Bioactivity of small intestinal submucosa and oxidized regenerated cellulose/collagen.

Objective: This study examined the bioactivity of porcine small intestinal submucosa (SIS Wound Matrix [SISWM], USP) and oxidized regenerated cellulose/collagen (ORC).

Design: Bioactivity was assessed in vitro as the ability to stimulate neurite outgrowth in rat pheochromocytoma (PC12) cells, proliferation of human fibroblasts, secretion of vascular endothelial growth factor (VEGF) from human fibroblasts, and in an in vivo angiogenesis model. In the angiogenesis model, SISWM and ORC were implanted subcutaneously into the mice, and vessel ingrowth was assessed at day 21 after implantation using fluorescence microangiography and histology.

Extracellular matrix as a strategy for treating chronic wounds.

The dermis normally directs all phases of skin wound healing following tissue trauma or disease. However, in chronic wounds, the dermal matrix is insufficient to stimulate healing and assistance by external factors is needed for wound closure. Although the concept of the extracellular matrix directing wound healing is not new, ideas about how best to provide the extracellular matrix components required to 'jump-start' the healing process are still evolving.

Matrix metalloproteinase 9 facilitates collagen remodeling and angiogenesis for vascular constructs.

Degradation of the extracellular matrix, facilitated by matrix metalloproteinases (MMPs), can lead to mechanical failure of vascular constructs, suggesting that MMP inhibition could improve survival of constructs. Therefore, we investigated the role of MMP-9 in collagen remodeling in vitro, focusing on the three major steps of production, degradation, and organization. Because an adequate blood supply is essential for survival of tissue-engineered constructs, we also evaluated the influence of MMP-9 deficiency on angiogenesis in vivo by implantation of thin biodegradable polymer scaffolds.