Biogenic Synthesis of Gold Nanoparticles and Their Antimicrobial Activities

2020 ◽  
pp. 216-233
Author(s):  
Snežana Radisavljević ◽  
Biljana Petrović
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Food Packaging ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Antimicrobial Activities ◽  
Physiochemical Properties

Gold nanoparticles (AuNPs) are widely used in biomedical applications, especially diagnostic and drug delivery. The antibacterial activity of nanoparticles depends on the dimensions of the particles. AuNPs may associate with the surface of the cell membrane and cause disorder such as respiration and permeability. The method of binding of particles for bacteria depends on their surface available for interaction. Smaller particles which have the larger surface area available for interaction will show better bactericidal effect than the larger particles. Useful antibacterial agents should also be toxic to various pathogenic bacteria with the ability to coat different surfaces like biomaterials, devices, textiles, food packaging, and so on. The biological and physiochemical properties of synthesized AuNPs have impact on the use of gold nanoparticles like antimicrobial agents, especially for water purification, as well as other biomedical applications.

scholarly journals Use of Lemongrass Leaf Ethanol Extract for Developing Alginate Based Antibacterial Edible Films

2020 ◽  
Vol 10 (2) ◽  
pp. 99-107
Keyword(s):  
Antibacterial Activity ◽  
Moisture Content ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Brown Seaweed ◽  
Ethanol Extract ◽  
Edible Films ◽  
Edible Film ◽  
Alcohol Extract

Alginates extracted from brown seaweed have a variety of prospective applications such as thickeners, stabilizers, or restructuring agents. Due to its properties as a natural polysaccharide, alginate is very potential to be used as edible films for food packaging purposes. Edible films are developed for food protection being excellent barriers to gases but not to moisture. Incorporation of antimicrobial agents into edible film formulation can extend product shelf life and reduce the risk of pathogenic bacterial growth on food. Therefore, this study was aimed to develop an alginate based antibacterial edible film. Antibacterial agent extracted from lemongrass leaves using ethanol was employed. The study was conducted by varying the addition levels of lemongrass ethanol extract to the alginate based edible films, i.e. 0.5%, 1.0% and 1.5%. Before being added to the alginate based edible films, the lemongrass ethanol extract was investigated for its antibacterial activity. The edible films obtained were analyzed in terms of physical, mechanical and chemical and microbiological parameters, including thickness, water vapor transmission rate (WVTR), brightness, tensile strength, elongation, moisture content, water solubility and antibacterial activity. Results showed that the higher addition levels of lemongrass ethanol extract tended to produce alginate based edible films with lower WVTR and brightness value as well as higher elongation, moisture content and water solubility. Edible film added with lemongrass ethanol extract resulted in this study demonstrated antibacterial activity against Staphylococcus aureus. The addition of lemongrass alcohol extract at 0.5% was considered as a recommended concentration level for producing alginate based antibacterial edible films.

scholarly journals Stimuli-Responsive Graphene Nanohybrids for Biomedical Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dinesh K. Patel ◽  
Yu-Ri Seo ◽  
Ki-Taek Lim
Keyword(s):  
Drug Delivery ◽  
Functional Groups ◽  
Hybrid Materials ◽  
Smart Materials ◽  
Biomedical Applications ◽  
Materials Science ◽  
High Surface ◽  
Single Layer ◽  
Stimuli Responsive ◽  
Physiochemical Properties

Stimuli-responsive materials, also known as smart materials, can change their structure and, consequently, original behavior in response to external or internal stimuli. This is due to the change in the interactions between the various functional groups. Graphene, which is a single layer of carbon atoms with a hexagonal morphology and has excellent physiochemical properties with a high surface area, is frequently used in materials science for various applications. Numerous surface functionalizations are possible for the graphene structure with different functional groups, which can be used to alter the properties of native materials. Graphene-based hybrids exhibit significant improvements in their native properties. Since functionalized graphene contains several reactive groups, the behavior of such hybrid materials can be easily tuned by changing the external conditions, which is very useful in biomedical applications. Enhanced cell proliferation and differentiation of stem cells was reported on the surfaces of graphene-based hybrids with negligible cytotoxicity. In addition, pH or light-induced drug delivery with a controlled release rate was observed for such nanohybrids. Besides, notable improvements in antimicrobial activity were observed for nanohybrids, which demonstrated their potential for biomedical applications. This review describes the physiochemical properties of graphene and graphene-based hybrid materials for stimuli-responsive drug delivery, tissue engineering, and antimicrobial applications.

scholarly journals Identification of Antimicrobial Peptides from the Microalgae Tetraselmis suecica (Kylin) Butcher and Bactericidal Activity Improvement

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 453 ◽  
Author(s):  
Guzmán ◽  
Wong ◽  
Román ◽  
Cárdenas ◽  
Alvárez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bioactive Peptides ◽  
De Novo ◽  
Helical Structure ◽  
Antimicrobial Activities ◽  
Peptide Sequence ◽  
Tetraselmis Suecica ◽  
Defense Strategies ◽  
Key Residues

The outburst of microbial resistance to antibiotics creates the need for new sources of active compounds for the treatment of pathogenic microorganisms. Marine microalgae are of particular interest in this context because they have developed tolerance and defense strategies to resist the exposure to pathogenic bacteria, viruses, and fungi in the aquatic environment. Although antimicrobial activities have been reported for some microalgae, natural algal bioactive peptides have not been described yet. In this work, acid extracts from the microalga Tetraselmis suecica with antibacterial activity were analyzed, and de novo sequences of peptides were determined. Synthetic peptides and their alanine and lysine analogs allowed identifying key residues and increasing their antibacterial activity. Additionally, it was determined that the localization of positive charges within the peptide sequence influences the secondary structure with tendency to form an alpha helical structure.

scholarly journals Evaluation and Comparison of Antibacterial Efficacy of Herbal Extracts in Combination with Antibiotics on Periodontal pathobionts: An in vitro Microbiological Study

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Plant Extracts ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Synergistic Activity ◽  
Antibacterial Efficacy ◽  
Herbal Extracts ◽  
Inhibition Zones

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.

Nanoformulations of core–shell type hydroxyapatite-coated gum acacia with enhanced bioactivity and controlled drug delivery for biomedical applications

2020 ◽  
Vol 44 (17) ◽  
pp. 7175-7185 ◽  
Author(s):  
Varun Prasath Padmanabhan ◽  
Subha Balakrishnan ◽  
Ravichandran Kulandaivelu ◽  
Sankara Narayanan T. S. N. ◽  
Muthukrishnan Lakshmipathy ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Controlled Drug Delivery ◽  
Core Shell ◽  
Gum Acacia ◽  
Shell Type

In this work, nanospherical hydroxyapatite (HAP) was prepared that has combined properties of controlled drug delivery, biocompatibility, and antibacterial activity to have applications in the biomedical sector.

scholarly journals Synthesis andIn VitroEvaluation of New Thiosemicarbazone Derivatives as Potential Antimicrobial Agents

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zafer Asım Kaplancıklı ◽  
Mehlika Dilek Altıntop ◽  
Belgin Sever ◽  
Zerrin Cantürk ◽  
Ahmet Özdemir
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Aromatic Aldehydes ◽  
Antitubercular Activity ◽  
Alamar Blue Assay ◽  
Alamar Blue ◽  
Inhibitory Effects ◽  
Microdilution Method ◽  
Broth Microdilution Method

In an effort to develop potent antimicrobial agents, new thiosemicarbazone derivatives were synthesizedviathe reaction of 4-[4-(trifluoromethyl)phenyl]thiosemicarbazide with aromatic aldehydes. The compounds were evaluated for their inhibitory effects on pathogenic bacteria and yeasts using the CLSI broth microdilution method. Microplate Alamar Blue Assay was also carried out to determine the antimycobacterial activities of the compounds againstMycobacterium tuberculosisH37Rv. Among these derivatives, compounds5and11were more effective againstEnterococcus faecalis(ATCC 29212) than chloramphenicol, whereas compounds1,2, and12and chloramphenicol showed the same level of antibacterial activity againstE. faecalis. Moreover, compound2and chloramphenicol exhibited the same level of antibacterial activity againstStaphylococcus aureus. On the other hand, the most potent anticandidal derivatives were found as compounds2and5. These derivatives and ketoconazole exhibited the same level of antifungal activity againstCandida glabrata. According to the Microplate Alamar Blue Assay, the tested compounds showed weak to moderate antitubercular activity.

scholarly journals Antimicrobial activity of ciprofloxacin-coated gold nanoparticles on selected pathogens

2014 ◽  
Author(s):  
◽  
Nivrithi Moodley
Keyword(s):  
Drug Delivery ◽  
Gold Nanoparticles ◽  
Cancer Cells ◽  
Cell Line ◽  
Colloidal Stability ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Bacterial Cells ◽  
Anti Cancer ◽  
Cancer Activity

Antibiotic resistance amongst bacterial pathogens is a crisis that has been worsening over recent decades, resulting in serious and often fatal infections that cannot be treated by conventional means. Diseases caused by these drug resistant agents result in protracted illnesses, greater mortality rates and increases in treatment costs. Improvements to existing therapies and the development of novel treatments are urgently required to deal with this escalating threat to human health. One of the more promising strategies to combat antibiotic resistance is the use of metallic nanoparticles. Research into this area has shown that the binding of antibiotics to nanoparticles enhances their antimicrobial effects, reduces side-effects due to requirement of lower dosages of the drug, concentrates the drug at the interaction site with bacterial cells and in certain cases, has re-introduced susceptibility into bacterial strains that have developed drug resistance. Furthermore, these nanoparticles can be used in cancer treatment in similar drug delivery roles. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, the aim of our research is to determine the effect of ciprofloxacin-conjugated gold nanoparticles as antimicrobial agents. To achieve this aim our objectives were: (i) to synthesize citrate-capped and ciprofloxacin-conjugated gold nanoparticles; (ii) to determine the physical and chemical characteristics of the ciprofloxacin-nanoparticle hybrid molecule; (iii) to investigate the antimicrobial activity of the conjugated nanoparticles against various species of common pathogens and (iv) to investigate the anti-cancer potential of the citrate-capped nanoparticles against a Caco-2 cell line. In this study, citrate-capped gold nanoparticles were conjugated to the antibiotic, ciprofloxacin, and their antibacterial and anti-cancer activity was evaluated. Initial experiments involved the synthesis and characterization of gold nanoparticles and ciprofloxacin conjugated nanoparticles. The gold nanoparticles were synthesized using the Turkevich citrate reduction technique which has been extensively used in studies thus far. The synthesized nanoparticles were characterized for specific absorbance using a UV-Spectrophotometer. The bond between the nanoparticles and ciprofloxacin was characterized by FTIR. Ultra structural details of the gold nanoparticles were established by TEM. The colloidal stability of the nanoparticles was determined by spectroscopic analysis. The antibacterial activity of the ciprofloxacin-conjugated gold nanoparticles was studied by exposure to pathogenic bacteria (Staphyloccocus aureus, E. coli, Klebsiella pneumoniae, Enterocococcus spp., Enterobacter spp., and Psuedomonas spp.). MIC values were measured to give indication of antimicrobial effect. These bactericidal properties of the conjugate nanoparticles were further investigated by electron microscopy. To evaluate the action of the citrate capped gold nanoparticles on cancer cells, we exposed Caco-2 cells to various concentrations of the nanoparticles and its effect was evaluated by measuring the viability of the cells. The results showed that 0.5 mM trisodium citrate reduced gold chloride to yield gold nanoparticles, which were spherical and 15 to 30 nm (by TEM characterization) and had an absorption maxima of 530 nm. The ciprofloxacin conjugated nanoparticles had an absorption maxima of 667nm. The colloidal stability, which is used to assess whether the synthesized particles will retain their integrity in solution showed that citrate-capped GNPs were most stable at 37°C over a 14 day storage period while ciprofloxacin-conjugated GNPs were found to be most stable at 4°C over a 14 day period. The FTIR results showed that chemical bonding in the conjugated nanoparticles occurs between the pyridone moiety of ciprofloxacin and the nanoparticle surface. The antimicrobial results of ciprofloxacin-conjugated GNPs had a significantly improved killing response compared to ciprofloxacin on both Gram positive and Gram negative bacteria. The citrate-capped GNPs are shown to exert a similar cytotoxic effect to gemcitabine on the Caco-2 cell line at a concentration of 0.5 mM. These results indicate that combining gold nanoparticles and ciprofloxacin enhances the antimicrobial effect of the antibiotic. The conjugate nanoparticles increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and thus enhance the binding and entry of antibiotics into bacteria. This has great implications for treatment of infection, as these antibiotic-conjugated nanoparticles can be incorporated into wound dressings, be administered intravenously as drug delivery agents, be engineered to possess multiple functionalities in addition to antibacterial activity and act as dual infection tracking and antimicrobial agents. Likewise, in this study, gemcitabine, an anticancer drug and gold nanoparticles were shown to kill cancer cells. In addition to their use in photothermal therapy and as drug delivery agents, the nanoparticles themselves possess anti-cancer activity against the Caco-2 cells. Thus, they have potential to act alone as a form of cancer treatment if functionalized with certain targeting agents that are specific to cancer cells, reducing the side-effects that come with regular chemotherapeutic drugs. It can be concluded that ciprofloxacin-conjugated gold nanoparticles enhance antibacterial effects of the antibiotic ciprofloxacin against bacterial cells and citrate-capped gold nanoparticles have anti-cancer activity against the Caco-2 cell line.

scholarly journals Plant-Mediated Zinc Oxide Nanoparticles: Advances in the New Millennium towards Understanding Their Therapeutic Role in Biomedical Applications

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1662
Author(s):  
Mahadevamurthy Murali ◽  
Nataraj Kalegowda ◽  
Hittanahallikoppal G. Gowtham ◽  
Mohammad Azam Ansari ◽  
Mohammad N. Alomary ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Biomedical Applications ◽  
Food Packaging ◽  
Biological Activities ◽  
Drug Loading ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Potential Candidate

Zinc oxide nanoparticles have become one of the most popular metal oxide nanoparticles and recently emerged as a promising potential candidate in the fields of optical, electrical, food packaging, and biomedical applications due to their biocompatibility, low toxicity, and low cost. They have a role in cell apoptosis, as they trigger excessive reactive oxygen species (ROS) formation and release zinc ions (Zn2+) that induce cell death. The zinc oxide nanoparticles synthesized using the plant extracts appear to be simple, safer, sustainable, and more environmentally friendly compared to the physical and chemical routes. These biosynthesized nanoparticles possess strong biological activities and are in use for various biological applications in several industries. Initially, the present review discusses the synthesis and recent advances of zinc oxide nanoparticles from plant sources (such as leaves, stems, bark, roots, rhizomes, fruits, flowers, and seeds) and their biomedical applications (such as antimicrobial, antioxidant, antidiabetic, anticancer, anti-inflammatory, photocatalytic, wound healing, and drug delivery), followed by their mechanisms of action involved in detail. This review also covers the drug delivery application of plant-mediated zinc oxide nanoparticles, focusing on the drug-loading mechanism, stimuli-responsive controlled release, and therapeutic effect. Finally, the future direction of these synthesized zinc oxide nanoparticles’ research and applications are discussed.

scholarly journals Antibacterial effect of silver nanoparticles on antibiotic resistant E. coli O157:H7 isolated from some dairy products

2020 ◽  
Vol 23 (4) ◽  
pp. 432-442
Author(s):  
W. Elsherif ◽  
D. Ali
Keyword(s):  
Food Safety ◽  
Dairy Products ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Health Concern ◽  
Penicillin G ◽  
Economic Losses ◽  
Ag Nps ◽  
E Coli

Food safety is a worldwide health goal so foodborne diseases are a main health concern. A total 150 of dairy products samples (locally made yoghurt, ice cream and Talaga cheese) (50 for each type) were examined for E.coli O157:H7 detection and PCR confirmation using fliCH7 gene. E. coli O157:H7 was detected at 18%, 4%, 8% respectively, in samples. The isolates showed broad antibiotic resistance against vancomycin (84.6%), penicillin G (76.9%), cloxacillin (69.2%) and tetracycline (61.5%). Because of increasing number of microorganisms that are resistant to multiple antibiotics causing continuing economic losses in dairy manufacturing, there is an urgent need for development of alternative, cost-effective, and efficient antimicrobial agents to overcome antimicrobial resistance. Here, silver nanoparticle (AgNPs) solution was prepared, identified by transmission electron microscopy (TEM) with an average size 26.5 nm and examined for bactericidal activity against E. coli O157:H7 by using well diffusion assay. The mean inhibition zones of 25 and 50 µg/ml concentrations of Ag-NPs were 15.0±1.2 and 20.9±1.4 mm, respectively. In addition, the statistical analysis showed highly significant differences in the bactericidal effect of different Ag-NPs concentrations on E. coli O157:H7 strains. Bacterial sensitivity to nanoparticles is a key factor in manufacture, so nanoparticles were considered suitable for long life application in food packaging and food safety.

scholarly journals Sponge-Associated Actinobacteria: Morphological Character and Antibacterial Activity against Pathogenic Bacteria

2017 ◽  
Vol 3 (1) ◽  
pp. 21-26
Author(s):  
SASMIATI FARACH DITA ◽  
SRI BUDIARTI ◽  
YULIN LESTARI
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Marine Ecosystem ◽  
Morphological Characteristics ◽  
Antibacterial Activities ◽  
Morphological Characters ◽  
Antimicrobial Activities ◽  
Shigella Dysenteriae ◽  
Rrna Gene

Sponge-associated actinobacteria may diverse and have potency to produce bioactive compounds. Diversity and antimicrobial activity of indigenous sponge-associated actinobacteria isolated from the marine ecosystem in Indonesia have not much been explored. This work aimed to assess morphological and antibacterial activity of sponge-associated actinobacteria. The morphological characteristics were examined based on their color of aerial and substrate mycelia, and pigmentation, while antibacterial activities were assayed using the antagonist technique. The selected actinobacterial isolate was identified using 16S rRNA gene. Various sponge-associated actinobacteria were successfully isolated from Hyrtios sp., Callyspongia sp., and Neofibularia sp. sponges. A total of 62 actinobacterial isolates were obtained, and each isolate showed a variety of morphological characters, which could be seen in aerial mass color, substrate mass color, and pigmentation. Actinobacterial isolates were tested against human pathogenic bacteria, i.e. Staphylococcus aureus and Methicillin-Resistant S. aureus, representing Gram-positive, and Escherichia coli EPEC K1-1 and Shigella dysenteriae, representing Gram-negative. Most of actinobacterial isolates had antimicrobial activities at least against one of pathogenic bacteria. High activity was shown by NOHa.2, isolated from Neofibularia, and HRHa.5 isolated from Hyrtios. The NOHa.2 showed the highest antimicrobial activity against S. dysenteriae, meanwhile, HRHa.5 showed antimicrobial activity against 3 of 4 tested bacterial pathogens. These data showed diversity of sponge-asccociated actinobacteria from marine ecosystem in Indonesia, and several of them have potency as source of antibacterial compounds

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