Small-molecule fluorescent probe for bioimaging of organ fibrosis: progress, challenges and prospects

Fibrosis represents a complex pathological process characterized by excessive extracellular matrix (ECM) deposition during aberrant tissue repair. This condition affects multiple organ systems particularly pulmonary, hepatic, cardiac, and renal systems, causing progressive architectural remodeling and eventual functional impairment. Organ fibrosis, a global health challenge affecting millions annually, imposes substantial burdens on healthcare systems worldwide. The dynamic spatiotemporal variations of fibrosis biomarkers directly reflect pathophysiological progression, highlighting the urgent need for advanced imaging systems capable of real-time biomarker monitoring. While traditional biopsy remains invasive, and conventional imaging techniques are often limited by factors such as radiation exposure and high costs. In contrast, emerging small molecule fluorescent probe with the advantages of non or minimally invasive nature, highly specific targeting capabilities, and potentially low cost, offers a promising approach to addressing the shortcomings of these traditional methods. This comprehensive review summarizes current fluorescent probe design strategies for key fibrotic biomarkers including reactive oxygen/nitrogen species, proteolytic enzymes, and characteristic microenvironmental alterations. Analyzing the probe designs, we identify current technical limitations and propose future development directions. It is anticipated that this review will facilitate the application of novel fluorescent probes in fibrosis research and provide valuable guidance for the diagnosis and treatment of organ fibrosis.