title: Assembly and functionalization of DNA-polymer microcapsules.
abstract: We report the synthesis and characterization of DNA-grafted poly(N-isopropylacrylamide) (PNIPAM) micelles, their assembly into multilayered thin films, and the subsequent generation and poly(ethylene glycol) (PEG) functionalization of DNA-PNIPAM microcapsules. Multilayer films were assembled by sequentially depositing DNA-grafted PNIPAM micelles containing the cDNA sequences polyA(30) or polyT(30) (i.e., PNIPAM-A(30) or PNIPAM-T(30)). DNA-polymer microcapsules were obtained by the alternate deposition of PNIPAM-A(30) and PNIPAM-T(30) onto silica particles, followed by removal of the template core. Upon removal of the silica core particle, shrinkage of between 30 and 50% was observed for the microcapsules. The presence of PNIPAM within the DNA-polymer hybrid film reduces the permeability of the microcapsules to macrosolutes (e.g., dextran) compared with microcapsules made solely of DNA. The hydrophobic core of the DNA-grafted PNIPAM micelles was designed to contain alkyne "click" groups, which were exploited to covalently couple azide-bearing low-fouling PEG to the DNA-PNIPAM microcapsules. The combination of hydrophobic and reactive "click" nanodomains, along with the degradability of DNA, offers a multifunctional and versatile DNA-polymer capsule system that is envisioned to find applications in the controlled delivery of therapeutics.
authors.affiliation: Centre for Nanoscience and Nanotechnology, Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cavalieri
authors.forename: Almar
authors.initials: A
authors.lastname: Postma
authors.forename: Lillian
authors.initials: L
authors.lastname: Lee
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D002214:Capsules / Q000737:chemistry*; D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D004337:Drug Carriers; D016650:Fluorescein-5-isothiocyanate; D008823:Micelles; D018613:Microscopy, Confocal; D009841:Oligonucleotides / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D001386:Azides; D002214:Capsules; D004337:Drug Carriers; D008823:Micelles; D009841:Oligonucleotides; D011108:Polymers; D012997:Solvents; D011791:Quartz; C052970:poly-N-isopropylacrylamide; D012822:Silicon Dioxide; D004247:DNA; D016650:Fluorescein-5-isothiocyanate