Folic-acid-targeted drug delivery system implementing Angelica gigas polysaccharide: A potential strategy for colorectal cancer treatment

The study focuses on the development of folate-targeted conjugates utilizing Angelica gigas polysaccharide (F2) as a drug carrier for colorectal cancer therapy. We synthesized F2-C-5-FU conjugates by linking carboxymethyl-5-fluorouracil (C-5-FU) with folic acid (FA) through ester bonding. The drug release behavior of F2-C-5-FU-FA was pH-dependent, favoring release under alkaline conditions. After 96 h in phosphate buffer (pH 7.4), the conjugate exhibited a cumulative release of 54.7%, which was higher compared to other pH environments. In vitro, F2-C-5-FU-FA showed enhanced cytotoxicity and increased cellular uptake in folate receptor-positive HCT-116 cells compared to A549 cells. The conjugate also induced G2/M cell cycle arrest and modulated the BAX/BCL-2 mRNA expression ratio through the MAPK and NF-κB signaling pathways. In vivo, F2-C-5-FU-FA increased tumor fluorescence intensity, prolonged drug circulation, and reduced organ toxicity to non-target organs. The treatment promoted cancer cell apoptosis by inhibiting the expression of apoptosis-related proteins. Overall, F2-C-5-FU-FA conjugates demonstrate potential as an effective drug delivery system for targeted colorectal cancer therapy.