Fig. 4From: Multi-mode biodegradable tumour-microenvironment sensitive nanoparticles for targeted breast cancer imaginga In vivo ultrasound imaging of tumors, livers, and subcutaneous areas at different time after injection of Fe3O4/Na2CO3@PLGA/Cy5.5/cRGD NPs. b Echo intensity rate as a function of time is calculated by tissue/blank, tissue represents the echo intensity of the tumor, liver, or subcutaneous area, blank represents the echo intensity before injectionBack to article page