Precision Photothermal Therapy for Thrombolysis: Utilizing NIR-II Gold Nanorods for Photoacoustic Imaging-Guided Thrombolysis

Photothermal thrombolysis effectively dissolves fibrin clots through the Landau damping effect while significantly reducing the risk of systemic hemorrhagic complications associated with thrombolytic agents. However, its performance is severely hampered by limited tissue penetration depth, poor precise localization, and optimal timing for laser irradiation. In this study, near-infrared (NIR)-II gold nanorods (GNRs) are reported, which can be used not only as an excellent photoacoustic (PA) contrast agent but also for imaging-guided photothermal thrombolysis. PA imaging offers a promising solution by combining rich optical contrast and high ultrasonic resolution in a single modality, enabling the precise detection of vasculature changes. Following intravenous injection, PA imaging monitored the accumulation of GNRs within carotid artery thrombosis in real time. This dynamic tracking could optimize the NIR irradiation time point, thereby maximizing the therapeutic efficacy of photothermal thrombolysis. With targeted irradiation of thrombus using a 1064 nm laser, the GNR-treated group exhibited a localized temperature elevation at the clot site, resulting in a significantly more pronounced reduction in the thrombus area compared to the control group. In a word, our GNRs could help pinpoint the optimal treatment window and enhance therapeutic outcomes, demonstrating significant clinical translational potential for thrombus diagnosis and therapy.