Sequence-Defined Oligomers from Hydroxyproline Building Blocks for Parallel Synthesis Applications.

The functionality of natural biopolymers has inspired significant effort to develop sequence-defined synthetic polymers for applications including molecular recognition, self-assembly, and catalysis. Conjugation of synthetic materials to biomacromolecules has played an increasingly important role in drug delivery and biomaterials. We developed a controlled synthesis of novel oligomers from hydroxyproline-based building blocks and conjugated these materials to siRNA.

Photocaged DNA provides new levels of transcription control.

Spot lit: photocaged nucleic acids have been used to regulate gene expression through the action of light. Whereas most methods target mRNAs, DNA decoys have recently been used to target DNA transcription by targeting specific DNA-transcription-factor interactions. This has allowed researchers to "turn-off" transcription through the action of light on caged nucleic acids for the first time.

Light-activated gene expression directs segregation of co-cultured cells in vitro.

Light-directed gene patterning methods have been described as a means to regulate gene expression in a spatially and temporally controlled manner. Several methods have been reported that use photocaged forms of small molecule effectors to control ligand-dependent transcription factors. Whereas these methods offer many advantages including high specificity and transient light-sensitivity, the free diffusion of the uncaged effector can limit both the magnitude and resolution of localized gene induction.