Researcher(s)
- Ailyn Lopez, Biomedical Engineering, University of Delaware
Faculty Mentor(s)
- Elise Corbin, Biomedical Engineering, University of Delaware
Abstract
Every year, 33 million musculoskeletal injuries are reported in the United States, with half of those being tendon-related injuries. To enhance the treatment of tendon injuries, it is essential to develop a model that accurately recapitulates the tenocyte cellular environment. Our objective was to create in vitro dynamic material platforms that effectively simulate the transition of tendons from a physiological to a pathophysiological state, characterized by either softening or stiffening events. Magnetorheological elastomers (MREs) provide a means to vary physiologically relevant elastic moduli by applying a magnetic field and simultaneously capturing changes in cell phenotypes. In this study, we created novel MRE formulations that mimic physiological (~300 kPa) and pathophysiological (~200 kPa and ~400 kPa) conditions to analyze changes in cell architecture and extracellular matrix deposition. We first created a softening event MRE consisting of 68%(v/v) of Sylgard 527 PDMS, 7%(v/v) 10:1 184 PDMS, and 25% (v/v) carbonyl iron particles (CIPs). This formulation can be softened from 288.6±14.8 kPa with 350mT applied to 183.7±16.1 kPa with no applied field. Next, we created a stiffening event MRE consisting of 65%/10%/25% that can be stiffened from 297.3±10.2 kPa (no field) to 425±7.8 kPa at 350mT. To minimize batch-to-batch variation, elastomers were mixed with 20% (w/w) toluene to reduce viscosity and CIP agglomeration. With these elastomers, we can induce temporal stiffening or softening events to study phenotypic changes of primary mouse tenocytes and track de novo ECM deposition compared to controls. Ultimately, an automated pipeline image analysis software, CellProfiler, will be used to identify and measure cell nuclei and cytoskeleton morphology. The changes observed in our experiments offer insight into changes seen at different physiological states and the advancement of in vitro tendon models.