Use of cyclic strain bioreactor for the upregulation of key tenocyte gene expression on Poly(glycerol-sebacate) (PGS) sheets

The inadequate donor source and the difficulty of using natural grafts in tendon repair and regeneration has led researchers to develop biodegradable and biocompatible synthetic based tissue equivalents. Poly(glycerol sebacate) (PGS) is a surface-erodible bioelastomer and has been increasingly investigated in a variety of biomedical applications. In this study, PGS elastomeric sheets were prepared by using a facile microwave method and used as elastomeric platform for the first time under mechanical stimulation to induct the tenocyte gene expression. It is revealed that elastomeric PGS sheets promote progenitor tendon cell structure by increasing proliferation and gene expression with regard to tendon extracellular matrix components. Human tenocytes were seeded onto poly(glycerol-sebacate) sheets and were cultured two days prior to transfer to dynamic culture in a bioreactor system. Cell culture studies were carried out for 12 days under 0%, 3% and 6% strain at 0.33 Hz. The PGS-cell constructs were examined by using Scanning Electron Microscopy (SEM), cell viability via live/dead staining using confocal microscopy, and GAG/DNA analysis. In addition, gene expression was examined using real-time polymerase chain reaction (RT-PCR). Tenocytes cultured upon PGS scaffolds under 6% cyclic strain exhibited tendon-like gene expression profile compared to 3% and 0% strain groups. The results of this study show that PGS is a suitable material in promoting tendon tissue formation under dynamic conditions.