Osteoarthritic Cartilage Loading with 2-Channel Mechanical Stimulator
Located in Department of Internal Medicine at Rush University, Dr. Rachel Miller studies the biomechanical pathways involved in Osteoarthritis pain. As a member of the Laboratory for Translational Research in Osteoarthritis, Dr. Miller is dedicated to elucidating these mechanisms that lead to debilitating pain in patients suffering from osteoarthritis, particularly in the knee joint. Dr. Miller approached Aurora Scientific as she was interested in a number of distinct applications centred on cartilage loading under an inverted microscope, from monolayer neuron cultures to intact animals.
Often a stepper motor has been used in areas such as this to indent tissue, however it was imperative that Dr. Miller be able to measure and visualize when the tissue is being mechanically stimulated with force feedback, something a stepper motor does not provide. Another caveat was that the attachments between our indenter and the animal tissue needed to be extremely lightweight yet rigid to negate any oscillations in the system. Because of the wide range of forces and resolution requirements, a single mechanical stimulator wouldn’t be feasible.
Dr. Miller consulted with Aurora Scientific and discussed in depth the challenges and requirements of her proposed applications. Because this was a new application area, together we decided it would be best to have Dr. Miller test one of our mechanical stimulators to ensure it was the right choice. Aurora Scientific travelled to Dr. Miller’s lab to aid in testing and to optimize the system’s configurations. After running a number of experiments, we determined the best solution would be our 300D 2-Channel Mechanical Stimulator which provides two independent indenters, each with optimal specifications, to cover the resolution and force range necessary for her cartilage loading experiments. The first channel would provide a low force (0.5N), high resolution (1 micron) solution for monolayer neuron cultures. In contrast, the second channel would consist of a larger force (5N) Indenter with greater stability for custom-fabricated attachments and tissue weights while also providing outstanding resolution (1 micron) for small, measurable stimulation.
With Dr. Miller’s engineering background and the help of Aurora Scientific, she was able to fabricate a number of rigid, lightweight attachments for her mechanical stimulators. This permitted her to be able to secure a mouse femur upright and vertically indent intact knee cartilage onto a glass coverslip while simultaneously imaging cell response. Because of this, Dr. Miller’s lab has been able to test out a number of different setups and optimize them for future projects including stimulation of her monolayer neuron cultures embedded in gel. This leads to the exciting proposition of mechanically stimulating the knee joint of intact mice while simultaneously imaging from dorsal root ganglion neurons to elucidate the central pain sensing mechanisms involved in Osteoarthritis.