As a proof of concept, conjugation PSP to a D-peptide activator of tumor suppressor p53 termed DPMI (1492.5 Da) generated hollow spheres ∼80 nm in diameter named as PSP-DPMI that disintegrated only in the acidic microenvironment of tumor tissues, followed by integrin-mediated cellular uptake of PSP-DPMI monomers. Taking full advantage of the EPR effect, tumor microenvironment sensitivity and RGD targeting, PSP-DPMI can specifically accumulate at the tumor site with a long residence time. The gene discussed is TP53; the disease is neoplasm.