Morphogenesis Guided by 3D Patterning of Growth Factors in Biological Matrices.

Three-dimensional (3D) control over the placement of bioactive cues is fundamental to understand cell guidance and develop engineered tissues. Two-photon patterning (2PP) provides such placement at micro- to millimeter scale, but nonspecific interactions between proteins and functionalized extracellular matrices (ECMs) restrict its use. Here, a 2PP system based on nonfouling hydrophilic photocages and Sortase A (SA)-based enzymatic coupling is presented, which offers unprecedented orthogonality and signal-to-noise ratio in both inert hydrogels and complex mammalian matrices.

Synthesis of Bifunctional Potassium Acyltrifluoroborates.

New bifunctional potassium acyltrifluoroborate (KAT) substrates have been synthesized in gram scale using optimized reaction conditions. Chemoselective transformation of functional groups in the presence of an acyltrifluoroborate has been demonstrated, and orthogonal reactions of bifunctional KAT reagents are reported. This allows for the incorporation of KAT moieties into peptides and dyes.

Synthesis of Biocompatible PEG Hydrogels by pH-Sensitive Potassium Acyltrifluoroborate (KAT) Amide Ligations.

The synthesis of novel PEG-based hydrogel via chemoselective potassium acyl trifluoroborate (KAT) and -carbamoyl hydroxylamines amide ligation is reported. The gelation kinetics, determined by dynamic rheometry, is pH dependent and allows fine-tuning of the gelation time. For a 4 wt % PEG hydrogel, at low acidic pHs (3 to 6) gelation proceeds rapidly within few minutes, comparable or existing the faster known gelation times.

Chemical sensing of polyols with shapeshifting boronic acids as a self-contained sensor array.

Boronic acid-substituted shapeshifting bullvalenes bearing a (13)C label are employed as sensor arrays for polyhydroxylated compounds, such as carbohydrates, flavanols, and sialic acids. The dynamic nature of the bullvalene core allows for covalent binding to a wide variety of analytes, allowing for specific analyte detection by a single NMR measurement. The resulting (13)C NMR patterns permit an inference to the identity of a particular analyte bound.

Synthetic studies toward A-74528.

A potentially biomimetic approach toward the complex polyketide A-74528 is described. It is based on highly substituted biaryl compounds, synthesized using advanced cross-coupling and condensation methodologies.