Functionalized Concave Cube Gold Nanoparticles as Potent Antimicrobial Agents against Pathogenic Bacteria
Satya Ranjan Sarker1,2, Shakil Ahmed Polash2,3, Md Nurul Karim1,3
1Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Science, RMIT University, Melbourne 3001, Victoria, Australia.
ACS Applied Bio Materials
|February 7, 2022
Summary
This study synthesized concave cube gold nanoparticles (AuNPs) functionalized with lipoic acid (LA) and glutathione (GSH). LA-functionalized AuNPs demonstrated significant antibacterial activity against Bacillus subtilis and excellent biocompatibility.
Area of Science:
- Nanomedicine and Nanobiotechnology
- Materials Science
- Antimicrobial Research
Background:
- Bulk gold is inert, but gold nanoparticles (AuNPs) offer diverse applications in nanomedicine.
- Functionalization of AuNPs with specific ligands can tailor their properties and applications.
- Concave cube AuNPs (CCAuNPs) present unique crystal facets for ligand binding.
Purpose of the Study:
- To synthesize and characterize monodisperse concave cube gold nanoparticles (CCAuNPs).
- To functionalize CCAuNPs with lipoic acid (LA) and glutathione (GSH).
- To evaluate the antibacterial activity and biocompatibility of functionalized CCAuNPs.
Main Methods:
- Synthesis of monodisperse CCAuNPs (76 nm).
- Functionalization of CCAuNPs with LA and GSH.
- UV-vis spectroscopy to confirm functionalization (∼10 nm bathochromic shift with LA).
- Antibacterial assays against Bacillus subtilis.
- Cell viability assays on HeLa, L929, and CHO-GFP cells.
- Hemocompatibility tests on human red blood cells.
Main Results:
- LA-functionalized CCAuNPs (CCAuLA) exhibited the highest antibacterial activity against Bacillus subtilis.
- CCAuNPs induce bacterial cell wall damage and reactive oxygen species production.
- CCAuNPs and their derivatives showed excellent hemocompatibility (<5% hemolysis at 80 μg/mL).
- High biocompatibility was observed with HeLa, L929, and CHO-GFP cells.
- LA enhanced antibacterial activity, while GSH improved biocompatibility.
Conclusions:
- CCAuNPs functionalized with LA and GSH offer a promising platform for nanomedicine.
- The antibacterial mechanism involves cell wall damage and ROS generation.
- Functionalized CCAuNPs demonstrate favorable biocompatibility and hemocompatibility profiles.
- Coulomb and hydrophobic interactions mediate CCAuNP-bacteria interactions.
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