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Updated: Aug 18, 2025
Author Spotlight: Metallic Nanocomposites to Eliminate Antibiotic-Resistant Bacteria
Published on: October 4, 2024
Stability, Toxicity, and Antibacterial Potential of Gallic Acid-Loaded Graphene Oxide (GAGO) Against
Suhaili Shamsi1, Ahmad Ashraful Hadi Abdul Ghafor2, Nur Hazwani Norjoshukrudin1
1Laboratory of Animal Biochemistry and Biotechnology, Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, 43400, Malaysia.
Background:
The impetuous usage of antibiotics has led to the perpetual rise of methicillin-resistant Staphylococcus aureus (MRSA), which has garnered the interest of potential drug alternatives, including nanomaterials.
Purpose:
The present study investigates the stability, toxicity, and antibacterial potential of gallic acid-loaded graphene oxide (GAGO) on several MRSA strains.
Methods:
The stability of a synthesized and characterized GAGO was monitored in different physiological media. The toxicity profile of GAGO was evaluated in 3T3 murine fibroblast cells and the embryonic zebrafish model. The antibacterial activity of GAGO against MRSA, methicillin-susceptible S. aureus (MSSA), and community-acquired MRSA; with or without Panton-valentine leucocidin gene (MRSA-pvl+ and MRSA-pvl-) was investigated through disk diffusion, CFU counting method, time-kill experiment, and high-resolution transmission electron microscopy (HRTEM) observation.
Results:
A stable GAGO nanocomposite has shown an improved toxicity profile in 3T3 murine fibroblast cells and zebrafish embryos, besides exhibiting normal ROS levels than graphene oxide (GO) and GA (gallic acid). The nanocomposite inhibited the growth of all bacterial strains employed. The effectiveness of the GAGO nanocomposite was comparable to cefoxitin (CFX), at ≥150 µg/mL in MRSA and MSSA. GAGO exhibited a significantly delayed response towards MRSA-pvl+ and MRSA-pvl-, with increased inhibition following 8 to 24 h of exposure, while comparable activity to native GA was only achieved at 24 h. Meanwhile, for MRSA and MSSA, GAGO had a comparable activity with native GA and GO as early as 2 h of exposure. HRTEM observation further reveals that GAGO-exposed cells were membrane compromised.
Conclusion:
In summary, the present study indicates the antibacterial potential of GAGO against MRSA strains, but further study is warranted to understand the mechanism of action of GAGO and its resistance in MRSA strains.
Insights
Gallic acid-loaded graphene oxide (GAGO) shows promise as an alternative antibacterial agent against methicillin-resistant Staphylococcus aureus (MRSA). This stable nanocomposite demonstrated reduced toxicity and effectively inhibited MRSA growth, comparable to cefoxitin.
Area of Science:
- Nanomaterials science
- Microbiology
- Drug discovery
Background:
- Antibiotic resistance, particularly methicillin-resistant Staphylococcus aureus (MRSA), necessitates novel therapeutic strategies.
- Nanomaterials are emerging as promising alternatives for combating antibiotic-resistant bacteria.
Purpose of the Study:
- To investigate the stability, toxicity, and antibacterial efficacy of gallic acid-loaded graphene oxide (GAGO) against various MRSA strains.
- To evaluate GAGO as a potential alternative to conventional antibiotics.
Main Methods:
- GAGO synthesis and characterization, stability testing in physiological media.
- Toxicity assessment in 3T3 murine fibroblast cells and zebrafish embryos.
- Antibacterial activity evaluation against MRSA, MSSA, and MRSA strains with and without the Panton-valentine leucocidin gene (MRSA-pvl+ and MRSA-pvl-) using disk diffusion, CFU counting, time-kill assays, and HRTEM.
Main Results:
- GAGO exhibited a favorable toxicity profile compared to graphene oxide (GO) and gallic acid (GA), with normal ROS levels.
- GAGO effectively inhibited all tested bacterial strains, showing comparable efficacy to cefoxitin (CFX) against MRSA and MSSA at ≥150 µg/mL.
- HRTEM confirmed membrane damage in GAGO-exposed bacterial cells, indicating a potential mechanism of action.
Conclusions:
- GAGO demonstrates significant antibacterial potential against MRSA strains.
- Further research is required to elucidate the precise mechanism of action and potential resistance pathways of GAGO in MRSA.
