In the last 9 years of my research career I have been developing mathematical models for biological systems.
My main research interest is the mechanics of the red blood cell, for which I have developed a coarse-grained molecular model of the entire cell membrane. The structural elements of cells are soft which implies that their mechanical properties may be quite different from conventional hard materials due to the relevance of entropy and thermal fluctuations. The model I implemented consists in coarse-graining the whole cell membrane and in simulating it via a finite-temperature molecular-dynamics method. The model allows quantitative comparison with experimental data and it facilitates the interpretation of elastic-property measurements obtained with experimental techniques like micropipette-aspiration and optical-tweezers. This model clarified a long-standing problem of the red blood cell mechanical properties, showing that it possible to have nanometersize thermal fluctuation with a finite value of the shear modulus.
In collaboration with the Institute of Reproduction and Developmental Biology (Imperial College London) I undertook a research project to understand the regulation of initiation of follicle growth in the mammalian ovary. Little is known about this mechanism, which is thought to be regulated by a network of signals. My work consisted in applying mathematical modeling to the spatial arrangement within the ovary in order to find relationships between follicles, surface epithelium and any other ovarian component, which can be involved in the mechanism of cell signaling. In particular I implemented a reaction diffusion model (Brownian dynamics) which helped understanding how growth factors production and receptor expression influence cell-signaling activity within the ovary. I am also using this model to investigate how morphogen concentration that orchestrates patterns formation in Drosophila embryo is affected by reaction rates and the geometry of the system. I am also using the model to interpret patch-clamp amperometry experiments in animal and human tissues.
During my first Post-doc project at Imperial College (London, 2001-2003) I implemented a computer model to study the role played by the space charge accumulation in dielectric breakdown. Over time insulators trap charge carriers to form a ‘space charge’ thought to be implicated in the breakdown. My work aimed at clarifying the contribution of electrons to space charge trapping and detrapping. In particular with my model I could predict the current voltage characteristics and space charge distribution of polyethylene from the electron trap distribution.
In my Ph.D. work at Swinburne University (Melbourne, 1998-2001) I used molecular simulation to investigate the role of three-body interatomic potentials in noble gas systems for two distinct phenomena: phase equilibria and shear flow. My results demonstrate that three-body interactions play an important role in the overall interatomic interactions of noble gases. This is shown by the excellent agreement between my simulation results and the experimental data for both equilibrium and non-equilibrium systems.
Dr. Marcelli is also working on the swallowing system and is a member of the Kent Speech and Swallowing Research Team.
Computational models for cell mechanics, cell signalling and financial problems - instrumentation for swallowing rehabilitation