For example, protease matrix metalloprotease 2 (MMP2)-responsive polymer–lipid–peptide NPs encapsulating DOX and antiplatelet antibody R300 (PLP-D-R) have been fabricated, wherein R300 release can be triggered by the presence of MMP2, which is abundantly expressed in tumor vascular endothelia and stroma. Here, MMP2 is linked to neoplasm.