Fluorescent probes for the visualization of membrane microdomain, deformation, and fusion.

The cell membrane, a fluid interface composed of self-assembled phospholipid molecules, is a vital component of biological systems that maintains cellular stability and prevents the invasion of foreign toxins. Due to its inherent fluidity, the cell membrane can undergo bending, shearing, and stretching, making membrane deformation crucial in processes like cell adhesion, migration, phagocytosis, and signal transduction. Within the plasma membrane are highly ordered dynamic structures formed by lipid molecules, known as "lipid rafts," whose dynamic dissociation and reorganization are prerequisites for membrane deformation. Fluorescent probes have emerged as vital tools for studying these dynamic processes, offering a non-destructive, in situ, and real-time imaging method. By strategically designing these probes, researchers can image not only the microdomains of cell membranes but also explore more complex processes such as membrane fusion and fission. This review systematically summarizes the latest advancements in the application of fluorescent probes for cell membrane imaging. It also discusses the current challenges and provides insights into future research directions. We hope this review inspires further studies on the dynamic processes of complex cell membranes using fluorescent probes, ultimately advancing our understanding of the mechanisms underlying membrane dissociation, reorganization, fusion, and separation, and fostering research and therapeutic development for membrane-associated diseases.