Introduction<br> <br>PART 1: DESGIN OF CPPS<br>Classification of cell-penetrating peptides<br>Arginine-rich cell-penetrating peptides: recent advances of design and applications for intracellular delivery<br>Cationic cell-penetrating peptides<br>Amphipathic cell-penetrating peptides<br>Hydrophobic cell-penetrating peptides<br>Foldamers<br> <br>PART 2: MECHANISM OF CPPS<br>Peptide Structure: Electrophysiological analysis, nuclear magnetic resonance analysis, and molecular dynamics simulation of direct penetration of cell-penetrating peptides through bilayer lipid membranes<br>Cellular uptake mechanisms of arginine-rich cell-penetrating peptides<br>Endosomal escape<br>Pharmacokinetics of therapeutic and diagnostic agents conjugated with cell-penetrating peptides<br> <br>PART 3: DELIVERY TOOLS<br>Drug delivery<br>Peptide & protein delivery<br>Cell-penetrating peptides for nucleic acid delivery<br>PPMOs: a case study for cell-penetrating peptide application<br>Cell penetrating peptide-conjugated polymer micelles for pDNA/siRNA delivery<br>Lipid-based nanoparticles using cell-penetrating peptides<br> <br>PART 4: APPLICATIONS<br>Cell-penetrating peptides as tools to facilitate oral delivery of biopharmaceuticals<br>Intranasal delivery<br>Clinical trials<br>Applications in plants