Enhanced differentiation of mesenchymal stem cells in coral-incorporated PCL/elastin scaffold enables 3D defect healing in osteoporosis rat model.

In osteoporosis, bone quality adversely affects the tissue structural competence which increases the risk of a complicated fracture healing. In the present study highly potent scaffold containing natural coral particles was designed and considered for the healing of critical size bone defect in osteoporosis rat model. Scaffold morphological evaluation confirmed the porous nanofibrous structure. Water uptake of about 900 % was obtained for the fabricated scaffold as the result of its composition and three-dimensional structure. Mechanical analysis revealed the compressive modulus of about 50 kPa for the fabricated coral-incorporated nanofibrous structure. In vitro cellular assessments revealed that the designed scaffold induces no toxicity and provides the proper substrate for cell attachment together with increased and prolonged cell proliferation. In vivo experiments demonstrated that implantation of the fabricated scaffold in the femoral defects of osteoporotic rats significantly increased the number of osteocytes and osteoblasts, and enhanced the BTV, and BMP-2 expression compared with the control group. Furthermore, it was observed that seeding the scaffolds with MSCs prior to implantation, resulted in substantial improvements in mRNA expression of the BMP-2 and VEGF genes and considerable enhancement in stereological findings such as significantly higher number of osteoblasts, osteocytes, TVB, and BTV.