The invention relates to modification of a
cell penetrating
peptide for realizing a low-
toxicity administration
system with a positive targeting selecting function. A shielding
peptide, an enzymolysis substrate
peptide and a
cell-penetrating peptide are connected in sequence, so that an activatable
cell penetrating peptide is formed; and a medicament and / or a tracer and / or a medicament carrier is connected or embedded or adsorbed to the
cell penetrating peptide, so that an administration
system is constructed. According to a shielding
peptide sequence, positive charges carried on the surface of the administration
system can be reduced or completely neutralized, the cell penetrating capability of the
cell penetrating peptide is shielded, and the
toxicity of the administration system on normal cells of an
organism is lowered; and an enzymolysis substrate
peptide sequence can be identified by
enzyme systems secreted specifically by different
pathological change tissue cells and fractured by
enzyme hydrolysis, so that a
cell penetrating peptide is released and is used for carrying a medicament and / or a medicament carrier through a
cell membrane, and the medicament enters cells and is brought into play. The invention aims to actively convey an antitumor medicament to tumor tissues in a targeted way and make the antitumor medicament enter
tumor cells to a larger extent by using the administration system which can be used for activating a cell penetrating function, so that the
toxicity at a non-tumor position is lowered while the antitumor effect of the medicament is enhanced.