Continuous supply of TGFß3 via adenoviral vector promotes type I collagen and viability of fibroblasts in alginate hydrogel.

ABSTRACT

In recent years, transforming growth factor-ß3 (TGFß3) has interested more and more researchers with its competence in engineered histogenesis. In the present study we employed recombinant adenoviral vectors to deliver the constitutively active TGFß3 gene to human dermal fibroblasts, which could maintain the continuous secretion of TGFß3 from the cells. The expression of type I collagen in the Ad-TGFß3 group increased significantly in comparison with other three groups Neg (cells without treatment of the adenovirus), Ad-null (cells with treatment of the adenovirus, without the inserted gene) and Ad-shRNA (cells with treatment of the adenovirus encoding shRNA specific for type I collagen). Additionally, we demonstrated that TGFß3 enhanced the expression of Smad4 while inhibiting that of MMP-9, thus promoting the collagen transcription via the Smad signal transduction pathway and restraining collagen degradation by MMP-9, which contributed to the increasing type I collagen expression level. As type I collagen mediates cell-material interactions by providing anchorage, the viability of encapsulated fibroblasts in Ad-TGFß3 group was significantly higher than that in other three groups. Accordingly, this approach forms an effective way to improve the compatibility of non-adhesive hydrogels containing anchorage-dependent cells.