Abstract
The plasma membrane protects the cell from the entry of bioactive hydrophilic macromolecules such as DNA, proteins, antibiotics, etc. Cell penetrating peptides (CPPs) are small peptides (< 20 amino acids), commonly positively charged, which can cross the cell membrane and deliver different cargos. CPPs can be used for the intracellular delivery of different macromolecules such as nucleotides, polymers, nanoparticles, liposomes and proteins. However, CPPs still present limitations related with cell selectivity, endosomal escape and cytotoxicity. It is thus essential to continue the study of CPPs for the delivery and the treatment of diseases with the next generation of therapeutic agents.