Human serum albumin nanocolloid (HSA nanocolloid)

Human serum albumin (HSA) nanocolloids are radiopharmaceutical agents consisting of denatured human albumin particles, typically sized between 50 and 100 nm (EMA, 2021). They are not biological targets but serve as vehicles for radionuclides, most commonly Technetium-99m, for diagnostic imaging. Following interstitial injection, these particles migrate through the lymphatic system and are trapped by macrophages in the sentinel lymph nodes via phagocytosis (Mariani et al., 2001). This allows for the precise mapping of lymphatic drainage in patients with breast cancer or melanoma. Additionally, they can be used for bone marrow scanning or imaging of inflammatory joints in rheumatoid arthritis (PubChem). Their clinical utility relies on the physical properties of the colloid rather than biochemical interaction with a specific receptor. They are essential tools in surgical oncology for identifying the first node to receive drainage from a tumor site. The safety profile is generally favorable, though it depends on the radioactive payload used.

Other names

NanocollAlbures99mTc-HSA nanocolloidTechnetium Tc 99m albumin nanocolloidHSA-NC

The mechanism involves passive transport through the lymphatic system followed by active phagocytosis by the reticuloendothelial system (RES), specifically by fixed macrophages in lymph nodes or the liver and spleen (EMA, 2021; Mariani et al., 2001).