Ultrasound and lipid-coated microbubbles for osteogenic differentiation of mesenchymal stem cells in 3D printed tissue scaffolds

Abstract

With increasing incidence of bone disorders in a rapidly aging, sedentary and overweight population, engineered bone tissues promise to be a better alternative for conventional bone grafts. However, bone tissue engineering currently suffers due to the inability to form mechanically strong porous structures that can be grown quickly. In this study, lipid-coated microbubbles (MB), traditionally used for contrast enhanced ultrasound imaging, were applied to harness the beneficial effects of ultrasound stimulation on proliferation and osteogenic differentiation of human mesenchymal stem cells (hMSCs) on 3D printed poly(lactic acid) (PLA) scaffolds. A significant increase in cell number was observed with low intensity pulsed ultrasound (LIPUS) treatment in the presence of MB after 1, 3, and 5 days of culture on scaffolds. Total protein content, alkaline phosphatase activity, and total calcium content were also found to increase with LIPUS with and without MB indicating enhancement in osteogenic differentiation...