title: Chimeric aptamers in cancer cell-targeted drug delivery.
abstract: Aptamers are single-stranded structured oligonucleotides (DNA or RNA) that can bind to a wide range of targets ("apatopes") with high affinity and specificity. These nucleic acid ligands, generated from pools of random-sequence by an in vitro selection process referred to as systematic evolution of ligands by exponential enrichment (SELEX), have now been identified as excellent tools for chemical biology, therapeutic delivery, diagnosis, research, and monitoring therapy in real-time imaging. Today, aptamers represent an interesting class of modern pharmaceuticals which with their low immunogenic potential mimic extend many of the properties of monoclonal antibodies in diagnostics, research, and therapeutics. More recently, chimeric aptamer approach employing many different possible types of chimerization strategies has generated more stable and efficient chimeric aptamers with aptamer-aptamer, aptamer-nonaptamer biomacromolecules (siRNAs, proteins) and aptamer-nanoparticle chimeras. These chimeric aptamers when conjugated with various biomacromolecules like locked nucleic acid (LNA) to potentiate their stability, biodistribution, and targeting efficiency, have facilitated the accurate targeting in preclinical trials. We developed LNA-aptamer (anti-nucleolin and EpCAM) complexes which were loaded in iron-saturated bovine lactofeerin (Fe-blf)-coated dopamine modified surface of superparamagnetic iron oxide (Fe(3)O(4)) nanoparticles (SPIONs). This complex was used to deliver the specific aptamers in tumor cells in a co-culture model of normal and cancer cells. This review focuses on the chimeric aptamers, currently in development that are likely to find future practical applications in concert with other therapeutic molecules and modalities.
authors.affiliation: Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (LIMBR), Centre for Biotechnology and Interdisciplinary Biosciences (BioDeakin), Institute for Technology and Research Innovation (ITRI), Geelong Technology Precinct (GTP), Deakin University, Victoria, Australia. jagat.kanwar@deakin.edu.au
authors.forename: Jagat R
authors.initials: JR
authors.lastname: Kanwar
authors.forename: Kislay
authors.initials: K
authors.lastname: Roy
authors.forename: Rupinder K
authors.initials: RK
authors.lastname: Kanwar
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000627:therapeutic use*; D016503:Drug Delivery Systems; D006801:Humans; D008024:Ligands; D009369:Neoplasms / Q000188:drug therapy*; D052156:SELEX Aptamer Technique; D014018:Tissue Distribution
chemical_list: D052157:Aptamers, Nucleotide; D008024:Ligands