title: Pharmacokinetics on a microscale: visualizing Cy5-labeled oligonucleotide release from poly(n-butylcyanoacrylate) nanocapsules in cells.
abstract: For successful design of a nanoparticulate drug delivery system, the fate of the carrier and cargo need to be followed. In this work, we fluorescently labeled poly(n-butylcyanoacrylate) (PBCA) nanocapsules as a shell and separately an oligonucleotide (20 mer) as a payload. The nanocapsules were formed by interfacial anionic polymerization on aqueous droplets generated by an inverse miniemulsion process. After uptake, the PBCA capsules were shown to be round-shaped, endosomal structures and the payload was successfully released. Cy5-labeled oligonucleotides accumulated at the mitochondrial membrane due to a combination of the high mitochondrial membrane potential and the specific molecular structure of Cy5. The specificity of this accumulation at the mitochondria was shown as the uncoupler dinitrophenol rapidly diminished the accumulation of the Cy5-labeled oligonucleotide. Importantly, a fluorescence resonance energy transfer investigation showed that the dye-labeled cargo (Cy3/Cy5-labeled oligonucleotides) reached its target site without degradation during escape from an endosomal compartment to the cytoplasm. The time course of accumulation of fluorescent signals at the mitochondria was determined by evaluating the colocalization of Cy5-labeled oligonucleotides and mitochondrial markers for up to 48 hours. As oligonucleotides are an ideal model system for small interfering RNA PBCA nanocapsules demonstrate to be a versatile delivery platform for small interfering RNA to treat a variety of diseases.
authors.affiliation: Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Tomcin
authors.affiliation: Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany.
authors.forename: Grit
authors.initials: G
authors.lastname: Baier
authors.affiliation: Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Landfester
authors.affiliation: Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany ; University Medical Center of the Johannes Gutenberg University, III Medical Clinic, Mainz, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Mailänder
mesh_terms: D002232:Carbocyanines / Q000737:chemistry / Q000493:pharmacokinetics*; D045744:Cell Line, Tumor; D016503:Drug Delivery Systems; D004655:Emulsions; D004659:Enbucrilate / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D053769:Nanocapsules / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry / Q000493:pharmacokinetics*
chemical_list: D002232:Carbocyanines; D004655:Emulsions; D005456:Fluorescent Dyes; D053769:Nanocapsules; D009841:Oligonucleotides; C085321:cyanine dye 5; D004659:Enbucrilate
keywords: colocalization; drug delivery; miniemulsion; mitochondria