Biosensor for early diagnosis of Parkinson's and Alzheimer's diseases
Diagnosis of neurodegenerative diseases in the early stagesChemPort.Ru based on the materials of Chemistry World:
Early diagnosis for Alzheimer's and Parkinson'sResearchers from the USA have developed a biosensor that allows diagnosing the early stages of Parkinson's and Alzheimer's diseases by measuring low concentrations of protein aggregates in the cerebrospinal fluid.
Neurodegenerative diseases are difficult to diagnose accurately in the early stages, since similar symptoms appear in the early stages of Alzheimer's and Parkinson's diseases. However, at the cellular level, these diseases differ – Alzheimer's syndrome is associated with the accumulation of beta-amyloid aggregates, and Parkinson's disease is associated with an increase in the concentration of alpha–synuclein aggregates, so these proteins can act as biological markers to distinguish between Alzheimer's syndrome and Parkinson's disease.
Nevertheless, according to Shalini Prasad, the currently existing diagnostic tests do not have sufficient sensitivity to distinguish between protein formations of different nature. Thus, the aim of the study, which was led by Prasad, was to develop a method for distinguishing aggregates of beta-amyloids and alpha-synucleins at low concentrations.
The biosensor microchip is integrated with a nanoporous membrane
made of aluminum oxide and a collector made of polydimethylsiloxane.
The sensor determines the content of certain protein aggregates in the analyte in 15 minutes.
The biosensor is a printed electronic circuit covered with a porous aluminum oxide membrane, to the pores of which antibodies specific to either beta-amyloid aggregates or alpha-synuclein aggregates were attached. The introduction of a sample of cerebrospinal fluid into the sensor leads to the fact that aggregates bind to specific antibodies, changing the electrical capacity of the device, while the change in capacity was proportional to the concentration of aggregates. Using a new sensor, the researchers measured the concentration of various aggregates in the cerebrospinal fluid of subjects who had classical methods (autopsy) have been diagnosed with Alzheimer's syndrome or Parkinson's disease, or not suffering from neurodegenerative diseases. It was found that the sensor allows you to identify various protein aggregates in the sample, which, according to the researchers, will allow for early diagnosis of Alzheimer's syndrome and Parkinson's disease.
Seth Love, an expert on intracellular processes associated with neurodegenerative diseases from the University of Bristol, says that the new technique represents a very promising technological approach to the diagnosis of Alzheimer's syndrome and Parkinson's disease. However, he adds that it is still necessary to check how successfully the new system can diagnose the relevant diseases at the early stages of their development, and not in samples of diluted cerebrospinal fluid taken from patients with end-stage neurodegenerative diseases.
Prasad states that researchers from his group are currently working on a new improved diagnostic system that will be able to distinguish forms of dementia with an even greater degree of resolution, hoping for its clinical trials.
Article by Michael R. Sierks et al. CSF levels of oligomeric alpha-synuclein and beta-amyloid as biomarkers for neurodegenerative disease is published in Integrative Biology.
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21.11.2011