Molecular Imaging of Cell Death Mechanisms

Molecular imaging of cell death mechanisms has rapidly evolved as a critical tool for both basic research and clinical decision-making. By visualising biochemical and structural hallmarks of apoptosis, necrosis and other regulated death pathways in vivo, these techniques enable non-invasive assessment of disease progression and therapeutic efficacy. Modalities such as positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) are coupled with targeted probes that bind to activated proteases, exposed membrane lipids or intracellular pH changes. Advances in probe design—ranging from enzyme-responsive nanoparticles to necrosis-avid small molecules—have improved sensitivity, specificity and temporal resolution, permitting early detection of cell death long before morphological changes become evident. The integration of these approaches is enhancing personalised treatment strategies across oncology, cardiology and neurology.

Research from Nature Portfolio

A novel caspase-3-sensitive nanoaggregation MRI contrast agent has been developed to amplify apoptotic signals within tumour tissue. Upon activation by caspase-3, the agent self-assembles into nanoparticles, increasing local retention and enhancing T1 relaxivity. This approach has achieved accurate, low-dose MRI detection of tumour response to chemotherapy and radiation, with signal intensity correlating with long-term treatment outcome. Another pioneering study has identified radioiodinated monomeric anthraquinones as necrosis-avid agents for early imaging of myocardial infarction. Among these, an iodine-labelled rhein derivative allowed clear SPECT/CT visualisation of necrotic myocardium as early as six hours post-injection, with high heart-to-organ contrast. This work lays the foundation for further development of necrosis-targeted radiopharmaceuticals for both SPECT and PET applications.

Molecular Imaging of Cell Death Mechanisms publication trend

The graph below shows the total number of articles in molecular imaging of cell death mechanisms across all publications each year (not limited to Nature Index journals).

Technical terms

Caspase-3: A cysteine protease that executes the cellular dismantling phase of apoptosis.
Phosphatidylserine: A phospholipid externalised on the plasma membrane of dying cells, serving as a target for death-sensing probes.
Positron Emission Tomography (PET): A nuclear imaging modality that detects pairs of gamma photons to quantify radiotracer distribution in vivo.
Single-Photon Emission Computed Tomography (SPECT): An imaging technique that captures single gamma photons emitted by radiotracers to generate three-dimensional images.
Magnetic Resonance Imaging (MRI): A non-ionising method that uses magnetic fields and radiofrequency pulses to produce anatomical and functional contrast.
Nanoaggregation: The process by which small molecules assemble into nanoparticles in situ, enhancing local imaging signal and retention.

References

1. Preclinical PET Imaging of Tumor Cell Death following Therapy Using Gallium-68-Labeled C2Am. Cancers (2023).
2. Molecular Imaging of Apoptosis: The Case of Caspase-3 Radiotracers. International Journal of Molecular Sciences (2021).
3. Molecular Magnetic Resonance Imaging of Tumor Response to Therapy. Scientific Reports (2015).
4. Discovery of Radioiodinated Monomeric Anthraquinones as a Novel Class of Necrosis Avid Agents for Early Imaging of Necrotic Myocardium. Scientific Reports (2016).