Lactoferrin Transport
Small molecules, including pharmaceutical drugs, require solute carriers of the SLC family (116) to effect their uptake (117–124). Lactoferrin, as a protein, is far too large to exploit such a route, and instead passes from the stomach via epithelial cells and into the blood using endocytosis (125, 126), especially via Peyer's patches (127), and when it is encapsulated (“enterically formulated”) in liposomes (128–130). This uptake then occurs mostly via the lymphatic rather than the portal circulation (131, 132). LF can also enter, and be reabsorbed from, the bile (125). Blood LF can further be transported to the CNS via cerebrospinal fluid (133, 134) and via the Blood Brain Barrier (63, 133).