Dermal fibroblasts cultured on small intestinal submucosa: Conditions for the formation of a neotissue

Small intestinal submucosa (SIS) is a naturally occurring, acellular biomaterial that has been used extensively as a soft tissue replacement, as a scaffold for tissue engineering, and as a substrate for the study of cells in 3D culture. The aim of this study is to define culture parameters that promote neotissue formation with the use of dermal fibroblasts and SIS. SIS sheets were seeded with dermal fibroblasts and cultured for 4 weeks. The resultant cell‐scaffold composites (CSCs) were cultured with media alone, media supplemented with ascorbic acid, or fibronectin‐pretreated SIS and ascorbic acid. CSCs were analyzed for cellular invasion into the scaffold, the rate of type I collagen production, MMP gelatinolytic activity, thickness, and ultrastructural morphology. CSCs treated with fibronectin and ascorbate showed an increase in Type I collagen production, no change in the MMP gelatinolytic activity, an increase in CSC thickness, and an organized neotissue on the surface of the SIS. Minimal cellular invasion was noted, suggesting that fibroblasts use the SIS as a template for neotissue growth rather than as a scaffold. These results indicate that fibronectin‐treated SIS cultured with dermal fibroblasts in the presence of ascorbic acid will promote true neotissue formation for future cardiovascular tissue engineering efforts. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005