Improving the mechanical properties in tissue engineered scaffolds

Scaffold-based tissue engineering research aims to aid in the repair and regeneration of bone defects. Scaffolds act as a basis for carrying cells or therapeutic agents for regenerative therapies. To achieve this, the scaffold should have appropriate osteoconductive, osteoinductive and biodegradable properties. To date, such structures have only been used with some success in low-load bearing applications, despite the large variety of biomaterials and fabrication techniques explored in the last two decades. Previous studies have illustrated the suitability of the Fused Deposition Modelling (FDM) process in fabricating PCL-20% β-TCP scaffolds for low-load bearing bone tissue engineering applications. This paper aims to demonstrate the possibility of increasing the mechanical properties of such scaffolds by introducing a through-hole. In addition, it is conjectured that such through-holes may also become useful for the channeling or storage of nutrients. A number of scaffolds with through-holes of various sizes were fabricated in order to study the effect of the through-hole diameter on the modulus (stiffness) of the complete scaffold. It was observed that the stiffness of the scaffolds varies with the diameter of the through-hole. After a certain through-hole diameter threshold the stiffness of the scaffold begins to increase above that of the original scaffold. An improvement of approximately 37% was observed in the PCL-20% β-TCP scaffolds. Also, it was noted that the threshold value for the through-hole diameter depends on the spacing of the adjacent filaments of the scaffolds.