Growth Factor Effects on Fibrochondrocytes Seeded on Electrospun Polycaprolactone Scaffolds

Current treatment modalities for TMJ disc disorders have produced limited results. Tissue engineering using poly(e-caprolactone) (PCL) fiber scaffolds may serve as a viable, alternative solution for TMJ disc repair. OBJECTIVE: Previous studies (JDR: 86(3): 69) suggest that transforming growth factors a (TGFa) and b (TGFb) have a chondrogenic influence on maturing discal fibrochondrocytes (FCs). Accordingly, the effects of TGFa and b on FCs seeded in PCL scaffolds fabricated by electrospinning was assessed in terms of cell viability, proliferation, and extracellular matrix (ECM) marker protein expression (collagens type I and II, aggrecan and decorin). METHODS: Electrospun PCL scaffolds were seeded with primary FCs, maintained in complete DMEM, and the resulting cell-PCL composites treated with TGFa and TGFb at concentrations of 10, 15 and 20 ng/ml over a 14 day period. Control cultures received no treatment. At the end of 1, 7 and 14 days, cell-seeded scaffolds were fixed with 2% paraformaldehyde and prepared for immunohistohemistry. Culture medium was collected and used for ELISA analysis. Cell proliferation was assessed via BrdU immunolabeling and ECM marker proteins were detected using quantitative immunohistochemistry. Marker proteins expressed and released into the media were quantified using ELISA. RESULTS: Cell viability studies indicated that PCL scaffolds were not cytotoxic. FCs proliferated faster in the presence of TGFa while all tested TGFb concentrations had a proliferative effect with the lowest TGFb concentration having the greatest proliferative effect. Immunohistochemical analyses revealed that marker proteins increased with all tested TGFb concentrations, however, no substantial difference in immunostaining was observed. ELISA studies showed that TGFb caused a greater increase in collagen type I and aggrecan expression relative to controls. TGFa had a minimal stimulative effect. CONCLUSION: The study demonstrates the emergent potential of growth factor-treated FC/PCL scaffolds as potential TMJ discal repair or replacement material.