Proposed Article Title
Tendon injuries have been a challenge for regenerative medicine as current treatments rely mainly on artificial polymers and/or extracellular matrix (ECM), which only mimic the architecture of mature tissue but do not promote regeneration. Moreover, due to the limitation in the number of tendons available in our body, transplantation is restricted. As a result, growing tendons from patients in vitro and transplantation is an appropriate option. Several studies have shown that ECM composition dramatically changes during tissue development, repair, and regeneration. However, the mechanism of ECM action on proliferation and inducing assembly of a tendon is unknown. This study focuses on the influences of ECM and substrate stiffness on tendon proliferation and migration, both behaviorally and molecularly. Mouse Achilles tendons were harvested and grown to obtain primary tendons cells. Cells were plated onto polydimethylsiloxane (PDMS) with the stiffness of 2, 15, 35, and 100 kPa, and coated with different ECMs. We quantified the percent proliferation using EdU incorporation and the migration using time-lapse imaging techniques. RNAs were isolated and performed quantitative polymerase chain reaction (qPCR) for molecular studies. The preliminary results with two-way analysis of variance (ANOVA) (N = 24) showed that ECM coating had significant impacts on proliferation (p < 0.0005) and migration (p < 0.0005), whereas substrate stiffness only affected proliferation (p < 0.004) but not migration (p = 0.540). The molecular study suggested that ECM and stiffness had no effect on tenascin-C and Sox9 gene expression. We are currently working on repeating the migration and proliferation experiment as well as conducting a qPCR analysis of gene expression of other genes. We believe that by understanding the mechanism of ECM in cell signaling and regulation, we will be able to discover how nature assembles tissue in vivo. This knowledge will be applicable to tissue regeneration and repair, and potentially lead to self-grown tendon transplant.
"Tendon Cell Behavior and Regeneration: Effects of Extracellular Matrix and Substrate Stiffness,"
The Journal of Purdue Undergraduate Research:
Vol. 4, Article 6.