Original source: Materials Today
Clusters of tiny gold particles promise a new way of treating Parkinson’s disease, the debilitating neurodegenerative condition that afflicts over 10 million individuals worldwide [Gao et al.,Biomaterials 194 (2019) 36-46].
Parkinson’s is characterized by motor symptoms such as tremors, rigidity, difficulty moving, as well as tiredness, pain, depression, and neurological impairment. The tell tale signs of the disease in the brain include Lewy bodies, which are made up of clumps of a misfolded protein involved in various neurological functions called a-Synuclein, and the death of dopamine-secreting neurons. While dopamine-related drugs can grant temporary relief, there are no treatments that halt or slow down the long-term development of the disease.
Now a team of researchers from Wuhan University of Technology and the Beijing Institute of Pharmacology and Toxicology in China have found that nanoclusters of N-isobutyryl-L-cysteine-coated gold particles less than 3 nm in size (known as AuNCs) appear to prevent the build-up of a-Synuclein and reverse some symptoms of neurological damage in mice.
“Conventionally, AuNCs are used as bio-probes, imaging or photothermal therapy agents, and nanocarriers for drugs because of their excellent biocompatibility, fluorescence, photothermal properties, and ability to pass through the blood brain barrier (BBB),” explains Taolei Sun, who led the research. “As far as we know, this is the first report of the direct medicinal effect of AuNCs, which will broaden their application prospects.”
In vitro tests reveal that AuNCs prevent the aggregation and growth of a-Synuclein fibrils, which make up Lewy bodies. Moreover, AuNCs appear to protect nerve cells against damage by the neurotoxin 1-methyl-4-phenylpyridine (MPP+), which primarily attacks dopamine-producing neurons in the brain, and is widely used as a cell model for studying potential drug treatments for Parkinson’s.
Most promisingly of all, however, is the researchers’ observation that AuNCs appear to be able to prevent some of the neurological symptoms induced in mice by the drug version of MPP+ (known as MPTP). Mice with neurological impairments including tremors, loss of balance, and slowness of movement showed improvements in their speed and distance travelled in open field and swimming tests, as well as motor coordination, when treated with AuNCs.
The researchers’ experiments also indicate that AuNCs are able to cross the BBB, which is a membrane separating the blood from the brain. While it serves as a very effective barrier preventing toxins or pathogens reaching the brain, it also prevents drugs and other treatment molecules reaching diseased brain tissue.
“These findings indicate that AuNCs may act as a novel candidate for Parkinson’s disease drug treatment,” says Sun.
The team now plans to work towards pre-clinical and clinical studies to explore the efficacy of AuNCs for treating the disease.