Evaluation of CTB-sLip for Targeting Lung Metastasis of Colorectal Cancer

Lung metastasis of colorectal cancer is common in the clinic; however, precise targeting for the diagnosis and therapy purposes of those lung metastases remains challenging. Herein, cholera toxin subunit b (CTB) protein was chemically conjugated on the surface of PEGylated liposomes (CTB-sLip). Both human-derived colorectal cancer cell lines, HCT116 and HT-29, demonstrated high binding affinity and cellular uptake with CTB-sLip. In vivo, CTB-sLip exhibited elevated targeting capability to the lung metastasis of colorectal cancer in the model nude mice in comparison to PEGylated liposomes (sLip) without CTB modification. CTB conjugation induced ignorable effects on the interaction between liposomes and plasma proteins but significantly enhanced the uptake of liposomes by numerous blood cells and splenic cells, leading to relatively rapid blood clearance in BALB/c mice. Even though repeated injections of CTB-sLip induced the production of anti-CTB antibodies, our results suggested CTB-sLip as promising nanocarriers for the diagnosis of lung metastasis of colorectal cancer.