ABSTRACT
The scaffold plays a central role in many tissue engineering efforts by providing a temporary structural framework for cell organization and tissue development (Langer & Vacanti, 1993). Among several challenges associated with scaffold-based strategies, the issue of adequate cell proliferation remains a crucial one. Cells, when first transplanted onto a scaffold are highly dependent on the diffusion of nutrients for survival since the area within the scaffold is avascular (Peters et al., 2002). This diffusion is sufficient only if the engineered tissue is a thin layer or the cell’s metabolic needs are low. But in the case of engineering large tissue masses which requires thick scaffold sections, most of the cells at the scaffold interior will die soon after seeding because of mass transfer limitations (Martin et al., 1998; Ellis & Chaudhuri, 2007). Furthermore, local disturbances in culture environment e.g., changes in osmotic pressure and pH manifested through the accumulation of metabolic waste derived from cells and/or acidic degradation by-products associated with synthetic scaffolds are detrimental to cell growth (Hutmacher, 2000; Kohn et al., 2002). For these reasons, it is crucial that scaffolds designed for tissue engineering applications are exposed at all times to sufficient quantities of neutral culture media during the in vitro growth phase. Unfortunately, most conventional
fabrication techniques produce thick foam structures with un-interconnected pores which facilitate the proliferation of cells only at the periphery of the scaffold (Sachlos & Czernuszka, 2003).
