Surface-Engineered HA-PEG-ICG/PLGA Nanoprobes with Vessels Targeting for Lymphatic System Visualization

Targeted imaging of the lymphatic system is essential for the early diagnosis and management of lymphatic disorders, such as lymphedema. In this study, we developed a lymphatic-targeted fluorescent nanoprobe by encapsulating indocyanine green (ICG) within poly(lactic-co-glycolic acid) (PLGA) nanoparticles, further surface-modified with hyaluronic acid-polyethylene glycol (HA-PEG) to enhance specificity (HA-PEG-ICG/PLGA NPs). The nanoparticles were synthesized via a microemulsion technique followed by surface cross-linking, and thoroughly characterized by ultraviolet–visible (UV–vis) spectroscopy, fluorescence emission analysis, Fourier transform infrared (FTIR) spectroscopy, and ζ-potential measurements, confirming their physicochemical stability and functionalization. In vitro cytotoxicity assays indicated excellent biocompatibility with both human keratinocytes (HaCaT) and mouse lymphatic endothelial cells (SVEC4–10). Confocal microscopy and quantitative fluorescence analyses revealed significantly enhanced uptake of HA-PEG-ICG/PLGA NPs in SVEC4–10 cells, which was attributed to HA-mediated binding to LYVE-1 receptors. In vivo imaging in C57BL/6JCrlBltw mice further demonstrated prolonged retention and selective fluorescence accumulation in lymphatic vessels following intraperitoneal administration, surpassing those of free ICG and ICG/PLGA controls. Collectively, these results confirm the potential of HA-PEG-ICG/PLGA NPs as a safe and effective nanoplatform for real-time lymphatic imaging. This targeted system holds promises for early lymphedema diagnosis, intraoperative lymphatic mapping, and future integration with theragnostic strategies for lymphatic-associated diseases.