title: Target binding influences permeability in aptamer-polyelectrolyte microcapsules.
abstract: Aptamer-polyelectrolyte microcapsules are prepared for potential use as triggered delivery vehicles and microreactors. The hollow microcapsules are prepared from the sulforhodamine B aptamer and the polyelectrolytes poly(allylamine hydrochloride) and poly(sodium 4-styrene-sulfonate), using layer-by-layer (LbL) film deposition templated on a sacrificial CaCO(3) spherical core. Scanning electron microscopy and confocal microscopy confirm the formation of spherical CaCO(3) cores and LbL-aptamer microcapsules. Colocalization studies with fluorescently-tagged aptamer and sulforhodamine B verify the ability of the aptamer to recognize its cognate target in the presence of the K(+) ions that are required for its characteristic G-quadruplex formation. Fluorescence recovery after photobleaching studies confirms a significant difference in the permeability of the aptamer-polyelectrolyte microcapsules for the sulforhodamine B dye target compared to control microcapsules prepared with a random oligonucleotide. These results suggest that aptamer-based 'smart' responsive films and microcapsules could be applied to problems of catalysis and controlled release.
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada.
authors.forename: Yasir
authors.initials: Y
authors.lastname: Sultan
authors.forename: Maria C
authors.initials: MC
authors.lastname: DeRosa
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry; D002214:Capsules / Q000737:chemistry*; D036681:Fluorescence Recovery After Photobleaching; D008855:Microscopy, Electron, Scanning; D010539:Permeability; D011108:Polymers / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D002214:Capsules; D011108:Polymers; D002119:Calcium Carbonate