transportan

Transportan is a synthetic cell-penetrating peptide (CPP) used as a delivery vector to transport various cargoes into cells. It is a chimeric peptide that combines sequences derived from galanin, a neuropeptide, and mastoparan, an amphipathic peptide from wasp venom. The design aims to harness galanin’s biological relevance with mastoparan’s membrane-penetrating properties to promote efficient cellular uptake.

Discovered in the late 1990s, transportan was described as a potent CPP by Pooga and colleagues. Since its initial characterization, it has served as a model peptide for studying CPP mechanisms and as a platform for developing cargo-delivery strategies. Several derivatives and truncated forms have been reported, most notably shorter variants such as Transportan 10 (TP10), which retain uptake capability while offering potentially altered pharmacokinetic and safety profiles.

Mechanistically, transportan can translocate across cellular membranes and form noncovalent or covalent associations with cargo. It is commonly used to facilitate delivery of peptides, nucleic acids, proteins, and nanoparticles in vitro, and has been explored for in vivo applications. Its amphipathic, cationic nature underpins its interaction with lipid bilayers, enabling membrane association and internalization, though exact pathways may involve both direct translocation and endocytic routes.

Applications and limitations: transportan has been employed to enhance intracellular delivery in diverse cell types, including neuronal models. While it can improve uptake of various cargoes, challenges include potential cytotoxicity at higher concentrations, proteolytic instability, and variable efficiency in vivo. Ongoing research focuses on optimizing derivatives, improving specificity, and assessing safety for therapeutic use.