Tissue Spheroids Encaged Into Microscaffolds with Internal Structure to Increase Cell Viability

Aggregates of pre-sorted cells form structures called tissue spheroids that have been widely used in the field of tissue engineering. The greater contact of the cells with the culture medium is directly related to cell viability and to the increase of proliferation rate. Due to the characteristics of a 3D environment, at some zones within the tissue spheroids some cells are not equally exposed to the environment, impacting in the formation of microenvironments with decreased oxygen, nutrients and soluble factors produced by cellular metabolism leading to the formation of low proliferation areas and consequently necrosis (cell death). The fusion of cells also changes the catabolites flow, generating a very heterogeneous diffusion. The idea of this project is to develop and improve a microscaffold based on the concept of lockyballs that have cell support function for tissue engineering. Lockyballs have hooks and loops which attach each other assuring a 3D cellularized mesh. The model has a spherical outer structure and inner hollow microsphere constituted by pores with diameters smaller than the cell ones, whose function would be to prevent cell entry and provide an environment suitable to diffusion gradient necessary for the cell viability of the spheroid avoiding necrosis. The first stage of the work consisted in the generation of different three dimensional models by Computer Aided Design (CAD) software Rhinoceros 5.0. At the second stage, the CAD model was imported into finite element method (FEM) software (ANSYS R16 Static) to perform computational simulation, which consisted of structural analyses. Computational simulations were essential to predict the diffusion phenomenon inside the whole 3D structure. The development of new microscaffolds models can enhance the regenerative capacity and 3D tissues construction.