Photoswitchable bactericidal effects from novel silica-coated silver nanoparticles

2011 ◽  
Author(s):  
Gustavo Fuertes ◽  
Esteban Pedrueza ◽  
Kamal Abderrafi ◽  
Rafael Abargues ◽  
Orlando Sáncheza ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bactericidal Effects

scholarly journals Certain Aspects of Silver and Silver Nanoparticles in Wound Care: A Minireview

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Marek Konop ◽  
Tatsiana Damps ◽  
Aleksandra Misicka ◽  
Lidia Rudnicka
Keyword(s):  
Silver Nanoparticles ◽  
Clinical Practice ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Wound Care ◽  
Wound Dressings ◽  
Major Health Problem ◽  
Major Health ◽  
Bactericidal Effects

Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. In this context silver and silver nanoparticles (AgNP) have been known to have inhibitory and bactericidal effects and was used throughout history for treatment of skin ulcer, bone fracture, and supporting wound healing. In all of these applications prevention and treatment of bacterial colonized/infected wounds are critical. In this context silver and its derivatives play an important role in health care. Silver is widely used in clinical practice in the form of silver nitrate and/or silver sulfadiazine. In the last few years silver nanoparticles entered into clinical practice as both antimicrobial and antifungal agents. In addition, nanosilver is used in coating medical devices (catheters) and as component of wound dressings. In this paper we present summarized information about silver and nanoparticles made of silver in the context of their useful properties, especially antibacterial ones, being of a great interest for researchers and clinicians.

scholarly journals Combating the melioidosis pathogen using antibiotics in combination with silver nanoparticles

2020 ◽  
Author(s):  
Sathit Malawong ◽  
Saengrawee Thammawithan ◽  
Pawinee Sirithongsuk ◽  
Sawinee Nasompag ◽  
Sakda Daduang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bacterial Cell ◽  
Inhibitory Concentration ◽  
Morphological Changes ◽  
Cell Structure ◽  
Cellular Damage ◽  
Bacterial Strains ◽  
Bacterial Cell Death ◽  
Bactericidal Effects ◽  
Conventional Antibiotics

Abstract Background Melioidosis is an infectious disease caused by the Gram-negative bacillus bacterium, Burkholderia pseudomallei. Due to the emerging resistance of B. pseudomallei to antibiotics, including ceftazidime (CAZ), the development of novel antibiotics and alternative modes of treatment has become an urgent issue. Here, we demonstrate an ability to synergistically increase the efficiency of antibiotics through their combination with silver nanoparticles (AgNPs). Method: Combinations of four conventional antibiotics, including CAZ, imipenem (IMI), meropenem (MER), or gentamicin sulfate (GENT), with AgNPs were tested for their bactericidal effects against three isolates of B. pseudomallei, including 1026b, H777, and 316c, using the microdilution checkerboard method of antibiotic and AgNPs mixing. Morphological changes in the bacteria after treatment with the combined antibiotic-AgNPs was observed using scanning electron microscopy (SEM). Result The combination of four antibiotics with AgNPs gave fractional inhibitory concentration (FIC) index values and fractional bactericidal concentration (FBC) index values ranging from 0.312 to 0.75 µg/mL and 0.252 to 0.625 µg/mL, respectively, against the three isolates of B. pseudomallei. SEM imaging revealed damage to the bacterial cell structure at the minimal inhibitory concentration (MIC) and FIC levels, while extreme severe cellular damage was observed at the FBC level. Surprisingly, at the FBC level, the bacteria produced large amounts of fibers that are the components of biofilm. Conclusion The study clearly shows that most of the combinatorial treatments exhibited synergistic antimicrobial effects against all three isolates of B. pseudomallei. The highest enhancing effect was observed for GENT with AgNPs. We also found that the combination of these antibiotics with AgNPs restored their bactericidal potency in the bacterial strains previously shown to be resistant to the antibiotic. The observed synergistic activities of conventional antibiotics with AgNPs suggest that it might also be possible to achieve equivalent or higher levels of bacterial cell death with lower concentrations of antibiotics using the combined treatments. These results support the use of the antibiotic/AgNPs combination as an alternative design strategy for new therapeutics to more effectively combat melioidosis.

Therapeutic Window of Ligand-Free Silver Nanoparticles in Agar-Embedded and Colloidal State: In Vitro Bactericidal Effects and Cytotoxicity

2012 ◽  
Vol 14 (5) ◽  
pp. B231-B239 ◽  
Author(s):  
Sebastian Grade ◽  
Jörg Eberhard ◽  
Philipp Wagener ◽  
Andreas Winkel ◽  
Csaba Laszlo Sajti ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Therapeutic Window ◽  
Bactericidal Effects ◽  
Ligand Free ◽  
Colloidal State

Anti-Cancer and Antibacterial Effects of Terfezia boudieri-Derived Silver Nanoparticles

2020 ◽  
Vol 23 ◽  
Author(s):  
Hashem Yaghoubi ◽  
Amin Izadpanah ◽  
Shahla Nedaei ◽  
Hossein Akbari ◽  
Elmira Mikaeili Agah ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Chemical Properties ◽  
Chemotherapeutic Agents ◽  
Dependent Manner ◽  
Biomedical Sciences ◽  
Synthesis Time ◽  
Physico Chemical ◽  
Anti Cancer ◽  
Bactericidal Effects ◽  
Terfezia Boudieri

Background: The use of nanoparticles has markedly increased in biomedical sciences. The silver nanoparticles (AgNPs) have been investigated for their applicability to deliver chemotherapeutic agents in cancer treatment. However, the existing chemical and physical methods of synthesizing AgNPs are considered inefficient and expensive, and are fraught with toxicity. Objective: Natural products have emerged as viable candidates for nanoparticle production, including the use of Terfezia boudieri (T. boudieri), a member of the edible truffle family. Accordingly, our goal was to synthesize AgNPs using the aqueous extract of T. boudieri (green synthesized AgNPs). Since certain infectious agents are linked to cancer, we further investigated their potential as anti-cancer and antibacterial agents. Methods: The physico-chemical properties of green synthesized AgNPs were analyzed by UV-Vis, FT-IR, XRD, SEM and TEM. In addition, their potential to inhibit cancer cell (MCF-7 and AGS) proliferation as well as the growth of infectious bacteria were investigated. Synthesis of AgNPs was confirmed by the presence of an absorption peak at 450nm by spectroscopy. Results: The size of nanoparticles ranged between 20-30nm and exerted significant cytotoxicity and bactericidal effects in a concentration and time dependent manner compared to T. boudieri extract alone. Interestingly, synthesis of smaller AgNPs correlated with longer synthesis time and enhanced cytotoxic and bactericidal properties. Conclusion: This study shows that synthesis of smaller AgNPs correlated with longer synthesis time and enhanced cytotoxic and anti-bacterial effects.

scholarly journals Near-atomic size highly positive silver nanoparticles are bactericidal targeting cell wall and adherent fimbriae expression

2021 ◽  
Author(s):  
Lok Pokhrel ◽  
Zachary Jacobs ◽  
Dmitriy Dikin ◽  
Shaw Akula
Keyword(s):  
Silver Nanoparticles ◽  
Cell Wall ◽  
Health And Safety ◽  
Next Generation ◽  
Atomic Size ◽  
E Coli ◽  
Bactericidal Effects ◽  
Patient Health ◽  
Hospital Acquired ◽  
Positively Charged

Abstract To tackle growing antibiotic resistance (AR) and hospital-acquired infections (HAIs), novel antimicrobials are warranted that are effective against HAIs and safer for human use. We hypothesize that near-atomic size positively charged silver nanoparticles (AgNPs) could specifically target bacterial cell wall and adherent fimbriae expression, serving as the next generation antimicrobial agent. Herein we show positively charged, 5 nm NH2–AgNPs were bactericidal; negatively charged, 45 nm Citrate–AgNPs were nontoxic; and Ag+ ions were bacteriostatic forming honeycomb-like potentially resistant phenotype, at 10µg Ag/mL in E. coli dh5a. Further, adherent fimbriae were expressed with Citrate–AgNPs, whereas NH2–AgNPs (0.5–10µg/mL) or Ag+ ions (10µg/mL) inhibited fimbriae expression. Potent bactericidal effects demonstrated by biocompatible NH2–AgNPs and the lack of toxicity of Citrate–AgNPs lend credence to the hypothesis that near-atomic size, positively charged AgNPs may serve as a next-generation antibacterial agent, potentially addressing the rising HAIs and patient health and safety.

scholarly journals Bactericidal and Biocompatible Properties of Plasma Chemical Oxidized Titanium (TiOB®) with Antimicrobial Surface Functionalization

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 866 ◽  
Author(s):  
Stefan Kranz ◽  
André Guellmar ◽  
Andrea Voelpel ◽  
Tobias Lesser ◽  
Silke Tonndorf-Martini ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibiotic Resistance ◽  
Surface Functionalization ◽  
Bacterial Colonization ◽  
Positive Control ◽  
Plasma Chemical ◽  
Functionalized Surfaces ◽  
Bactericidal Properties ◽  
Major Interest ◽  
Bactericidal Effects

Coating of plasma chemical oxidized titanium (TiOB®) with gentamicin-tannic acid (TiOB® gta) has proven to be efficient in preventing bacterial colonization of implants. However, in times of increasing antibiotic resistance, the development of alternative antimicrobial functionalization strategies is of major interest. Therefore, the aim of the present study is to evaluate the antibacterial and biocompatible properties of TiOB® functionalized with silver nanoparticles (TiOB® SiOx Ag) and ionic zinc (TiOB® Zn). Antibacterial efficiency was determined by agar diffusion and proliferation test on Staphylocuccus aureus. Cytocompatibility was analyzed by direct cultivation of MC3T3-E1 cells on top of the functionalized surfaces for 2 and 4 d. All functionalized surfaces showed significant bactericidal effects expressed by extended lag phases (TiOB® gta for 5 h, TiOB® SiOx Ag for 8 h, TiOB® Zn for 10 h). While TiOB® gta (positive control) and TiOB® Zn remained bactericidal for 48 h, TiOB® SiOx Ag was active for only 4 h. After direct cultivation for 4 d, viable MC3T3-E1 cells were found on all surfaces tested with the highest biocompatibility recorded for TiOB® SiOx Ag. The present study revealed that functionalization of TiOB® with ionic zinc shows bactericidal properties that are comparable to those of a gentamicin-containing coating.

scholarly journals Rapid Method for Detecting Bactericidal Effects of Mangrove Derived Silver Nanoparticles Using Resazurin Microdilution Assay

2021 ◽  
Vol 9 (8) ◽  
pp. 2438-2442
Author(s):  
Asmathunisha N
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Vital Role ◽  
Bacterial Strains ◽  
E Coli ◽  
Inhibition Concentration ◽  
Resazurin Assay ◽  
Bactericidal Effects

Abstract: Nanoparticles plays a vital role in the field of antimicrobial agents against pathogenic microorganisms. Screening of nanoparticles for antimicrobial activities is a time consuming and cumbersome process. Recently, a simple technique of using the dye resazurin has been used as an indicator of bacterial growth for testing antimicrobial activity on microtitre plate. However, this technique does not quantify the microbial load. Therefore, the present work was attempted to find a new antibacterial method employing the dye resazurin assay and haemocytometric counting of microbes for testing silver nanoparticles synthesised from Xylocarpus mekongensis .The bacterial strains E. coli, S. aureus and P. aeruginosa (multi-drug resistant strain) were used to evaluate the screening of mangrove extracts. Minimum inhibition concentration (MIC) was also calculated for the silver nanoparticles using ciproflaxcin as reference antibiotic. The antibacterial activity Xylocarpus mekongensis was carried out against all the three bacteria by the same method and the values were compared with reference antibiotic. The present study has suggested a rapid, dependable, easy and inexpensive method, suitable for testing the antibacterial activity of silver nanoparticles which are promising to develop as new antibacterials. Keywords: Mangroves, Silver, Nanoparticles, Resazurin, Antibacterials

Bactericidal Effects of Silver Nanoparticles on Lactobacilli and the Underlying Mechanism

2018 ◽  
Vol 10 (10) ◽  
pp. 8443-8450 ◽  
Author(s):  
Xin Tian ◽  
Xiumei Jiang ◽  
Cara Welch ◽  
Timothy R. Croley ◽  
Tit-Yee Wong ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Underlying Mechanism ◽  
Bactericidal Effects
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