Application of Nanoparticles to the Analysis of Biomarkers

iv ABSTRACT Nanotechnology is any technology which studies and exploits phenomena and materials that only occur at the scale of single atoms and small molecules: the nanometer scale. At this small scale, nanomaterials display unique physical and chemical features that lead to new properties depending on the size. When it decreases, in fact, the surface/volume ratio increases considerably, giving nanostructure unique optical, mechanical, photochemical, electronic and magnetic properties not seen at the bulk scale, which makes them attractive for a wide range of applications, such as environmental monitoring, detection of pathogens, proteomics, genomics, drug delivery, catalysis and bioanalysis. Within nanomaterials, nanoparticles have received great interest due to their attractive electronic, optical, thermal, catalytic properties and potential application in the fields of physics, chemistry, biology, medicine, and material sciences. Nanoparticles are clusters of a few hundred to a few thousand atoms sized between 1 and 100 nanometers, that behave as whole units in terms of transport and properties. They can be composed of a single constituent material (metal, semiconductor or oxide) or be a composite of several materials and can be realized in a variety of shapes, morphologies and phases. “Biomarker” can be defined as a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. As the definition suggests, there are many types of biomarkers, including biochemical markers, physiologic markers, anatomic markers, histological markers and physical markers. They can be used in clinical practice to identify risk for or diagnose a disease, assess disease severity or progression, predict prognosis, or guide treatment. Tumor markers are substances, most often proteins, that can be found in the blood or urine when cancer is present. They can be products of the cancer cells themselves, or made by the body in response to cancer or other conditions.