PNMA2 and neoplasm: Alibolandi et al. also employed this concept by using polymersomes composed of PEG-b-poly(lactic acid) (PEG-b-PLA) block copolymers in which the two blocks were linked by a synthetic peptide with sequence PVGLIG.76 The latter was selected because it can be cleaved by matrix metalloproteinase 2 (MM2), another enzyme that is overexpressed in tumour tissue.140In vitro studies demonstrated a seven-fold increase in anticancer drug (SN38) release in the presence of MM2 for polymersomes bearing the peptide linker.