Photoacoustic probes for inflammation-related biomarker imaging: Mechanisms, design, and applications

Inflammation, a self-protective mechanism of the body against injury or infection, underlies a range of physiological and pathological processes. However, persistent or excessive inflammatory responses may lead to various diseases such as encephalitis, pneumonia, hepatitis, myocarditis, gastroenteritis, arthritis, etc. Therefore, accurate and sensitive monitoring of inflammatory processes is crucial for diagnosing and treating these diseases. Biomarker levels during inflammation directly reflect the body's health status, providing valuable insights for diagnosis and treatment. In recent years, photoacoustic imaging technology, as a new molecular imaging technology, can realize high-resolution imaging of biological tissues and has good biocompatibility and depth imaging ability. In the imaging of inflammation-related markers, photoacoustic imaging techniques combined with specific photoacoustic probes have made significant research progress. In addition, there are future challenges in building novel photoacoustic probes for inflammatory diseases. This review aims to provide a comprehensive summary of the design strategies and bioimaging usages of photoacoustic probes for various inflammatory markers since 2021. The review covers the fundamental design concepts and recognition processes of these probes, as well as the key inflammatory diseases and associated biomarkers they target. Additionally, it delves into the current limitations and anticipated challenges encountered in the use of photoacoustic probes in biological applications. Looking ahead, the review highlights the emerging trend towards the development of high-performance photoacoustic probes with longer wavelengths, multi-detection capabilities, quantitative analysis, and multi-mode imaging. It is anticipated that these advancements will facilitate the detection of inflammatory diseases and expand the diagnostic and therapeutic options available for a range of medical conditions. Overall, this review aims to contribute to the ongoing progress in the field of photoacoustic imaging and its potential to revolutionize disease management.