[Synthesis and properties of methylene carboxamide mimetics of nucleic acids based on morpholine nucleosides].

Uracyl and adenine containing oligocarboxamide mimetics of nucleic acids based on morpholine nucleosides (MorGly) are synthesized using peptide chemistry methods. Conditions for an analysis of homogeneity of protonated at physiological pH oligomers using a capillary electrophoresis are proposed. Studies of thermostability of complementary complexes formed by MorGly oligomers revealed that melting temperature dramatically depends on heterocyclic base composition (uracyl or adenine). Cooperative interactions realized at junctions in tandem complexes give more contribution to the thermostability in the case of complexes formed by modified oligomers than native oligodeoxyriboadenilates. Adenine containing MorGly oligomers form more stable complexes with poly(U) than native oligodeoxyriboadenilate of the same length. Complexes formed by modified oligomers with polyribonucleotides are more stable in compare with polydeoxyribonucleotide.

Quantitative determination of AVI-7100 (Radavirsen), a phosphorodiamidate morpholino oligomer (PMOplus® ), in human plasma using LC-MS/MS.

AIM: AVI-7100 (Radavirsen) is a 20-mer phosphorodiamidate morpholino oligomer (PMOplus®) for the treatment of influenza. Results/methodology: An automated solid-phase extraction method was used to extract plasma samples (200 µl). The extracts were analyzed using liquid chromatography coupled with tandem mass spectrometry under the positive ionization mode. This method was fully validated over the calibration curve range of 5.00-1000 ng/ml. The between-run precision and accuracy ranged from 0.0 to 5.2% relative standard deviation and 91.6 to 100.0% of nominal for all quality control concentrations, including the lower limit of quantitation. DISCUSSION/CONCLUSION: This is the first liquid chromatography coupled with tandem mass spectrometry method for the measurement of AVI-7100 concentrations in human plasma. It has been used to support regulated bioanalysis.

Spatiotemporal control of embryonic gene expression using caged morpholinos.

Embryonic development depends on spatial and temporal control of gene function, and deciphering the molecular mechanisms that underlie pattern formation requires methods for perturbing gene expression with similar precision. Emerging chemical technologies can enable such perturbations, as exemplified by the use of caged morpholino (cMO) oligonucleotides to photo-inactivate genes in zebrafish embryos with spatiotemporal control. This chapter describes general principles for cMO design and methods for cMO assembly in three steps from commercially available reagents. Experimental techniques for the microinjection and photoactivation of these reagents are described in detail, as well as the preparation and application of caged fluorescein dextran (cFD) for labeling irradiated cells. Using these protocols, cMOs can be effective tools for functional genomic studies in zebrafish and other model organisms.