Resumen de An experimental model to mimic the mechanical behavior of a scaffold in a cartilage defect
Line Vikingsson
The main purpose of this thesis is the design and characterization of an experimental cartilage model. The in vitro model is composed of a macro and micro- porous Polycaprolactone scaffold with a Poly(Vinyl Alcohol) filling. The scaffold/hydrogel construct has been subjected to repeating number of freezing and thawing cycles in order to crosslink the hydrogel, inside the scaffold¿s pores. The Poly(Vinyl Alcohol) resembles the growing cartilaginous tissue inside the scaffolds pores, as it gets denser and stiffer for each cycle of freezing and thawing. The in vitro model allows to study a variety of characteristics of the scaffold and hydrogel, revealing interesting features. The importance of water flow on the mechanical properties is studied, so as the influence of micro-porosity. It can be seen that the hydrogel density and micro-porosity influence in distinct ways on the mechanical properties of porous scaffolds. The permeability of the scaffolds is studied and is seen independent of crosslinking density, inside the porous scaffolds. The experimental cartilage model has also been applied on a macro porous acrylic scaffold. The results show that the water has different effect on the mechanical properties, for macro, or macro and micro-porous scaffolds. The in vitro cartilage model has elastic modulus, aggregate modulus and permeability values in the same order as human articular cartilage. The model is useful to predict the mechanical behavior of porous scaffolds in vivo. A scaffold implant device for animal studies has been designed, and implanted in two different in vivo trials. The results show that the fixation and anchoring to the subchondral bone influence the tissue repair.
