Figure 1.
The cationic, amphipathic structure of peptoids and monomers.
A, top-view of the cationic, amphipathic structure of peptoids (upper), and side-view of the helical structure of peptoid 1 (bottom); B, peptoid monomer side-chain structures with shorthand names.
Table 1.
Sequences and molecular properties of peptoids and comparator peptides.
Table 2.
Peptoid Cytotoxicity in cancer cell lines and control cells.
Figure 2.
Cell viability curves of peptoids.
A, cell viability of MCF-7 cells treated with peptoid 1 for different time periods. Cell viability was measured with MTS assays; B, cell viability curve of 1achiral in MCF-7 and primary dermal fibroblast cells. 1achiral was more toxic to MCF-7 cells.
Figure 3.
Activity of docetaxel and peptoids in MCF-7 and MCF-7/TxT50 cells.
MCF-7/TxT50 cells were selected by docetaxel screening and are resistant due to overexpression of MDR1. Figures show the cell viability of MCF-7 and MCF-7/TxT50 cells treated with docetaxel (A), peptoid 1 (B) and 1achiral (C) for 72 h. Cell viability was measured with MTS assays.
Figure 4.
A, live cell confocal images. MCF-7 cells were treated with 8 µM of CF-peptoid 1 for 1 h, and cells were imaged with ×63 oil lens. MCF-7 cells were treated with peptoids for indicated time and cell viability was measured with MTS assays after another 48 h incubation with fresh media (B), or measured via the Guava assay immediately after peptoid treatment (C), or quantified with LDH leakage immediately (D). E, correlation of LDH leakage and cell viability upon peptoid treatment measured with MTS assays, with r2 = 0.955.
Figure 5.
Reduction of tumor volumes in a human breast cancer xenograft mouse model treated with peptoid 1.
Cancer cells (8×104 cells) isolated from the second generation xenografts of human breast cancer tissues were implanted s.c. into the lower left mammary fat pads of 5–6-week-old immunocompromised NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) female mice. Two weeks after cell implantation, 100 µl of peptoid 1 and control peptoids were injected into xenografts at 110 µM in PBS (∼1 mg/kg) three times a week, up to 8 weeks. Tumor sizes were measured by a caliper. P = 0.0014, t test.