HPMA copolymer-phospholipase C and dextrin-phospholipase A2 as model triggers for polymer enzyme liposome therapy (PELT).

'Polymer Enzyme Liposome Therapy' (PELT) is a two-step anticancer approach in which a liposomal drug and polymer-phospholipase conjugate are administered sequentially to target the tumour interstitium by the enhanced permeability and retention effect, and trigger rapid, local, drug release. To date, however, the concept has only been described theoretically. We synthesised two polymer conjugates of phospholipase C (PLC) and A2 (PLA2) and evaluated their ability to trigger anthracycline release from the clinically used liposomes, Caelyx