Designing a Low-Cost, Open-Source Incubator for Long-Term Imaging of Osteoclast Development and Behavior

Osteoporosis, characterized by the deterioration of bone structure, results from an imbalance between osteoclast-mediated resorption and osteoblast-driven formation. Affecting over 200 million people globally, it leads to fragile bones and increased fracture risk, imposing significant healthcare burdens. Current treatments do not address the cellular mechanisms or collective behavior of osteoclasts (OCs). OCs form when mononuclear precursor cells fuse into multinucleated (5-10 nuclei avg.) cells. In this state, the OCs secrete acids and enzymes to dissolve bone matrix, releasing calcium and phosphate into the bloodstream and promoting bone formation. To develop tools for high throughput studies of the collective dynamics of OCs and their interactions with the microenvironment, we developed a low-cost, open-source incubator for week-long bright-field imaging under controlled conditions (37 °C, 80% relative humidity, and 5% CO₂). Using this platform, we observed OC development, including fusion, fission into osteomorphs (fragmented OCs), and apoptosis (cell death). Notably, preliminary trials showed that OC apoptosis triggered increased motility and recruitment of precursors and neighboring OCs (n=5). We hypothesize that signals released during apoptosis trigger local activation and migration, resulting in coordinated, emergent behavior. By enabling real-time study of these dynamics, this work offers insight into the cellular basis of bone resorption beyond molecular pathways.