Thrombin and NIR dual-responsive system driven by heat-gas for thrombus targeted therapy

Drug thrombolysis is the main means of clinical treatment for thrombotic-related diseases. However, serious bleeding complications caused by low drug delivery efficiency and secondary vascular embolism usually lead to unsatisfactory therapeutic effects. Herein, we constructed a thrombin and near-infrared (NIR) dual-responsive drug-loaded intelligent system to solve the above problems. The CREKA-modified polydopamine (PDA) nanoparticles (NPs) were crosslinked by thrombin-responsive peptide (Pep), to obtain Pep-PPC nanocarriers with special mesoporous nanostructures. Subsequently, NO donor BNN6 and thrombolytic drug UK were loaded on the surface and into the mesoporous of Pep-PPC, to get the multifunctional Pep-NO@PPC/UK. In vitro and in vivo results proved that Pep-NO@PPC/UK could effectively recognize and aggregate at the thrombus site via CREKA-mediated active targeting. Then local abundant thrombin cleaved the nanoplatform to release UK. Meanwhile, PDA converted NIR light into heat and synchronously triggered NO release. This transformed the DDS into a “heat-gas” dual propulsion nanomotor in situ, driving deep penetration of UK in thrombus tissue. Under the combined action of UK and PTT, arterial thrombosis rapidly dissolved with relatively low bleeding risk. More importantly, NO generated in situ could prevent re-embolism of blood vessels at the thrombolytic site by inhibiting activated platelet aggregation, ultimately improving vascular reperfusion rate through a combination of attack and defense mode.