Simone Cassani

Tissue engineering is a promising path towards the treatment of damaged cartilage due to pathologies, such as osteoarthritis, injuries and normal wear and tear. This work aims at mathematically modeling the phenomena of cartilage growth, by developing a hybrid cellular automaton model that couples a discrete and stochastic modeling approach for the chondrocytes (cells) processes, such as movement and cell division, with a continuous description for the production of extracellular matrix, the scaffold degradation, and the evolution of the nutrients in the construct, with a particular focus on the effect of porosity.

The model suggests that the initial value of the scaffold porosity might affect the quantitative outcome and the temporal dynamics of laboratory experiments. A different initial value of scaffold porosity will yield to changes in the number of cell-to-cell collisions resulting in a higher cell count for low initial porosity at day 30 in agreement with literature results. In addition, the model suggests that cell sentitivity to porosity directly affect the efficiency of cell movement, resulting in a different cell count at day 30.

Despite the abundance of imaging techniques and results from clinical studies, the consequences of alterations in the values of systemic blood pressure (BP), intraocular pressure (the pressure inside the eye globe, IOP) and functionality of vascular regulation on retinal hemodynamics are still controversial and unclear. This work focuses on the development of a reduced model that describes the blood circulation in the retina through the analogy with an electric circuit.

The model supports the clinical hypothesis that veins play a crucial role in retinal circulation, since elevated IOP (typical of high tension glaucoma patients) has a stronger effect on veins causing an alteration of the pressure distribution upstream of the venous compartments. Furthermore, the model explains the controversy in clinical studies in which the same medical procedure leads to different outcomes on the patients. The model predicts that a similar change of IOP leads to different changes in the measured physiological parameters depending on the individual value of BP and the functionality of AR, and this finding was recently confirmed by an independent clinical study on nearly 10,000 individuals, confirming that the incidence of glaucoma was correlated to the individual level of BP.