Fig. 3

In vitro CEST imaging and Z-spectra of PEG-PAM-PAN@DOX. a Cartoon depicting PEG-PAM-PAN@DOX NPs; b Z-spectra of PEG-PAM-PAN@DOX showed that the CEST effects were at approximately 0.5 ppm; c CEST imaging of PEG-PAM-PAN@DOX at different pH; d CEST imaging of PEG-PAM-PAN@DOX at different saturation time (s) and that these increased with the saturation time; e CEST imaging of PEG-PAM-PAN@DOX at different saturation power (μT) and the peaked at 1.5 μT