Bone tissue engineering provides advanced solutions to overcome the limitations of currently used therapies for bone reconstruction. Dynamic culturing of cell-biomaterial constructs positively affects the cell proliferation and differentiation. In this study, we present a precisely flow-controlled microfluidic system employed for the investigation of bone-forming cell responses cultured on fibrous collagen matrices by applying two flow rates, 30 and 50 μL/min. We characterized the collagen substrates morphologically by means of scanning electron microscopy, investigated their viscoelastic properties, and evaluated the orientation, proliferation and osteogenic differentiation capacity of pre-osteoblastic cells cultured on them. The cells are oriented along the direction of the flow at both rates, in contrast to a random orientation observed under static culture conditions. The proliferation of cells after 7 days in culture was increased at both flow rates, with the flow rate of 50 μL/min indicating a significant increase compared to the static culture. The alkaline phosphatase activity after 7 days increased at both flow rates, with the rate of 30 μL/min indicating a significant enhancement compared to static conditions. Our results demonstrate that precisely flow-controlled microfluidic cell culture provides tunable control of the cell microenvironment that directs cellular activities involved in bone regeneration.
Keywords: MC3T3-E1 pre-osteoblasts; cell orientation; collagen; microfluidics; osteogenic differentiation.