Fig. 5From: Recent advances in applications of multimodal ultrasound-guided photoacoustic imaging technologyPreparation of dual-responsive AuNNP@SN38 Ve loaded with BLZ-945. The smaller AuNNP@PEG/PSN38VP then penetrated the deeper tumor regions and released the SN38 prodrug in the reductive environment, leading to tumor cell apoptosis. PA imaging in the NIR-II window further enabled drug release monitoring and guided therapy [23]Back to article page