Nanoindentazione su membrane biologiche con Microscopia a Forza Atomica

In this study nanoindentation measurements with the Atomic Force Microscopy technique on a cellular membrane are reported. The membrane studied is the Zona Pellucida, which surrounds mammalian eggs. In particular, it is characterized the variation of the mechanical properties of the membrane during the maturation and fertilization processes of the oocyte. The classical infinitesimal strain theory has been applied in order to analyze the indentation curves and to derive the Young’s modulus of the membrane. The limits of applying this model to a nanoindentation measurement with AFM are presented. Finite element models have been developed to describe the force-indentation curve and the effects of the indentation depth, tip geometry, non-linearity and heterogenity of the material on the finite indentation problem are examined.