Investigation of the Antibacterial Activity and in vivo Cytotoxicity of Biogenic Silver Nanoparticles as Potent Therapeutics

ABSTRACTThe emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapyin vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activityin vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand thein vivorelevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activitiesin vivoagainstSalmonellainfection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.

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In Vivo Study of the Antibacterial Chitosan/Polyvinyl Alcohol Loaded with Silver Nanoparticle Hydrogel for Wound Healing Applications

International Journal of Polymer Science ◽

10.1155/2019/7382717 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 5

Author(s):

Tan Dat Nguyen ◽

Thanh Truc Nguyen ◽

Khanh Loan Ly ◽

Anh Hien Tran ◽

Thi Thanh Ngoc Nguyen ◽

...

Keyword(s):

Wound Healing ◽

Silver Nanoparticles ◽

Antibacterial Activity ◽

Polyvinyl Alcohol ◽

Healing Rate ◽

Antibacterial Effects ◽

Topical Gel ◽

Significant Difference

Silver nanoparticles have attracted great interests widely in medicine due to its great characteristics of antibacterial activity. In this research, the antibacterial activity and biocompatibility of a topical gel synthesized from polyvinyl alcohol, chitosan, and silver nanoparticles were studied. Hydrogels with different concentrations of silver nanoparticles (15 ppm, 30 ppm, and 60 ppm) were evaluated to compare their antibacterial activity, nanoparticles’ sizes, and in vivo behaviors. The resulted silver nanoparticles in the hydrogel were characterized by TEM showing the nanoparticles’ sizes less than 22 nm. The in vitro results prove that the antibacterial effects of all of the samples are satisfied. However, the in vivo results demonstrate the significant difference among different hydrogels in wound healing, where hydrogel with 30 ppm shows the best healing rate.

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Enhancement of the Antibacterial Activity of Silver Nanoparticles against Phytopathogenic BacteriumRalstonia solanacearumby Stabilization

Journal of Nanomaterials ◽

10.1155/2016/7135852 ◽

2016 ◽

Vol 2016 ◽

pp. 1-15 ◽

Cited By ~ 13

Author(s):

Juanni Chen ◽

Shili Li ◽

Jinxiang Luo ◽

Rongsheng Wang ◽

Wei Ding

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Synergistic Effects ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Tween 80 ◽

Phytopathogenic Bacterium ◽

Crop Disease

In this paper, the enhanced antibacterial activity of silver nanoparticles (AgNPs) against the phytopathogenic bacteriumRalstonia solanacearumafter stabilization using selected surfactants (SDS, SDBS, TX-100, and Tween 80) was examined, in comparison with silver ion. Tween 80 was found to be the most preferable stabilizer of AgNPs due to the beneficial synergistic effects of the AgNPs and surfactant. However, all the surfactants nearly had no effects on the antibacterial activity of Ag+.In vitro, Tween 80-stabilized AgNPs showed the highest bactericidal activity againstR. solanacearum. Further measurements using TEM, fluorescence microscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that though Ag+and Tween 80-Ag+induced high toxicity, Tween 80-stabilized AgNPs displayed most severe damage when in direct contact with cells, causing mechanistic injury to the cell membrane and strongly modifying and destructing the cellular proteins. Meanwhile,in vivo, the pot experiments data indicated that the control efficiency of Tween 80-stabilized AgNPs on tobacco bacterial wilt was 96.71%, 90.11%, and 84.21%, at 7 days, 14 days, and 21 days, respectively. Based on the results evidencing their advantageous low dosage requirements and strong antimicrobial activity, Tween 80-stabilized AgNPs are a promising antibacterial agent for use in alternative crop disease control approaches.

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