Controllable Thrombolysis Using a Nanobubble-Imaging-Guided rtPA Targeted Delivery Strategy.

Objective: The objective of this work is to design and fabricate a novel multifunctional nanocarrier combining thrombus-targeted imaging and ultrasound-mediated drug delivery for the theranostics of thrombotic diseases. Impact Statement: This study develops a new technology that can accurately visualize the thrombus and deliver drugs with controllable properties to diagnose and treat thrombotic diseases. Introduction: Thrombotic diseases are a serious threat to human life and health. The diagnosis and treatment of thrombotic diseases have always been a challenge. In recent years, nanomedicine has brought new ideas and new methods for the theranostics of thrombotic diseases. However, there are also many problems need to be solved, such as biosafety and stability of nanocarriers, early diagnosis, and timely treatment of thrombotic diseases, difficulty in clinical translation. Methods: The S1P@CD-PLGA-rtPA nanobubbles (NBs) were prepared by integrating sulfur hexafluoride (SF₆)-loaded poly (D, L-lactide-co-glycolide) (PLGA) NBs, cyclodextrin (CD), sphingosine-1-phosphate (S1P), and recombinant tissue plasminogen activator (rtPA). Results: S1P@CD-PLGA-rtPA NBs had rapid and excellent thrombosis targeting imaging performance based on the specific interaction of S1P-S1PR1 (sphingosine-1-phosphate receptor 1). Furthermore, S1P@CD-PLGA-rtPA NBs that specifically targeting to the thrombosis regions could also respond to external ultrasound to achieve accurate and efficient delivery of rtPA to enhance the thrombolysis effectiveness and efficiency. Conclusion: This study proposes a new idea and strategy of targeting thrombus in rats via the specific interaction of S1P-S1PR1. On this basis, the acoustic response properties of bubble carriers could be fully utilized by combining thrombus-specific targeted imaging and ultrasound-mediated drug delivery for effective thrombolysis, which is expected to be applied in targeted diagnosis and treatment of thrombotic diseases in the future.