Extended Data Fig. 9: Ultrasound power delivery in the tissue and biosafety evaluation.
From: H-bonded organic frameworks as ultrasound-programmable delivery platform

a, To measure ultrasound power transfer efficiency through tissue, pork skin of varying depths was placed on a 1.5-MHz, 2.40-MPa FUS transducer. The results showed that 1.5-MHz ultrasound could penetrate up to 20 mm, with a power transfer efficiency of 37% at 10 mm depth; mean ± s.e.m.; n = 3. b, The in vivo ultrasound power transfer in the mouse head with FUS focus length of 5 mm. The ultrasound peak pressure heat map in the mouse head shows that around 0.90 MPa was delivered to the mouse VTA when 1.40 MPa primary ultrasound peak pressure was used. c, Ultrasound-induced blood-brain barrier opening evaluation through Evans blue staining. (i) Brains from mice injected with microbubbles and given 20 s ultrasound at 1.0 MPa (left) and 0.75 MPa (right). (ii) Brains from mice without microbubbles given 20 s ultrasound at 1.0 MPa. (iii) Brains from mice without microbubbles given 20 s ultrasound at 1.5 MPa. Red circles show ultrasound-treated areas. d, The evaluation of ultrasound-induced thermal effects at the focus. Real-time temperature detection was conducted at the mice VTA during FUS stimulation (1.5 MHz, 1.55 MPa, duration 20 s). No substantial temperature changes were observed during the initial 10 s of ultrasound exposure, with only a slight increase of approximately 1.25 °C detected after the 20 s stimulus. Mean ± s.e.m., n = 3 independent experiments for each sample. e, The in vivo ultrasound power transfer in rat heads with FUS focus length of 10 mm. The ultrasound peak pressure heat map in the rat head shows that around 1.19–1.39 MPa was delivered to the rat VTA when 2.45 MPa primary ultrasound peak pressure was used.