AbstractBendamustine (BEN) is a FDA‐approved bifunctional DNA‐alkylating chemotherapy drug, but it suffers from short half‐life, instability, and poor biocompatibility in the clinical application. Due to unique biostability of d‐amino acid‐containing peptides (D‐peptides), constructing D‐peptide‐small molecule drug conjugates is emerging as a promising strategy for cancer therapy. Here, a high‐affinity MDM2‐targeted D‐peptide (peptide 5) is discovered by applying structure‐based drug design (SBDD). Taking the advantages of d‐amino acids, a novel self‐assembling D‐peptide‐small molecule drug conjugate (BEN‐FF‐peptide 5) is developed by simultaneously conjugating small molecule drug BEN and peptide 5 to the self‐assembling peptide. In vitro results demonstrate that BEN‐FF‐peptide 5 exhibits superior cellular uptake ability, good biostability in human serum and strong inhibitory effect on the growth of human breast cancer (MCF‐7) cells. In vivo study reveals that BEN‐FF‐peptide 5 significantly inhibits the growth of MCF‐7 cells‐derived xenograft in nude mice with no obvious side effects. This work provides a useful strategy to construct D‐peptide‐small molecule drug conjugates for high‐efficacy and low‐toxicity cancer therapy.
