MADIA has the ambition to move the AD and PD diagnostic ability significantly beyond the state of the art by increasing the sensitivity against selected biomarkers by THREE orders of magnitude and by advancing for the first time an in vitro diagnostic technology able to sense the protein unfolding pathologies leading to harmful aggregations like oligomers, fibrils, plaques. The progress of MADIA beyond the state-of-the art is reported in the next table:
|The challenge||State-of-the-art||MADIA progress beyond the state-of-the-art|
|Very early diagnosis / High detection sensitivity and specificity||10 -13 g/ml (0.1 pg) for proteins in general
10-12 g/ml (pg) for AD and PD
|Demonstrating 10-15 g/ml (fg) for amyloid and at least 10-14 g/ml (10 fg) for other target AD and PD biomarkers
Evaluation of the possibility to achieve by this technology the level of 10-16 g/ml (0.1 fg)
|More accurate diagnosis of a disease||Currently, there exists no in-vitro methods to monitor the early aggregation of amyloids||First in vitro technology/tool to control the formation of oligomers and fibrils in the range from 10-15 g/ml (possibly 10-16 g/ml) up to nanograms/ml and further. This is expected to have a breakthrough effect on the development of innovative, stratified therapies|
|Size of the ill-formations||The size of the pathological aggregates can be determined only by dynamic light scattering or small angle X-Ray scattering||Capability to detect the size of aggregates through MNP-BM behaviour in the microfluidics device with a logarithmic scale accuracy (by order of magnitude) by a simple in vitro analysis|
Such ambitious results are expected thanks to the integration of 3 innovative technologies, namely Functionalised magnetic nanoparticles (MNPs), Magnetic sensors and Microfluidics.
The MNPs used in MADIA will fulfil the following key requirements: 1) to be non-toxic; 2) to have magnetic properties required for the proposed detection; 3) to be provided with an appropriate surface chemistry for further bio-functionalization and also to display a large stability under different experimental conditions used for such bio-functionalization; and 4) to feature a narrow size-dispersion.
Such MNPs will be functionalised in order to be conjugated to targeted biomarkers (BM), designed to become a reference Alzheimer’s (AD) and Parkinson (PD) diseases diagnostic tool in the standard clinical practice, forming BM-MNP aggregates.
Figure 2: MNPs functionalisation with Aptamer or Antobodies.
The magnetic sensing strategy will be based on the detection of the diffusion rate of BM-MNPs by magnetoresistive sensors. Researchers from Bielefeld University will develop magnetoresistive sensors that are capable of detecting a small number of magnetic particles that move through the sensing volume. The sensors will be optimized with respect to the requirements of dynamic sensor readout and their integration in a microfluidic environment. The research group at Bielefeld University has demonstrated know-how and infrastructure to design and realize magnetic thin film systems and patterned high performance magnetoresistive sensors.
Figure 3: GMR sensors (spiral shaped) with different amounts of magnetic particles on top.
Figure 4: Sensing scheme of the magnetoresistive sensor proposed in MADIA.
Microfluidic devices are effective in performing analyses on samples of small volumes, and enable multiple analysis in parallel. Handling of biological fluids in volumes below 1 µL leads to an improved, fast screening and diagnostics in current assays based on optical readout (ELISA, biolumescence or chemiluminescence). The aspect ratio of the microfluidic chambers will be a fundamental parameter investigated in MADIA in order to optimize the signal coming from diffusing magnetic nanoparticles and aggregates.
Figure 5: microfluidic device.