Abstract
In vivo optical imaging has become an invaluable tool for visualizing and monitoring biological processes in living organisms. A key component of these imaging techniques is the use of fluorescent dyes that can selectively target and label specific tissues or cell types. This review provides an overview of the current state of tissue-seeking dyes for in vivo applications. We discuss the design principles and chemical structures of dyes that have been developed to target various tissues of interest, including tumors, nerves, bones, vasculatures, and other tissues. The review covers the photophysical properties, targeting mechanisms, and in vivo performance of these dyes. Particular emphasis is placed on dyes that have demonstrated clinical translation or have high potential for future clinical use. The review also examines the challenges and considerations in developing effective tissue-seeking dyes, such as achieving high specificity, overcoming biological barriers and minimizing toxicity. Finally, we highlight emerging trends and future directions in the field, including the integration of tissue-seeking dyes with advanced imaging modalities and theranostic applications. Overall, this review provides a focused summary of the current landscape of tissue-seeking dyes and their pivotal role in advancing in vivo optical imaging and its biomedical applications.