The overall focus of this project is to recreate a new organ in the laboratory starting from a native kidney completely decellularized and subsequently recellularized with stem cells. To this aim, we have developed a perfusion system for decellularization and recellularization of intact rat kidneys. We have previously shown that perfusion of rat kidney with detergents allowed to obtain optimal cellular removal and maintenance of intact 3D architecture of renal extracellular matrix. Then, we have optimized several recellularization techniques infusing cells through renal artery, renal vein and ureter. Immunohistochemical analysis have confirmed that the infusion techniques used allow the adhesion and survival of cells in the kidney but with differences in their distribution.

The goal of the project is to study mechanical stresses generated by the bloodstream on endothelial cells that line the inner wall of blood vessels. To establish the role of shear stresses in the failure of vascular accesses in dialyzed patients, we developed experimental systems to submit endothelial cells to physical force under controlled conditions. Estimated values were imposed on endothelial cells with a programmable system based on a cone-plate geometry. The device consists in a rotating cone generating controlled values of shear stress on a plate, where the endothelial cells are located. Exposure of endothelial cells to oscillating forces induced a significant increase in the production of biochemical signals involved in the development of intimal hyperplasia and therefore in the failure of vascular access.

The research line is aimed at the study of a well-defined structural 3D substrate, called “nichoid”, for the in vitro culture of stem cells. The nichoid reproduces the geometry and mechanical stimuli to which stem cells are physiologically exposed in the stem cell niche and allows to evaluate the effect of 3D substrates on pluripotency maintenance of stem cells in vitro. We have demonstrated the ability of 3D synthetic niches to sustain murine embryonic stem cells and rat mesenchymal stem cells pluripotency more efficiently than the traditional 2D substrate.

Computerized axial micro tomography (microTAC) is a diagnostic method that allows to generate high-resolution images of anatomical structures for the morphological analysis of skeletal tissues and, with the use of a contrast medium, of soft tissues. One of the most widely used contrast media ex vivo is Microfil, radiopaque silicone polymer, which allows the visualization of the vascular network. Analysis of the obtained images allow to evaluate vessel diameter and branching level. The use of microTAC, with the infusion of contrast medium, also allowed us to study the vascularization and growth of renal cysts in an experimental polycystic kidney model. Further application of microTAC concerns the study of cardiovascular structures that can be highlighted using a solution based on iodine (Lugol's reagent) that is absorbed by tissues in proportion to their density. 3D analysis allows us to study the morphological and volumetric alterations of the heart cavities. In collaboration with the Laboratory of Tumor Microenvironment, we are evaluating the possibility of studying the evolution of angiogenesis (formation of new blood vessels) in models of mouse tumors by perfusion with Microfil. We will use microTAC as a non-invasive technique for analyzing bone tissue alterations caused by tumors. We are also evaluating the growth of tumor metastases in the liver by infusing a nanoparticle contrast medium in vivo.