Abstract
Small-interfering RNA (siRNA), an efficacious manner of RNA interference (RNAi) for gene therapy, furnishes a considerable strategy for cancer treatment by silencing the targeted message RNA (mRNA). Though cationic polymer materials could protect the siRNA through electrostatic interaction from leakage and degradation in the extracellular condition, the low mRNA knockdown efficiency of gene carrier is always hampered by the insufficient capability to release siRNA in cytoplasm. To address the dilemma, herein I developed the PEG-b-PDMAEMA-b-PPy triblock copolymer micelleplexes that could protect siRNA from leakage in physiological condition and respond to photo-stimulus for boosting siRNA release in a spatiotemporal manner. The siRNA release studies of PEG113-b-PDMAEMA31-b-PPy30 micelleplexes demonstrated in heparin that induces instability of gene carriers manifested 15% accumulative release of siRNA after 10 hours in PBS (pH= 7.4, ionic strength= 0.14 M) without UV-irradiation. Meanwhile, the accumulative release of siRNA from micelleplexes triggered by UV-irradiation for 10 minutes was around 40% after 10 hours incubation. The photoresponsive core-shattering micelleplexes equipped with enhanced stability and triggered release would provide a new platform for systemic gene delivery.