What does the formation of CPP mean?

Cell peptides (CPPs) are short peptides that facilitate cellular uptake of various molecular cargo (from small chemical molecules to nanosize particles and large fragments of DNA). The "cargo" is ociated with the peptides either through chemical linkage via covalent bonds or through non-covalent interactions. The function of the CPPs are to deliver the cargo into cells, a process that commonly occurs through endocytosis with the cargo delivered to the endosomes of living mammalian cells.