Photodynamic Antimicrobial Strategies in Polymer Systems

Photodynamic antimicrobial strategies in polymer systems harness light‐activated processes to inactivate or kill microorganisms on surfaces and within materials. At their core, these approaches rely on photosensitiser molecules embedded, covalently attached or encapsulated within a polymer matrix. Upon illumination with visible or near‐infrared light, the photosensitiser transfers energy to molecular oxygen, generating reactive oxygen species (ROS) such as singlet oxygen and hydrogen peroxide. These ROS diffuse into microbial cells, oxidising lipids, proteins and nucleic acids, leading to rapid cell death. The integration of photosensitisers into polymers offers advantages of sustained activity, minimised leaching and tunable mechanical properties. Applications span self‐sterilising hospital touch surfaces, air and water filters, wound dressings and medical device coatings. Recent advances focus on enhancing light penetration, extending antimicrobial spectra to drug‐resistant bacteria, fungi and viruses, and combining nanomaterials to boost ROS yield. The global significance of these materials lies in their potential to curb healthcare‐associated infections and to reduce reliance on conventional antibiotics, thereby mitigating the spread of antimicrobial resistance.

Research from Nature Portfolio

Recent studies have demonstrated that embedding both crystal violet and thiolated gold nanoclusters into a polymer network yields potent photobactericidal activity under low‐intensity white light. The incorporation of gold clusters promotes alternative electron transfer pathways, enhancing hydrogen peroxide production while reducing competing photochemical routes, thus achieving broad‐spectrum killing of antibiotic‐resistant strains. Complementary work has shown that medical‐grade silicone loaded with crystal violet, methylene blue and 2 nm gold nanoparticles exhibits rapid and simultaneous inactivation of Gram‐positive bacteria, yeasts and bacteriophages under ambient hospital lighting. Structural analyses revealed that photodynamic treatment induces membrane damage and cell aggregation, offering mechanistic insight into surface‐mediated microbial eradication.

Photodynamic Antimicrobial Strategies in Polymer Systems publication trend

The graph below shows the total number of articles in photodynamic antimicrobial strategies in polymer systems across all publications each year (not limited to Nature Index journals).

Technical terms

Photodynamic inactivation: The process by which light-activated photosensitisers transfer energy to oxygen to produce reactive species that kill microorganisms.

Photosensitiser: A molecule that absorbs light and initiates generation of reactive oxygen species.

Reactive oxygen species (ROS): Highly reactive molecules such as singlet oxygen and hydrogen peroxide that damage cellular components.

Polymer matrix: A continuous polymeric scaffold in which photosensitisers or nanoparticles are immobilised.

Nanofibre: A fibre with diameter in the nanometre range, offering high surface area for photosensitiser loading.

Quantum dot: A semiconductor nanocrystal that harvests light and transfers energy to photosensitiser molecules.

References

1. Revisiting Current Photoactive Materials for Antimicrobial Photodynamic Therapy. Molecules (2018).
2. Singlet Oxygen Induces Oxidation of Cellular DNA*. Journal of Biological Chemistry (2000).
3. Photosensitizer-Embedded Polyacrylonitrile Nanofibers as Antimicrobial Non-Woven Textile. Nanomaterials (2016).
4. Photobactericidal activity activated by thiolated gold nanoclusters at low flux levels of white light. Nature Communications (2020).
5. Photodynamic Antimicrobial Polymers for Infection Control. PLOS ONE (2014).
6. A Light-Activated Antimicrobial Surface Is Active Against Bacterial, Viral and Fungal Organisms. Scientific Reports (2017).
7. Photoactivable Polymers Embedded with Cadmium-Free Quantum Dots and Crystal Violet: Efficient Bactericidal Activity against Clinical Strains of Antibiotic-Resistant Bacteria. ACS Applied Materials & Interfaces (2019).