Figure 3.

ICLs but not FPLs label the tumor microenvironment. (A) EPC/DSPE-PEG2000/DiD or EPC/DSPE-PEG2000/Cy5-DSPE liposomes were prepared (Table 1). The probes have the same fluorescent headgroup but different lipid parts. (B, C) 4T1 mice were injected i.v. with DiD or Cy5-DSPE liposomes. Flow cytometry of the tumor single-cell suspension 4 days postinjection shows that about 17% of cells were labeled with DiD and over 50% were F4/80+ macrophages (n = 3 mice). (D) Microscopy image of single-cell suspension of tumors after staining for F4/80.