Hydrophobic structure of hairpin ten-ring pyrrole-imidazole polyamides enhances tumor tissue accumulation/retention in vivo

Abstract To examine the hydrophobic structure of PI polyamides on tumor accumulation in vivo , PI polyamide-fluorescein conjugates 1 – 5 with the distinct number of N -methylimidazole (Im) units were synthesized. There existed an inverse relationship between the Im unit number of the compounds and their hydrophobicity. Compound 1 with one Im unit and 3 with three Im units accumulated and retained preferentially in tumor tissues compared to 5 with five Im units. These results suggest the importance of a PI polyamide’s primary structure, which partly contributes to its hydrophobic property, on its accumulation and/or retention in tumor tissues in vivo .