BBN/C1-C2

The study analyzed the biodistribution of Cy7.5-labeled BBN/C1-C2 peptide based on bombesin and knottin U5-Sth1a and produced using solid-phase peptide synthesis. The investigation was carried out on a mouse model Nu/Nu with a prostate cancer solid tumor (PC-3 culture) transplanted into the right side, expressing GRPR, using real-time surface fluorescent imaging on days 2 and 5 after intravenous administration of the molecules under study.

The biodistribution analysis showed the selective binding of the BBN/C1-C2 molecule to a tumor, as well as its holding power on the tumor surface for up to 5 days without internalization into cells with low accumulation in normal organs and tissues.

We managed to obtain a stable molecule; however, U5-Sth1a toxin tropic to ion channels was used as a scaffold, so the resulting molecule retained the domain responsible for attaching to the target channel and typical for knottin. In the future, when using the molecule as a ligand for radiotherapy, it can have a negative effect on the patient's heart due to the supplementary radiation load. In this regard, the BBN/C1-C2 molecule requires the extension study.