Efficient gene delivery targeted to the brain using a transferrin-conjugated polyethyleneglycol-modified polyamidoamine dendrimer.

The blood-brain barrier (BBB) poses great difficulties for gene delivery to the brain. To circumvent the BBB, we investigated a novel brain-targeting gene vector based on the nanoscopic high-branching dendrimer, polyamidoamine (PAMAM), in vitro and in vivo. Transferrin (Tf) was selected as a brain-targeting ligand conjugated to PAMAM via bifunctional polyethyleneglycol (PEG), yielding PAMAM-PEG-Tf.

Characterization of lactoferrin receptor in brain endothelial capillary cells and mouse brain.

We present, herein, the evidence for lactoferrin (Lf) binding sites in brain endothelial capillary cells (BCECs) and mouse brain. The results from confocal microscopy showed the presence of Lf receptors on the surface of BCECs and the receptor-mediated endocytosis for Lf to enter the cells. Saturation binding analyses revealed that Lf receptors exhibited two classes of binding sites in BCECs (high affinity: dissociation constant (K (d)) = 6.