Targeted Delivery of siRNA Therapeutics to Malignant Tumors

Figure 6

Enhanced tumor uptake of MMP2-degraded NP. Several tumors secrete high levels of the MMP2 enzyme into their stroma. By incorporating the substrate, GPLGIAGQ, between PEG and the NP, the MMP2 cleaved the peptide and releases PEG from the NP. This enables the NP to bind to the negatively charged surface of tumor cells with subsequent endocytosis of the NP.