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A hierarchical carbon material containing nanopores (micropores and mesopores) and micrometric sized capillaries (macropores) is produced using a combination of hard and soft templates. The hard template is a polypropylene (PP) cloth which decomposes during pyrolysis leaving a macroporous structure. The soft template is a cationic polyelectrolyte which stabilizes the resorcinol/formaldehyde (RF) resin porous structure during drying to give a nanoporous RF resin. The method produces a nanocomposite of the porous RF resin with an imbibed PP cloth. The composite is then pyrolyzed in a inert gas atmosphere to render a carbon material having macropores as well as micro/mesopores. The material exhibits both a large surface area (S_BET = 742 ± 2 m²/g) due to nanopores and goof fluid permeability due to micrometric sized pores. The macropores can be oriented during fabrication. The nanoporous surface can be used to support metal nanoparticles for fuel cell while the macropores allow easy flux of gas and liquids through the monolithic material.

In this chapter we discuss how to engineer 3D pulmonary tissue constructs in vitro using primary isolates of foetal mouse distal lung cells. When cultured in hydrogel-based 3D constructs, the mixed cell population, comprised epithelial, mesenchymal and endothelial cells, organised into alveolar forming unit (AFU)-like sacculated structures, which, in terms of morphology and cytodifferentiation, were reminiscent of native distal lung. By using a unique, serum-free medium supplemented with a cocktail of tissue-specific growth factors, we were able to induce concomitant alveolisation and neovascularisation when culturing the cells in the hydrogels, but not in scaffolds composed of synthetic polymers. Our data suggest that our in vitro model is capable of recapitulating the parallel morphogenesis of epithelial and endothelial pulmonary tissue components, which may occur through dynamic paracrine interactions. These results also stress the importance of the complex input from co-cultures, tissue-specific growth factors and integrin signalling for successful tissue engineering in vitro. In a mouse model in vivo, incorporation of the primary lung cell isolates into Matrigel plugs, implanted either subcutaneously (s.c.), or under the kidney capsule, leads to the formation of sacculated AFUs in close proximity to patent capillaries. Effective functional vascularisation, however, was only observed upon addition of angiogenic growth factors to the scaffolds and their controlled release over time. Use of a fluorescent cell tracker confirmed that the neovessels in the constructs comprised endothelial cells from both the host and the grafts. These data demonstrate that it is feasible to generate vascularised pulmonary tissue constructs in vivo with proper epithelial differentiation, and that the degree of vascularisation may be manipulated by incorporating the release of an angiogenic factor within the construct.