Targeting Nanomotor with Near-Infrared/Ultrasound Triggered-Transformation for Polystage-Propelled Cascade Thrombolysis and Multimodal Imaging Diagnosis.

Nowadays, cardiovascular and cerebrovascular diseases caused by venous thromboembolism become main causes of mortality around the world. The current thrombolytic strategies in clinics are confined primarily due to poor penetration of nanoplatforms, limited thrombolytic efficiency, and extremely-low imaging accuracy. Herein, a novel nanomotor (NM) is engineered by combining iron oxide/perfluorohexane (PFH)/urokinase (UK) into liposome nanovesicle, which exhibits near-infrared/ultrasound (NIR/US) triggered transformation, achieves non-invasive vein thrombolysis, and realizes multimodal imaging diagnosis altogether. Interestingly, a three-step propelled cascade thrombolytic therapy is revealed from such intelligent NM. First, the NM is effectively herded at the thrombus site under guidance of a magnetic field. Afterwards, stimulations of NIR/US propel phase transition of PFH, which intensifies penetration of the NM toward deep thrombus dependent on cavitation effect. Ultimately, UK is released from the collapsed NM and achieves pharmaceutical thrombolysis in a synergistic way. After an intravenous injection of NM in vivo, the whole thrombolytic process is monitored in real-time through multimodal photoacoustic, ultrasonic, and color Doppler ultrasonic imagings. Overall, such advanced nanoplatform provides a brand-new strategy for time-critical vein thrombolytic therapy through efficient thrombolysis and multimodal imaging diagnosis.

Sprayable oxidized polyvinyl alcohol with improved degradability and sufficient mechanical property for fruit preservation.

Besides their limited preservation capacity and low biosafety, traditional fruit preservation procedures exacerbate "white pollution" because they utilize excessive plastic. Herein, an environmentally friendly one-pot method was developed to obtain degradable polyvinyl alcohol (PVA), where the hydroxyl radicals generated through the reaction between hydrogen peroxide (H2O2) and iron ions functioned to oxidize PVA. The oxidized PVA (OPVA-1.0) with abundant ketone groups, reduced crystallinity, and short molecular chains was completely degraded into H2O and CO2 after being buried in the soil for ∼60 days. An improvement in its degradation rate did not weaken the mechanical properties of OPVA-1.0 compared to other modified PVA films because the adverse effect of decreased crystallinity on its mechanical performance was offset by its ion coordination. Alternatively, the tensile strength or toughness of OPVA-1.0 was enhanced due to its internal multi-level interactions including molecular chain entanglement, hydrogen bonding, and metal coordination bonds. More interestingly, OPVA-1.0 was water-welded into various products in a recyclable way owing to its reversible physical bonds, where it was sprayed, dipped, or brushed conformally onto different perishable fruits to delay their ripening by 5-14 days. Based on the cellular biocompatibility and biosafety evaluations in mice, OPVA-1.0 obtained by the facile oxidation strategy was demonstrated to alleviate "white pollution" and delay the ripening of fruits effectively.