The need to monitor the biological condition of an organism has led to the search for appropriate indicators: "biomarkers".
The project idea of BioDivErSI is the development of an innovative and versatile prototype instrument based on the combination of an electrospray ionization (ESI) source, mass spectrometry (MS) and other ionization sources as a new technology for "discovery" and chemical and structural characterization of biomarkers in their native form, i.e. in the structure associated with their biological function. Among biomarkers, BioDivErSI has focused attention on the identification and characterization of microRNAs (miRNAs). MiRNAs are endogenous small non-coding RNAs that negatively regulate the translation of messenger RNAs (mRNAs) coding in a specific sequence. These biomolecules have acquired a certain relevance among biomarkers as variations in their expression are associated with numerous pathologies. The ability to link these changes to disease states highlights their value as biomarkers. Their highly specific expression and function allows the accurate molecular classification of, for example, tumors, and in recent years approximately 2000 miRNAs that intervene in tumor pathophysiology have been discovered and validated. The objective of BioDivErSI was the design and development of an original instrumentation that couples an ESI source with a mass spectrometer (MS) and other ionizing sources, to produce molecular beams of miRNAs and their multiply charged complexes, controlling their structure by selecting a particular state of charge, and study the binding interactions of the species present in the sample under analysis. The second objective was the characterization of isolated model miRNA sequences and their interaction with target molecules. The ESI-MS analysis was supported by Molecular Dynamics (DM) studies and machine learning activities for the construction and use of a database of species with charge states representative of the miRNA and the complexes.