Novel drug-delivery method and engineered antibodies to fight neurodegenerative diseases

Researchers at the University of Ottawa have mapped out a dual-action therapeutic strategy to cross the blood-brain barrier and eliminate pathological proteins linked to Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and dementia

Published in Nature Biomedical Engineering, the study demonstrates how extracellular vesicles can deliver engineered antibodies directly into brain tissue, where they activate the body’s natural cellular recycling system to clear disease-causing protein aggregates.

Overcoming the blood-brain barrier with extracellular vesicles

A central challenge in treating neurodegenerative conditions is the blood-brain barrier, a natural physiological defence that restricts circulating foreign substances from entering the central nervous system.

Under traditional intravenous administration, approximately only 1 in 10,000 antibody drugs successfully penetrates into brain tissue, with the vast majority remaining trapped in the bloodstream.

To overcome this bottleneck, a research team led by Dr Derrick Gibbings and Dr Huishan Guo utilised extracellular vesicles, naturally occurring, cell-derived nanoparticles, to transport therapeutics across blood vessel walls.

The team demonstrated that these biological vesicles effectively cross into brain tissue, serving as reliable drug-delivery vehicles for targeted biopharmaceuticals.

Targeted clearance via engineered autophagy receptors

Delivering antibodies into the brain addresses only half of the therapeutic challenge; standard antibodies often bind to pathological proteins without successfully degrading them.

To resolve this limitation, the researchers re-engineered the antibodies to engage autophagy, the cell’s natural waste-disposal mechanism:

1. Autophagy tagging:

   • The antibodies were modified with molecular tags that direct bound target proteins, specifically pathological Tau and TDP-43, into cellular autophagosomes for degradation.

2. Preclinical validation:

   • In cell cultures and mouse models of Alzheimer’s, dementia, and ALS, these targeted autophagy receptors significantly enhanced the clearance of disease-causing protein deposits.

3. Symptomatic improvement:

   • Animal models receiving the combined extracellular vesicle and engineered antibody treatment exhibited measurable improvements in motor and cognitive symptoms.

Industry context and translational outlook

While conventional neuro-antibody clinical trials have yielded limited patient benefit despite substantial biotechnology investment, this new combination strategy offers a mechanistic blueprint to improve both drug delivery and target clearance. The uOttawa team is now working to advance these preclinical findings toward clinical trial protocols to evaluate safety and efficacy in human patients.