Fig. 3.

(a) In vivo tumour targeting, investigated with 4T1 tumour-bearing BALB/c mice. Compared with parental ferritins, P@FA-FRTs were more efficiently accumulated in tumours, especially for late time points. (b) Ex vivo imaging to compare tumour uptake between P@FA-FRTs and P@FRTs. (c) Immunofluorescence staining results. Consistent with the in vivo observation, stronger fluorescence signals were observed when the animals were injected with P@FA-FRTs. Red, IRDye800; green, phycoerythrin (anti-CD31). Scale bars: 100 µm.