Recent advances of cell surface modification based on aptamers

Cell surface engineering represents one of the most vanguard fields in biomedical research. This technology aims to artificially retrofit the surfaces of different types of cells by means of strategies based on gene editing, chemical conjugation, or physical modification to endow cells with new properties that can serve human needs. Aptamers, a class of functional single-stranded nucleic acids, have been frequently employed in recent years as versatile building blocks to achieve this purpose. In this review, we will introduce recent progress in aptamer-based cell surface modification from three aspects divided by cell types: mammalian cells, bacterial cells, and biomimicking protocells. First, we discuss the deployment of aptamers on mammalian cell membranes to visualize specific membrane components, probe local microenvironments, modulate the structures and biological functions of membrane-bound proteins, and reprogram cell‒cell interaction modes. Next, we summarize the use of aptamers to recognize bacterial surface biomarkers and regulate the biodistribution of probiotic bacteria. Then, we highlight the scientific value of biomimicking protocells for membrane-related studies and aptamer-functionalized protocells for biomedical applications. Finally, we provide an overview of current technical challenges that confront the development of aptamer-based cell surface modification and suggest possible solutions from multiple perspectives.