Drug-Controlled Release Based on Complementary Base Pairing Rules for Photodynamic-Photothermal Synergistic Tumor Treatment.

Controlled drug release systems can enhance the safety and availability but avoid the side effect of drugs. Herein, the concept of DNA complementary base pairing rules in biology is used to design and prepare a photothermal-triggered drug release system. Adenine (A) modified polydopamine nanoparticles (A-PDA, photothermal reagent) can effectively bind with thymine (T) modified Zinc phthalocyanine (T-ZnPc, photosensitizer) forming A-PDA = T-ZnPc (PATP) complex based on A = T complementary base pairing rules. Similar to DNA, whose base pairing in double strands will break by heating, T-ZnPc can be effectively released from A-PDA after near infrared irradiation-triggered light-thermal conversion to obtain satisfactory photodynamic-photothermal synergistic tumor treatment. In addition, PDA can carry abundant Gd3+ to provide magnetic resonance imaging guided delivery and theranostic function.