Optimization of Hydroxyapatite β-Tricalcium Phosphate – Fibrin Constructs for Human Mesenchymal Stem Cell Proliferation and Mechanical Strength

Bone graft substitutes are commonly used as an alloplastic source for complex bone repair. Human mesenchymal stem cells (hMSCs) have become an idealistic source for bone repair and regeneration due to their potential to differentiate into osteogenic precursors. The purpose of engineering synthetic bone grafts it to successfully find a substitute that is biocompatible, bioresorbable, and has osteoconductive characteristics. The purpose of this study is to construct a bone biocomposite with an optimal amount of biphasic hydroxyapatite/β-tricalcium phosphate (HA-TCP) powder to promote hMSC proliferation with sufficient mechanical stiffness. Results have indicated an increase in metabolic proliferation over a 2-week time period. The constructs seeded with hMSCs exhibited a 3 to 9 fold or greater increase in proliferation depending on the formulation of the construct. This work demonstrates that higher volumes of HA-TCP promote hMSC proliferation in the constructs while maintaining sufficient mechanical stiffness. Optimizing the components of the scaffolds will allow for the most innovative biomimetic bone composite for mesenchymal stem cell differentiation into osteoblasts in an in vivo model.