HEIDI DOUGLASS | h.douglass@unsw.edu.au

Researchers within the Brain Ageing Research Laboratory at UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA) and Dr Vipul Agarwal from the School of Chemical Engineering have offered renewed insight into ‘Quantum dot’ research, revealing its promising application in Alzheimer’s disease diagnosis and therapy.

“Quantum dots are emerging nanomaterials that are making their way into Alzheimer’s disease research,” explained lead author and Research Assistant, Maria Villalva. “Quantum dots have the potential to be used for early diagnosis as well as treatment of Alzheimer’s disease”. 

Alzheimer’s disease is a complex neurodegenerative disorder and the most prevalent of all the dementias in the ageing population. Clinically, it is characterised by memory deficits as well as cognitive decline and loss of independence.

The presence of amyloid plaques in the brain is a hallmark of Alzheimer’s disease.

Co-Director of CHeBA and co-author on the paper, Professor Perminder Sachdev, explains that beta-amyloid, the main component of the plaques, remains an important target for diagnosis as well as treatment.

"The problem is that most patients only begin presenting symptoms and signs of Alzheimer’s disease such as memory loss and cognitive decline long after the progression of plaque formation, and quite late in the disease process."

Professor Perminder Sachdev

“Therefore, relying on symptoms of memory loss and cognitive decline to make a diagnosis makes it difficult to diagnose Alzheimer’s disease early and provide earlier intervention,” says Professor Sachdev.

The review, published in Nanomedicine, examined thirty-four publications to investigate the potential of Quantum dots to target amyloid plaques in the brain, which can be adapted for diagnostic and therapeutic purposes. Quantum dots are able to cross the blood-brain barrier; a tightly regulated system of cells that prevents foreign substances from being transported from the blood to the brain, as well as facilitating the entry of essential nutrients. The blood-brain barrier has been shown to act as a physical limitation for treatment of Alzheimer’s disease.

Ms Villalva says the review also looked at the potential toxicity of Quantum dots; a major obstacle in their progression into clinical Alzheimer’s disease research.

"Our findings indicate that carbon-based Quantum dots, specifically graphene Quantum dots, not only have been proven to be efficient in crossing the blood-brain barrier but also demonstrated lower toxicity."

Maria Villalva

“The unique properties of Quantum dots, and their versatility to combine to various biomolecules render them a promising diagnostic and therapeutic tool for Alzheimer’s disease,” says Ms Villalva.

Leader of the Brain Ageing Research Laboratory and Senior Research Fellow at CHeBA, Dr Nady Braidy, says that further studies are needed to monitor the blood-brain barrier integrity and to establish a gold standard toxicity measure before Quantum dots are used in clinical medicine.