Here, we developed a cathepsin B inhibitor using a peptide and bile acid for anticancer therapy. Among the peptide sequences that cathepsin B can recognize, positively charged Arg-Arg (RR) was used as a cathepsin-B-specific peptide without any linkers. A hydrophobic bile acid (BA) was coupled via amide linkages to further enhance the inhibitory effects of the peptides. Out of several types of bile acids, ursodeoxycholic acid (UDCA), a safe drug approved by the US Food and Drug Administration (FDA), was used for this study. The nano-sized Arg-Arg and BA conjugate (RR-BA) can be self-assembled in an aqueous solution, forming nanoparticles due to the strong positive charge and the hydrophobicity of bile acids. This pharmaceutical substance has shown promising results in mouse colorectal cancer (CT26) cell treatment and animal experiments. This type of pharmaceutical therapy could be a potential option for cancer treatment.

Here, we developed a cathepsin B inhibitor using a peptide and bile acid for anticancer therapy. Among the peptide sequences that cathepsin B can recognize, positively charged Arg-Arg (RR) was used as a cathepsin-B-specific peptide without any linkers. A hydrophobic bile acid (BA) was coupled via amide linkages to further enhance the inhibitory effects of the peptides. Out of several types of bile acids, ursodeoxycholic acid (UDCA), a safe drug approved by the US Food and Drug Administration (FDA), was used for this study. The nano-sized Arg-Arg and BA conjugate (RR-BA) can be self-assembled in an aqueous solution, forming nanoparticles due to the strong positive charge and the hydrophobicity of bile acids. This pharmaceutical substance has shown promising results in mouse colorectal cancer (CT26) cell treatment and animal experiments. This type of pharmaceutical therapy could be a potential option for cancer treatment.