Innovative Composite HA Scaffold Rapid Prototyping for Bone Reconstruction: An In Vitro Pilot Study

The ability to control the architecture and strength of a bone tissue engineering scaffold is critical to achieve a harmony between the scaffold and the host tissue. The scaffold attempts to mimic the function of the natural extracellular matrix, providing a temporary template for the growth of target tissues. The study of nanocrystalline calcium phosphate physical-chemical characteristics and, thereafter, the possibility to imitate bone mineral for the development of new advanced biomaterials is constantly growing. Scaffolds should have suitable architecture and strength to serve their intended function. Rapid prototyping (RP) technique is applied to tissue engineering to satisfy this need and to create a scaffold directly from the scanned and digitized image of the defect site. Design and construction of complex structures with different shapes and sizes, at micro and macro scale, with fully interconnected pore structure and appropriate mechanical properties are possible by using RP techniques. In this study we present a new biocompatible hybrid scaffold obtained through two different experimental methods and formed by synthetic biomimetic Hydroxyapatite (HA) nanocrystals with high surface reactivity which synergistically interacts with Poly(e-caprolactone) (PCL) and polylactic acid (PLLA). The aim of this pilot study is to test the adhesion and the proliferation of human mesenchymal stem cells (MSC) on both the scaffolds. MSC growth and distribution was evaluated 24 h and 7 days after in-vitro seeding. The results allowed the conclusion that these scaffolds are biocompatible and allow the colonization and proliferation of MSC, therefore, due to their mechanical properties, they are adequate for bone tissue engineering.