(805d) Promoting Ligamentogenic Differentiation of Mesenchymal Stem Cells in Controlled Microenvironments

The bone-ligament interface is a complex structure that transmits forces through zones of bone, fibrocartilage, and ligament[1]. Human mesenchymal stem cells (hMSCs) offer potential as a single, autologous cell source for restoration of the bone-ligament interface after ligament reconstruction due to their ability to differentiate into osteoblasts[2], chondrocytes[3], and ligament/tendon fibroblasts[4]. However, conditions leading to ligamentogenic differentiation of hMSCs are not yet well-established. In this work, we aim to develop in vitroculture conditions that promote the ligamentogenic differentiation of hMSCs.  We hypothesize that a combination of microenvironment cues found during ligament development, including growth factor and integrin binding and cell-cell junctions, play a key role in this differentiation lineage. Towards this, we have isolated and characterized hMSCs from bone marrow and screened the effects of soluble and tethered microenvironment cues on their ligamentogenic differentiation.  Specifically, hMSCs have been cultured with bone morphogenic protein-12 (BMP-12) and bone morphogenic protein-13 (BMP-13), and the effect of these soluble cues on ligament-related gene expression and protein production has been assessed. Further, we have synthesized poly(ethylene glycol) hydrogels with thiol-norbornene photopolymerization[5] as a blank slate culture system on which cell adhesion and orientation can be controlled. Using these hydrogels, we have examined the effects of collagen-related integrin-binding sequences on hMSC gene expression and protein production.  We aim to use the results of these studies towards the development of a multiphased biomaterial for hMSC delivery for bone-ligament interface regeneration.

References

[1]      P. J. Yang and J. S. Temenoff, “Engineering orthopedic tissue interfaces.,” Tissue engineering. Part B, Reviews, vol. 15, no. 2, pp. 127–141, Jun. 2009.

[2]      N. Jaiswal, S. E. Haynesworth, A. I. Caplan, and S. P. Bruder, “Osteogenic differentiation of purified, culture-expanded human mesenchymal stem cells in vitro,” Journal of Cellular Biochemistry, vol. 64, no. 2, pp. 295–312, 1997.

[3]      F. Barry, R. E. Boynton, B. Liu, and J. M. Murphy, “Chondrogenic differentiation of mesenchymal stem cells from bone marrow: differentiation-dependent gene expression of matrix components.,” Experimental Cell Research, vol. 268, no. 2, pp. 189–200, Aug. 2001.

[4]      M. Haddad-Weber, P. Prager, M. Kunz, L. Seefried, F. Jakob, M. M. Murray, C. H. Evans, U. Nöth, and A. F. Steinert, “BMP12 and BMP13 gene transfer induce ligamentogenic differentiation in mesenchymal progenitor and anterior cruciate ligament cells.,” Cytotherapy, vol. 12, no. 4, pp. 505–513, Jul. 2010.

[5]      B. D. Fairbanks, M. P. Schwartz, A. E. Halevi, C. R. Nuttelman, C. N. Bowman, and K. S. Anseth, “A versatile synthetic extracellular matrix mimic via thiol-norbornene photopolymerization,” Advanced Materials, vol. 21, no. 48, pp. 5005–5010, Dec. 2009.