Cell-penetrating peptides are a type of short peptide that can carry macromolecular substances into cells. Their membrane-penetrating ability does not rely on classic endocytosis. Cell-penetrating peptides are all positively charged polypeptide fragments of varying lengths, which are rich in basic amino acid residues such as arginine and lysine. Their secondary structures all have an α-helical spatial conformation. Taking advantage of these characteristics, membrane-penetrating peptides with stronger penetrating power and higher efficiency have been artificially synthesized, and they have successfully carried macromolecular substances into cells to exert biological activities. Therefore, cell-penetrating peptides can promote other biomolecules, such as drugs, proteins or nucleic acids, to cross the cell membrane and enter the interior of the cell. This ability makes cell-penetrating peptides potentially useful in drug delivery and biomedical research. To this end, CD Bioparticles develops and provides the most comprehensive range of cell-penetrating peptide products for related research.