Photothermal and Sonodynamic Antibacterial Therapies

Photothermal and sonodynamic antibacterial therapies exploit external energy sources—light and ultrasound, respectively—to generate localized effects that eradicate pathogenic bacteria while minimising damage to surrounding tissues. In photothermal approaches, agents absorb near-infrared (NIR) light and convert it into heat, raising local temperatures sufficiently to disrupt bacterial membranes, denature proteins and accelerate ion release. Sonodynamic therapy employs ultrasound-activated sensitizers that produce reactive oxygen species (ROS) or release bioactive ions under acoustic cavitation, leading to oxidative stress and membrane disruption in microbial cells. Both modalities offer antibiotic-free alternatives for treating drug-resistant infections and biofilm-associated wounds, with the further potential to combine with immunomodulatory or osteogenic strategies in implantable materials.

Research from Nature Portfolio

One foundational study developed zinc-doped Prussian blue nanoparticles as a photothermal agent capable of selectively clearing methicillin-resistant Staphylococcus aureus in cutaneous wound models. Upon NIR irradiation, these nanoparticles rapidly generate heat and facilitate zinc ion penetration, altering bacterial metabolic pathways and achieving high-efficiency killing without systemic toxicity. The treatment also upregulated genes involved in tissue remodelling, promoted collagen deposition and accelerated wound repair. This work demonstrated that rational design of photothermal nanomaterials can yield dual benefits of antimicrobial potency and enhanced tissue regeneration, underscoring the clinical promise of light-triggered antibacterial platforms.

Photothermal and Sonodynamic Antibacterial Therapies publication trend

The graph below shows the total number of articles in photothermal and sonodynamic antibacterial therapies across all publications each year (not limited to Nature Index journals).

Technical terms

Photothermal therapy: Antibacterial treatment that uses light-absorbing agents to convert light energy, typically in the near-infrared range, into localized heat to kill microbes.

Sonodynamic therapy: Technique using ultrasound and sonosensitising agents to generate reactive oxygen species under acoustic cavitation for microbial inactivation.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that can damage cellular components, leading to bacterial death.

Near-infrared (NIR) light: Wavelengths of light (typically 700–1,100 nm) that penetrate tissues and are absorbed by photothermal agents.

Sonosensitiser: A compound that, upon ultrasound activation, produces cytotoxic species such as ROS to disrupt bacterial cells.

Biofilm: Structured community of bacteria encased in a self-produced polymeric matrix that confers increased resistance to antibiotics and host defences.

References

1. Elimination of methicillin-resistant Staphylococcus aureus biofilms on titanium implants via photothermally-triggered nitric oxide and immunotherapy for enhanced osseointegration. Military Medical Research (2023).
2. Zinc-doped Prussian blue enhances photothermal clearance of Staphylococcus aureus and promotes tissue repair in infected wounds. Nature Communications (2019).
3. Highly Effective and Noninvasive Near‐Infrared Eradication of a Staphylococcus aureus Biofilm on Implants by a Photoresponsive Coating within 20 Min. Advanced Science (2019).
4. Ultrasonic Interfacial Engineering of MoS2‐Modified Zn Single‐Atom Catalysts for Efficient Osteomyelitis Sonodynamic Ion Therapy. Small (2021).