title: Re-entrant DNA gels.
abstract: DNA is acquiring a primary role in material development, self-assembling by design into complex supramolecular aggregates, the building block of a new-materials world. Using DNA nanoconstructs to translate sophisticated theoretical intuitions into experimental realizations by closely matching idealized models of colloidal particles is a much less explored avenue. Here we experimentally show that an appropriate selection of competing interactions enciphered in multiple DNA sequences results into the successful design of a one-pot DNA hydrogel that melts both on heating and on cooling. The relaxation time, measured by light scattering, slows down dramatically in a limited window of temperatures. The phase diagram displays a peculiar re-entrant shape, the hallmark of the competition between different bonding patterns. Our study shows that it is possible to rationally design biocompatible bulk materials with unconventional phase diagrams and tuneable properties by encoding into DNA sequences both the particle shape and the physics of the collective response.
authors: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.
authors: Francesca
authors: F
authors: Bomboi
authors: Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Campus Scientifico, Edificio Alfa, via Torino 155, 30170 Venezia Mestre, Italy.
authors: Flavio
authors: F
authors: Romano
authors: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.|Dipartimento di Biologia e Biotecnologie C. Darwin, Sapienza Università di Roma, 00185 Roma, Italy.
authors: Manuela
authors: M
authors: Leo
authors: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.
authors: Javier
authors: 0000-0002-9994-8461
authors: J
authors: Fernandez-Castanon
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Fratelli Cervi 93, I-20090 Segrate (MI), Italy.
authors: Roberto
authors: 0000-0003-0434-7741
authors: R
authors: Cerbino
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Fratelli Cervi 93, I-20090 Segrate (MI), Italy.
authors: Tommaso
authors: 0000-0003-4898-4400
authors: T
authors: Bellini
authors: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.|Istituto Sistemi Complessi-CNR, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.
authors: Federico
authors: F
authors: Bordi
authors: Istituto di Biologia e Patologia Molecolari-CNR, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.
authors: Patrizia
authors: P
authors: Filetici
authors: Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.|Istituto Sistemi Complessi-CNR, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy.
authors: Francesco
authors: F
authors: Sciortino
mesh_terms: D001483:Base Sequence; D003102:Colloids / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D044367:Phase Transition; D013696:Temperature
chemical_list: D003102:Colloids; D005782:Gels; D004247:DNA