Chitosan is considered an elective scaffolding material in articular cartilage engineering due to its structural similarity with various Glycosamminogicans found in articular cartilage. Its poor mechanical properties, though, must be enhanced through a crosslinking treatment. Arginine (Arg) and tripolyphosphate (TPP), have been chosen as crosslinking agents, and their influence onto the chemico-physical properties (morphology, mechanical performances and stability behavior) of the resulting chitosan scaffold have been elucidated. The methodological conditions to produce a scaffold for the cartilage regeneration with tunable structural and chemical physical properties have been assessed. Furthermore, this study introduces Arginine as an innovative stabilizing agent.

Osteochondral defects are a common problem in both human medicine and veterinary practice although with important limits concerning the cartilaginous tissue regeneration. Interest in the subchondral bone has grown, as it is now considered a key element in the osteochondral defect healing. The aim of this work was to generate and to evaluate the architecture of three cell-free scaffolds made of collagen, magnesium/hydroxyapatite and collagen hydroxyapatite/wollastonite to be implanted in a sheep animal model. Scaffolds were designed in a bilayer configuration and a novel “Honey” configuration, where columns of hydroxyapatite were inserted within the collagen matrix. The use of different types of scaffolds allowed us to identify the best scaffold in terms of integration and tissue regeneration. The animals included were divided into four groups: three were treated using different types of scaffold while one was left untreated and represented the control group. Evaluations were made at 3 months through CT analysis. The novel “Honey” configuration of the scaffold with hydroxyapatite seems to allow for a better reparative process, although we are still far from obtaining a complete restoration of the defect at this time point of follow-up.