Effects of Mechanical Stimulation on Differentiation of Adipose-Derived Stem Cells

INTRODUCTION: One in two women and one in four men over the age of 50 will have an osteoporosisor low bone mass-related fracture in their lifetime. Delayedor non-union occurs in 10–15% of patients resulting from various risk factors including fracture location, poor mechanical stability, and aging. Traditional treatment strategies include internal fixation and autologous bone graft, but challenges with donor site morbidity and limited tissue harvest highlight the need for unique sources of osteogenic precursors. Adipose-derived stem cells (ASCs) represent a rich supply of autologous multipotent stem cells; however, a major obstacle to the use of stem cells in the clinic is the inability to precisely control lineage commitment in a time-specific manner. Thus, developing methods for enhancing osteoinduction in multipotent cells in a controlled and timely manner is critical to advancing stem cell therapies for orthopaedic applications. Pulsatile fluid flow and vibration have been shown to enhance ASC osteogenic differentiation, and orbital shaking upregulates mechanosensitive genes in primary murine osteoblasts. The goal of this project was to determine the effect of oscillatory fluid flow (OFF) and orbital shaking (OS)-induced fluid flow on lineage commitment of ASCs. Based on previous data, we hypothesized that shortand long-term mechanical stimulation enhances ASC osteogenic differentiation, alkaline phosphatase (ALP) activity and mineralization.