Fluorescent chemosensors and their possible application for the diagnosis of Parkinson's disease

Parkinson's disease is a neurodegenerative disease directly related to aging and linked to the loss of function of the nervous system. The Chilean and the global current socio demographic scenario are characterized by an increase in life expectancy rates due to medical and technological advances that allow people to live longer, therefore leading to an increasingly aging population. In terms of numbers, industrialized countries have a high incidence of Parkinson's disease in people between 55 and 65 years old, and its prevalence reaches to approximately 3 out of 1000 people. This figure increases dramatically to 4 out of every 100 people over 80 years.

Due to the impact of this neurodegenerative disease, in 1997 the World Health Organization (WHO) declared April 11 as World Parkinson's Day, coinciding with the anniversary of the birth of James Parkinson, the neurologist who discovered the disease. This ailment is currently defined as a complex and progressive disease which is characterized by involuntary tremors of the extremities. Although it has been known since 1817 this condition has no cure, so the available pharmacological treatment only reduces symptoms. Besides, its diagnosis is only viable through histopathological analysis of the post-mortem brain, by identifying protein aggregates that include iron cation residues (III). This scenario, beyond being arid and bleak, shows an under explored research niche.

As mentioned before, this disease is related to the presence of the iron cation (III), which monitoring could be used for the early detection of the disease. There are several types of sophisticated techniques, such as atomic absorption spectroscopy and voltammetry, among others, that can perform this monitoring, however, the high costs of the equipment, the need of specialized training, supplies and sample pre-treatment, increase the costs of its implementation and lengthens the results delivery time. In contrast, the use of fluorescent chemosensors presents many advantages such as high sensitivity, simple and expeditious use, a low implementation cost and a rapid and non-destructive response. A very useful quality of these chemosensors is their application in optical images, a tool that allows the detection of ions in living cells, providing a real time response.

 What are we doing about it?

The Research and Postgraduate Education Institute of the Faculty of Health Sciences of the Universidad Central de Chile, houses the Medical and Bioinorganic Chemistry Research Group (QMEDBIN), which among its lines of research is developing fluorescent chemosensors with the capacity to detect ions related to the development and evolution of neurodegenerative diseases, including iron (III). These fluorescent chemosensors are expected to have low toxicity in human cells to achieve optimal biocompatibility and can be replicated in biological fluids and real cell systems. We also aim to create a kit that can be used for an early diagnosis of this disease.

Despite the fact that advances have been made in the development of chemo sensors, in order to contribute from science to the diagnosis of Parkinson’s disease, their applications in the field of medicine still need to be investigated and verified.