Eradicating group A streptococcus bacteria and biofilms using functionalised multi-wall carbon nanotubes

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Microbiology

Background:

• Group A Streptococcus (GAS) infections pose significant health risks.
• Current treatments can be limited by antibiotic resistance and collateral damage.
• Targeted therapies are needed for effective bacterial eradication.

Purpose of the Study:

• To functionalize multi-wall carbon nanotubes (MWCNTs) with antibodies against GAS.
• To investigate the targeted photothermal ablation of planktonic and biofilm GAS using functionalized MWCNTs.
• To assess the safety and efficacy of this approach on ex vivo tissue models.

Main Methods:

• Covalent attachment of GAS antibodies to carboxylated MWCNTs.
• Incubation of functionalized MWCNTs with GAS (planktonic and biofilm).
• Exposure to 800 nm infrared light (1.3 W/cm²) for photothermal ablation.
• Colony-forming unit determination and histological analysis of adjacent tissues.

Main Results:

• Approximately 14% of functionalized MWCNTs attached to GAS, enabling photothermal ablation.
• Infrared light and MWCNTs alone did not decrease bacterial viability.
• Antibody-labeled MWCNTs significantly enhanced GAS killing in both planktonic and biofilm states compared to unlabeled MWCNTs.
• Photothermal ablation was localized, causing no collateral damage to adjacent porcine skin tissue.

Conclusions:

• Functionalized MWCNTs act as effective localized photothermal agents against GAS.
• This technology holds promise for clinical applications in treating soft tissue bacterial infections.
• Further research may lead to novel therapeutic strategies for combating bacterial infections.