Long-Term Engraftment and Fetal Globin Induction upon Gene Editing in Bone-Marrow-Derived CD34 Hematopoietic Stem and Progenitor Cells.

To develop an effective and sustainable cell therapy for sickle cell disease (SCD), we investigated the feasibility of targeted disruption of the gene, either within exon 2 or at the GATAA motif in the intronic erythroid-specific enhancer, using zinc finger nucleases in human bone marrow (BM) CD34 hematopoietic stem and progenitor cells (HSPCs). Both targeting strategies upregulated fetal globin expression in erythroid cells to levels predicted to inhibit hemoglobin S polymerization. However, complete inactivation of resulting from bi-allelic frameshift mutations in exon 2 adversely affected erythroid enucleation.

Relative performance of alkynes in copper-catalyzed azide-alkyne cycloaddition.

Copper-catalyzed azide-alkyne cycloaddition (CuAAC) has found numerous applications in a variety of fields. We report here only modest differences in the reactivity of various classes of terminal alkynes under typical bioconjugative and preparative organic conditions. Propargyl compounds represent an excellent combination of azide reactivity, ease of installation, and cost.

Degradable conjugates from oxanorbornadiene reagents.

Oxanorbornadienedicarboxylate (OND) reagents were explored for purposes of binding and releasing drugs from serum albumins as representative macromolecular carriers. Being highly reactive Michael acceptors, ONDs form adducts with thiols and amines, which then undergo retro-Diels-Alder fragmentation. A study of more than 30 model adducts revealed a number of modifications that can be used to influence adduct stability.

Copper-Catalyzed Azide-Alkyne Click Chemistry for Bioconjugation.

The copper-catalyzed azide-alkyne cycloaddition reaction is widely used for the connection of molecular entities of all sizes. A protocol is provided here for the process with biomolecules. Ascorbate is used as reducing agent to maintain the required cuprous oxidation state.