Mediated Imaging and Improved Targeting of Farnesylthiosalicylic Acid Delivery for Pancreatic Cancer via Conjugation with Near-Infrared Fluorescence Heptamethine Carbocyanine Dye

S-trans-trans-Farnesylthiosalicylic acid (FTS) is a Ras Inhibitor that exhibits desirable Anticancer property and currently undergoing clinical trials for pancreatic Cancer (PC). However, its poor water solubility and low bioavailability have severely hampered clinical applications. A strategy to improve FTS bioavailability is to develop a suitable drug delivery method. Here, we use a near-infrared fluorescence (NIRF) heptamethine carbocyanine (HC) dye conjugated with FTS (to produce FTS-148) as a drug delivery system to enhance FTS bioavailability. We further investigate its tumor-targeting functions. FTS-148 displayed better bioavailability and photophysical property and selective recognition of Cancer cells. FTS-148 significantly reduced PC cell proliferation, and more effective than FTS in restricting tumor growth both in a cell-derived xenograft (CDX) model and a patient-derived tumor xenograft (PDX) model. FTS-148 can specifically recognize PC cells in mice subcutaneous models or rabbit orthotopic models and allows real-time monitoring of the therapeutic effects by NIRF optical imaging. FTS-148 treatment significantly reduced Ras expression in PC cells and increased tumor tissue Apoptosis. In short, FTS conjugated with HC dye had enhanced bioavailability and tumor-targeting property. It provides a potential agent for imaging and therapy of PC.