Fig. 4

a Synthesis schematic of anti-granzyme B antibodies (MBGzb) and isotype antibodies (MBcon). b After injecting MBGzb or MBcon into mice, contrast-enhanced ultrasound images were obtained on POD 2 and 5. Reproduced with permission from ref. [75] Copyright 2023 Jin et al. c Biotin-avidin–biotin linking scheme for the fabrication of CD3-targeted nanobubbles (NBCD3). d Representative in vitro imaging images of NBCD3 and NBcon at different concentrations. e B-mode ultrasound images of isograft and allograft rats after injection with NBCD3 or NBcon. Reproduced with permission from ref. [76] Copyright 2018 Elsevier