Figure 4. LC is not taken up by tumor cells, but plays a role in depletion of macrophages in the tumor. (A) Mice (n = 5 per group) with established MCA205 tumors were treated with BODIPY-labeled L-PBS and trafficking of the liposomes to various tissues was assessed. Very little uptake of the liposomes was observed in TAMs. (B and C) Mice (n = 5 per group) with established MCA205 tumors were untreated (control) or were treated with LC twice over 2 weeks and then tumor tissues were collected and processed for flow cytometry. In (B), representative flow plots of control vs LC treated tumor tissue. (C), The percentages of CD11b⁺F4/80⁺ TAMs were assessed by flow cytometry. In mice treated with LC, there were significantly fewer TAMs (*p < 0.05, Mann-Whitney U test) than in control mice. Similar results were seen in two additional experiments.