In vivo SELEX of bone targeting aptamer in prostate cancer bone metastasis model

Purpose: PB is one of the most severe complications of late stage prostate cancer and negatively impacts patient quality of life. A major challenge for the treatment of cancer bone metastasis is the management of efficient drug delivery to metastatic bone lesion. We aimed to explore the use of aptamers as promising tools to develop a targeted drug delivery system for PBs. Materials and methods: In vivo SELEX was applied to identify bone targeting aptamer in a mouse model with PBs. Results: The aptamer (designated as "PB") with the highest bone targeting frequency in mice bearing PC3 PB was selected for further analysis. The PB aptamer specifically targeted modulated endothelial cells in response to cancer cells in the bones of mice bearing PC3 PBs. The targeting efficiency of the PB aptamer conjugated to gold particles was verified in vivo. Conclusion: This investigation highlights the promise of in vivo SELEX for the discovery of bone targeting aptamers for use in drug delivery.