Transferrin adsorption onto PLGA nanoparticles governs their interaction with biological systems from blood circulation to brain cancer cells.

Purpose: Nanomedicines represent an alternative for the treatment of aggressive glioblastoma tumors. Behaviour of PLGA-nanoparticles (NPs) was here investigated as a function of their protein adsorption characteristics at the different biological interfaces they are expected to face in order to reach brain cancer cells.
Methods: NPs were studied for size, zeta potential, blood half-life, in vitro endocytic behavior and in vivo accumulation within healthy rat brain and brain tumors.
Results: While slightly modifying size (80 to 90 nm) and zeta potential (-44 to -32 mV) protein coating of PLGA-NPs by bovine serum albumin (BSA) or transferrin (Tf) greatly prolonged their blood half-life when intravenously injected in rats and mice. In contrast with THP-1 monocytes, differentiated THP-1 macrophages, F98 glioma cells and astrocytes internalized BSA- and Tf-NPs in vitro. Increase of Tf-NP uptake by F98 cells through caveolae- and clathrin-mediated pathways supports specific interaction between Tf and overexpressed Tf-receptor. Finally, in vivo targeting of healthy brain was found higher with Tf-NPs than with BSA-NPs while both NPs entered massively within brain-developed tumors.
Conclusion: Taken together, those data evidence that Tf-NPs represent an interesting nanomedicine to deliver anticancer drugs to glioma cells through systemic or locoregional strategies at early and late tumor stages.