In Vivo Distribution and Therapeutic Efficacy of Radioiodine-Labeled pH-Low Insertion Peptide Variant 3 in a Mouse Model of Breast Cancer

Figure 3

Binding fractions of ¹²⁵I-labeled pHLIPs to MDA-MB-231 cells at different pH values. The binding fractions to MDA-MB-231 cells from pH 7.8 to 6.2 were , , , , and for ¹²⁵I-WT-pHLIP and , , , , and for ¹²⁵I-Var3-pHLIP, respectively. The cell binding fraction at pH 6.2 was significantly higher than those at pH 7.4 () and 7.8 (). With an excess of unlabeled peptide, the binding fractions of ¹²⁵I-WT-pHLIP or ¹²⁵I-Var3-pHLIP to cells at pH 6.2, respectively, decrease to and . .