Sequential Release Platform of Heparin and Urokinase with Dual Physical (NIR-II and Bubbles) Assistance for Deep Venous Thrombosis

Trident-inspired fucoidan-based armor-piercing microcapsule for programmed acute pulmonary embolism treatment

Pulmonary embolism remains the third leading cause of human mortality after malignant tumors and myocardial infarction. Commonly available thrombolytic therapeutic agents suffer from the limitations of very short half-life, inadequate targeting, limited clot penetration, and a propensity for severe bleeding. Inspired by the trident, we developed the armor-piercing microcapsule (MC), fucoidan-urokinase-S-nitrosoglutathione-polydopamine@MC (FUGP@MC), which exhibited a triple combination of photothermal, mechanical and pharmacological thrombolysis for the therapeutic treatment of acute pulmonary embolism (APE). Briefly, the outermost fucoidan layer was utilized for targeting to the APE area. Programmed APE treatment was triggered by near-infrared (NIR) light irradiation. Photothermal thrombolytic therapy was carried out by photothermal conversion of polydopamine. The photothermal conversion broke the S-nitroso bond in S-nitrosoglutathione (GSNO) and produced large amounts of nitric oxide (NO) for mechanical thrombolysis, which subsequently disrupted the interfacial structure of microcapsule to stimulate the release of the urokinase (UK), leading to a triple synergistic thrombolytic effect. The results demonstrated that the embolization residual rate of FUGP@MC (contained ≈ 1452.5 IU/kg UK) group was significantly lower than that of UK (10,000 IU/kg) group (6.35 % VS 16.78 %). Remarkably, FUGP@MC demonstrated a reliable in vivo biosafety proficiency. In summary, trident-inspired armor-piercing microcapsule FUGP@MC reveals a potential avenue for advancing pulmonary embolism therapeutics and promises to be a safer alternative candidate to current drug approaches.

NIR Light-Fuse Drug-Free Photothermal Armor-Piercing Microcapsule for Femoral Vein Thrombosis Therapy

Acute thrombosis and its complications are leading global causes of disability and death. Existing thrombolytic drugs, such as alteplase and urokinase (UK), carry a significant bleeding risk during clinical treatments. Thus, the development of a novel thrombolysis strategy is of utmost urgency. Based on the previous work, the hollow structure of microcapsules (MC) is fabricated. Subsequently, armor-piercing MC, known as Fucoidan/S-Nitrosoglutathione/Melanin@MC (FGM@MC) is obtained, using a layer-by-layer (LBL) self-assembly method. Utilizing near-infrared (NIR) light as a trigger, the FGM@MC demonstrated photothermal thrombolysis at the site of thrombus due to its stable and outstanding photothermal properties. Simultaneously, photothermal stimulation leads to the release of a significant amount of nitric oxide from the FGM@MC, resulting in cavitation effects for mechanical thrombolysis. In vivo experiments confirmed the stable release of nitric oxide under NIR light irradiation. Treatment of femoral vein thrombosis in rats revealed that the thrombolytic effectiveness of FGM@MC+NIR (53.71%) is comparable to that of UK (59.70%). Notably, FGM@MC does not interfere with the coagulation function of rats and exhibits a favorable safety profile. In conclusion, this study demonstrates that the drug-free armor-piercing microcapsule has significant potential in the treatment of thrombosis, offering a safe and effective alternative to traditional thrombolytic therapies.

Biomimetic platelet-camouflaged drug-loaded polypyrrole for the precise targeted antithrombotic therapy

Lower extremity deep venous thrombosis (LEDVT) affects patient's quality of life for a long time, and even causes pulmonary embolism, which threatens human health. Current anticoagulant drugs in clinical treatment are hampered by the risk of bleeding due to poor targeting and low drug penetration. Here, we used platelet (PLT)-like biological targeting to enhance the delivery and accumulation of nanomedicines in thrombus and reduce the risk of bleeding. Meanwhile, the parallel strategy of "thrombus thermal ablation and anticoagulation" was applied to increase the permeability of drugs in thrombus and achieve the optimal antithrombotic effect. Polypyrrole (PPy) and rivaroxban (Riv, an anticoagulant drug) were co-assembled into platelet membrane-coated nanoparticles (NPs), PLT-PPy/Riv NPs, which actively targeted the thrombotic lesion at multiple targets in the platelet membrane and were thermally and drug-specific thrombolysed by 808 nm laser irradiation. The combination therapy resulted in up to 90% thrombolysis in a femoral vein thrombosis model compared to single phototherapy or drug therapy. The results showed that the nanoformulation provided a new direction for remote precise and controlled sustained thrombolysis, which was in line with the trend of nanomedicine towards clinical translation.

Biomimetic Nanoplatelets to Target Delivery Hirudin for Site-Specific Photothermal/Photodynamic Thrombolysis and Preventing Venous Thrombus Formation

Due to the high recurrence rate and mortality of venous thrombosis, there is an urgent need for research on antithrombotic strategies. Because of the short half-life, poor targeting capabilities, bleeding complications, and neurotoxic effects of conventional pharmacological thrombolysis methods, it is essential to develop an alternative strategy to noninvasive thrombolysis and decrease the recurrence rate of venous thrombosis. A platelet-mimetic porphyrin-based covalent organic framework-engineered melanin nanoplatform, to target delivery of hirudin to the vein thrombus site for noninvasive thrombolysis and effective anticoagulation, is first proposed. Owing to the thrombus-hosting properties of platelet membranes, the nanoplatform can target the thrombus site and then activate hyperthermia and reactive oxygen species for thrombolysis under near-infrared light irradiation. The photothermal therapy/photodynamic therapy combo can substantially improve the effectiveness (85.7%) of thrombolysis and prevent secondary embolism of larger fragments. Afterward, the highly loaded (97%) and slow-release hirudin (14 days) are effective in preventing the recurrence of blood clots without the danger of thrombocytopenia. The described biomimetic nanostructures offer a promising option for improving the efficacy of thrombolytic therapy and reducing the risk of bleeding complications in thrombus associated diseases.

A targeting mesoporous dopamine nanodrug platform with NIR responsiveness for atherosclerosis improvement

Atherosclerosis (AS), the formation of plaque lesions in the walls of arteries, causes many mortalities and morbidities worldwide. Currently, achieving site-specific delivery and controlled release at plaques is difficult. Herein, we implemented the strategy of constructing a bionic multifunctional nanoplatform (BM-NP) for targeting and improving plaques. BM-NPs were prepared based on probucol-loaded mesoporous polydopamine (MPDA) carriers and were coated with platelet membranes to impart bionic properties. In vitro experiments confirmed that BM-NPs, which respond to near-infrared (NIR) for drug release, remove reactive oxygen species (ROS), thereby reducing the level of oxidized low-density lipoprotein (ox-LDL) and ultimately helping to inhibit macrophage foaming. In vivo experiments proved that BM-NPs actively accumulated in plaques in the mouse right carotid artery (RCA) ligation model. During treatment, BM-NPs with NIR laser irradiation more effectively reduced the area of plaque deposition and slowed the thickening of the arterial wall intima. More importantly, BM-NPs showed the advantage of inhibiting the increase in triglyceride (TG) content in the body, and good biocompatibility. Hence, our research results indicate that intelligent BM-NPs can be used as a potential nanotherapy to precisely and synergistically improve AS.