Mucus is a selectively permeable hydrogel that protects epithelia from pathogens, while permitting the passage of helpful agents. The selection criteria of mucus are not well understood, preventing us from predicting the transport of pathogens and limiting our ability to design drugs that penetrate through mucus. Natural substrates that diffuse through mucus are composed of complex arrangements of charge and hydrophobicity. Inspired by this, we characterize the combined impact of charge and hydrophobicity on the transport of peptides in mucus.

The transcription factor c-Myc is a master regulator aberrant in ~70% of human cancers. Inhibition of c-Myc or proteins interacting with c-Myc is a promising strategy for treating many cancers, yet potent and selective inhibitors of c-Myc-mediated transcription have not been developed. Here, we present our general strategy for development of novel small molecules inhibiting c-Myc activity using small molecule microarrays for high-throughput screening against tens of thousands of compounds.