Objective To develop albumin-binding indocyanine green (ICG) and assess its potential for near-infrared ?uorescence imaging and intraoperative navigation in lung cancer. Methods ABD-tri was recombinantly expressed by genetic engineering. Its albumin-binding capability was determined using size-exclusion chromatography, and its albumin-dependent binding to lung cancer cells was evaluated by flow cytometry. ICG was conjugated to ABD-tri to generate the fluorescent probe ABD-tri-ICG. The potential of ABD-tri-ICG for near-infrared ?uorescence imaging and imaging-guided tumor resection was evaluated in mice bearing subcutaneous tumor grafts of lung cancer. Results ABD-tri was highly expressed in Escherichia coli (E. coli) and was purified to homogeneity via a simple affinity chromatography. ABD-tri bound both human and murine serum albumin, contributing to its binding to lung cancer cells. ICG was effectively conjugated to ABD-tri to produce the fluorescence probe ABD-tri-ICG after mixing and incubation at room temperature for 1 h. In mice bearing lung cancer tumor grafts, intravenously injected ABD-tri-ICG enabled clear visualization of tumors with diameters ranging from 5 to 7 mm within 0.5-24 h post-injection. The tumor grafts were resected under the guidance of by ABD-tri-ICG-mediated near-infrared ?uorescence imaging. ConclusionIntravenous injection of ABD-tri-ICG allows rapid and sustained visualization of lung cancer tumor grafts and enables intraoperative navigation in mice, warranting further evaluation on the clinical translation of ABD-tri-ICG.
