title: Impact of size, secondary structure, and counterions on the binding of small ribonucleic acids to layered double hydroxide nanoparticles.
abstract: Use of ribonucleic acid (RNA) interference to regulate protein expression has become an important research topic and gene therapy tool, and therefore, finding suitable vehicles for delivery of small RNAs into cells is of crucial importance. Layered double metal hydroxides such as hydrotalcite (HT) have shown great promise as nonviral vectors for transport of deoxyribose nucleic acid (DNA), proteins, and drugs into cells, but the adsorption of RNAs to these materials has been little explored. In this study, the binding of small RNAs with different lengths and levels of secondary structure to HT nanoparticles has been analyzed and compared to results obtained with small DNAs in concurrent experiments. Initial experiments established the spectrophotometric properties of HT in aqueous solutions and determined that HT particles could be readily sedimented with near 100% efficiencies. Use of RNA+HT cosedimentation experiments as well as electrophoretic mobility shift assays demonstrated strong adsorption of RNA 25mers to HT, with twofold greater binding of single-stranded RNAs relative to double-stranded molecules. Strong affinities were also observed with ssRNA and dsRNA 54mers and with more complex transfer RNA molecules. Competition binding and RNA displacement experiments indicated that RNA-HT associations were strong and were only modestly affected by the presence of high concentrations of inorganic anions.
authors.affiliation: Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, Texas 78666.
authors.forename: Blanca V
authors.initials: BV
authors.lastname: Rodriguez
authors.affiliation: Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, Texas 78666.
authors.forename: Jorge
authors.initials: J
authors.lastname: Pescador
authors.affiliation: Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, Texas 78666.
authors.forename: Nicole
authors.initials: N
authors.lastname: Pollok
authors.affiliation: Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, Texas 78666 and Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Beall
authors.affiliation: Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas 78212.
authors.forename: Corina
authors.initials: C
authors.lastname: Maeder
authors.affiliation: Chemistry and Biochemistry, Texas State University, 601 University Drive, San Marcos, Texas 78666.
authors.forename: L Kevin
authors.initials: LK
authors.lastname: Lewis
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000032:analysis*; D001692:Biological Transport; D016503:Drug Delivery Systems; D008276:Magnesium Hydroxide / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry*; D012313:RNA / Q000737:chemistry / Q000378:metabolism*
chemical_list: C010467:hydrotalcite; D000536:Aluminum Hydroxide; D012313:RNA; D008276:Magnesium Hydroxide