Figure 5.

Scheme on the design of ligand-conjugated nanoparticles across the blood–brain barrier (BBB) via transferrin receptor-mediated transcytosis. (A). Transferrin (Tf)-tagged pegylated liposome. Tf (black oval) is approximately 4 nm, while a liposome is 100 nm in diameter (reprinted with permission from [116]). (B) Polyethylene glycol (PEG)-coated Fe₃O₄ with lactoferrin (Lf) conjugated to its surface (reprinted with permission from [119]). (C). The process of loperamide (LOP)-loaded nanoparticle preparation from nano-emulsion and its potential use as a nanocarrier system crossing the BBB (reprinted with permission from [118]).