Preparation and characterization of spiked gold nanobipyramids and its antibacterial effect on methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus

• Published in: Journal of Genetic Engineering and Biotechnology 2023-12, Vol.21 (1), p.121, Article 121
• Main Authors: Huynh, Phat Trong, Le Tran, Khanh Thi, Nguyen, Tham Thi Hong, Lam, Vinh Quang, Phan, Ngan Thi Kim, Ngo, Thanh Vo Ke
• Format: Article
• Language: English
• Subjects: Absorption spectra; Antibacterial activity; Antibacterial agents; Antibacterial materials; Antibiotic resistance; Antibiotics; Bacteria; Bacterial infections; Ceftaroline; Cytoplasm; Dalfopristin; Drug resistance; Drug resistance in microorganisms; Gold; Gram-positive bacteria; Health aspects; Metabolism; Methicillin; Minimum inhibitory concentration; Nanomaterials; Nanoparticles; Photodynamic therapy; Polyethylene glycol; Quinupristin; Scanning electron microscopy; Silver; Staphylococcus aureus; Staphylococcus infections
• ISSN: 1687-157X; 2090-5920
• DOI: 10.1186/s43141-023-00589-4

Background This paper reports the preparation of a new family of spiked gold nanoparticles, spiked gold nanobipyramids (SNBPs). This protocol includes the process to synthesize gold nanobipyramids (NBPs) using combined seed-mediated and microwave-assisted method and procedure to form spikes on whole surface of gold nanobipyramid. We also evaluated the antibacterial activity against both methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) in various concentrations of SNBPs and NBPs by well diffusion assay, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) determination. The effect of SNBPs on exposed bacteria was observed by scanning electron microscopy. Results The UV-Vis of purified NBPs exhibited two absorption bands located at 550 nm and 849 nm with yield of bipyramidal particles more than 90%. The average size of NBPs was 76.33 ± 10.11 nm in length and 26.57 ± 2.25 nm in diameter, respectively, while SNBPs were prolongated in length and achieved 182.37 ± 21.74 nm with multi-branches protruding whole surface areas. In antibacterial evaluations, SNBPs and NBPs showed antibacterial activity with MIC of 6.25 [mu]l/ml and 12.5 [mu]l/ml, respectively, for MSSA while 12.5 [mu]l/ml and 25 [mu]l/ml, respectively, for MRSA. Besides, MBC values of SNBPs and NBPs were found to be 12.5 [mu]l/ml and 25 [mu]l/ml, respectively, against MSSA while 25 [mu]l/ml and 50 [mu]l/ml, respectively, against MRSA. Furthermore, scanning electron microscopy observation showed the mechanism that SNBPs damaged the outer membrane, released cytoplasm, and altered the normal morphology of MRSA and MSSA, leading to bacterial death. Conclusions This report suggests that these SNBPs are potential antibacterial agents that can be applied as antibacterial materials to inhibit the growth of human bacterial pathogen infections related to antibiotic-resistant bacteria.