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Show 28 Rinchen college of engineering Physical stresses and cellular mechanics play significant roles in diseases like cancer, malaria, sickle cell anemia, asthma and glaucoma. This device will serve as a tool to study cell differentiation, stimulation and aid in stem cell research. A microscale, highthroughput, cheap and easily producible device design to study rat mesenchymal stem cell differentiation and proliferation under various physical stresses has been proposed here. The device is completely manufactured with PDMS (Polydimethylsiloxane). The design of the device comprises of three layers of PDMS bonded to each other by treatment with an oxygen plasma (Dyne-A-mite 3D Treater). The top layer of the device comprises of cell culture chambers, the middle layer is a 10 microns thick PDMS membrane and the bottom layer is composed of channels for vacuum appli-cation. The complete device is then bonded with a glass slide. The pattern for the PDMS mold is created using a laser cutter (Universal laser Systems).The cells under study can be incorporated from the top layer into each culture chamber through several of the inlets. The vacuum pump can be attached through a hole on the top layer. Both compressive and tensile stresses can be produced simultaneously within one device (something lacking in currently available macroscale devices). The device due to its transparent structure can be easily studied under a microscope. Rat mesenchymal stem cells were cultured in the microstimulator chip (Figure 1) without the presence of any differentiation inducers. The cells were than induced with cyclic equibiaxial deformation at 5 kPa at 0.2 Hz for 16 days. AP (Alkaline phosphatase) levels were monitored over 16 days and total protein content was also monitored. The results showed an in-creased in AP levels over 16 days of stimulation, indicating osteogenic differentiation of the rat mesenchy-mal stem cells (Figure 2). In the absence of any differentiation inducers in the culture, increase in AP levels was primarily due to the physical stresses applied to the cells. A MICROSTIMULATOR FOR STUDYING RAT MESENCHYMAL STEM CELL DIFFERENTIATION AND PROLIFERATION UNDER PHYSICAL STRESSES Rinchen (Bruce Gale) Department of Bioengineering, Department of Mechanical Engineering University Of Utah UNDERGRADUATE RESEARCH ABSTRACTS Bruce Gale Figure.1 Device Dimensions: Glass slide: 75x25x1 mm, Vacuum chamber: 50x20x4 mm, Membrane: 50x20x .01 mm, Culture Chamber: 50x20x4 mm Figure. 2 A (Annular) and C (circular) represent the type of culture chamber. Small, Mid and large indicate the size of the chamber. The results indicate an increase in AP activity due to cyclic equibiaxial deformation over a number of days, thus differentiation of the rat MSCs to osteogenic cells. |