Imprinted polymers for the recognition/quantitation of the peptide hormone hepcidin

Hereditary Hemochromatosis (HH) is a genetic disorder in which excess iron accumulates in the body. This results in multi-organ damage, including liver cirrhosis, diabetes, sexual dysfunction, and heart failure. Iron overload is also a severe complication of other genetic disorders, such as thalassemias. HH is caused by mutations on few genes, including HAMP that encodes for hepcidin. Hepcidin is a recently discovered hormone produced by the liver [1]. It is a key regulator of iron metabolism, i.e. by diminishing intestinal iron absorption, the major route of iron body entering. Developing a diagnostic method for HH, in easily available biological samples (urine, blood) is of paramount importance for proper clinical evaluation of iron overloaded patients. Until now there is a single (immunochemical) method for the quantitation of hepcidin [2], which unfortunately, is not available to the vast majority of patients, even those referring to highly specialized centres. Here we synthesised molecularly imprinted (MIP) sorbents for the recognition of hepcidin with the aim of developing an available method to measure urinary hepcidin. The best monomers for the MIP were chosen with a modelling approach, the polymers were synthesised in bulk and as polymeric films. The binding of hepcidin model solution on MIP and control was evaluated spectrofluorimetrically. Parameters influencing the binding, such as pH and saline concentration were optimised. Results indicate IF = 3.5, binding time of 10 min. Reusability of the MIP resulted in a loss of approximately the 30% of the original binding ability. In view of developing a quantitation method for biomedical appplication, the binding of hepcidin directly from physiological samples (urine), and of samples spiked with known concentration of hepcidin, were tested.