Real-Time Calcium Imaging

We employ a custom fluorescence microscope system to investigate the response of native cell types in the diarthrodial joint, namely chondrocytes and synovial fibroblasts, to physical and molecular cues relevant to the pathology of osteoarthritis.  Utilizing calcium sensitive fluorescent dyes, we can study the behavior of these cells types in both 2D culture and native and engineered tissues.  By better understanding the behavior of these cells under normal and pathologic conditions, we are seeking to elucidate the mechanisms by which this disease progresses, and in parallel inform future efforts to engineer replacement tissues.

2D cell migration response

Cell migration occurs during both physiological processes such as embryonic morphogenesis as well as pathological processes including tissue repair and inflammatory response. However, the delayed and poor healing ability of articular cartilage is thought to be due, in large part, to insufficient migration to the damage site by cells that have the potential to repair the lesion. We have investigated the application of an applied DC electric field to enhance and direct cell migration to amplify the intrinsic repair process. These electric field strengths are on the same order of magnitude as those that are generated at the cut surface of wounds and in developing embryos. These studies have confirmed that in vitro application of electric fields elicit galvanotaxis (migration) and galvanotropism (shape change) for a number of cell types including chondrocytes, fibroblasts, meniscal cells, and keratinocytes. In such a manner, manipulation of this stimulus may represent a potential tool to aid in the reparative response of wounded cartilage.