There is a pressing need for further advancement in tissue engineering of functional organs with a view to providing a more clinically relevant model for drug development and reduce the dependence on organ donation. Polymer based scaffolds, such as polycaprolactone (PCL), have been highlighted as a potential avenue for tissue engineered kidneys, but there is little investigation down this stream.Focus within kidney tissue engineering has been on 2-dimensional cell culture and decellularised tissue. Electrospun polymer scaffolds can be created with a variety of fibre diameters and have shown a great potential in many areas. The variation in morphology of tissue engineering scaffold has been shown to effect the way cells behave and integrate. In this study we examined the cellular response to scaffold architecture of novel electrospun scaffold for kidney tissue engineering. Fibre diameters of 1.10±0.16 µm and 4.49±0.47 µm were used with 3 distinct scaffold architectures. Traditional random fibres were spun onto a mandrel rotating at 250 rpm, aligned at 1800 rpm with novel cryogenic fibres spun onto a mandrel loaded with dry ice rotating at 250 rpm. Human kidney epithelial cells were grown for 1 and 2 weeks. Fibre morphology had no effect of cell viability in scaffolds with a large fibre diameter but significant differences were seen in smaller fibres. Fibre diameter had a significant effect in aligned and cryogenic scaffold. Imaging detailed the differences in cell attachment due to scaffold differences. These results show that architecture of the scaffold has a profound effect on kidney cells; whether that is effects of fibre diameter on the cell attachment and viability or the effect of fibre arrangement on the distribution of cells and their alignment with fibres. Results demonstrate that PCL scaffolds have the capability to maintain kidney cells life and should be investigated further as a potential scaffold in kidney tissue engineering.

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Two types of cellulose-based materials, 6-carboxycellulose with 2.1 or 6.6 wt% of -COOH groups, were prepared and tested for potential use in tissue engineering. The materials were functionalized with arginine, i.e. an amino acid with a basic side chain, or with chitosan, in order to balance the relatively acid character of oxidized cellulose molecules, and were seeded with vascular smooth muscle cells (VSMC). The cell adhesion and growth were then evaluated directly on the materials, and also on the underlying polystyrene culture dishes. Of these two types of studied materials, 6-carboxycellulose with 2.1 wt% of -COOH groups was more appropriate for cell colonization. The cells on this material achieved an elongated shape, while they were spherical in shape on the other materials. The number of cells and the concentration (per mg of protein) of contractile proteins alpha-actin and SM1 and SM2 myosins, i.e. markers of the phenotypic maturation of VSMC, were also significantly higher on this material. Functionalization of the material with arginine and chitosan further improved the phenotypic maturation of VSMC. Chitosan also improved the adhesion and growth of these cells. In comparison with the control polystyrene dishes, the proliferation of cells on our cellulose-based materials was relatively low. This suggests that these materials can be used in applications where high proliferation activity of cells is not desirable, e.g. proliferation of VSMC on vascular prostheses. Alternatively, the cell proliferation might be enhanced by another more efficient modification, which would require further research.