Pharmacological neurochemistry

The major research interest of our group is the development and applications of techniques, which allow the monitoring of chemical signals in vivo in the brain and other organs. We are particularly interested in minimally invasive techniques, microdialysis, biosensors, and related bioanalytical methods.

Clinical microdialysis

The microdialysis technique for the continuous sampling of the interstitial fluid of tissues and organs was developed in our laboratory in the early 1970s and was first published in 1974. Today there are more than 10,000 microdialysis papers published on animal physiology/pharmacology and over 1,000 microdialysis papers on human brain and peripheral organs especially in the fields of intensive care, diabetes, and tissue metabolism.

We are continuing our research on clinical microdialysis with three specific aims:

• To discover and characterize chemical markers of ischemia and cell degradation in microdialysis samples from human tissues and organs.
• To determine the clinical relevance of these markers for the diagnosis and treatment of patients in intensive care.
• To develop clinical routines for the efficient use of microdialysis in the intensive care setting.

Microdialysis provides the very close and reliable chemical correlates to behavioural measures of physiology and pathology of the living body. This fact has made microdialysis especially attractive for use in experimental neuropharmacology, as well as in the clinics.

We have developed several ultra-sensitive HPLC techniques for the determination of trace levels of monoamines and other classical neurotransmitters (acetylcholine, serotonin, noradrenaline, dopamine, histamine, Asp, Glu, Gly, GABA) in the brain microdialysates.

Development of nanoscale bioassay technologies

In continuation of this effort we are carrying out a multi-disciplinary project with the aim to develop nanoscale bioassay technologies based on electrogenerated chemiluminescence, which will allow ultra-sensitive, non-isotopic detection of biomolecules at concentrations bellow 10-12 M and in 100-200 nl sample volumes.

Reagents utilizing electrochemically generated luminescence of novel tris(2,2´-bipyridyl)ruthenium(II) molecular labels have been synthesized and are used as labels for monoamines and neuropeptides.

Biological diagnostic tools using microsystems and supersensitive magnetic detection

In parallel to our research on neurochemical monitoring techniques, we have initiated a series of studies on the applications of functionalized superparamagnetic nanoparticles as specific contrast enhancers in magnetic resonance imaging (MRI).

Initially, we have focused on nanoparticle-based labelling and tracking of stem cells transplanted into the brain or spinal cord. Current research objectives are:

• To examine the possibilities of using functionalized nanoparticles for labelling amyloid plaques in animal models of Alzheimer's disease
• To develop and evaluate long-circulating blood pool agents, which will allow enhanced sensitivity for measurements of drug effects in pharmacological MRI
• Initiate studies on controlled drug release from specially-designed nanoparticles aiming for brain targeting.

All the projects require a multidisciplinary effort and imply active interaction and collaboration with clinicians, organic chemists, materials chemistry scientists, physicists and engineers, experimental MRI scientists, as well as with industrial partners.