The effect of charge at the surface of silver nanoparticles on antimicrobial activity against gram-positive and gram-negative bacteria: a preliminary study

By Abbas Abbaszadegan, Y. Ghahramani, Ahmad Gholami, B. Hemmateenejad, Samira Dorostkar, Mohammadreza Nabavizadeh, H. Sharghi. 2015

596 citations recorded by the source corpus.

The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative).The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

Subfields: Biomedical Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/db4ad18e600e0bfb5a19e49f3ffe7f4ba7c39d59

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In Biomedical Engineering

1. Sang Hun Lee
2. Bong-Hyun Jun
3. S. Tjong

In Materials Chemistry

1. Sang Hun Lee
2. Bong-Hyun Jun
3. C. Liao
4. S. Tjong
5. Yuchao Li
6. Dimitris Bikiaris

Citations in the corpus

• Silver nanoparticles: Synthesis, medical applications and biosafety (2020, background): “facilitate the adherence of AgNPs on bacterial membranes through electrostatic attraction [156].”
• Potential antibacterial mechanism of silver nanoparticles and the optimization of orthopedic implants by advanced modification technologies (2018, background): “The positive charge confers electrostatic attraction between AgNPs and negatively charge cell membrane of the microorganisms, thereby facilitates AgNP attachment onto cell membranes.(27) Hence, enhanced antibacterial effects can be obtained by altering the surface charge of AgNPs to achieve stronger”
• Bactericidal and Cytotoxic Properties of Silver Nanoparticles (2019, background): “Thus, the capping agent and stabilizers used to prevent the aggregation of colloidal nanoparticles inevitably exert an influence on their surface charges [156,158,164].”
• Green Synthesis of Metallic Nanoparticles: Applications and Limitations (2021, background): “This is because the surface to volume ratio of the NPs considerably increases with a decrease in the particle size [266].”
• Antibacterial approaches in tissue engineering using metal ions and nanoparticles: From mechanisms to applications (2021, background): “attachment of the silver ions and silver nanoparticles to the cell wall and membrane due to the electrostatic attraction between the negatively charged bacterial surface and the positively charged silver compounds [71].”
• Silver Nanoparticles: Synthesis and Application for Nanomedicine (2019, background): “The cell wall in Gram-positive bacteria is composed of a negatively-charged peptidoglycan layer with approximately 30 nm in thickness, whereas Gram-negative bacteria have a peptidoglycan layer of only 3 to 4 nm [31,75].”
• Metal-Based Nanoparticles as Antimicrobial Agents: An Overview (2020, background): “However, an increase in the concentration of AgNPs allows the attenuation of electrostatic repulsion through a bacterial surface saturation method [94].”
• Silver Nanoparticles and Their Antibacterial Applications (2021, background): “[48] suggests that the electrostatic attraction between positively charged AgNPs and negatively charged bacterial cells is necessary for the antibacterial effectiveness of the AgNPs, and this attraction is managed by the charge of the AgNPs and the microorganisms.”