Formulation and Characterization of Patent Blue Dye Nanoliposome Labeled with ^99m Tc-HMPAO and <i>In Vivo</i> Evaluation by Sentinel Lymph Node Mapping

OBJECTIVE(S): Sentinel lymph node (SLN) mapping commonly involves presurgical administration of a radioactive colloid and intraoperative injection of a blue dye near the tumor. Combining gamma scintigraphy and visual inspection could reduce false-negative rates. This study introduces novel imaging agents-radioactive nanoliposomes (NLs) encapsulating patent blue dye-for lymph node scintigraphy. MATERIALS AND METHODS: Tc-HMPAO). Lymphatic drainage of the radiolabeled liposomes was assessed in BALB/c mice following subcutaneous footpad injections. Planar imaging was performed at 0.5 and 1 hour postinjection. RESULTS: Tc-HMPAO-non-PEG-NLs had an increased lymph node accumulation through entire time after injection (11.95 ± 0.8% ID/g, 22.95 ± 4.56% ID/g, 29.71 ± 2.16% ID/g at 1, 2, and 4 hours, respectively). Encapsulation efficiency of patent blue dye was determined to be 1.26 ± 0.1%. CONCLUSION: Tc-HMPAO PEG-NLs and non-PEG-NLs containing Paten Blue dye are promising agents for SLN mapping, offering distinct advantages in uptake kinetics and retention for lymphatic imaging and visual detection.