PDADMAC/Alginate-Coated Gold Nanorod For Eradication of Staphylococcus Aureus Biofilms

Int J Nanomedicine. 2024 Apr 23:19:3697-3714. doi: 10.2147/IJN.S452085. eCollection 2024.

Abstract

Introduction: Over 75% of clinical microbiological infections are caused by bacterial biofilms that grow on wounds or implantable medical devices. This work describes the development of a new poly(diallyldimethylammonium chloride) (PDADMAC)/alginate-coated gold nanorod (GNR/Alg/PDADMAC) that effectively disintegrates the biofilms of Staphylococcus aureus (S. aureus), a prominent pathogen responsible for hospital-acquired infections.

Methods: GNR was synthesised via seed-mediated growth method, and the resulting nanoparticles were coated first with Alg and then PDADMAC. FTIR, zeta potential, transmission electron microscopy, and UV-Vis spectrophotometry analysis were performed to characterise the nanoparticles. The efficacy and speed of the non-coated GNR and GNR/Alg/PDADMAC in disintegrating S. aureus-preformed biofilms, as well as their in vitro biocompatibility (L929 murine fibroblast) were then studied.

Results: The synthesised GNR/Alg/PDADMAC (mean length: 55.71 ± 1.15 nm, mean width: 23.70 ± 1.13 nm, aspect ratio: 2.35) was biocompatible and potent in eradicating preformed biofilms of methicillin-resistant (MRSA) and methicillin-susceptible S. aureus (MSSA) when compared to triclosan, an antiseptic used for disinfecting S. aureus colonisation on abiotic surfaces in the hospital. The minimum biofilm eradication concentrations of GNR/Alg/PDADMAC (MBEC50 for MRSA biofilm = 0.029 nM; MBEC50 for MSSA biofilm = 0.032 nM) were significantly lower than those of triclosan (MBEC50 for MRSA biofilm = 10,784 nM; MBEC50 for MRSA biofilm 5967 nM). Moreover, GNR/Alg/PDADMAC was effective in eradicating 50% of MRSA and MSSA biofilms within 17 min when used at a low concentration (0.15 nM), similar to triclosan at a much higher concentration (50 µM). Disintegration of MRSA and MSSA biofilms was confirmed by field emission scanning electron microscopy and confocal laser scanning microscopy.

Conclusion: These findings support the potential application of GNR/Alg/PDADMAC as an alternative agent to conventional antiseptics and antibiotics for the eradication of medically important MRSA and MSSA biofilms.

Keywords: MRSA; MSSA; PDADMAC; S. aureus; biofilm; gold nanorod.

MeSH terms

  • Alginates* / chemistry
  • Alginates* / pharmacology
  • Animals
  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Biofilms* / drug effects
  • Cell Line
  • Gold* / chemistry
  • Gold* / pharmacology
  • Metal Nanoparticles / chemistry
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Methicillin-Resistant Staphylococcus aureus / physiology
  • Mice
  • Microbial Sensitivity Tests
  • Nanotubes* / chemistry
  • Polyethylenes* / chemistry
  • Polyethylenes* / pharmacology
  • Quaternary Ammonium Compounds* / chemistry
  • Quaternary Ammonium Compounds* / pharmacology
  • Staphylococcal Infections / drug therapy
  • Staphylococcus aureus* / drug effects
  • Staphylococcus aureus* / physiology

Substances

  • Gold
  • Quaternary Ammonium Compounds
  • Alginates
  • Anti-Bacterial Agents
  • poly-N,N-dimethyl-N,N-diallylammonium chloride
  • Polyethylenes

Grants and funding

This study was funded by an Impact-oriented Interdisciplinary Research Grant (IIRG) (project codes: IIRG003B-19FNW and IIRG003C-19FNW) from the Universiti Malaya and the Ministry of Higher Education, Malaysia. This work was supported in part by the National Science and Technology Council (NSTC), Taiwan, ROC. (NSTC 112-2321-B-A49-005, NSTC 111-2112-M-A49-025, MSTC 110-2923-M-009-005-MY3, NSTC 111-2927-I-A49-004, and NSTC 112-2927-I-A49-001), and the Ministry of Education through the SPROUT Project and the Center for Intelligent Drug Systems and Smart Biodevices (IDS2B) of NYCU, Taiwan, ROC. Taiwan-Malaysia Semiconductor and Biomedical Oversea Science and Research Innovation Center, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, ROC, for CCC.