Sequence-Defined DNA Polymers: New Tools for DNA Nanotechnology and Nucleic Acid Therapy.

ConspectusStructural DNA nanotechnology offers a unique self-assembly toolbox to construct soft materials of arbitrary complexity, through bottom-up approaches including DNA origami, brick, wireframe, and tile-based assemblies. This toolbox can be expanded by incorporating interactions orthogonal to DNA base-pairing such as metal coordination, small molecule hydrogen bonding, π-stacking, fluorophilic interactions, or the hydrophobic effect. These interactions allow for hierarchical and long-range organization in DNA supramolecular assemblies through a DNA-minimal approach: the use of fewer unique DNA sequences to make complex structures.

Enhancing siRNA efficacy in vivo with extended nucleic acid backbones.

Therapeutic small interfering RNA (siRNA) requires sugar and backbone modifications to inhibit nuclease degradation. However, metabolic stabilization by phosphorothioate (PS), the only backbone chemistry used clinically, may be insufficient for targeting extrahepatic tissues. To improve oligonucleotide stabilization, we report the discovery, synthesis and characterization of extended nucleic acid (exNA) consisting of a methylene insertion between the 5'-C and 5'-OH of a nucleoside.

An Immunodeficiency Disorder Presenting in the Neonatal Period.

Primary immunodeficiency (PID) Disorders include a variable group of diseases that are classified according to the functional defects encountered. Chronic granulomatous disease (CGD) is inherited as an X-linked recessive disorder in many cases, and it is the clinical model of disorders of phagocytosis. Skin and solid organs abscesses are the most common presenting symptoms; we will report the case of a four-day-old boy admitted to our hospital for a neck mass with purulent discharges associated with umbilical stump and circumcision site infection; the diagnosis of CGD was later confirmed by the Dihydrorhodamine (DHR) test that turned out to be positive.

Quantifying the activity profile of ASO and siRNA conjugates in glioblastoma xenograft tumors in vivo.

Glioblastoma multiforme is a universally lethal brain tumor that largely resists current surgical and drug interventions. Despite important advancements in understanding GBM biology, the invasiveness and heterogeneity of these tumors has made it challenging to develop effective therapies. Therapeutic oligonucleotides-antisense oligonucleotides and small-interfering RNAs-are chemically modified nucleic acids that can silence gene expression in the brain.