The invention belongs to the medicinal preparation field, relates to a
cell-penetrating
peptide modified
nanoparticle, and concretely relates to a
nanoparticle delivery system for oral polypeptide and
protein medicines, and its preparation method. The
medicine delivery system is composed of the
nanoparticle,
cell-penetrating peptides modified on the surface of the nanoparticle, and the polypeptide
protein medicines sealed by the nanoparticle, wherein the average particle size range of the
medicine delivery system is 10-500nm. The
cell-penetrating
peptide modified nanoparticle and glucosaminoglycan having electronegative cell surfaces undergo electric property attraction and then undergo
endocytosis, so the cell-penetrating
peptide modified nanoparticle and the glucosaminoglycan are integrally taken into cells; and the cell-penetrating peptide modified nanoparticle has an alimentary canal
mucous membrane penetrating capability after the cell-penetrating peptide modified nanoparticle is orally taken, and can deliver the polypeptide
protein medicines carried by the cell-penetrating peptide modified nanoparticle to the
whole body for
blood circulation, so the oral biological utilization degree of the medicines are improved. The cell-penetrating peptide modified nanoparticle has the advantages of improvement of the stability of polypeptide and protein medicines in the alimentary canal, reduction of the application amount of cell-penetrating peptides, and reduction of possible toxic side effects caused by the cell-penetrating peptides.