ON076460 melanin exhibited excellent antimicrobial activity against all tested bacteria and fungi. Klebsiella pneumoniae ATCC 13883 and P. digitatum were mostly affected by melanin registering the inhibition zone diameters of 37.51 ± 0.012 and 44.25 ± 0.214 mm, respectively. Moreover, Curvularia soli AS21 ON076460 melanin indicated a significant antiviral efficacy (77% inhibition) of Herpes simplex virus (HSV1). The melanin pigment showed antioxidant activities with IC50 of 42 ± 0.021 and 17 ± 0.02 µg/mL against DPPH and NO, respectively. Melanin had cytotoxic action against human breast cancer and skin cancer cell lines (Mcf7and A431) as well as exerting a low percentage of cell death against normal skin cell lines (Hfb4). Melanin was effective in wound management of human skin cells by 63.04 ± 1.83% compared with control (68.67 ± 1.10%). The novelty in the study is attributed to the possibility of using gamma rays as a safe method in small economic doses to stimulate melanin production from the fungi that have been isolated. In summary, melanin produced from fungi has significant biological activities that encourage its usage as a supportive medical route.

Study on the antibacterial effect of CuO nanoparticles on Klebsiella pneumonia bacteria: Efficient treatment for colorectal cancer

Colorectal cancer (CRC) is a widespread type of cancer across the world. One efficient therapy approach is the use of antibiotic agents, but one of the main issues related to treating CRC is microbial resistance to antibiotics. As microbes are becoming more resistant to antibiotics and other traditional antimicrobial agents, nanobiotechnology has made it possible to employ nanomaterials with the aim of creating a new generation of antimicrobial agents. In the present study, we have assessed the antimicrobial potential of CuO nanoparticles (NPs) against gram-negative bacteria like Klebsiella pneumoniae carrying PKS genes responsible for encoding colibactin as the key factor for CRC development. For this purpose, the antibacterial effects of conventional antibacterial agents, including erythromycin, piperacillin, and ampicillin, as well as CuONPs, were compared on isolated strains from cancerous candidates. The obtained results revealed that isolates (K. pneumoniae) showed resistance toward the mentioned conventional antibiotics, but CuONPs showed efficient antibacterial properties against K. pneumonia with a MIC = 62 μg/mL. On the other hand, a synergistic antibacterial effect was obtained when CuONPs were used in combination with conventional antibiotics, which are ineffective when used alone. Therefore, CuONPs can be introduced as an excellent antimicrobial agent against K. pneumoniae bacteria in CRC, especially when they are combined with other antibiotics since they can activate the antimicrobial activity of the conventional antibiotics.

Antibacterial activity of novel synthesized chitosan-graft-poly(N-tertiary butylacrylamide)/neodymium composites for biomedical application

In this present study, composites of chitosan-graft-poly(N-tertiary butylacrylamide) (CH-graft-poly(N-tert-BAAm)) copolymer, with Neodymium (Nd), an important rare earth element, were prepared by precipitation technique. Nd was successfully incorporated into the polymer of different weight percentages (0.5%, 1%, and 2%) without any degradation. The effect of neodymium additives on the structural, morphological, and antibacterial activities against gram-positive bacteria and gram-negative bacteria of the polymer was analyzed using various instrument techniques. X-ray diffraction (XRD) results together with Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) studies confirmed the morphology of Nd-doped CH-graft-poly(N-tert-BAAm) composites without any other impurities. The antibacterial effect of Nd was studied by adding it to the copolymer in a weight ratio of 0.5%-2%. The antibacterial effect of neodymium concentration on four different strains of bacteria was investigated: Escherichia coli (ATCC 25922) (E. coli), Pseudomonas aeruginosa (DSM 50071) (P. aeruginosa), Bacillus subtilis (DSM 1971) (B. subtilis), and Staphylococcus aureus subsp. aureus (ATCC 25923) (S. aureus). The antibacterial activities of the obtained composites were determined using the Agar Well Diffusion Assay Method. Experimental results show that Nd binds well to CH-graft-poly(N-tert-BAAm). Activity against E. coli, P. aeruginosa, B. subtilis, and S. aureus subsp. aureus creates a potential for pharmaceutical and biomedical applications.

Padina boergesenii-Mediated Copper Oxide Nanoparticles Synthesis, with Their Antibacterial and Anticancer Potential

The utilization of nanoparticles derived from algae has generated increasing attention owing to their environmentally sustainable characteristics and their capacity to interact harmoniously with biologically active metabolites. The present study utilized P. boergesenii for the purpose of synthesizing copper oxide nanoparticles (CuONPs), which were subsequently subjected to in vitro assessment against various bacterial pathogens and cancer cells A375. The biosynthesized CuONPs were subjected to various analytical techniques including FTIR, XRD, HRSEM, TEM, and Zeta sizer analyses in order to characterize their stability and assess their size distribution. The utilization of Fourier Transform Infrared (FTIR) analysis has provided confirmation that the algal metabolites serve to stabilize the CuONPs and function as capping agents. The X-ray diffraction (XRD) analysis revealed a distinct peak associated with the (103) plane, characterized by its sharpness and high intensity, indicating its crystalline properties. The size of the CuONPs in the tetragonal crystalline structure was measured to be 76 nm, and they exhibited a negative zeta potential. The biological assay demonstrated that the CuONPs exhibited significant antibacterial activity when tested against both Bacillus subtilis and Escherichia coli. The cytotoxic effects of CuONPs and cisplatin, when tested at a concentration of 100 µg/mL on the A375 malignant melanoma cell line, were approximately 70% and 95%, respectively. The CuONPs that were synthesized demonstrated significant potential in terms of their antibacterial properties and their ability to inhibit the growth of malignant melanoma cells.

Gamma rays-assisted bacterial synthesis of bimetallic silver-selenium nanoparticles: powerful antimicrobial, antibiofilm, antioxidant, and photocatalytic activities

BACKGROUND

Bimetallic nanoparticles (BNPs) has drawn a lot of attention especially during the last couple of decades. A bimetallic nanoparticle stands for a combination of two different metals that exhibit several new and improved physicochemical properties. Therefore, the green synthesis and design of bimetallic nanoparticles is a field worth exploring.

METHODS

In this study, we present a green synthesis of silver nanoparticles (Ag NPs), selenium (Se) NPs, and bimetallic Ag-Se NPs using Gamma irradiation and utilizing a bacterial filtrate of Bacillus paramycoides. Different Techniques such as UV-Vis., XRD, DLS, SEM, EDX, and HR-TEM, were employed for identifying the synthesized NPs. The antimicrobial and antibiofilm activities of both the Ag/Se monometallic and bimetallic Ag-Se NPs were evaluated against some standard microbial strains including, Aspergillus brasiliensis ATCC16404, Candida albicans ATCC10231, Alternaria alternate EUM108, Fusarium oxysporum EUM37, Escherichia coli ATCC11229, Bacillus cereus ATCC15442, Klebsiella pneumoniae ATCC13883, Bacillus subtilis ATCC15442, and Pseudomonas aeruginosa ATCC6538 as a model tested pathogenic microbes. The individual free radical scavenging potentials of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs were determined using the DPPH radical scavenging assay. The degradation of methylene blue (MB) dye in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was used to assess their photocatalytic behavior.

RESULTS

According to the UV-Vis. spectrophotometer, the dose of 20.0 kGy that results in Ag NPs with the highest O.D. = 3.19 at 390 nm is the most effective dose. In a similar vein, the optimal dose for the synthesis of Se NPs was 15.0 kGy dose with O.D. = 1.74 at 460 nm. With a high O.D. of 2.79 at 395 nm, the most potent dose for the formation of bimetallic Ag-Se NPs is 15.0 kGy. The recorded MIC-values for Ag-Se NPs were 62.5 µg mL- 1, and the data clearly demonstrated that C. albicans was the organism that was most susceptible to the three types of NPs. The MIC value was 125 µg mL- 1 for both Ag NPs and Se NPs. In antibiofilm assay, 5 µg mL- 1 Ag-Se NPs inhibited C. albicans with a percentage of 90.88%, E. coli with a percentage of 90.70%, and S. aureus with a percentage of 90.62%. The synthesized NPs can be arranged as follows in decreasing order of antioxidant capacity as an antioxidant result: Ag-Se NPs > Se NPs > Ag NPs. The MB dye degradation in the presence of the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs was confirmed by the decrease in the measured absorbance (at 664 nm) after 20 min of exposure to sunlight.

CONCLUSION

Our study provides insight towards the synthesis of bimetallic NPs through green methodologies, to develop synergistic combinatorial antimicrobials with possible applications in the treatment of infectious diseases caused by clinically and industrial relevant drug-resistant strains.

Unveiling anticancer, antimicrobial, and antioxidant activities of novel synthesized bimetallic boron oxide-zinc oxide nanoparticles

Bimetallic nanoparticles have received much attention recently due to their multifunctional applications, and synergistic potential at low concentrations. In the current study, bimetallic boron oxide-zinc oxide nanoparticles (B2O3-ZnO NPs) were synthesized by an eco-friendly, and cost-effective method through the utilization of gum arabic in the presence of gamma irradiation. Characterization of the synthesized bimetallic B2O3-ZnO NPs revealed the successful synthesis of bimetallic NPs on the nano-scale, and good distribution, in addition to formation of a stable colloidal nano-solution. Furthermore, the bimetallic B2O3-ZnO NPs were assessed for anticancer, antimicrobial and antioxidant activities. The evaluation of the cytotoxicity of bimetallic B2O3-ZnO NPs on Vero and Wi38 normal cell lines illustrated that bimetallic B2O3-ZnO NPs are safe in use where IC50 was 384.5 and 569.2 μg ml-1, respectively. The bimetallic B2O3-ZnO NPs had anticancer activity against Caco 2 where IC50 was 80.1 μg ml-1. Furthermore, B2O3-ZnO NPs exhibited promising antibacterial activity against E. coli, P. aeruginosa, B. subtilis and S. aureus, where MICs were 125, 62.5, 125 and 62.5 μg ml-1 respectively. Likewise, B2O3-ZnO NPs had potential antifungal activity against C. albicans as unicellular fungi (MIC was 62.5 μg ml-1). Moreover, B2O3-ZnO NPs displayed antioxidant activity (IC50 was 102.6 μg ml-1). In conclusion, novel bimetallic B2O3-ZnO NPs were successfully synthesized using gum arabic under gamma radiation, where they displayed anticancer, antimicrobial and antioxidant activities.

Optimization of Melanin Production by Streptomyces antibioticus NRRL B-1701 Using Arthrospira (Spirulina) platensis Residues Hydrolysates as Low-Cost L-tyrosine Supplement

Melanin is a functional pigment that is used in various products. It can be produced by Streptomyces antibioticus NRRL B-1701 when supplemented with L-tyrosine. Arthrospira (Spirulina) platensis is a cyanobacterium with high protein content, including the protein phycocyanin (PC). During PC's extraction, biomass residues are generated, and these residues still contain various amino acids, especially L-tyrosine, which can be used as a low-cost supplement for melanin production. Thus, this study employed a hydrolysate of A. platensis biomass residue for L-tyrosine substitution. The effects of two drying methods, namely, lyophilization and dying via a hot air oven, on the proximate composition and content of L-tyrosine in the biomass residue were evaluated. The highest L-tyrosine (0.268 g L-tyrosine/100 g dried biomass) concentration was obtained from a hot-air-oven-dried biomass residue hydrolysate (HAO-DBRH). The HAO-DBRH was then used as a low-cost L-tyrosine supplement for maximizing melanin production, which was optimized by the response surface methodology (RSM) through central composite design (CCD). Using the RSM-CCD, the maximum level of melanin production achieved was 0.24 g/L, which is approximately four times higher than it was before optimization. This result suggests that A. platensis residue hydrolysate could be an economically feasible and low-cost alternative source of L-tyrosine for the production of melanin.

Nanotechnology: a contemporary therapeutic approach in combating infections from multidrug-resistant bacteria

In the 20th century, the discovery of antibiotics played an essential role in the fight against infectious diseases, including meningitis, typhoid fever, pneumonia and Mycobacterium tuberculosis. The development of multidrug resistance in microflora due to improper antibiotic use created significant public health issues. Antibiotic resistance has increased at an alarming rate in the past few decades. Multidrug-resistant bacteria (superbugs) such as methicillin-resistant Staphylococcus aureus (MRSA) as well as drug-resistant tuberculosis pose serious health implications. Despite the continuous increase in resistant microbes, the discovery of novel antibiotics is constrained by the cost and complexities of discovery of drugs. The nanotechnology has given new hope in combating this problem. In the present review, recent developments in therapeutics utilizing nanotechnology for novel antimicrobial drug development are discussed. The nanoparticles of silver, gold and zinc oxide have proved to be efficient antimicrobial agents against multidrug-resistant Klebsiella, Pseudomonas, Escherichia Coli and MRSA. Using nanostructures as carriers for antimicrobial agents provides better bioavailability, less chances of sub-therapeutic drug accumulation and less drug-related toxicity. Nanophotothermal therapy using fullerene and antibody functionalized nanostructures are other strategies that can prove to be helpful.

Cefotaxime incorporated bimetallic silver-selenium nanoparticles: promising antimicrobial synergism, antibiofilm activity, and bacterial membrane leakage reaction mechanism

In this research, we reported for the first time the simple incorporation of antibiotic cefotaxime (CFM) with the synthesized Ag NPs, Se NPs, and bimetallic Ag-Se NPs by gamma rays, as a promising cost-effective, and eco-friendly method. The synthesized nanocomposites were characterized by UV-Vis. spectroscopy, XRD, EDX, HR-TEM, SEM/mapping, and EDX studies. The antimicrobial synergistic potential was investigated after CFM drug incorporation. Antibiofilm activity, growth curve assay, and effect of UV illumination were examined against some pathogenic microbes. The antibacterial reaction mechanism was evaluated by protein leakage assay and SEM imaging. HRTEM imaging confirmed the spherical shape and an average diameter of 10.95, 20.54, and 12.69 nm for Ag NPs, Se NPs, and Ag-Se NPs, respectively. Ag NPs-CFM, Se NPs-CFM, and Ag-Se NPs-CFM possessed antimicrobial activity against Staphylococcus aureus (40, 42, and 43 mm ZOI, respectively), Escherichia coli (33, 35, and 34 mm ZOI, respectively) and Candida albicans (25, 22, and 23 mm ZOI, respectively). CFM-incorporated Ag-Se NPs were able to inhibit biofilm formation of S. aureus (96.09%), E. coli (98.32%), and C. albicans (95.93%). Based on the promising results, the synthesized nanocomposites showed superior antimicrobial potential at low concentrations and continued-phase durability; they may find use in pharmaceutical, and biomedical applications.

Green synthesis of copper oxide nanoparticles using Abutilon indicum leaves extract and their evaluation of antibacterial, anticancer in human A549 lung and MDA-MB-231 breast cancer cells

In currently, biosynthesis of copper oxide nanoparticles (CuO NPs) are most widely used numerous in biological applications such as biosensor, energy, medicine, agriculture, environmental and industrial wastewater treatment. The hierarchical CuO NPs was synthesized via green chemistry method by using of Abutilon indicum (A. indicum) leaf extract, its nontoxic, facile and low-cost approaches. Biogenic synthesized CuO NPs was characterized by using a UV-visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Field mission scanning electron microscopy (FE-SEM) with Energy-dispersive X-ray spectroscopy (EDX) analysis. The synthesized CuO NPs was performed antibacterial activity against human pathogenic organisms of both Gram negative (Escherichia coli and Salmonella typhi) and Gram positive (Bacillus subtilis and Staphylococcus aureus) bacteria by using agar well diffusion method. Biological synthesized CuO NPs was showed potential bactericidal activity against Gram positive bacteria of B. subtilis than compared to Gram negative bacteria of E. coli. The cytotoxic effect of A. indicum mediated synthesized CuO NPs was evaluated against to human lung A549 and breast MDA-MB-231cancer cell lines by determined using of MTT assay. In furthermore, photocatalytic dye degradation was performed that synthesized CuO NPs have effectively removed 78% of malachite green dye molecule. Our investigation results suggested that the green synthesized CuO NPs potential biological activity of antibacterial activity against Gram positive bacterial, anticancer activity was effectively against MDA-MB-231cancer cell line and good dye degradation was exhibited in malachite green. The A. indicum aqueous leaf extract mediated synthesized CuO NPs has strongly suggested promising nano-biomaterials for fabrication of biomedical applications.

Preparation and related properties of melanin iron supplement

In this study, BM-Fe (black sesame melanin-iron complex) was prepared and characterized. The results showed that the carboxyl hydroxyl group of BSM (black sesame melanin) participated in the chelation of iron ions. EDS (energy dispersive spectroscopy) and XPS (X-ray photoelectron spectroscopy) results confirmed the presence of iron ions in BM-Fe. The results of DLS (dynamic light scattering) showed that the average particle sizes of BSM and BM-Fe were 844.9 nm and 294.3 nm, respectively, indicating that the structure of BM-Fe with a smaller particle size was formed after the binding of iron ions with the active group on BSM. Finally, the in vitro iron dissolution, iron ion identification, in vitro iron ion reduction, antioxidant activity, cytotoxicity and moisture resistance properties of BM-Fe and FST (ferrous sulfate tablets, a commonly used iron supplement) were comprehensively compared. The results showed that BSM combined with iron instead of physically mixing, and BM-Fe was easily reduced in the gastrointestinal environment. BM-Fe had good bioavailability and retained the excellent characteristics (such as oxidation resistance and biocompatibility) of BSM, and had the potential to be applied in the treatment of iron-deficiency-related diseases. In summary, BM-Fe prepared in this study not only retained the excellent characteristics of BSM but also had a good effect on iron supplementation, high bioavailability and low side effects. Comprehensive analysis showed that the performance of BM-Fe prepared in this study was similar to or even better than that of the control (FST). Thus, BM-Fe is expected to become a new comprehensive multi-functional iron supplement and has a broad developmental prospect.

Natural Melanin: Current Trends, and Future Approaches, with Especial Reference to Microbial Source

Melanin is a universal natural dark polymeric pigment, arising in microorganisms, animals, and plants. There is a couple of pieces of literature on melanin, each focusing on a different issue, the goal of the present review is to focus on microbial melanin. It has numerous benefits with very few drawbacks. The current situation and expected trends are discussed. Intriguing, numerous studies have provoked a serious necessity for a comprehensive assessment of microbial melanin pigments. So that, such review would help scholars from diverse backgrounds to realize the importance of melanin pigments isolated from microorganisms, with this aim in mind, information, and hypothesis from this review could be the paradigm for studies on melanin in the next era.

Biotechnological advances for improving natural pigment production: a state-of-the-art review

In current years, natural pigments are facing a fast-growing global market due to the increase of people's awareness of health and the discovery of novel pharmacological effects of various natural pigments, e.g., carotenoids, flavonoids, and curcuminoids. However, the traditional production approaches are source-dependent and generally subject to the low contents of target pigment compounds. In order to scale-up industrial production, many efforts have been devoted to increasing pigment production from natural producers, via development of both in vitro plant cell/tissue culture systems, as well as optimization of microbial cultivation approaches. Moreover, synthetic biology has opened the door for heterologous biosynthesis of pigments via design and re-construction of novel biological modules as well as biological systems in bio-platforms. In this review, the innovative methods and strategies for optimization and engineering of both native and heterologous producers of natural pigments are comprehensively summarized. Current progress in the production of several representative high-value natural pigments is also presented; and the remaining challenges and future perspectives are discussed.

Preparation and disinfection properties of graphene oxide/trichloroisocyanuric acid disinfectant

Due to the impact of the new crown epidemic in recent years, disinfectants have played an increasingly important role, so the research and development of new high-efficiency nano-disinfectants are urgent issues. In this study, graphene oxide (GO) was first prepared by the modified Hummer method. Then, the GO/trichloroisocyanuric acid (TCCA) composite was prepared by loading TCCA into GO with the blending method. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and atomic force microscopy were used to characterize the composite. The results showed that TCCA was successfully loaded on the surface of GO or intercalated among GO layers. Next, the antibacterial performance of the composite againstEscherichia coliandStaphylococcus aureuswas tested by the 96-well plate assay. A bactericidal kinetic curve, bacterial inhibition tests, and the mechanism of bacterial inhibition were discussed. The results showed that the minimum inhibitory concentration (MIC) of the GO/TCCA composite (GO:TCCA ratio = 1:50) was 327.5μg ml^-1againstE. coliand 655μg ml^-1againstS. aureus. At the MIC, the inhibition rate of the GO/TCCA composite exceeded 99.46% againstE. coliand 99.17% againstS. aureus. The bactericidal kinetic curves indicate that the GO/TCCA composite has an excellent bactericidal effect againstE. coliandS. aureus.

Graphene oxide and its nanocomposites with EDTA or chitosan induce apoptosis in MCF-7 human breast cancer

To achieve the advanced anticancer activity of nanocomposites fabricated with graphene oxide (GO), a novel procedure was used during the fabrication of chitosan (CS) or ethylene diamine tetra acetic acid (EDTA). The synthesized GO-based nanocomposites were distinguished through different analytical techniques. The cytotoxic activity was examined using MTT assays against three different cancer cell lines. Cell cycle distribution and apoptosis were studied by flow cytometry. Caspase-8, caspase-9, and VEGFR-2 levels were determined using the ELISA technique. HRTEM results revealed a regular 2D thin sheet with a transparent surface in non-modified GO and for GO-CS, the surface of GO has clear cuts and lines had developed due to CS insertion. Concerning the MCF-7 breast cancer cell line, the lowest IC50 values were recorded, suggesting the most powerful cytotoxic effect on breast cancer cells. Treatment with GO-EDTA resulted in the lowest IC50 value of 3.8 ± 0.18 μg mL-1. As indicated by the annexin V-FITC apoptosis assay, the total apoptosis highest percentage was in GO-EDTA treatment (30.12%). In addition, the study of cell cycle analysis showed that GO-EDTA arrested the cell cycle primarily in the G0/G1 phase (33.74%). CS- and EDTA-conjugated GO showed an anti-cancer activity through their cytotoxic effect against the MCF-7 breast cancer cell line.

Improving the diagnosis of bovine tuberculosis using gold nanoparticles conjugated with purified protein derivative: special regard to staphylococcal protein A and streptococcal protein G

Different ancillary immunodiagnostic tests were traditionally-established for diagnosis of bovine tuberculosis (BTB) either cellular or humoral as tuberculin skin test (TST), gamma interferon (INF-γ), and indirect enzyme-linked immunosorbent assay (iELISA). These tests had been consumed more time and expensive, and needed sophisticated equipment. To dissolve these problems, serological diagnosis depending on humoral immunity is the aim of this work. Herein, slide-based agglutination test was chosen as a rapid and simple field test based on purified protein derivative (PPD) antigen in addition to some supplementation materials such as Staphylococcal protein A (SPA) and Streptococcal protein G (SPG) to improve detection of BTB antibody in serum samples. Gold nanoparticles (Au NPs) were synthesized by gamma ray, and after complete characterization, the synthesized Au NPs were spherical, small-sized, and stable without any impurities. Addition of such supplementation reagents for serodiagnosis of tuberculosis is of paramount important for the detection of serum antibodies against tuberculosis (TB) and it was considered an easily simple and possible way for improving TB diagnosis. In this work, 70 animals tested positive for TST as well as 20 animals tested negative for TST were used for the diagnosis of BTB depending on humoral immune response based on PPD slide agglutination test using reporter regents (SPA and/or SPG) either native or recombinant. The agglutination density was recorded and read in 4 degrees of positivity with scores ranging from negative (-) to very strong reaction (++++) occurred in different times of agglutination. Groups showed 100% positive reactivates employed in Exp. 1, 2, and 3 with differentiation of slide agglutination test density and was rated from moderate positivity (2+) to very strong (4+), with predominant positivity in density of (3+). Pink-colored intensity is associated with the strengthened reactions between PPD-conjugated Au NPs and serum antibody of each tested samples, which allows for visual rapid, simple, and effective attractive diagnosis of BTB. The specificity and sensitivity of the serological tests were characterized. TST offers the highest sensitivity (83.6%) among the other immunoassays, while the lowest specificity was recorded in TST (57.4%). SPA/SPG offers the best performance in term of combined sensitivity and specificity (performance index) of 175.4. Therefore, the development and uses of detection reagent (such as SPA and/or SPG) slide co-agglutination test (COAT), either native or recombinant (rSPA/SPG) for the detection of TB antibodies based on PPD antigen, as well as the uses of Au NPs rSPA/SPG as detection conjugate based on the same antigen, were also performed as a simple, rapid, sensitive, specific, eco-friendly, and low cost, which shows a great potential in field and lab diagnosis of BTB. So, high reduction in reagents that yields reactions similarly as traditional techniques was needed.

Nanoparticles as therapeutic options for treating multidrug-resistant bacteria: research progress, challenges, and prospects

Resistance to antimicrobial agents has been alarming in recent years and poses a huge public health threat globally according to the WHO. The increase in morbidity and mortality resulting from microbial infections has been attributed to the emergence of multidrug-resistant microbes. Associated with the increase in multidrug resistance is the lack of new and effective antimicrobials. This has led to global initiatives to identify novel and more effective antimicrobial agents in addition to discovering novel and effective drug delivery and targeting methods. The use of nanoparticles as novel biomaterials to fully achieve this feat is currently gaining global attention. Nanoparticles could become an indispensable viable therapeutic option for treating drug-resistant infections. Of all the nanoparticles, the metals and metal oxide nanoparticles appear to offer the most promise and have attracted tremendous interest from many researchers. Moreover, the use of nanomaterials in photothermal therapy has received considerable attention over the years. This review provides current insight on antimicrobial resistance as well as the mechanisms of nanoparticle antibacterial activity. It offers an in-depth review of all the recent findings in the use of nanomaterials as agents against multi-resistant pathogenic bacteria. Also, nanomaterials that can respond to light stimuli (photothermal therapy) to kill microbes and facilitate enhanced drug delivery and release are discussed. Moreover, the synergistic interactions of nanoparticles with antibiotics and other nanomaterials, microbial adaptation strategies to nanoparticles, current challenges, and future prospects were extensively discussed.

Microbial melanin: Recent advances in biosynthesis, extraction, characterization, and applications

Melanin is a common name for a group of biopolymers with the dominance of potential applications in medical sciences, cosmeceutical, bioremediation, and bioelectronic applications. The broad distribution of these pigments suggests their role to combat abiotic and biotic stresses in diverse life forms. Biosynthesis of melanin in fungi and bacteria occurs by oxidative polymerization of phenolic compounds predominantly by two pathways, 1,8-dihydroxynaphthalene [DHN] or 3,4-dihydroxyphenylalanine [DOPA], resulting in different kinds of melanin, i.e., eumelanin, pheomelanin, allomelanin, pyomelanin, and neuromelanin. The enzymes responsible for melanin synthesis belong mainly to tyrosinase, laccase, and polyketide synthase families. Studies have shown that manipulating culture parameters, combined with recombinant technology, can increase melanin yield for large-scale production. Despite significant efforts, its low solubility has limited the development of extraction procedures, and heterogeneous structural complexity has impaired structural elucidation, restricting effective exploitation of their biotechnological potential. Innumerable studies have been performed on melanin pigments from different taxa of life in order to advance the knowledge about melanin pigments for their efficient utilization in diverse applications. These studies prompted an urgent need for a comprehensive review on melanin pigments isolated from microorganisms, so that such review encompassing biosynthesis, bioproduction, characterization, and potential applications would help researchers from diverse background to understand the importance of microbial melanins and to utilize the information from the review for planning studies on melanin. With this aim in mind, the present report compares conventional and modern ideas for environment-friendly extraction procedures for melanin. Furthermore, the characteristic parameters to differentiate between eumelanin and pheomelanin are also mentioned, followed by their biotechnological applications forming the basis of industrial utilization. There lies a massive scope of work to circumvent the bottlenecks in their isolation and structural elucidation methodologies.

Anti-bacterial and wound healing-promoting effects of zinc ferrite nanoparticles

BACKGROUND

Increasing antibiotic resistance continues to focus on research into the discovery of novel antimicrobial agents. Due to its antimicrobial and wound healing-promoting activity, metal nanoparticles have attracted attention for dermatological applications. This study is designed to investigate the scope and bactericidal potential of zinc ferrite nanoparticles (ZnFe₂O₄ NPs), and the mechanism of anti-bacterial action along with cytocompatibility, hemocompatibility, and wound healing properties.

RESULTS

ZnFe₂O₄ NPs were synthesized via a modified co-precipitation method. Structure, size, morphology, and elemental compositions of ZnFe₂O₄ NPs were analyzed using X-ray diffraction pattern, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. In PrestoBlue and live/dead assays, ZnFe₂O₄ NPs exhibited dose-dependent cytotoxic effects on human dermal fibroblasts. In addition, the hemocompatibility assay revealed that the NPs do not significantly rupture red blood cells up to a dose of 1000 µg/mL. Bacterial live/dead imaging and zone of inhibition analysis demonstrated that ZnFe₂O₄ NPs showed dose-dependent bactericidal activities in various strains of Gram-negative and Gram-positive bacteria. Interestingly, NPs showed antimicrobial activity through multiple mechanisms, such as cell membrane damage, protein leakage, and reactive oxygen species generation, and were more effective against gram-positive bacteria. Furthermore, in vitro scratch assay revealed that ZnFe₂O₄ NPs improved cell migration and proliferation of cells, with noticeable shrinkage of the artificial wound model.

CONCLUSIONS

This study indicated that ZnFe₂O₄ NPs have the potential to be used as a future antimicrobial and wound healing drug.

New insight into melanin for food packaging and biotechnology applications

Melanin is a dark brown to black biomacromolecule with biologically active multifunctional properties that do not have a precise chemical structure, but its structure mainly depends on the polymerization conditions during the synthesis process. Natural melanin can be isolated from various animal, plant, and microbial sources, while synthetic melanin-like compounds can be synthesized by simple polymerization of dopamine. Melanin is widely used in various areas due to its functional properties such as photosensitivity, light barrier property, free radical scavenging ability, antioxidant activity, etc. It also has an excellent ability to act as a reducing agent and capping agent to synthesize various metal nanoparticles. Melanin nanoparticles (MNP) or melanin-like nanoparticles (MLNP) have the unique potential to act as functional materials to improve nanocomposite films' physical and functional properties. Various food packaging and biomedical applications have been made alone or by mixing melanin or MLNP. In this review, the general aspects of melanin that highlight biological activity, along with a description of MNP and the use as nanofillers in packaging films as well as reducing and capping agents and biomedical applications, were comprehensively reviewed.

Gum Arabic polymer-stabilized and Gamma rays-assisted synthesis of bimetallic silver-gold nanoparticles: Powerful antimicrobial and antibiofilm activities against pathogenic microbes isolated from diabetic foot patients

In this research, irradiation by gamma rays was employed as an eco-friendly route for the construction of bimetallic silver-gold nanoparticles (Ag-Au NPs), while Gum Arabic polymer was used as a capping agent. Ag-Au NPs were characterized through UV-Vis., XRD, EDX, HR-TEM, FTIR, SEM/mapping and EDX analysis. Antibiofilm and antimicrobial activities were examined against some bacteria and Candida sp. isolates from diabetic foot patients. Our results revealed that the synthesis of Ag-Au NPs depended on the concentrations of tetra-chloroauric acid and silver nitrate. HR-TEM analysis confirmed the spherical nature and an average diameter of 18.58 nm. FTIR results assured many functional groups in Gum Arabic which assisted in increasing the susceptibility of incorporation with Ag-Au NPs. Our results showed that, Ag-Au NPs exhibited the highest antimicrobial performance against B. subtilis (14.30 mm ZOI) followed by E. coli (12.50 mm ZOI) and C. tropicalis (11.90 mm ZOI). In addition, Ag-Au NPs were able to inhibit the biofilm formation by 99.64%, 94.15%, and 90.79% against B. subtilis, E. coli, and C. tropicalis, respectively. Consequently, based on the promising properties, they showed superior antimicrobial potential at low concentration and continued-phase durability, they can be extensively-used in many pharmaceutical and biomedical applications.

Biogenic synthesis of silver nanoparticles using Gliocladium deliquescens and their application as household sponge disinfectant

The topic of this investigation was to evaluate the microbial contamination of household sponges, biosynthesize of silver nanoparticles (Ag NPs) by Gliocladium deliquescens cell-free supernatant, and estimate the efficiency of Ag NPs as an acceptable disinfectant. The 2³ factorial design was applied for the optimization of Ag NPs synthesis. Silver nitrate (AgNO₃) concentration was the main positive impact on Ag NP biosynthesis. Various gamma irradiation doses were used in Ag NP production where the highest yield production was at 25.0 kGy. Ag NPs were characterized by UV-Vis. spectroscopy, The Fourier-transform infrared spectroscopy analysis (FTIR), dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscope (TEM). Ag NPs were monodispersed spherical-shaped with 9.68 nm mean size. Two hundred sponge samples that were collected from different Egyptian household furniture and kitchens were highly contaminated by various contaminants including Salmonella spp., Staphylococcus spp., coliform bacteria, Gram-negative bacteria, yeasts, and molds. Ag NPs showed functional antimicrobial activity against all the microbial contaminants; Salmonella spp. was completely inhibited by Ag NP (50.0 μg/mL) treatment. The Ag NPs have the maximum inhibition zone against Salmonella spp. (14 mm) compared with the Staphylococcus spp. (12.3 mm). The minimum inhibitory concentration (MIC) of Ag NPs against Salmonella spp. and Staphylococcus spp. were 6.25 μg/ mL and 12.5 μg/ mL, respectively. The antibiofilm activity of Ag NPs was the highest at the concentration of 50.0 μg/mL recording 63.3 % for Salmonella spp. and 54.5 % for Staphylococcus spp. Ag NPs may find potent disinfectant applications for household purposes.

Carbon-dot-loaded CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2 nanocomposite with enhanced photocatalytic and antimicrobial potential: An engineered nanocomposite for wastewater treatment

Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of chloramine-T trihydrate. In addition, reaction kinetics, degradation mechanism and various parameters affecting the photocatalytic efficiency (nanocomposite dose, chloramine-T initial concentration, and reaction pH) were analyzed in detail. Further, the antimicrobial activities of the prepared nanocomposite were tested and the effect of UV-activation on the antimicrobial abilities of the prepared nanocomposite was analyzed. Finally, a comparison between the antimicrobial abilities of the current nanocomposite and our previously-reported nanocomposite (CoxNi1-xFe2O4; x = 0.9/SiO2/TiO2) had been carried out. Our results revealed that the prepared nanocomposite possessed a high degree of crystallinity, confirmed by XRD, while UV-Vis. recorded an absorption peak at 299 nm. In addition, the prepared nanocomposite possessed BET-surface area of (28.29 ± 0.19 m2/g) with narrow pore size distribution. Moreover, it had semi-spherical morphology, high-purity and an average particle size of (19.0 nm). The photocatalytic degradation efficiency was inversely-proportional to chloramine-T initial concentration and directly proportional to the photocatalyst dose. In addition, basic medium (pH 9) was the best suited for chloramine-T degradation. Moreover, UV-irradiation improved the antimicrobial abilities of the prepared nanocomposite against E. coli, B. cereus, and C. tropicalis after 60 min. The observed antimicrobial abilities (high ZOI, low MIC and more efficient antibiofilm capabilities) were unique compared to our previously-reported nanocomposite. Our work offers significant insights into more efficient water treatment and fosters the ongoing efforts looking at how pollutants degrade the water supply and the disinfection of water-borne pathogenic microorganisms.

Fabrication of Ultra-Pure Anisotropic Zinc Oxide Nanoparticles via Simple and Cost-Effective Route: Implications for UTI and EAC Medications

The purposes of this work are to evaluate the antimicrobial, antibiofilm, anticancer, and antioxidant abilities of anisotropic zinc oxide nanoparticles (ZnO NPs) synthesized by a cost-effective and eco-friendly sol-gel method. The synthesized ZnO NPs were entirely characterized by UV-Vis, XRD, FTIR, HRTEM, zeta potential, SEM mapping, BET surface analyzer, and EDX elemental analysis. Antimicrobial and antibiofilm activities of ZnO NPs were investigated against multidrug-resistant (MDR) bacteria and yeast causing serious diseases like urinary tract infection (UTI). The anticancer activity was performed against Ehrlich ascites carcinoma (EAC). Additionally, antioxidant scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was observed. The synthesized ZnO NPs exhibited an absorption peak at 385.0 nm characteristic to the surface plasmon resonance (SPR). Data obtained from HRTEM, SEM, and XRD confirmed the anisotropic crystalline nature of the prepared ZnO NPs with an average particle size of 68.2 nm. The calculated surface area of the prepared ZnO NPs was 10.62 m²/g and the porosity was 13.16%, while pore volume was calculated to be 0.013 cm³/g and the average pore size was about 3.10 nm. The prepared ZnO NPs showed promising antimicrobial activity against all tested UTI-causing pathogens. It showed a prominent antimicrobial capability against Candida tropicalis with a zone of inhibition (ZOI) reaching 22.4 mm, 13 mm ZOI for Bacillus subtilis, and 12.5 mm ZOI for Pseudomonas aeruginosa. Additionally, the prepared ZnO NPs showed enhanced biofilm repression of about 79.33%, 72.94%, and 33.68% against B. subtilis, C. tropicalis, and P. aeruginosa, respectively. Moreover, the prepared ZnO NPs had a powerful antioxidant property with 33.0% scavenging ability after applied DPPH assay. Surprisingly, upon ZnO NPs treatment, cancer cell viability reduced from 100 to 58.5% after only 24 h due to their unique antitumor activity. Therefore, according to these outstanding properties, this study could give insights for solving serious industrial, pharmaceutical, and medical challenges, particularly in the EAC and UTI medications.

Gentamicin-Assisted Mycogenic Selenium Nanoparticles Synthesized Under Gamma Irradiation for Robust Reluctance of Resistant Urinary Tract Infection-Causing Pathogens

The purpose of this research is to compare and enhance the antimicrobial and antibiofilm potentials of the biogenic selenium nanoparticles (Se NPs) produced by cost-effective and eco-friendly green methods. The synthesis of Se NPs is described in this manuscript by two different methods: a biogenic process using Penicillium chrysogenum filtrate and by utilizing gentamicin drug (CN) following the application of gamma irradiation. Se NPs were characterized by UV-Vis., HRTM, FTIR, XRD, DLS, SEM, and EDX mapping technique. Antimicrobial and antibiofilm activities of the synthesized Se NPs were investigated against multidrug-resistant (MDR) bacteria and yeast causing severe diseases such as urinary tract infection (UTI). The biogenic Se NPs exhibited an absorption peak at 435.0 nm while Se NPs-CN showed an absorption peak at 350.0 nm which is related to the surface plasmon resonance (SPR). Data obtained from HRTEM, SEM/mapping, and XRD analysis confirmed the mono-dispersion and crystalline nature of the prepared samples with an average diameter of 33.84 nm and 22.37 nm for the mycogenic Se NPs and Se NPs-CN, respectively. The synthesized Se NPs-CN possesses an encouraging antimicrobial potential with respect to the biogenic Se NPs against all examined UTI-causing microbes. Remarkably, Se NPs-CN showed antimicrobial potential toward Candida albicans with a zone of Inhibition (ZOI) recorded at 26.0 mm, 23.0 mm ZOI for Escherichia coli and 20.0 mm ZOI against Staphylococcus aureus. In addition, the incorporated Se NPs-CN displayed an enhanced percentage of biofilm inhibition of 88.67%, 87.93%, and 85.20% against S. aureus, P. aeruginosa, and E. coli, respectively. Accordingly, the novelty of the present research involves the green synthesis of mono-dispersed Se NPs and combining the synergistic potential of CN with Se NPs for potential biomedical, pharmaceutical, and therapeutic applications especially in the treatment of UTI. Graphical Abstract.

Merits of photocatalytic and antimicrobial applications of gamma-irradiated Co x Ni1-x Fe2O4/SiO2/TiO2; x = 0.9 nanocomposite for pyridine removal and pathogenic bacteria/fungi disinfection: implication for wastewater treatment

In this paper, we report a layer-by-layer approach for the preparation of a concentric recyclable composite (Co x Ni1-x Fe2O4/SiO2/TiO2; x = 0.9) designed for wastewater treatment. The prepared composite was investigated by X-ray diffraction spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy (SEM) supported with energy dispersive X-ray (EDX) spectroscopy to analyze crystallinity, average particle size, morphology and elemental composition, respectively. The antimicrobial activities of the prepared composite have been investigated against multi-drug-resistant bacteria and pathogenic fungi using a variety of experiments, such as zone of inhibition, minimum inhibitory concentration, biofilm formation and SEM with EDX analysis of the treated bacterial cells. In addition, the effects of gamma irradiation (with different doses) and UV irradiation on the antibacterial abilities of the prepared composite have been evaluated. Moreover, the effect of gamma irradiation on the crystallite size of the prepared composite has been studied under varying doses of radiation (25 kGy, 50 kGy and 100 kGy). Finally, the photocatalytic efficiency of the prepared composite was tested for halogen-lamp-assisted removal of pyridine (artificial wastewater). Various parameters affecting the efficiency of the photocatalytic degradation, such as photocatalyst dose, pyridine concentration, pH, point of zero charge and the presence of hydrogen peroxide, have been studied. Our results show that the synthesized composite has a well-crystallized semi-spherical morphology with an average particle size of 125.84 nm. In addition, it possesses a high degree of purity, as revealed by EDX elemental analysis. Interestingly, the prepared composite showed promising antibacterial abilities against almost all the tested pathogenic bacteria and unicellular fungi, and this was further improved after gamma and UV irradiation. Finally, the prepared composite was very efficient in the light-assisted degradation of pyridine and its degradation efficiency can be tuned based on various experimental parameters. This work provides a revolutionary nanomaterial-based solution for the global water shortage and water contamination by offering a new wastewater treatment technique that is recyclable, cost effective and has an acceptable time and quality of water.

Factorial design-optimized and gamma irradiation-assisted fabrication of selenium nanoparticles by chitosan and Pleurotus ostreatus fermented fenugreek for a vigorous in vitro effect against carcinoma cells

The novelty of the present work looks in the synthesis of aqueous dispersed selenium nanoparticles (Se NPs) using gamma rays with the aid of various natural macromolecules such as citrus pectin (CP), sodium alginate (Alg), chitosan (CS) and aqueous extract of fermented fenugreek powder (AEFFP) using Pleurotus ostreatus for investigating their impact in vitro toward carcinoma cell. The synthesized Se NPs were characterized by XRD, UV-Vis., DLS, HRTEM, SEM, EDX and FTIR. Nucleation and growth mechanisms were also discussed. The factorial design was applied to examine the importance of multiple parameters on Se NPs production with a special focus on temperature and gamma rays influences. FTIR spectrum exhibited the existence of several functional groups in Se NPs-capping macromolecules. Results revealed that Se NPs' size was dramatically-influenced by the type of stabilizer, precursors concentration, pH and the absorbed gamma rays dose. The current research reported the promising antitumor application of Se NPs against Ehrlich Ascites Carcinoma (EAC) and human Colon Adenocarcinoma (CACO) in vitro. The proliferation of EAC was significantly-hindered by Se NPs-CS (38.0 μg/ml) at 60 kGy (IC₅₀ = 23.12%) and Se NPs-AEFFP (19.00 μg/ml) at 15 kGy (IC₅₀ = 7.21%). Also, Se NPs control the generation of CACO cells, IC₅₀ was recorded as 25.32% for Se NPs-CS (38.0 μg/ml) and 8.57% for Se NPs-AEFFP (19.00 μg/ml).

Antibacterial and Antifungal Activity of Novel Synthesized Neodymium-Substituted Cobalt Ferrite Nanoparticles for Biomedical Application

Neodymium (Nd)-substituted cobalt ferrite nanoparticles (NPs), i.e., CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs, were synthesized by the sonochemical method. The compositional characterization was done by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Antistaphylococcal activity was found to be enhanced, i.e., survival rate was 50%, 45%, 40%, and 30% with the increase in the ratio of Nd (0.0 ≤ x ≤ 0.2), whereas anticandidal activity was found efficient, i.e., 9%, 20%, 22%, and 40% survival rate at all the four ratios. The morphogenesis studies indicated that the synthesized metal–ligand, improves the antimicrobial capacity by binding them strongly to the microbial walls. To the best of our knowledge, this is the first report which demonstrates the series of CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs being active towards Staphylococcus aureus and Candida albicans and encourages its potential candidature for pharmaceutical and biomedical purposes.

The Statistical Optimisation of Recombinant β-glucosidase Production through a Two-Stage, Multi-Model, Design of Experiments Approach

β-glucosidases are a class of enzyme that are widely distributed in the living world, with examples noted in plants, fungi, animals and bacteria. They offer both hydrolysis and synthesis capacity for a wide range of biotechnological processes. However, the availability of native, or the production of recombinant β-glucosidases, is currently a bottleneck in the widespread industrial application of this enzyme. In this present work, the production of recombinant β-glucosidase from Streptomyces griseus was optimised using a Design of Experiments strategy, comprising a two-stage, multi-model design. Three screening models were comparatively employed: Fractional Factorial, Plackett-Burman and Definitive Screening Design. Four variables (temperature, incubation time, tryptone, and OD600 nm) were experimentally identified as having statistically significant effects on the production of S.griseus recombinant β-glucosidase in E. coli BL21 (DE3). The four most influential variables were subsequently used to optimise recombinant β-glucosidase production, employing Central Composite Design under Response Surface Methodology. Optimal levels were identified as: OD600 nm, 0.55; temperature, 26 °C; incubation time, 12 h; and tryptone, 15 g/L. This yielded a 2.62-fold increase in recombinant β-glucosidase production, in comparison to the pre-optimised process. Affinity chromatography resulted in homogeneous, purified β-glucosidase that was characterised in terms of pH stability, metal ion compatibility and kinetic rates for p-nitrophenyl-β-D-glucopyranoside (pNPG) and cellobiose catalysis.