A synthetic icosahedral DNA-based host–cargo complex for functional in vivo imaging

• Published in: Nature communications 2011-06, Vol.2 (1), p.339-339, Article 339
• Main Authors: Bhatia, Dhiraj, Surana, Sunaina, Chakraborty, Saikat, Koushika, Sandhya P., Krishnan, Yamuna
• Format: Article
• Language: English
• Subjects: 631/1647/245; 631/57/2268; 631/92; 639/925/926/1049; Animals; Anisotropy; Biopolymers - chemistry; Caenorhabditis elegans; Cells, Cultured; DNA - chemistry; Drosophila; Fluorescence; Humanities and Social Sciences; Hydrogen-Ion Concentration; Image Processing, Computer-Assisted; Macromolecular Substances - chemical synthesis; Macromolecular Substances - chemistry; Microscopy; multidisciplinary; Nanotechnology - methods; Oligonucleotides; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms1337

The encapsulation of molecular cargo within well-defined supramolecular architectures is highly challenging. Synthetic hosts are desirable because of their well-defined nature and addressability. Encapsulation of biomacromolecules within synthetic hosts is especially challenging because of the former's large size, sensitive nature, retention of functionality post-encapsulation and demonstration of control over the cargo. Here we encapsulate a fluorescent biopolymer that functions as a pH reporter within synthetic, DNA-based icosahedral host without molecular recognition between host and cargo. Only those cells bearing receptors for the DNA casing of the host–cargo complex engulf it. We show that the encapsulated cargo is therefore uptaken cell specifically in Caenorhabditis elegans . Retention of functionality of the encapsulated cargo is quantitatively demonstrated by spatially mapping pH changes associated with endosomal maturation within the coelomocytes of C. elegans . This is the first demonstration of functionality and emergent behaviour of a synthetic host–cargo complex in vivo . Encapsulating molecules within supramolecular frameworks for potential biological application is challenging. Bhatia et al. incorporate a fluorescent polymer within an icosahedral DNA nanocapsule, and show that it can be used to target specific cells in vivo and map pH spatially and temporally.