Photothermal Nanomaterials for Imaging and Cancer Therapy

Photothermal nanomaterials harness the capacity of tailored nanoparticles and organic chromophores to convert light into heat, enabling both high-contrast imaging and targeted ablation of malignant tissues. Key advances have focused on agents active in the second near-infrared (NIR-II, 1000–1700 nm) window, owing to deeper tissue penetration, reduced scattering and low background autofluorescence. Materials range from self-assembled J-aggregate dyes and π-extended organic frameworks to donor–acceptor conjugated oligomers and hybrid nanocarbon–porphyrin systems. By combining strong NIR absorption with high photothermal conversion efficiency and biocompatible encapsulation, these agents permit real-time photoacoustic or fluorescence imaging and precise photothermal therapy (PTT). Integration of tumour-targeting ligands, activatable self-assembly strategies and biodegradable carriers has further enhanced accumulation at disease sites and minimised off-target effects. Collectively, this multidisciplinary field bridges molecular design, colloidal engineering and translational oncology to offer non-invasive diagnostics and synergistic treatment modalities.

Research from Nature Portfolio

Recent studies have demonstrated an in situ self-assembly strategy to generate activatable NIR-II J-aggregates that remain stable in vivo and enable long-term tumour imaging and guided surgical resection. By fusing an orderly self-assembling dye to a simple haemicyanine scaffold, the resulting probe achieves high stability without external carriers and precise NIR-II navigation of tumour margins, reducing metastatic risk.

Another breakthrough introduced organic NIR-II absorbing theranostic nanoparticles formed by co-assembling a boron difluoride formazanate dye with a biocompatible polymer. These particles combine efficient photoacoustic imaging with deep-tissue photonic hyperthermia, producing dramatic inhibition of orthotopic hepatocellular carcinoma in vivo.

Foundational work on BODIPY-based J-aggregation has yielded second near-infrared fluorescence agents with narrow emission bands at 1010 nm. The sterically tuned meso-substituted dyes self-assemble into stable J-aggregates for lymph node imaging and fluorescence-guided surgery, illustrating the potential of supramolecular organisation in NIR-II bioimaging.

Photothermal Nanomaterials for Imaging and Cancer Therapy publication trend

The graph below shows the total number of articles in photothermal nanomaterials for imaging and cancer therapy across all publications each year (not limited to Nature Index journals).

Technical terms

Photothermal therapy (PTT): A treatment modality in which agents absorb light and convert it into heat to induce tumour cell death.

Near-infrared II (NIR-II) window: The spectral region from 1000 to 1700 nm, offering deep tissue penetration and low scattering for biomedical imaging and therapy.

Photothermal conversion efficiency (PCE): The fraction of absorbed optical energy that is dissipated as heat by a photothermal agent.

J-aggregation: An ordered molecular assembly that produces narrow, red-shifted absorption bands and enhanced photophysical properties.

Photoacoustic imaging: A hybrid modality in which pulsed light absorption generates ultrasound waves, enabling high-resolution images of optical contrast.

References

1. In situ orderly self-assembly strategy affording NIR-II-J-aggregates for in vivo imaging and surgical navigation. Nature Communications (2023).
2. A Terrylene–Anthraquinone Dyad as a Chromophore for Photothermal Therapy in the NIR-II Window. Journal of the American Chemical Society (2023).
3. A Nanographene‐Porphyrin Hybrid for Near‐Infrared‐Ii Phototheranostics. Advanced Science (2024).
4. J-aggregates of meso-[2.2]paracyclophanyl-BODIPY dye for NIR-II imaging. Nature Communications (2021).
5. Easy but Efficient: Facile Approach to Molecule with Theoretically Justified Donor–Acceptor Structure for Effective Photothermal Conversion and Intravenous Photothermal Therapy. Advanced Science (2024).