Nanomaterial-Enhanced Photodynamic Therapy for Tumor Hypoxia

Photodynamic therapy (PDT) harnesses light-activated photosensitisers to generate cytotoxic reactive oxygen species (ROS) that selectively destroy malignant cells. Its clinical potential is often impeded by the hypoxic microenvironment of solid tumours, where limited oxygen supply restricts ROS production and reduces treatment efficacy. Nanomaterial-based strategies have emerged to overcome this barrier by supplying or generating oxygen in situ, modulating tumour vasculature and microenvironment, and improving photosensitiser delivery and activation. Perfluorocarbon nanodroplets, catalytic nanoenzymes and biomimetic carriers serve as oxygen reservoirs or generators, while upconversion and mitochondria-targeting nanoplatforms enable deeper light penetration and precise subcellular localisation. By integrating imaging capabilities, these multifunctional nanomaterials provide real-time monitoring of oxygen levels and therapeutic responses. Innovations in nanocarrier design not only enhance ROS yield under hypoxia but also facilitate combination approaches with chemotherapy or immunotherapy, thereby broadening the clinical reach of PDT. The global significance of these advances lies in their potential to transform PDT into a robust, minimally invasive modality for hypoxia-rich solid tumours, offering improved tumour control with reduced systemic toxicity.

Research from Nature Portfolio

Recent studies have demonstrated the enhancement of PDT efficacy through oxygen-rich nanocomposites. Perfluorocarbon-loaded nanodroplets have been shown to store and release dissolved oxygen, extending singlet oxygen lifetime and markedly inhibiting tumour growth under light irradiation. Multifunctional nanocomposites combining an oxygen-generating prodrug and platinum(IV) moieties have reversed hypoxia-induced resistance by on-demand O₂ production and concurrent chemotherapeutic Pt(II) release, achieving synergistic photo-chemo antitumour effects. Biomimetic “artificial red cells,” which co-encapsulate haemoglobin and photosensitiser, provide self-monitoring oxygen supply and fluorescent/photoacoustic imaging to guide and sustain PDT, leading to complete tumour suppression in preclinical models.

Nanomaterial-Enhanced Photodynamic Therapy for Tumor Hypoxia publication trend

The graph below shows the total number of articles in nanomaterial-enhanced photodynamic therapy for tumor hypoxia across all publications each year (not limited to Nature Index journals).

Technical terms

Photodynamic therapy (PDT): A treatment that uses light-activated agents to produce reactive oxygen species and kill tumour cells.

Tumour hypoxia: A state of low oxygen concentration within a tumour microenvironment that limits therapeutic efficacy.

Photosensitiser: A molecule that, upon light absorption, transfers energy to molecular oxygen to generate cytotoxic ROS.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that induce oxidative damage in cells.

Nanoplatform: A nanoscale carrier or scaffold engineered to deliver therapeutic or diagnostic agents selectively to diseased tissues.

Perfluorocarbon: An oxygen-carrying fluorinated compound used in nanodroplets to enhance local oxygen availability for PDT.

References

1. Oxygen and Pt(II) self-generating conjugate for synergistic photo-chemo therapy of hypoxic tumor. Nature Communications (2018).
2. Perfluorocarbon nanoparticles enhance reactive oxygen levels and tumour growth inhibition in photodynamic therapy. Nature Communications (2015).
3. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy. Scientific Reports (2016).
4. Biomimetic Liposomal Nanoplatinum for Targeted Cancer Chemophototherapy. Advanced Science (2021).
5. Self-generating oxygen enhanced mitochondrion-targeted photodynamic therapy for tumor treatment with hypoxia scavenging. Theranostics (2019).
6. Recent Advances in Strategies for Addressing Hypoxia in Tumor Photodynamic Therapy. Biomolecules (2022).