Liposome-CPP Combinations Triple Delivery of an Alzheimer's Peptide Drug Into Cells

Researchers tested free RI-AG03, liposome-conjugated RI-AG03, and liposome-conjugated RI-AG03 with polyR or TAT CPP sequences. Cellular uptake was measured by fluorescence. Uptake mechanisms were probed with macropinocytosis inhibitors. Intracellular trafficking was visualized with co-localization microscopy. Peptide detachment from liposomes was confirmed inside cells.

Tau aggregation is a hallmark of Alzheimer's disease. Tau aggregates form inside cells, so any tau-blocking drug must get inside cells to work. This study shows that liposome-CPP systems can deliver the tau inhibitor peptide into cells with three times higher efficiency, and the peptide avoids lysosomal degradation by detaching from the carrier once inside.

Tau aggregation is a hallmark of Alzheimer's. Getting tau-blocking drugs inside neurons is a major challenge. This combination delivery approach shows promising results that could advance Alzheimer's drug development.

In vitro cell culture study only. No animal model testing. The cells used may not represent the blood-brain barrier or neuronal cells that are the actual targets. Liposome-CPP systems face challenges in vivo including immune clearance, off-target uptake, and difficulty crossing the blood-brain barrier. Whether RI-AG03 actually inhibits tau aggregation inside cells was not tested in this study.