Antibacterial Photodynamic Therapy Applications in Biofilm Infections

Photodynamic therapy (PDT) employs light-activated photosensitising agents to generate cytotoxic reactive oxygen species that disrupt bacterial cells. When directed against biofilms—microbial communities encased in an extracellular polymeric matrix—PDT offers a non-antibiotic strategy to overcome multidrug resistance, improve penetration into dense structures and modulate local conditions. Recent innovations focus on near-infrared activation for deeper tissue reach, incorporation of gas-releasing elements to boost oxidative damage, microenvironment targeting to synergise with antibiotics and the integration of diagnostic imaging. Together, these advances address biofilm heterogeneity, hypoxic niches and physical barriers, paving the way for more effective eradication and potential promotion of tissue repair.

Research from Nature Portfolio

Recent studies have explored microenvironmental engineering to enhance photodynamic efficacy and antibiotic activation. One strategy harnesses PDT-induced oxygen depletion to intensify biofilm hypoxia, triggering anaerobic antibiotic prodrugs within methicillin-resistant Staphylococcus aureus and achieving robust biofilm clearance alongside macrophage-mediated wound repair. Foundational work on multifunctional silicon-based nanoagents has demonstrated combined fluorescence imaging and broad-spectrum photodynamic killing under red-light irradiation, effectively targeting both Gram-positive and Gram-negative biofilms in vivo. These platforms exemplify theranostic approaches that enable precise localisation, real-time monitoring and potent antimicrobial action within complex biofilm environments.

Antibacterial Photodynamic Therapy Applications in Biofilm Infections publication trend

The graph below shows the total number of articles in antibacterial photodynamic therapy applications in biofilm infections across all publications each year (not limited to Nature Index journals).

Technical terms

Photodynamic therapy (PDT): A technique using light-activated compounds and oxygen to generate cell-killing reactive oxygen species.

Biofilm: A structured microbial community embedded in a self-produced extracellular polymeric matrix attached to surfaces.

Photosensitiser: A molecule that produces reactive oxygen species upon exposure to light of a specific wavelength.

Reactive oxygen species (ROS): Highly reactive oxygen-derived molecules, including singlet oxygen and free radicals, that damage cellular structures.

Hypoxia: A low-oxygen condition within biofilm microenvironments that influences microbial metabolism and treatment response.

References

1. Enhancing near-infrared II photodynamic therapy with nitric oxide for eradicating multidrug-resistant biofilms in deep tissues. Bioactive Materials (2023).
2. Potentiating hypoxic microenvironment for antibiotic activation by photodynamic therapy to combat bacterial biofilm infections. Nature Communications (2022).
3. Multifunctional nanoagents for ultrasensitive imaging and photoactive killing of Gram-negative and Gram-positive bacteria. Nature Communications (2019).
4. Biofilm Microenvironment-Responsive Nanotheranostics for Dual-Mode Imaging and Hypoxia-Relief-Enhanced Photodynamic Therapy of Bacterial Infections. Research (2020).