(203f) The Effect of Growth Factor Supplementation On Tendon Cell Migration, Viability, and Gene Expression In Anisotropic Collagen-Glycosaminoglycan Scaffolds

It is estimated that over 62 million tendon and ligament injuries occur annually. The current clinical gold-standard for the treatment of tendon injuries is the use of autograft or allograft tissue. However, these approaches have limitations including donor site morbidity for the former and limited tissue availability for the latter. Optimized biomaterial constructs such as tissue engineering scaffolds could serve as potential alternatives. Collagen-glycosaminoglycan (CG) scaffolds have been used as regenerative templates for soft tissues like dermis and more recently bone and osteochondral tissue [1]. We have recently developed anisotropic CG scaffolds with aligned pore tracks for tendon tissue engineering [2]. Here we use these scaffolds to explore the effects of growth factor supplementation through both soluble and insoluble modes of presentation on tendon cell (TC) behavior.

Platelet-derived growth factor-BB (PDGF-BB) and insulin-like growth factor-1 (IGF-1) have both demonstrated dose-dependent effects on TC migratory capacity and viability in anisotropic CG scaffolds [2]. In this study two additional factors (basic fibroblast growth factor (bFGF) and stromal cell-derived factor-1α (SDF-1α)) were investigated as potential stimulators of TC bioactivity. Transwell assays were used to assess the effect of different growth factor doses and combinations on TC chemotaxis into CG scaffolds. Studies also compared the efficacy of growth factors presented freely in culture media (soluble) versus immobilized in CG scaffolds via carbodiimide chemistry [3] or direct photolithography [4] (insoluble). Ongoing work is exploring the effects of PDGF-BB, IGF-1, and bFGF, and SDF-1α on TC alignment, viability, metabolic activity, soluble collagen synthesis, and expression of tendon markers (collagen I and III, COMP, and tenomodulin).

References

1. Harley B.A.C. and L.J. Gibson. Chemical Engineering Journal, 2008. 137(1): p. 102-121.
2. Caliari S.R. and B.A.C. Harley. Biomaterials, in press.
3. Shen Y.H. et al. Acta Biomater, 2008. 4(3): p. 477-89.
4. Martin T.A. et al. Biomaterials, 2011. 32(16): p. 3949-3957.