Therapeutic peptides targeting intracellular molecules

Intracellular targets. (A) simplified illustration of a typical mammalian cells with a list of classes of intracellular "druggable" molecules. The increasing popularity of peptides and proteins targeted therapeutics is primarily attributed to their inherent advantages, such as precise targeting and the reduction of side effects, compared to traditional nonspecific small molecular drugs. In recent times, another achievement in peptide-based therapeutics is identified in their potential to target intracellular protein–protein interactions (PPI) deemed previously "undruggable". As a matter of fact, precision targeting of intracellular PPI is a newfound hope for a large number of conditions which had no treatment. The review explores potential intracellular targeting strategies by peptide-based molecules, with their potential mode of activity in biological system, the transport mechanisms involved, targeting strategies and common barriers that need to be overcome. It also discusses the challenges of lab to clinic translation focusing on intracellular delivery of peptides.