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As information messengers for cell‐to‐cell communication, exosomes, typically small membrane vesicles (30–150 nm), play an imperative role in the physiological and pathological processes of living systems. Accumulating studies have demonstrated that exosomes are potential biological candidates for theranostics, including liquid biopsy‐based diagnosis and drug delivery. However, their clinical applications are hindered by several issues, especially their unspecific detection and insufficient targeting ability. How to upgrade the accuracy of exosome‐based theranostics is being widely explored. Aptamers, benefitting from their admirable characteristics, are used as excellent molecular recognition elements to empower exosomes for precision theranostics. With high affinity against targets and easy site‐specific modification, aptamers can be incorporated with platforms for the specific detection of exosomes, thus providing opportunities for advancing disease diagnostics. Furthermore, aptamers can be tailored and functionalized on exosomes to enable targeted therapeutics. Herein, this review emphasizes the empowering of exosomes by aptamers for precision theranostics. A brief introduction of exosomes and aptamers is provided, followed by a discussion of recent progress in aptamer‐based exosome detection for disease diagnosis, and the emerging applications of aptamer‐functionalized exosomes for targeted therapeutics. Finally, current challenges and opportunities in this research field are presented. [ABSTRACT FROM AUTHOR]

Aptamers are emerging as promising molecular tools in cancer‐targeted theranostics. Improving their in vivo stability has been a critical issue in promoting clinical translation, but such efforts could lead to more serious side effects resulting from prolonged retention in healthy organs. To address this problem, we developed an environment‐responsive stabilization strategy for the selective enhancement of aptamer biostability in the tumor microenvironment (TME). Briefly, by means of the end extension of an ATP‐responsive protection (ARP) module, the designed aptamer could be protected from nuclease degradation through the specific incorporation of ATP. Based on our in vivo results, this ARP‐aptamer probe was effectively accumulated in tumors via aptamer‐based molecular recognition. It showed selectively prolonged tumor retention time, but rapid digestion in healthy organs. Our strategy should provide a new paradigm for the development of organ‐specific nucleic acid‐based imaging and therapeutic agents. [ABSTRACT FROM AUTHOR]