Innovative Photoacoustic Contrast Agent Enhances Tumor Imaging Safety and Cost-Effectiveness

Researchers from the Indian Institute of Science have developed a novel, biocompatible small molecule that significantly improves tumor imaging with photoacoustic (PA) tomography. Unlike conventional imaging techniques such as Positron Emission Tomography (PET), which involves radioactive tracers and is costly, this new contrast agent offers a safer and more economical alternative.

The traditional method of tumor detection with PET involves injecting radioactive substances like fluorodeoxyglucose (¹⁸F-FDG) that accumulate in metabolically active tumor cells. Although effective, PET scans are expensive and present radiation exposure risks, especially with repeated use.

The new approach utilizes a specially designed molecule called GPc, consisting of four glucose units attached to a zinc-phthalocyanine scaffold. When exposed to near-infrared (NIR) laser light, the molecule absorbs energy and creates pressure waves that are captured as sound signals, allowing the construction of detailed 3D images of the tumor. This technique is particularly advantageous for visualizing superficial tumors.

What sets GPc apart is its enhanced sensitivity and contrast, making it easier to distinguish tumor regions from surrounding healthy tissue. The molecule’s design ensures efficient cellular uptake without being metabolized, unlike glucose itself. Studies confirmed that GPc enters tumor cells via glucose transporters but does not compete with glucose for metabolism, which suggests its safety and effectiveness as a contrast agent.

Using advanced assays, researchers demonstrated that GPc behaves similarly to ¹⁸F-FDG in targeting tumor sites, yet it avoids the drawbacks of radioactive exposure. Its ability to produce clear images using a low-cost, non-ionizing laser makes PA tomography a promising, less invasive alternative for tumor detection.

Overall, this innovation has the potential to transform tumor imaging by providing a safer, more affordable, and accessible diagnostic tool that effectively highlights regions with high metabolic activity, common in many types of cancer.

Source: https://medicalxpress.com/news/2025-06-photoacoustic-contrast-agent-safer-effective.html