Unsaturated Fatty Acid-Conjugated Amonafide Fluorescent Prodrugs for Autophagy Disruption and Cancer Theranostics

Despite the powerful antitumor activity of amonafide (ANF), its use in the clinic has been limited by dose-dependent toxicities. To address this challenge, we developed a series of unsaturated fatty acid-amonafide conjugates, leveraging the biocompatibility and inherent tumor-targeting capacity of unsaturated fatty acids. Through amidation reactions, five conjugates were synthesized and evaluated. ANF-DHA stood out as the most promising candidate, demonstrating not only targeted cytotoxicity against cancer cells but also the ability to overcome chemoresistance. Additionally, the design allows for selective fluorescence activation by fatty acid amide hydrolase (FAAH), making it useful for monitoring ANF release in cancer cells. Mechanistic studies revealed that ANF-DHA induces autophagic cell death, effectively disrupting survival pathways in drug-resistant tumors. Our results indicate that modifying ANF by conjugating it with unsaturated fatty acids represents a promising therapeutic platform for enhancing tumor targeting, mitigating side effects, and enabling real-time visualization of drug release.